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1.
Neotrop. ichthyol ; 19(4): e210010, 2021. graf, mapas, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1351161

ABSTRACT

Damselfishes are known keystone species of reef environments, however large-scale distribution patterns are poorly studied in the southwestern Atlantic. We evaluated main drivers of distribution of three conspicuous damselfishes, along tropical and subtropical coastal systems, in Brazil. Abundances were assessed against wave exposure, depth (within 1-7 m in tropical and 1-11 m in subtropical reefs) and benthic cover. Despite differences between systems, exposure and depth consistently explained damselfishes distribution. Stegastes fuscus, the larger damselfish species of the genus in the southwestern Atlantic, was dominant in both systems, inhabiting preferably shallow and sheltered reefs. Conversely, Stegastes variabilis occupied shallow habitats with higher exposure. Stegastes pictus was absent from tropical reefs sampled, inhabiting depths >7 m, in subtropical reefs. Species were weakly associated with benthic features, which poorly predicted changes in abundances. Regardless, S. fuscus showed association with articulated calcareous algae, and S. variabilis juveniles associated with erect macroalgae. Despite occurring in very distinctive reef systems, Brazilian damsels habitat requirements are consistent in both tropical and subtropical reefs. While highly persistent species, long term monitoring will inform us how they respond to pervasive global changes and human impacts along Brazilian reefs.(AU)


Os peixes donzela são espécies-chave em ambientes recifais, contudo seus padrões de distribuição em grande escala são pouco conhecidos no sudoeste do Atlântico. Avaliamos os principais descritores de distribuição para três espécies comuns em sistemas recifais tropicais e costões rochosos subtropicais costeiros no Brasil, em resposta a diferentes regimes de exposição a ondas, profundidade e cobertura bentônica. Apesar das grandes diferenças entre estes sistemas, a exposição das ondas e a profundidade consistentemente explicaram sua distribuição. Stegastes fuscus é numericamente dominante, sendo a maior espécie do gênero no Atlântico sudoeste, dominando recifes rasos e menos hidrodinâmicos, enquanto S. variabilis foi mais abundante em habitats com maior hidrodinamismo. Stegastes pictus foi ausente nos recifes rasos tropicais amostrados e, nos recifes rochosos subtropicais, foi mais abundante em profundidades acima de 7 m. Características do substrato influenciaram pouco a densidade, porem S. fuscus apresentou associação a algas calcárias articuladas, enquanto juvenis de S. variabilis se associaram a macroalgas eretas. Peixes donzelas são generalistas e persistentes, ocorrendo em ambientes distintos, e mesmo assim, regulados de forma especifica e consistente ao longo da costa. O monitoramento a longo prazo nos informará como elas responderão às constantes mudanças globais e impactos antrópicos nos recifes brasileiros.(AU)


Subject(s)
Animals , Seaweed , Perciformes , Ecosystem , Fishes
2.
Acta biol. colomb ; 25(3): 374-385, sep.-dic. 2020. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1149018

ABSTRACT

RESUMEN Pareques acuminatus (familia Sciaenidae) es una especie carnívora de tamaño pequeño, que se distribuye en el Atlántico occidental entre Carolina del Norte y Bermudas hasta Brasil. Los estudios sobre la biología y ecología de P. acuminatus son escasos y en Colombia no se han realizados trabajos concernientes a la especie. El propósito de este estudio fue conocer aspectos de reproducción, morfología y ecología con el fin de ampliar su conocimiento en el Caribe colombiano. Entre 2017 y 2018 se realizaron capturas en cinco localidades por medio de buceo libre y se realizaron censos visuales del hábitat donde fue observada. Se evaluó la morfometría y merística, se identificaron las fases reproductivas y se estimó la fecundidad parcial mediante el método gravimétrico. Un total de 85 individuos fueron recolectados con una LT entre 33 y 185 mm (123,7±36,3 mm) siendo más frecuentes aquellos entre 121-142 mm (42 %) seguidos de los de 143-164 mm (20 %). Se distinguieron 39 hembras, 34 machos y 12 juveniles indeterminados debido a su pequeño tamaño. La talla de las hembras maduras fue a partir de una LT de 118 mm, siendo una especie asincrónica con dos fases reproductivas (en desarrollo y con capacidad de desove). La fecundidad parcial estimada fue de 8744 ± 3900 oocitos y la fecundidad relativa con relación a la talla fue de 64,15 ± 25,51 oocitos/mm, con un diámetro de 0,53 ± 0,04 mm. Pareques acuminatus es una especie típica de hábitats arrecifales someros y se encontró en conjunto con Myripristis jacobus, Canthigaster rostrata, Haemulon steindachneri, H. flavolineatum, Stegastes partitus y Chromis multilineata, que fueron las especies comunes en todas las localidades.


ABSTRACT The highhat, Pareques acuminatus, is a carnivorous, small sized species, with distribution in the western Atlantic from North Carolina and Bermuda to Brazil. Studies on the biology and ecology of P. acuminatus are scarce and in Colombia no work has been done concerning this specie. For this reason, this study focused on knowing the biology of this sciaenid and determining ecological aspects in order to expand its knowledge in the Colombian Caribbean. Captures of the highhat were made by free diving between 2017 and 2018 and visual fish censuses were taken on the habitat where it was observed between 2017 and 2018. The morphometrics and meristics were taken, the reproductive phases identified, and the partial fecundity estimated by the gravimetric method. A total of 85 individuals were collected with a TL between 33 and 185 mm (123.7 ± 36.3 mm) with individuals between 121-142 mm (42 %) as the more frequent, followed by 143-164 mm (20 %). There were 39 females, 34 males and 12 indeterminate juvenile specimens. Females reach mature state with 118 mm TL, being an asynchronous species, with two reproductive phases (phase in development and phase capable of spawning). The estimated partial fecundity was 8744 ± 3900 oocytes, and the relative fecundity in relation to size was 64.15 ± 25.51 oocitos/mm with a diameter of 0.53 ± 0.04 mm. The highhat is a typical specie of shallow reef habitats, and was found mainly accompanied by Myripristis jacobus, Canthigaster rostrata, Haemulon steindachneri, H. flavolineatum, Stegastes partitus and Chromis multilineata between 2017 and 2018.

3.
Neotrop. ichthyol ; 18(1): e190054, 2020. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1098419

ABSTRACT

Among the four butterflyfishes of the genus Chaetodon present in the western Atlantic, the banded butterflyfish Chaetodon striatus has the largest distribution range, spanning 44 degrees of latitude (from Massachusetts, USA to Santa Catarina, Brazil). Although the ecology of the banded butterflyfish has been well studied over its entire range, nothing is known about its phylogeography and how biogeographic barriers structure its populations. To assess the level of genetic connectivity among populations from distinct biogeographic provinces and environmental conditions, we collected samples from seven localities: Puerto Rico, in the Caribbean, and Tamandaré, Salvador, Abrolhos, Trindade Island, Arraial do Cabo and Florianópolis, in Brazil. One nuclear (rag 2) and two mitochondrial (control region and cyt b) molecular markers were sequenced. Our findings are consistent with a recent population expansion, around 30-120 thousand years ago, which was found for all populations. Haplotype network analyses point to the Caribbean as a refugium before the population expansion. Results show no geographic pattern of genetic diversity. Indeed, a lack of population structure was found and no isolation was observed across oceanographic barriers, as well as between coral and rocky reef ecosystems. Furthermore, no directionality in the migration pattern was found among populations. Since ecological and environmental characteristics are very diverse across such a vast geographic range, the lack of genetic differentiation suggests that C. striatus evolved ecological plasticity rather than local adaptation in the western Atlantic.(AU)


O peixe-borboleta listrado, Chaetodon striatus, possui a maior distribuição geográfica dentre as quatro espécies de peixes-borboleta do gênero Chaetodon presentes no Oceano Atlântico Ocidental, abrangendo 44° de latitude (entre Massachusetts, EUA até o sul do Brasil). A ecologia alimentar desta espécie é bastante conhecida, considerando a ampla distribuição, porém, pouco se sabe sobre a filogeografia e como as barreiras biogeográficas estruturam as populações. Para acessar a conectividade genética entre as populações de diferentes províncias biogeográficas e diferentes condições ambientais, foram coletadas amostras de sete localidades: Porto Rico, no Caribe, e Tamandaré, Salvador, Abrolhos, Ilha da Trindade, Arraial do Cabo e Florianópolis, no Brasil. Foram sequenciados um gene nuclear (rag 2) e dois genes mitocondriais (região controle e cit B). Para todas as populações, foi identificada uma expansão populacional recente, em torno de 30-120 mil anos atrás. A análise de rede de haplótipos sugere que o Caribe serviu como refúgio antes desta expansão populacional. Os resultados indicam que não há padrão geográfico de diversidade genética. Apesar da existência de barreiras oceanográficas e diferenças na constituição dos recifes (rochosos e coralíneos), não foi encontrada estruturação populacional. Também, não encontramos padrão na direção de migração entre as populações. Os resultados sugerem que C. striatus apresenta plasticidade ecológica, uma vez que não há diferenciação genética entre as populações que habitam ecossistemas tão diferentes ao longo da ampla distribuição no Atlântico Ocidental.(AU)


Subject(s)
Animals , Ecosystem , Phylogeography , Phylogeography/methods , Fishes/genetics , Genes, Mitochondrial
4.
Rev. bras. parasitol. vet ; 29(1): e018319, 2020. graf
Article in English | LILACS | ID: biblio-1058008

ABSTRACT

Abstract Scuticociliatosis, caused by an opportunistic ciliate protozoan, is responsible for significant economic losses in marine ornamental fish. This study reports the occurrence of Uronema spp., parasitizing ten species of marine reef fish at an ornamental fish wholesaler: Blue green damselfish (Chromis viridis), Vanderbilt's Chromis (Chromis vanderbilti), Pennant coralfish (Heniochus acuminatus), Threespot angelfish (Apolemichthys trimaculatus), Goldspotted angelfish (Apolemichthys xanthopunctatus), Sea goldie (Pseudanthias squamipinnis), Orchid dottyback (Pseudochromis fridmani), Threadfin butterflyfish (Chaetodon auriga), Vagabond butterflyfish (Chaetodon vagabundus), and Bluecheek butterflyfish (Chaetodon semilarvatus). Diseased fish showed disorders such as hemorrhages and ulcerative lesions on the body surface. Histopathological analysis of the muscle, liver, gut, kidney, spleen, gills, and stomach revealed hemorrhages and degeneration of muscle fiber, vacuolar degeneration of hepatocyte, inflammatory process and granuloma in the liver, atrophy of intestinal villi, inflammatory process and granuloma in the kidney, melanomacrophage centers, as well as inflammatory process in the spleen, epithelial cells hyperplasia and granuloma formation in the gills, and vacuolar degeneration and eosinophils in the stomach. Due to the severity of the disease, it is necessary to implement biosecurity measures with rapid and accurate diagnosis to minimize the risk of economic losses caused by Uronema spp.


Resumo Scuticociliatose, causada pelo protozoário ciliado oportunista, é responsável por significativas perdas econômicas em peixes marinhos ornamentais. O estudo relata a ocorrência de Uronema spp., parasitando dez espécies de peixes de recife em um distribuidor de peixes ornamentais: "Blue green damselfish" (Chromis viridis), "Vanderbilt's Chromis" (Chromis vanderbilti), "Pennant coralfish" (Heniochus acuminatus), "Threespot angelfish" (Apolemichthys trimaculatus), "Goldspotted angelfish" (Apolemichthys xanthopunctatus), "Sea goldie" (Pseudanthias squamipinnis), "Orchid dottyback" (Pseudochromis fridmani), "Threadfin butterflyfish" (Chaetodon auriga), "Vagabond butterflyfish" (Chaetodon vagabundus), e "Bluecheek butterflyfish" (Chaetodon semilarvatus). Peixes doentes apresentaram distúrbios como hemorragias e lesões ulcerativas na superfície do corpo. A análise histopatológica do músculo, fígado, intestino, rim, baço, brânquias e estômago revelou hemorragias e degeneração das fibras musculares, degeneração vacuolar de hepatócitos, processo inflamatório e granuloma no fígado, atrofia das vilosidades intestinais, processo inflamatório e granuloma no rim, centros de melanomacrófagos e processo inflamatório no baço, hiperplasia das células epiteliais, bem como formação de granuloma nas brânquias e degeneração vacuolar e eosinófilos no estômago. Devido à gravidade da doença, é necessário implementar medidas de biossegurança com diagnóstico rápido e preciso para minimizar o risco de perdas econômicas causadas por Uronema spp.


Subject(s)
Animals , Perciformes/parasitology , Ciliophora Infections/veterinary , Ciliophora/classification , Fish Diseases/parasitology , Brazil , Ciliophora Infections/parasitology , Ciliophora Infections/pathology , Fish Diseases/pathology
5.
The Filipino Family Physician ; : 143-151, 2018.
Article in English | WPRIM | ID: wpr-965258

ABSTRACT

Background@#Ciguatera fish poisoning (CFP) is a disease caused by the ingestion of poisonous coral reef fish. To the best of the author’s knowledge, no attempt has so far been made to consolidate available reports of outbreaks in order to characterize the toxidrome of CFP in the Philippines. @*Objective@#To review and consolidate data from epidemiologically-documented CFP outbreaks in order to characterize the toxidrome of CFP in the Philippines and identify the areas of high risk for outbreaks.@*Methods@#Epidemiologic reports of CFP outbreaks in the Philippines were reviewed. A compilation of symptoms of CFP patients was done to describe the toxidrome. High risk areas in the Philippines were identified.@*Results@#Ten reports were retrieved related to 17 CFP outbreaks from 1988 to 2010. No epidemiologic reports were found after 2010. Consolidation of reported symptoms showed a CFP toxidrome with prominent paresthesia, muscle weakness, and myalgia with some gastrointestinal symptoms. Based on the reports, the high risk islands identified were Palawan, Panay, Romblon, the islands in the Cuyo Pass, and Basilan. Cases of CFP continue to be encountered but are not reported to public health epidemiologists.@*Conclusion@#When put together, the reports describe a CFP toxidrome where the neurologic symptoms predominate over the gastrointestinal symptoms. Most of the cases occurred in the west central and southern portion of the archipelago suggesting a higher risk for CFP in that area. Cases of what appear to be CFP continue to be diagnosed although they are not reported to government epidemiology units. More systematic surveillance of CFP by government agencies is needed.


Subject(s)
Ciguatera Poisoning , Philippines
6.
Braz. j. biol ; 76(3): 743-749, tab, graf
Article in English | LILACS | ID: lil-785025

ABSTRACT

Abstract Many aspects of sex change in reef fishes have been studied, including behavior and social organization. However, gonad histology remains the most robust way to identify sexual patterns in fishes. Some uncommon tissues remain poorly described, such as the accessory gonadal structures found in species from the Gobiidae family, which are rare in other bony fishes. This is the first report of the testicular gland in Gramma brasiliensis and for the Grammatidae family. Between April 2011 and February 2012 eighty specimens were collected during four dive campaigns on the Taipus de Fora reef (13°56’20”S 38°55’32”W), Bahia, Northeast Brazil, and their sex was determined. Thirteen per cent of the active-females and 90% of the active-males had testicular gland tissue in their ovotestis. This discovery led to additional research into the characteristics of the gland tissue and its relationship with gonadal maturation. Three patterns of testicular gland development were found in Brazilian basslet ovotestis. Both ova and sperm-producing gonad contained testicular gland tissue, and the appearance of this tissue seems to be the first modification of ovotestis tissue marking the beginning of the protogynous sex-change process in G. brasiliensis.


Resumo Diversos aspectos da troca de sexo em peixes recifais vem sendo estudados, incluindo comportamentos e organização social. Entretanto, a histologia das gônadas continua sendo a maneira mais robusta para se identificar padrões sexuais em peixes. Alguns tecidos incomuns, tais como as estruturas anexas a gônada encontradas em espécies da família Gobiidae e raras em outras espécies são pouco estudados. Este trabalho é a primeira descrição da glândula testicular em Gramma brasiliensis e para a família Grammatidae. Entre abril de 2011 e fevereiro de 2012, oitenta espécimes foram coletados durante quatro amostragens no recife de Taipus de Fora (13°56’20”S 38°55’32”W), Bahia, Brasil, e tiveram seus sexos determinados. Treze por cento das fêmeas ativas e noventa por cento dos machos ativos apresentaram tecido da glândula testicular em suas gônadas. Esta descoberta levou ao estudo da características dessa estrutura e sua relação com a maturação gonadal. Foram identificados três padrões de desenvolvimento da glândula testicular nas gônadas do Gramma brasiliensis. Tanto as gônadas produtoras de espermatozoides quanto as de oócitos apresentaram tecido da glândula testicular, e o surgimento desse tecido parece ser a primeira modificação gonadal do início da troca de sexo protogínica em G. brasiliensis.


Subject(s)
Animals , Male , Female , Testis/physiology , Perciformes/physiology , Adaptation, Physiological/physiology , Hermaphroditic Organisms/physiology , Brazil , Gonads/physiology
7.
Neotrop. ichthyol ; 14(4): e160133, 2016. tab, graf, ilus, mapas
Article in English | LILACS, VETINDEX | ID: biblio-829291

ABSTRACT

Fishing pressure affects the behavior of reef fish, especially of fishery-targeted species. In this context, it is critical to understand if fish behavior is preserved in no-take areas (NTAs), which are considered the best instrument for the recovery of fish stocks. Comparing the flight initiation distances (FIDs) of fish inhabiting multiple-use areas (MUAs), where fishing is allowed (including spearfishing), and NTAs is a useful approach to test whether NTAs can be effective as fish refuges. Here, we compared whether the FIDs of two target (Sparisoma axillare and Scarus trispinosus ) and one non-target (Halichoeres poeyi ) labrids are greater in the MUAs than in the NTAs. We also investigated whether group size (GS) and body size (BS) exert any effect on the FID. We sampled four MUAs and four NTAs in the Abrolhos Bank (Brazil). We found that only for the targeted species FID was shorter inside the NTAs and that the BS had a positive effect on the FID of all species. The GS and BS of the fish are greater in the NTAs than in the multiple-use areas only for S. trispinosus . Our study shows that fish, especially those species that are fishery targets, display an avoidance behavior against spearfishermen likely as a consequence of fishing pressure. We suggest that the NTAs in Abrolhos are not only important sites for the recovery of fish stocks but also possibly act as a repository area of naïve fish (fish that allow human approach), for reefs open for fishing.(AU)


A pressão pesqueira afeta o comportamento de peixes recifais, especialmente nas espécies alvo de pesca. Nesse contexto é importante entender se áreas fechadas a pesca ("no-take areas": NTAs), consideradas como melhor instrumento para recuperação dos estoques pesqueiros, garantem a integridade dos comportamentos dos peixes. Comparar distâncias iniciais de fuga ("fligth initiation distance": FIDs) de espécies entre recifes de uso múltiplos ("multiple-use areas": MUAs), onde a pesca é permitida (incluindo a pesca submarina), e as NTAs é uma abordagem útil para testar se as NTAs podem ser efetivas como refúgios para peixes recifais. Nesse trabalho FIDs de duas espécies alvo (Sparisoma axillare e Scarus trispinosus ) e uma não alvo (Halichoeres poeyi ) foram comparadas entre MUAs e NTAs. A possível influência do tamanho do grupo ("group size": GS) e o tamanho do corpo ("body size": BS) sobre FID também foram investigados. Foram amostradas quatro MUAs e quatro áreas NTAs no banco dos Abrolhos (Brasil). Nossos resultados mostraram que apenas FID das espécies alvo de pesca foi menor dentro de NTAs e que o BS teve um efeito positivo no FID de todas as espécies. Dentro da NTA, GS e BS foram maiores do que em recifes abertos à pesca apenas para S. trispinosus . Finalmente, sugerimos que NTAs em Abrolhos não são apenas importantes como recuperação dos estoques pesqueiros, mas estão possivelmente atuando como uma área repositória de peixes "ingênuos" (peixes que permitem aproximação humana) para os recifes onde a pesca é permitida.(AU)


Subject(s)
Animals , Behavior, Animal , Fishes/anatomy & histology , Fishes/classification , Fisheries
8.
Rev. biol. trop ; 63(supl.1): 97-116, abr. 2015. tab, graf
Article in Spanish | LILACS, SaludCR | ID: biblio-958130

ABSTRACT

Resumen El presente trabajo tuvo como objetivos 1) Describir la estructura de la comunidad de peces de arrecife de la Isla del Caño y 2) Completar una lista de las especies de peces costeros registrados hasta el día de hoy. Para el primer objetivo, se realizaron 50 censos de cilindro en 10 lugares alrededor de la Isla del Caño, en los cuales se contabilizaron 79 especies pertenecientes a 32 familias. La familia más abundante fue Pomacentridae, y la especie más abundante fue Chromis atrilobata. Los peces planctívoros y carnívoros fueron los más abundantes. En los análisis realizados, destacó la existencia de una relación entre la cobertura coralina y la presencia de peces herbívoros ramoneadores. Adicionalmente, al comparar la composición de especies por sitio, se encontró que El Barco cuenta con una presencia abundante de pargos. Para el segundo objetivo, se recopilaron los registros publicados de especies para la Isla y se adicionaron 35 nuevos registros, para un total de 212 especies; lo cual representa aproximadamente 17% de la diversidad de peces costeros en el Pacífico Tropical Oriental. Este trabajo presenta una línea de base para el monitoreo de peces en esta área marina protegida.


Abstract Biogeographically, the Caño Island Biological Reserve (CIBR) is of strategic importance, since it is located in the center of the Panamic Province (Costa Rica and Panama), characterized by a peak in fish species richness within the Tropical Eastern Pacific (TEP). Despite its importance, fish community structure around the island has not been deeply studied, and coastal fish diversity records need to be updated. The aims of the study were: 1) to describe the community structure of the reef fish community of CIBR and 2) to update the list of the coastal fish species recorded until today. For the first objective, 50 stationary fish counts were conducted at 10 locations around Caño Island, in which 79 species, belonging to 32 families, were registered. The most abundant family was Pomacentridae, and the most abundant species was Chromis atrilobata. Planktivorous and carnivorous fish were the most abundant. The existence of a relationship between coral cover and the presence of herbivorous grazers was highlighted within the analysis. Additionally, species composition was compared by site and this revealed that "El Barco" has an abundant presence of snappers. For the second objective, published fish species records were collected for the CIBR and 35 new records were added, for a total of 212 coastal fish species, which represents approximately 17% of coastal fish diversity in the TEP. This work presents a baseline for fish monitoring and mangement measures in this marine protected area. Rev. Biol. Trop. 63 (Suppl. 1): 97-116. Epub 2015 April 01.


Subject(s)
Plankton , Ecosystem , Coral Reefs , Herbivory , Fishes/classification , Carnivora , Costa Rica
9.
Rev. biol. trop ; 62(supl.3): 418-431, Jul.-Sep. 2014. ilus, graf, mapas, tab
Article in English | LILACS, SaludCR | ID: lil-757347

ABSTRACT

Reef fish assemblages in the Caribbean are under increasing pressure from human activities. Inadequate enforcement of legislation coupled with unreliable and data-poor landings in Tobago have led to the unregulated exploitation of reef fish for decades. This study addresses the lack of data on major reefs. Visual observations of fish fauna were conducted from November 2011-May 2013 at open access reef sites (Speyside, Charlotteville, Culloden, Arnos Vale, Mt. Irvine, La Guira, Kilgwyn, Plymouth and Black Rock) and one protected area (Buccoo Reef Marine Park). Belt transects surveys were used to determine fish density, species diversity and abundance at the 10-15m depth contour. Fish sizes were converted to biomass using the length-weight relationship of fish W=aLb. Most fish assemblages were dominated by small herbivores (<15cm), in particular Pomacentridae and Scaridae. Few large predators (>40cm) e.g. Serranidae, were noted, which is indicative of fishing pressure. MDS ordination identified three fish assemblages: i) northeastern, ii) southwestern and iii) intermediate. The northwestern cluster (Speyside and Charlotteville) were most representative of reef fish assemblages across the entire island, and exhibited the highest species richness, diversity and biomass. However, the southwestern cluster the highest numerical abundance. The marine protected area contained higher fish biomass, abundance, diversity and richness, but it was only representative of reef fish assemblages on the southwest of the island and not the entire Tobago. Research on the reef fishery, particularly spear fishing, is recommended to determine impact.


Los ensamblajes de peces de arrecife en el Caribe están bajo una creciente presión de las actividades humanas. La ejecución inadecuada de la legislación, junto con los desembarques poco fiables y con escasez de datos en Tobago han llevado a una explotación sin reglas durante décadas. Este estudio aborda la falta de datos sobre las comunidades de peces de arrecife en los principales arrecifes. Las observaciones visuales se llevaron a cabo desde noviembre 2011 hasta mayo 2013 en sitios de acceso a los arrecifes abiertos (Speyside, Charlotteville, Culloden, Arnos Vale, el monte Irvine, La Guira, Kilgwyn, Plymouth y Negro Rock) y un área protegida (El parque Buccoo Marine Reef). Se utilizaron encuestas para determinar la densidad de peces, la diversidad y abundancia de especies a 10-15m de profundidad del contorno. El tamaño de los peces se convirtió a biomasa utilizando la relación talla- peso de los peces W=aLb. La mayoría de las comunidades de peces son dominadas por pequeños herbívoros (<15cm), en particular Pomacentridae y Scaridae. Pocos depredadores grandes (>40cm), por ejemplo Serranidae, se observó, lo que es indicativo de la presión de pesca. El análisis de escala multidimensional identificó tres conjuntos distintos de peces indicados como i) del noreste, ii) al suroeste y iii) grupos intermedios. El grupo del noroeste (Speyside y Charlotteville ) es más representativo de comunidades de peces de arrecife en toda la isla, y mostró la mayor riqueza de especies, diversidad y biomasa. Sin embargo, se observó la abundancia más alta de peces en el grupo del suroeste. El área marina protegida contenia mayor biomasa, abundancia, diversidad y riqueza de peces, pero era el único representante de las asociaciones de peces arrecifales en el suroeste de la isla y no de todo Tobago. Se recomienda determinar los impactos de la pesca en los arrecifes, particularmente con el uso de arpón.


Subject(s)
Fishing Industry , Coral Reefs , Fishes , Ecosystem , Caribbean Region , Food Chain
10.
Rev. biol. trop ; 62(supl.3): 273-286, Jul.-Sep. 2014. graf, tab
Article in English | LILACS, SaludCR | ID: lil-757323

ABSTRACT

Grenada is highly dependent on coral reefs as a source of food and to support tourism. Local and global environmental stressors threaten these reefs. Legislation was created for this MPA in 2001, permanent mooring buoys were deployed in 2009 and enforcement of fishing restrictions began in 2010. Initiatives to address point and nonpoint source pollution from the land have recently begun, aimed at reducing stress on reef area. This study documents benthic cover and fish populations associated with reefs in a Marine Protected Area (MPA) along Grenada’s southwest coast from 2008 through 2012. Both Point Line Intercept and Photo Quadrat methods were used to assess benthic cover along permanent 30m transects (8 in and 12 outside the area) annually. Fish and Diadema antillarum urchin relative abundance were determined based on 2m wide belt surveys along the same transects. The predominant substrate cover was algae, ranging from 41% in 2009 to 74.2% in 2011. A general trend of increasing algal cover was noted. Combined annual survey results prior (2008-2010) and after controls were implemented (2011-2012) showed a significant increase in algal cover. The predominant algal form was macroalgae comprising 65.4% - 90.8% of total algae. Live hard coral percent cover ranged from 8.7% to 21.1%. Little annual variation was observed in percent live coral cover. Branching corals (34.1% - 52.3% of total living hard coral) were the most common. Of the 19 living hard coral species identified, Porites porites (21%-23%) and Porites astreoides (20%) dominated percentage composition. Madracis mirabilis contributed 21% of total live hard coral outside the MPA but only 8.7% in the MPA. Of the 63 species of fish identified in the study areas Chromis spp. (71.5% - 46%) was the dominant group. Wrasse had a significant increase from 6.9% in 2008 to 21.5% in 2010 inside the MPA with a similar increase peaking in 2011 outside the MPA. There was a noticeable (though not statistically significant) increase in piscivorous fishes in the MPA in 2012. This is a promising indication that fishing restrictions in the MPA may be having an effect. Diadema antillarum density was low, ranging from 4.58 to 0.21 urchins/100m² outside and 0.28 to 0.10 urchins/100m² inside despite a stocking attempt in the area in 2011.


Granada es muy dependiente de los arrecifes coralinos como fuente de alimento y apoyo al turismo. Factores estresantes locales y globales amenazan con estos arrecifes. La legislación fue creada para esta área protegida en el 2001, boyas de amarre fueron colocadas en 2009 y las restricciones a la pesca comenzaron a implementarse a partir del 2010. Iniciativas para reducir el estrés por contaminación terrestre, de fuentes puntuales y no-puntuales, en la zona comenzaron recientemente. Este estudio documenta la cobertura bentónica y poblaciones de peces asociados a los arrecifes del área marina Protegida (MPA) a lo larfo de la costa suroeste de Granada del 2008 al 2012. Se utilizaron los métodos de Punto Línea Intercepción (PLI) y Cuadrantes Fotográficos (PQ) para evaluar anualmente la cobertura bentónica a lo largo de transectos permanentes de 30m (ocho dentro y 12 fuera del MPA). La abundancia relativa de peces y del erizo negro Diadema antillarum a través de censos visuales de 2m de ancho a lo largo de los mismos transectos lineales. La cobertura de sustrato estuvo dominada por algas con 41% en 2009 y 74.2% en 2011. Se notó una tendencia general de aumento en la cobertura algal. La combinación de los resultados antes de las encuestas (2008-2010) y después de la implementación de los controles del MPA (2011-2012) mostró un aumento significativo en la cobertura algal. La forma algal predominante fue macroalgas que consta el 65.4% y el 90.8% del total de algas. El porcentaje de cobertura de coral durovarió entre un 8.7% y un 21.1%. Se observó una pequeña variación anual en el porcentaje de cobertura de coral vivo. Los corales ramificados (34.1%-52.3% del total de corales duros) fueron la forma de coral más común encontrada durante el estudio. De las 19 especies de corales duros identificados, Porites porites (21% - 23%) y Porites astreoides (20%) dominaron el porcentaje de composición. Madracis mirabilis contribuyó en un 21% del total de corales duros fuera del MPA pero solo un 8.7% en el MPA. De las 63 especies de peces identificadas en el área de estudio Chromis spp. (71.5% - 46%) fue el grupo dominante. Los lábridos (Labridae) mostraron un aumento significativo de su abundancia de un 6.9% en 2008 a un 21.5% en 2010 dentro del MPA con un pico de incremento similar en el 2011 fuera de la MPA. Hubo un aumento notable (aunque no significativo estadísticamente) en los peces piscívoros dentro del MPA en 2012. Esto es una indicación prometedora de que las restricciones de pesca en la MPA pueden estar dando efecto. La densidad de Diadema antillarum fue baja, osciló entre 4.58 y 0.21 erizos/100m² fuera del MPA y entre 0.28 y 0.10 erizos/100m² dentro del MPA a pesar de la existencia de un programa de repoblación de la especie llevado a cabo en el 2011.


Subject(s)
Benthic Flora , Marine Conservation Area , Coral Reefs , Fishes , Grenada
11.
Biota Neotrop. (Online, Ed. ingl.) ; 14(1): e20130071, Jan.-Mar. 2014. graf
Article in English | LILACS | ID: biblio-950988

ABSTRACT

During a predation event a juvenile grouper, rock hind Epinephelus adscensionis, fed upon the redlip blenny Ophioblennius trinitatis. It is important to highlight that both individuals had pretty much the same size during the predation event (around 5 cm); however, the grouper ingested the whole prey.


Durante um evento de predação um indivíduo juvenil de Epinephelus adscensionis (peixe-gato) alimentou-se de Ophioblennius trinitatis (macaquinho). É importante destacar que ambos os peixes apresentavam praticamente o mesmo tamanho (aproximadamente 5 cm); no entanto, a garoupa engoliu a presa inteira.

12.
Neotrop. ichthyol ; 11(3): 597-606, jun. 2013. tab, graf
Article in English | LILACS | ID: lil-690110

ABSTRACT

The oogenesis is a key stage in the reproductive development of an organism, which can be best understood from histological analysis of ovaries in different maturity stages. In order to provide information on the reproductive biology of the black triggerfish, M. niger, in particular on its oogenesis process, this study aimed at identifying and characterizing the oocyte development stages and its organization within the different stages of ovarian maturation based on specimens from São Pedro e São Paulo Archipelago. In this present report, a number of 294 ovaries were histologically analyzed. It was verified that they are composed of ovigerous lamellae containing oocytes at different development stages. Five different stages of oogenesis were identified: young cells, with an average size of 12.9 ìm; previtellogenic oocytes (perinucleolar), with an average size of 53.5 ìm; cortical-alveoli oocytes with an average size of 83.1 ìm; vitellogenic oocytes, with an average size of 160.4 ìm and mature oocytes, with an average size of 289.8 ìm. In addition to the germ cells, some somatic structures were also identified, such as: ovarian wall, follicular cells and blood vessels. Based on the type and number of oocytes observed, four stages of ovarian maturation were identified: early maturation, represented by only 2.2% of the sample; middle maturation, represented by 9.9%; mature, represented by 44.2% and resting, represented by 43.9%. The identification of five oocyte development stages in the ovarians from M. niger, suggested that the specie follows a pattern similar to that described for other marine fish.


A oogênese é um estágio chave no desenvolvimento reprodutivo de um organismo, o qual pode ser melhor compreendido a partir de análises histológicas dos ovários em diferentes estágios de maturidade. A fim de fornecer informações sobre a biologia reprodutiva do cangulo-preto, M. niger, em especial sobre o seu processo de oogênese, este estudo teve como objetivo identificar e caracterizar as fases do desenvolvimento ovocitário e sua organização dentro dos diferentes estágios de maturação ovariana, baseado em espécimes do Arquipélago de São Pedro e São Paulo. No presente estudo, um número de 294 ovários foram analisados histologicamente. Foi verificado que eles são constituídos por lamelas ovígeras contendo ovócitos em diferentes estágios de desenvolvimento. Foram identificados cinco diferentes estágios da oogênese: células jovens, com tamanho médio de 12,9 ìm; ovócitos pré-vitelogênicos (perinucleolares), com tamanho médio de 53,5 ìm; ovócitos alvéolo-corticais, com tamanho médio de 83,1 ìm; ovócitos vitelogênicos, com tamanho médio de 160,4 ìm e ovócitos maduros, com tamanho médio de 289,8 ìm. Além das células germinativas, algumas estruturas somáticas também foram identificadas, tais como: parede do ovário, células foliculares e vasos sanguíneos. Baseado no tipo e número de ovócitos observados, quatro estágios de maturação ovariana foram identificados: início de maturação, representado por apenas 2,2% da amostra; média maturação, representado por 9,9%; madura, representado por 44,2% e em repouso representado por 43,9%. A identificação de cinco estágios do desenvolvimento ovocitário nos ovários de M. niger, sugere que a espécie segue um padrão semelhante ao descrito para outros peixes marinhos.


Subject(s)
Animals , Oogenesis/genetics , Ovary/anatomy & histology , Reproduction/physiology , Aqua Marina , Fishes/classification
13.
Braz. j. biol ; 73(2): 391-396, maio 2013. tab, graf
Article in English | LILACS | ID: lil-680011

ABSTRACT

The Haemulon plumieri is a typical reef-associated and tropical species found in warm and temperate waters of the Western Atlantic. Due to the large fishing effort directed to H. plumieri, the knowledge about its reproductive biology is essential for correct stock management and conservation. The aim of this study was to characterise reproductive biology with a focus on its seasonal variation of gonadal maturation stages, first maturation size and fecundity. Specimens were monthly collected and a total of 119 females and 136 males were analysed. The reproductive cycle of Haemulon plumieri is seasonal, with higher activity between March and May. Size at first maturity (L50) was estimated at 16.86 and 18.55 cm for females and males, respectively. The total fecundity ranged between 17,816 and 120,333 mature oocytes per female and relative fecundity was 235 ± 63 oocyte.g−1 whereas batch fecundity varied between 20 and 25% from total fecundity. Since the species is widely caught, we suggest a closed season from March to May and to establish a minimum catch size of 18.5 cm for both sexes, since there is no evident sexual dimorphism.


O Haemulon plumieri é uma espécie tropical, associada aos recifes, encontrada em águas quentes e temperadas do Atlântico Oeste. Em razão do grande esforço de pesca direcionado para a captura desta espécie, o conhecimento acerca da biologia reprodutiva é essencial para um correto manejo e a sua preservação. O objetivo do presente estudo foi caracterizar a biologia reprodutiva com um foco na variação sazonal dos estágios de maturação, no tamanho de primeira maturação e na fecundidade. Espécimens foram mensalmente coletados e um total de 119 fêmeas e 136 machos foi analisado. O ciclo reprodutivo de Haemulon plumieri é sazonal, com maior atividade entre os meses de março e maio. O tamanho de primeira maturação (L50) foi estimado em 16,86 cm para as fêmeas e 18,55 cm para os machos. A fecundidade total variou de 17.816 a 120.333 oócitos maturos por fêmeas e a fecundidade relativa foi 235 ± 63 oócitos.g−1, enquanto que a fecundidade parcial variou entre 20 e 25% da fecundidade total. Uma vez que a espécie é amplamente capturada, sugere-se que seja definido um período de defeso de março a maio e que se estabeleça um tamanho mínimo de captura de 18,5 cm, para ambos os sexos, já que não há dimorfismo sexual evidente.


Subject(s)
Animals , Female , Male , Perciformes/physiology , Reproduction/physiology , Brazil , Coral Reefs , Perciformes/classification , Seasons , Sexual Maturation/physiology
14.
Neotrop. ichthyol ; 11(4): 809-814, 2013. graf
Article in English | LILACS | ID: lil-697862

ABSTRACT

Serranus aliceae n. sp. is described from Rio de Janeiro and Espírito Santo States, southeastern Brazilian coast. The species is readily distinguished from its congeners by the following combination of characters: scales around the caudal peduncle 20 or 21; total gill rakers on first branchial arch 23-29; cheek-scales rows 5 or 6; and by the coloration of live specimens, which are reddish with a broad, conspicuous, white stripe from post-orbital region to the caudal-fin base and a white abdomen. The new species apparently inhabits the deeper (30 or more meters) portions of reef environments along the subtropical Brazilian coast, and is possibly associated with upwelling cold-water masses. The species was observed hovering above rocky bottoms, feeding on micro-crustaceans, squid larvae, and zooplankton. This new species increases to eight the number of valid Serranus species recorded in the southwestern Atlantic.


Serranus aliceae sp. n. é descrita do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil. Esta espécie é facilmente distinguível de suas congêneres pela seguinte combinação de caracteres: escamas ao redor do pedúnculo caudal 20 ou 21; rastros no primeiro arco branquial 23-29; 5 ou 6 séries de escamas na bochecha e pelo colorido de espécimes vivos, que têm corpo avermelhado com uma larga e evidente faixa branca que se estende da região pós-orbital à base da nadadeira caudal, e o ventre branco. A espécie nova aparentemente habita a parte profunda (30 metros ou mais) de ambientes recifais ao longo da costa subtropical brasileira, e possivelmente está associada a áreas de ressurgência. A espécie foi observada pairando acima de fundos rochosos, alimentando-se de microcrustáceos, larvas de lulas e zooplâncton. Esta espécie nova aumenta para oito o número de espécies válidas de Serranus registradas no Atlântico Sudoeste.


Subject(s)
Animals , Coral Reefs , Species Specificity , Fishes/classification
15.
Neotrop. ichthyol ; 10(3): 633-642, Sept. 2012. ilus, tab
Article in English | LILACS | ID: lil-653601

ABSTRACT

This study aimed to assess abundance and habitat use by juvenile and adult damselfishes, as much as the benthic cover of different reefs on Isla Colon, Bocas del Toro, Panama. Reefs were selected considering different levels of wave exposure and depths. Damselfish and benthic communities were distinct between reefs. The most abundant species in the sheltered deeper reef was Stegastes planifrons followed by S. leucostictus, and they were also recorded in the sheltered shallower reef. Low densities of S. partitus and S. variabilis were also observed in the sheltered deeper reef, as these species are apparently restricted to higher depths. Additionally, these reefs presented patches with high cover of live and dead massive coral. Shallow depths presented high abundances of S. adustus, indicating a preference of this species for shallow habitats and exhibiting a two-fold increase in abundance at higher wave surge. Also, Microspathodon chrysurus reached higher numbers in shallow depths. Furthermore, the exposed reef presented a high cover (%) of algae groups and the fire-coral Millepora alcicornis, acknowledged as a preferred habitat for M. chrysurus and other reef fish. In this study, distinct habitat uses were observed, with patterns regulated by depth and/or wave exposure levels and/or availability of specific benthic cover. For site-attached species as damselfish, habitat specialization, competition and/or non-random recruitment patterns have been found to rule distributional patterns. Similar results for damselfish relative abundances were found compared to studies conducted within Panama and other reefs throughout the Caribbean region over three decades ago, indicating strong habitat affinity for the most abundant species. However, severe reductions of habitat availability following coral mass-mortality events may have disrupted their distributional patterns.


Este estudo teve como objetivo avaliar a abundância e uso do habitat por juvenis e adultos de peixes-donzela, assim como as comunidades bentônicas em distintos recifes de Isla Colon, Bocas del Toro, Panamá. Os recifes foram escolhidos considerando diferentes níveis de exposição a ondas e profundidade. As comunidades de peixes e bentos estudadas se mostraram distintas. A espécie mais abundante em recifes com maior profundidade e abrigados foi Stegastes planifrons, seguida por S. leucostictus, que também foram observadas em recifes rasos abrigados. As baixas abundâncias de S. partitus e S. variabilis também foram observadas no primeiro recife citado e estas espécies foram aparentemente restritas à profundidade maiores. Adicionalmente, estes mesmos recifes apresentaram uma vasta cobertura de corais massivos, vivos ou mortos. Stegastes adustus apresentou sua maior abundância em baixas profundidades, indicando uma preferência por habitats rasos, aumentando em duas vezes com a exposição a ondas. Os recifes rasos também tiveram maior abundância de Microspathodon chrysurus. Além disso, o recife com maior exposição apresentou extenso percentual de cobertura por algas e o coral-de-fogo Millepora alcicornis, reconhecido habitat preferencial de M. chrysurus e outras espécies de peixes. Neste trabalho, diferentes padrões de uso do habitat foram encontrados, sendo regulados pela profundidade e/ou exposição e ainda a disponibilidade de determinada cobertura bentônica. Para espécies fortemente associadas ao substrato, a especialização, a competição e padrões não aleatórios do recrutamento são conhecidos determinantes dos padrões distribucionais. Este estudo apresentou resultados similares a outros conduzidos há 30 anos no Panamá e outros recifes do Caribe, indicando que as espécies mais abundantes mantêm forte afinidade com o habitat. Entretanto, severas reduções na disponibilidade de habitat, seguidas de eventos de mortalidade em massa, podem ter possivelmente afetado seus padrões de distribuição.


Subject(s)
Animals , Benthic Fauna/analysis , Ecosystem/analysis , Perciformes/growth & development , Marine Environment/analysis
16.
Rev. biol. trop ; 60(2): 683-698, June 2012. ilus, graf, mapas, tab
Article in English | LILACS | ID: lil-657811

ABSTRACT

Many coral reef fish exhibit habitat partitioning throughout their lifetimes. Such patterns are evident in the Caribbean where research has been predominantly conducted in the Eastern region. This work addressed the paucity of data regarding Honduran reef fish distribution in three habitat types (seagrass, mangroves, and coral reefs), by surveying fish on the islands of Utila and Cayos Cochinos off the coast of Honduras (part of the Mesoamerican barrier reef). During July 2nd - Aug 27th 2007 and June 22nd - Aug 17th, 2008, visual surveys (SCUBA and snorkel) were performed in belt transects in different areas: eleven coral reef, six seagrass beds, and six mangroves sites. Juvenile densities and total habitat surface area were used to calculate nursery value of seagrass and mangroves. A total of 113 fish species from 32 families were found during underwater surveys. Multi-dimensional analyses revealed distinct clusters of fish communities in each habitat type by separating fish associated with seagrass beds, mangroves, and coral reefs. Coral reefs showed the highest mean fish species richness and were dominated by adult fish, while juvenile fish characterized seagrass beds and mangrove sites. Habitat use differed widely at the fish species level. Scarus iseri (Striped Parrotfish), the most abundant fish in this study, were found in all three habitat types, while Lutjanus apodus (Schoolmaster Snapper) juveniles were located primarily in mangroves before migrating to coral reefs. Many species used seagrass beds and mangroves as nurseries; however, the nursery value could not be generalized at the family level. Furthermore, for some fish species, nursery value varied between islands and sites. Our results suggest that connectivity of seagrass, mangrove, and coral reef sites at a species and site levels, should be taken into consideration when implementing policy and conservation practices. Rev. Biol. Trop. 60 (2): 683-698. Epub 2012 June 01.


Muchos peces de arrecifes de coral estan sometidos a la fragmentación del habitat a lo largo de su vida. Estos patrones son evidentes en el Caribe donde la investigación se llevó a cabo, principalmente en la región este. La motivación para la realización de este trabajo fue la escasez de datos sobre la distribución de peces de arrecife de Honduras en tres tipos de hábitat (pastos marinos, manglares y arrecifes de coral), por lo que se realizaron censos de peces en las islas de Utila y Cayos Cochinos en la costa de Honduras (parte del Sistema Arrecifal Mesoamericano). Del 2 de Julio al 27 de agosto 2007 y del 22 de junio al 17 agosto 2008, se realizaron censos visuales (buceo y snorkel) en transectos de diferente área: 11 en arrecifes de coral, 6 en praderas de pastos marinos y 6 en manglares. La densidad de jóvenes y el área total de la superficie del hábitat se utilizaron para calcular el valor de la zona de crianza de pastos marinos y manglares. Un total de 113 especies de peces de 32 familias fueron encontrados durante los censos. Análisis Multi-dimensionales reveló distintos grupos de comunidades de peces en cada tipo de hábitat por la separación de los peces asociados a los lechos de pastos marinos, manglares y arrecifes de coral. Los arrecifes de coral presentaron el mayor promedio de riqueza de especies de peces y fueron dominados por peces adultos, mientras que los jóvenes se caracterizaron por encontrarse en praderas de pastos marinos y zonas de manglares. El uso del hábitat difiere ampliamente a nivel de especies de peces. Scarus iseri (loro rayado), el pez más abundante en este estudio, se encontró en los tres tipos de hábitats, mientras que Lutjanus apodus, los jóvenes, se encontraron principalmente en los manglares antes de emigrar a los arrecifes de coral. Muchas especies utilizan las praderas marinas y los manglares como criaderos, sin embargo, el valor de criadero no puede ser generalizado a nivel familiar. Además, para algunas especies de peces, el valor de criadero varió entre las islas y los sitios. Nuestros resultados sugieren que la conectividad de los pastos marinos, manglares y arrecifes de coral a nivel de especies y sitios, debe ser tomado en cuenta para la aplicación de políticas y prácticas de conservación.


Subject(s)
Animals , Coral Reefs , Fishes/classification , Poaceae , Rhizophoraceae , Ecosystem , Honduras , Population Density
17.
Rev. biol. trop ; 60(supl.1): 71-87, Mar. 2012. graf, tab
Article in English | LILACS, SaludCR | ID: lil-657855

ABSTRACT

Annual benthic and fish population surveys were completed at five locations in the nearshore waters along Grenada´s southwest coast during 2008-2010. Two survey sites are located in a newly launched Marine Protected Area (MPA). Photo Quadrat (PQ) and Point Line Intercept (PLI) surveys were used to determine substrate cover. Algae was the primary live cover increasing significantly from 45.9% in 2008 to 52.7% in 2010 (PLI). Algae was also predominant (61.0%-59.3%) in the PQ surveys although annual variation was not significant. Hard coral cover ranged from 16.5% to 15.4% (PLI) and 11.4% to12.0% (PQ) with no significant differences between years. Branching and encrusting corals occurred more frequently than massive corals. In the three annual surveys neither algal cover nor hard coral varied significantly between MPA and non-protected areas (PLI). Relative abundance of fishes along 30x2m belt transects did not vary significantly among years however density of fishes decreased significantly across years for most major groups. Chromis spp. dominated the survey sites at 65.2% in 2008 and 49.8% in 2010, followed by territorial damselfish,11.1% and 15.5%, wrasse increased from 7.3% to 15.5%. Both the substrate cover and fish survey data analyses indicated a stable but degraded community. Annual surveys are planned at these sites for the foreseeable future. Existing and future data from this project will be valuable in determining the efficacy of MPA management, guiding resource management decisions and monitoring the health status of Grenada’s valuable reef systems.


Un estudio sobre poblaciones bentónicas y de peces fue realizado en cinco localidades en la zona costera en el suroeste de Grenada entre 2008 y 2010. Dos sitios se ubicaron en una Área Marina Portegida (AMP) recientemente creada. Para determinar la cobertura se utilizaron foto-cuadrantes (FQ) y transectos de intersección de puntos (TIP). Las algas fueron el principal componente del bentos, aumentando significativamente de 45,9% en 2008 a 52,7% en 2010 (TIP). Las algas también fueron predominantes (61,9%-59,3) en los FQ, aunque las diferencias anuales no fueron significativas. La cobertura de corales pétreos tenía un ámbito de 16,5% a 15,4% (TIP) y de 11,4% a 12,0% (FQ), sin diferencias significativas entre años. Los corales ramificados e incrustantes fueron más frecuentes que los corales masivos. En los tres años no hubo diferencias significativas entre las AMPs y las áreas no protegidas. La abundancia relativa de peces a lo largo de un transecto de 30x2m no varió significativamente entre los años, sin embargo, la densidad de peces decreció significativamente a través de los años, para los grupos principales. Chromis spp. predominó con 65,2% en 2008 y 49,8% en 2012, seguido por damiselas territoriales, 11,1% y 15,5%, y los lábridos aumentaron de 7,3% a 15,5%. Tanto la coberura del sustrato como los datos de peces indican una comunidad estable pero degradada. Sondeos anuales están planeados para el futuro. Los datos existentes y futuros de este proyecto serán muy útiles para determinar la eficacia de la gestión de las AMPs y el estado de salud de los sistemas arrecifales de Grenada.


Subject(s)
Benthic Flora/analysis , Grenada , Seaweed/classification , Spain , Protected Areas/analysis
18.
Neotrop. ichthyol ; 10(2): 383-388, 2012. ilus, tab
Article in English | LILACS | ID: lil-640803

ABSTRACT

In this study we analyze the population structure and diet of the coney Cephalopholis fulva at Trindade Island, Brazil, through direct observation with SCUBA diving in 11 reef sites around the Island, up to 50 m deep. Diet was based on 77 individuals collected with speargun. Mean population density and biomass were estimated at 29 individuals/100 m² and 13 kg/100 m², respectively. This species is regularly distributed along the costal environments of the Trindade Island, with no significant differences in densities and biomass detected among the different collection habitats (reef crest, reef slope, and reef plateau). However, significantly higher densities were observed micro-habitats with greater structural complexity, which may offer more shelter and food to C. fulva. Four food item groups were identified from the gut contents of C. fulva: Annelida, Crustacea, Teleostei, and Testudinata. It is the first record of predation of the green turtle Chelonia mydas hatchlings by the coney. Trindade Island seems to present the densest concentration of C. fulva in all Brazilian and Caribbean ecosystems inhabited by this species. Scarcity of competitors, predators, and fishing pressure may explain the high densities observed in the Island.


Foram analisadas a estrutura populacional e a dieta do catuá Cephalopholis fulva na Ilha da Trindade, Brasil. Os dados foram obtidos através de censos visuais com mergulho autônomo em 11 locais no entorno da ilha, em profundidades de até 50 m. A dieta e a proporção sexual foram baseadas na análise de 77 indivíduos coletados com arpão. A densidade populacional e biomassa foram estimados em 29 indivíduos/m² e 13 kg/100 m², respectivamente. A espécie apresentou distribuição uniforme nos ambientes costeiros da ilha, não tendo sido registradas diferenças significativa em sua densidade e biomassa entre os diferentes habitats estudados (crista, talude e platô recifal). Entretanto, foi observado preferência por micro-habitats de alta complexidade estrutural. Foram registrados quatro grupos de itens alimentares no conteúdo estomacal de C. fulva: Annelida, Crustacea, Teleostei e Testudinata. É feito aqui o primeiro registro de predação de juvenis da tartaruga-verde (Chelonia mydas) por C. fulva. Trindade parece apresentar os maiores valores de densidade para o catuá, quando comparada a outras localidades do Brasil e Caribe. A escassez de competidores, predadores e a pressão pesqueira são possíveis fatores que podem explicar as altas densidades observadas para C. fulva na Ilha da Trindade.


Subject(s)
Animals , Biomass , Bass/growth & development , Diet/veterinary , Animal Distribution/classification , Population Density
19.
Rev. biol. trop ; 58(supl.3): 163-174, Oct. 2010. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-638096

ABSTRACT

Ichthyofauna associated to a shallow reef in Morrocoy National Park, Venezuela. Morrocoy National Park is one of the most studied coastal marine enviroments in Venezuela; however, efforts have been concentrated in south zone. In this study we select a shallow reef located in the north zone, characterized the benthic community and the structure of the fish community was studied using visual censuses. The benthic community was dominated by dead coral covered by algae (31%) and the live coral coverage was 12%. A total of 65 fish species belonging to 24 families were recorded, being Pomacentridae (43%), Scaridae (19%) and Haemulidae (15%) the most abundant families. Significant differences in the fish species abundances were found along the depth gradient, which could be related to the habitat characteristics, nevertheless herbivorous species dominance was evident at all depth strata. There seems to be a trend towards greater richness and density in the south zone reefs, and these differences may be related to the presence of extensive seagrass meadows and mangrove forests in that area or to differences in the recruitment patterns. Rev. Biol. Trop. 58 (Suppl. 3): 163-174. Epub 2010 October 01.


El Parque Nacional Morrocoy representa uno de los ambientes marino costero mejor estudiado en Venezuela, sin embargo, los esfuerzos se han concentrado en la zona sur. Se seleccionó un arrecife ubicado en la zona norte del parque, se caracterizó la comunidad bentónica y se realizaron censos visuales para describir la estructura de la comunidad íctica. Este arrecife presenta un grado de afectación intermedio al compararlo con otras zonas dentro del parque, siendo el sustrato dominante coral muerto cubierto por algas (31%) y la cobertura de coral vivo fue del 12%. La ictiofauna estuvo conformada por 65 especies pertenecientes a 24 familias, siendo Pomacentridae (43%), Scaridae (19%) y Haemulidae (15%) las más importantes. Se observaron diferencias significativas en las abundancias de la mayoría de las especies entre los estratos de profundidad, lo cual podría estar relacionado a características del hábitat. Sin embargo, la dominancia de las especies de herbívoros fue evidente en todos los estratos. Parece existir una tendencia a una mayor riqueza y abundancia en los arrecifes de la zona sur, y estas diferencias pueden estar relacionadas más que al estado del arrecife, a la presencia de una extensa zona de praderas y manglares en esa zona o a diferencias en los patrones de reclutamiento.


Subject(s)
Animals , Biodiversity , Coral Reefs , Fishes/classification , Population Density , Venezuela
20.
Rev. biol. trop ; 58(supl.1): 51-65, May 2010. ilus, graf, tab
Article in English | LILACS | ID: lil-637954

ABSTRACT

In spite of their economic importance, coral reef communities of the world are rapidly decreasing, and an adequate management planification is needed. The benthic and fish communities of Dos Mosquises Sur and Madrizquí at Los Roques National Park, and Caiman and Cayo Norte at Morrocoy National Park, in Venezuela were monitored during 2003 and 2004. The CARICOMP method was used to describe the benthic community, and the AGRRA protocol was applied to the fish community assessment. The benthic cover of five broad living categories (i.e. corals, algae, sponge and octocorals) differed across the sites (Nested ANOVA, p < 0.05), but there were no statistical differences between parks. Despite being on different parks, the benthic cover in Dos Mosquises Sur and Cayo Norte was similar (76% based on Bray-Curtis), whereas Caiman differed greatly (57- 68%) from all other sites. The cover of hard coral, algae, sponges and octocorals was similar between 2003 and 2004 in all four sites. Similarly, the fish community structure of both parks did not change over time, and was dominated by herbivores (Pomacentridae, Scaridae and Acanthuridae). However, commercially important carnivores (e.g. Lutjanids and Serranids) were more abundant in Los Roques than in Morrocoy. Although it was expected that the benthic cover and fish community would reflect greater differences between Los Roques and Morrocoy, only the fish community appeared healthier in Los Roques, whereas Cayo Norte (Morrocoy), had a coral cover similar or higher than both sites of Los Roques. Thus, our results suggest that in Venezuela, oceanic reef sites are not necessarily ‘healthier’ (i.e. higher coral cover) than land-influenced coral communities. The addition of three new sites and the reincorporation of Caiman has improved and expanded the monitoring capabilities in Venezuela and it represents the first step towards the consolidation of a coral reef monitoring program for the country. Rev. Biol. Trop. 58 (Suppl. 1): 51-65. Epub 2010 May 01.


En este estudio se describe la condición de las comunidades bentónicas e ictícolas en cuatro arrecifes que fueron monitorizados durante 2003 y 2004 en Venezuela: Dos Mosquises Sur y Madrizquí en el Parque Nacional Archpiélago Los Roques y Caimán y Cayo Norte en el Parque Nacional Morrocoy. Para ello, empleamos los protocolos de CARICOMP y AGRRA para describir la comunidad bentónica e ictícola, respectivamente. La cobertura de los cinco principales grupos bentónicos difirió entre arrecifes (ANOVA anidado, p < 0.05) más no entre parques. A pesar de pertenecer a diferentes parques la estructura de la comunidad bentónica entre Dos Mosquises Sur y Cayo Norte mostró un índice de similitud (Bray-Curtis) de 76%, mientras que Caiman difirió entre 57 y 68% con respecto a todos los arrecifes. Como se esperaba, la cobertura coralina, algas esponjas y octocorales no cambió entre 2003 y 2004. De forma similar, la comunidad de peces tampoco cambió en el tiempo y estuvo dominada por especies de herbívoros (Pomacentridae, Scaridae and Labridae). Sin embargo, en Los Roques los carnívoros de importancia comercial (e.g. lutjanidos y serranidos) fueron más abundantes que en Morrocoy. Aunque se esperaba encontrar diferencias en la comunidad bentónica e ictícola de Los Roques y Morrocoy, solo la de peces reflejó las diferencias, encontrándose en mejor estado de salud en Los Roques, mientras que CNOR, localizado en Morrocoy, presentó una cobertura similar o ligeramente mayor que los arrecifes localizados en Los Roques. Por lo tanto, los resultados de este estudio muestran que los arrecifes oceánicos no necesariamente se encuentran en mejor estado que los costeros. La inclusión de 3 nuevos sitios y la reincorporación de Caimán ha expandido y mejorado las capacidades de monitoreo de Venezuela y representa el primer paso hacia la creación de un sistema de monitoreo de arrecifes en el país.


Subject(s)
Animals , Anthozoa/classification , Coral Reefs , Environmental Monitoring/methods , Fishes/classification , Atlantic Ocean , Population Density , Venezuela
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