ABSTRACT
Resumen Se describe la diversidad y composición de especies las playas de arena del Pacífico Sur de Costa Rica. En las playas de arena de la región, se colectó individuos de la infauna por medio de barrenos. Para la zona de entre mareas arenosa el número de especies estrictamente marina varió de 5 a 13 taxones, número que es intermedio con los reportados previamente para estos ambientes en Costa Rica. En la zonas de arena, el supralitoral lo dominó el isópodo Cirolana salvadorensis, mientras nereidos y un gusano de la Familia Pisionidae dominaron en el infralitoral. Otros organismos encontrados en las playas fueron cangrejos del género Uca, cangrejos anomuros (Emerita), galletas de mar (Mellita longifissa) y varios grupos de poliquetos tubícolas permanentes o temporales de la familias Onuphidae, Spionidae, Magelonidae y Glyceridae. Las playas mostraron variación en su fauna atribuible en ciertos casos a la exposición al oleaje, teniendo menos fauna en las playas más reflectivas. Se mencionan acitivades humanas que pueden explicar la baja riqueza de especies encontrada en algunas de las playas analizadas.
Abstract The diversity and species composition of the intertidal sandy beaches in the southern Pacific coast of Costa Rica were studied by means of cores collected along perpendicular transects to the beaches. The numbers of strictly marine species varied between 5 to 13 taxa, representing an intermediate value compared to those previously reported for these environments in Costa Rica. The isopod Cirolana salvadorensis was the dominant species in the supralittoral zone, whereas polychaete worms belonging to the families Nereididae and Pisionidae dominated the low intertidal zone. Others organisms collected in the beaches were the crabs of the genus Uca, anomurans crabs (Emerita), sand dollars (Mellita longifissa) and several taxa of polychaete tubeworms, such as the Onuphidae, Spionidae, Magelonidae, and Glyceridae. The high faunal difference among the sites is possibly explained by their exposure to the wave energy, with fewer individuals in the more reflective beaches. In addition, human activities might also be responsible for the low infaunal diversity found in some of these beaches. This is the first effort to describe the benthonic fauna of beaches from this area. Rev. Biol. Trop. 63 (Suppl. 1): 273-285. Epub 2015 April 01.
Subject(s)
Animals , Benthic Fauna/classification , Brachyura/classification , Biodiversity , Costa RicaABSTRACT
The objective of this study was to analyze the population biology and color patterns of Cardisoma guanhumi Latreille, 1828 in a mangrove area in Natal, Rio Grande do Norte, Brazil. Crabs were collected monthly between February 2010 and January 2012 and totaled 1,837 individuals. Sex ratios were similar between males and females in the first year and differed in the second. Sex ratios by size class differed statistically in the extremes of the distribution, with an abundance of males in the large size classes. There was no difference (p > 0.05) in carapace width between males and females in the first year, but in the second year, males were larger than females (p = 0.003), showing the importance of considering interannual variation in such studies. Both sexes presented a unimodal distribution. The size of first maturing of the females was 6.00 cm. Asymptotic carapace width for males was 9.4 cm and females for 9.2 cm, using the Wetherall method. There was no defined modal progression, which made the determination of the Von Bertalanffy growth parameter K impossible. Juveniles were found throughout all months of the year, demonstrating that there was no defined period of recruiting, although slightly fewer juveniles were found in the dry season. Four color patterns were observed, the three first patterns were the same for both sexes, while the fourth pattern was observed in females only. The four color patterns identified could be clearly related to the stage of development (size) and sexual maturity of the animal.
O objetivo deste artigo foi analisar a biologia populacional e os padrões de coloração da carapaça de Cardisoma guanhumi Latreille, 1828 em uma área de manguezal em Natal, Rio Grande do Norte, Brasil. Os caranguejos foram coletados mensalmente entre fevereiro de 2010 e janeiro de 2012 e totalizaram 1837 caranguejos. A proporção sexual foi semelhante para machos e fêmeas (1:1) no primeiro ano e diferiu no segundo ano. A proporção sexual por classe de tamanho diferiu estatisticamente nas classes extremas da distribuição, com abundância de machos nas superiores. Não houve diferença (p ≥ 0,05) entre as larguras de carapaça de machos e fêmeas no primeiro ano, porém no segundo os machos foram maiores que as fêmeas (p = 0,003), revelando à importância de se considerar as variações interanuais nestes estudos. Ambos os sexos apresentaram distribuição unimodal. O tamanho de primeira maturação sexual das fêmeas foi 6,00 cm. A largura de carapaça assintótica para machos foi de 9,4 cm e para as fêmeas de 9,2 cm, usando o método Wetherall. Não houve progressão modal definida, o que impossibilitou a determinação do parâmetro de crescimento k de Von Bertalanffy. Foram encontrados juvenis ao longo de todos os meses do ano, mostrando não haver um período de recrutamento definido, embora a abundância de juvenis tenha sido menor na estação seca. Foram observados quatro padrões de coloração, três para ambos os sexos e um quarto padrão observado apenas para as fêmeas. Os quatro padrões de coloração da carapaça estão claramente relacionados ao estágio de desenvolvimento (tamanho) e à maturidade sexual do animal.
Subject(s)
Animals , Female , Male , Brachyura/anatomy & histology , Pigmentation , Brazil , Brachyura/classification , Brachyura/growth & development , Population Density , Seasons , Sex RatioABSTRACT
The structurally diverse rocky shores along the northern coast of the state of São Paulo, Brazil, support a varied fauna and provide refuges for many organisms. Some of these environments allow for extensive microhabitats, among them the sand reefs formed by the polychaete Phragmatopoma lapidosa, which occupy much of this area. The beauty of the landscape attracts large numbers of tourists, who contribute to the damage to the sand reef colonies, causing an imbalance in the patterns of population distribution and of this ecosystem. We describe the structure and population biology of the redfinger rubble crab Eriphia gonagra, and investigated the differential occupation of the habitat by each demographic category of this species. Crabs were sampled monthly for two consecutive years on the rocky coast of Grande Beach, Ubatuba, São Paulo, during spring low tides. Sampling was carried out over an area of approximately 1200 m2, during two hours on the rock surface and another two hours on the sand reefs. A total of 1407 crabs were collected; 776 on the sand reef (SR) and 631 on the rocky shore (RO). The majority of juvenile crabs inhabited the SR, while adult crabs were equally distributed in both microhabitats. This study showed that the SR is a natural nursery ground for the establishment of the early juvenile stages of E. gonagra, which use the reefs as a refuge and food resource. Many other organisms (mollusks, echinoderms, polychaetes etc.) settle on the reefs, and these areas may be among the most important in maintaining benthic diversity in the region.
Os costões rochosos do litoral norte paulista, devido à sua constituição diversificada, sustentam uma grande diversidade de espécies animais e vegetais, além de proporcionar uma série de abrigos para proteção de muitos organismos. Em alguns destes costões ocorre a formação de microhabitats, entre eles os recifes de areia formadas pelo poliqueta Phragmatopoma lapidosa, que ocupam grande parte desta área. A paisagem diferenciada do local atrai um grande número de turistas, o que contribui para a deterioração das colônias que constituem esse recife, causando um desequilíbrio nos padrões de distribuição das populações desse ecossistema. Este trabalho visou levantar informações sobre a estrutura e dinâmica populacional de Eriphia gonagra, além de investigar uma ocupação diferencial do habitat por diferentes grupos etários deste caranguejo. Os caranguejos foram amostrados mensalmente, durante dois anos consecutivos, no costão rochoso da Praia Grande, Ubatuba, São Paulo, Brasil, em períodos de marés baixas de sizígia. A coleta ativa dos indivíduos foi efetuada em uma área de aproximadamente 1200 m2 por um período de duas horas na superfície rochosa e outras duas horas nos recifes de areia. Foi capturado um total de 1407 indivíduos, sendo 776 no recife de areia (SR) e 631 na superfície rochosa (RO). A maior parte dos jovens habita o recife, enquanto adultos encontram-se igualmente distribuídos nas duas áreas amostradas. Este estudo mostra que os recifes de areia podem ser considerados berçários de suma importância para o estabelecimento dos estágios juvenis de E. gonagra, que utilizam tais locais para proteção e alimentação. Muitos outros organismos (moluscos, equinodermos, poliquetas etc) se estabelecem sobre os recifes, sendo que essas áreas podem estar entre as mais importantes na manutenção da diversidade bêntica na região.
Subject(s)
Animals , Female , Male , Brachyura/classification , Ecosystem , Brazil , Brachyura/physiology , Population Density , Population Dynamics , Seasons , Sex RatioABSTRACT
Species of Plocamium are known as prolific sources of halogenated secondary metabolites exhibiting few explored ecological roles. In this study the crude extracts from specimens of P. brasiliense collected in two distinct places, Enseada do Forno and Praia Rasa, Búzios, Estado do Rio de Janeiro, were evaluated as defense against the sea urchin Lytechinus variegatus and the crab Acanthonyx scutiformis. These specimens produce a similar amount of crude extract and also halogenated monoterpene compound-types, but individuals of P. brasiliense from Praia Rasa exhibit a major compound representing about 59% of the total chemicals. Natural concentrations of the crude extracts obtained from both specimens of P. brasiliense significantly inhibited the herbivory by the sea urchin L. variegatus, but had no significant effect on the feeding by A. scutiformis, a crab commonly associated to chemically defended host. Crude extract from P. brasiliense collected at Praia Rasa was more efficient as defense against L. variegatus than that crude extract from populations of this alga from Enseada do Forno, probably due to presence of a major secondary metabolite. These two studied population live under different environmental conditions, but they are only about 30 Km apart. However, it is impossible to affirm that environmental characteristics (abiotic or biotic) would be responsible for the difference of defensive potential found in the two populations of P. brasiliense studied here. Further genetic studies will be necessary to clarify this question and to explain why populations of a single species living in different but close locations can exhibit distinct chemicals.
Espécies de Plocamium são conhecidas como fontes prolíficas de metabólitos secundários halogenados com significados ecológicos pouco conhecidos. Neste trabalho extratos brutos de espécimes de P. brasiliense coletados em duas localidades distintas, Enseada do Forno e Praia Rasa, Búzios, Estado do Rio de Janeiro, foram avaliados como defesa química contra o ouriço Lytechinus variegatus e o caranguejo Acanthonyx scutiformis. Estes espécimes produzem teores similares de extrato bruto e tipos de substâncias monoterpenos halogenados, mas os indivíduos da Praia Rasa possui um componente majoritário representando 59% do total de metabólitos. Concentrações naturais dos extratos brutos destes espécimes inibiram significativamente o consumo por L. variegatus, mas não causaram qualquer efeito sobre A. scutiformis, um caranguejo comumente associado a P. brasiliense, um hospedeiro quimicamente defendido. O extrato bruto de P. brasiliense coletada na Praia Rasa foi mais eficiente como defesa frente a L. variegatus do que aquele obtido de população desta alga da Enseada do Forno, provavelmente pela presença de uma substância majoritária. Estas duas populações de P. brasiliense estudadas vivem sob diferentes condições ambientais, mas distantes somente cerca de 30 km. Entretanto, é impossível afirmar que características ambientais (abióticas ou bióticas) seriam responsáveis pelas diferenças de potencial defensivo encontrados nestas duas populações de P. brasiliense estudadas. Futuros estudos genéticos são necessários para esclarecer esta questão e para explicar porque populações de uma mesma espécie vivendo em regiões tão próximas, mas ambientalmente distintas, produzem substâncias distintas.
Subject(s)
Animals , Brachyura/physiology , Herbivory/physiology , Plocamium/chemistry , Sea Urchins/physiology , Brachyura/classification , Plant Physiological Phenomena/physiology , Sea Urchins/classificationABSTRACT
The blue land crab, Cardisoma guanhumi Latreille, 1828 (Brachyura: Gecarcinidae) is officially included in the list of over-exploited species in Brazil, although still abundantly found in the state of Santa Catarina, the southern limit of its distribution. This species was found in forested areas, gardens, and grassy areas, including crabs with carapace width larger than 80mm. The existence of this population with these characteristics is surprising, since there is only one official record of the species in the southern region. The objectives of this study are to estimate the abundance and occupation patterns of C. guanhumi in this region. Correlations with conservation were discussed. The absolute abundance of crabs in the middle of summer activity was established for an area of 100,000 m2. A smaller area was mapped and divided into sampling units for statistical analyses. We distributed approximately 240 crabs in a forested area of about 3,000 m2 and 150 crabs in grassy areas (90,000 m2). The statistical test of Kruskal-Wallis test showed that there are significant differences between the sizes of the openings of the galleries inside the forest and that located in grassy areas. In the forest, the openings tend to be much larger. Burrows were found at a distance of 150 metres from the channel. The number of galleries was higher in the forested area, although the burrows were more densely grouped in grassy areas. Although C. guanhumi seems to be adjusting well to changes caused by human occupation, small forested areas are more conducive to growth and conservation of this species.
O Guaiamum, Cardisoma guanhumi Latreille, 1828 (Brachyura: Gecarcinidae) é uma espécie oficialmente inclusa na lista de espécies sobre-explotadas no Brasil, ainda encontrada em abundância no Estado de Santa Catarina, seu limite austral de distribuição. Esta espécie foi encontrada tanto em áreas florestais quanto em jardins e áreas abertas, sendo comuns caranguejos de grande porte (largura da carapaça > 80mm). A existência dessa população com tais características surpreende, pois há apenas um registro oficial da espécie na região sul. Os objetivos deste estudo é estimar a abundância desta espécie na região, inferir padrões de distribuição relacionados ao tipo de ecossistema e ao tamanho das aberturas de toca. Essas informações foram relacionadas à conservação desta população. A abundância absoluta de caranguejos em atividade no meio do verão foi estabelecida para uma área de 100.000 m2. Uma área menor foi mapeada e dividida em unidades amostrais, utilizadas para análises estatísticas. Contamos aproximadamente 240 caranguejos distribuídos em uma área de floresta de aproximadamente 3.000 m2 e 150 caranguejos em áreas abertas equivalentes a 90.000 m2. O teste estatístico de Kruskal-Wallis evidenciou que há diferenças significativas entre os tamanhos das aberturas das galerias no interior da floresta em relação às localizadas em áreas abertas. Na floresta, as aberturas tendem a ser muito maiores. Foram encontradas tocas a uma distância de 150 metros do canal. O número de galerias foi maior na área florestada, embora as tocas sejam mais densamente agrupadas em áreas abertas. Embora C. guanhumi pareça estar se adaptando bem as mudanças provocadas pela ocupação humana, as pequenas áreas florestadas são mais propícias para o crescimento e a conservação desta espécie.
Subject(s)
Animals , Ecosystem , Brachyura/classification , Seasons , Brazil , Population DensityABSTRACT
The brachyuran crabs are iteroparous species which present a high diversification of reproduction patterns, which may have evolved as a species-specific response to environmental conditions. Tropical species commonly present a year-round reproduction due to stable environment conditions. Goniopsis cruentata is a crab species widely distributed along the Western Atlantic, inhabiting practically every microhabitat in the mangrove ecosystem. The aim of the present study is to determine the breeding period of the crab Goniopsis cruentata in Northeastern Brazil and also to evaluate the influence of water salinity, rainfall and air and water temperature on it. A total of 71 ovigerous females, captured from August-2007 to July-2008, were used to assess the breeding period of this species. It was analyzed by the monthly proportion of ovigerous females. A correlation was applied to verify the influence of the abiotic factors on the breeding period. The present population bred seasonal-continuously with peaks in the dry period, which was not associated with monthly variations of salinity, rainfall and air and water temperatures. Therefore, according to statistical analyses, our hypothesis was refuted. However, breeding was intensified in the dry period, when salinity and temperatures were higher and rainfall was lower. We conclude that, even though breeding is not related to monthly variation of environmental factors, it occurs in periods of higher salinity and temperatures and lower rainfall.
Los cangrejos Brachyura son especies iteróparas, que presentan alta diversificación en los patrones de reproducción, que pueden haber evolucionado como una respuesta específica de la especie a las condiciones ambientales. Las especies tropicales frecuentemente presentan una reproducción en todo el año debido a las condiciones estables del medio. El cangrejo Goniopsis cruentata es una especie ampliamente distribuida en largo del Atlántico occidental, y que habita prácticamente cada micro-hábitat en el ecosistema de manglar. El objetivo del presente estudio fue evaluar el periodo de reproducción del cangrejo G. cruentata en el noreste de Brasil. Un total de 71 hembras ovadas, fueron capturadas entre agosto 2007 y julio 2008, y utilizadas para obtener el periodo de reproducción de esta especie. Nuestra hipótesis es que, ya que las zonas tropicales no presentan gran variación de las temperaturas, las oscilaciones temporales de la salinidad son el principal factor que influye en la actividad reproductiva de G. cruentata. Se analizó el período reproductivo mediante la proporción mensual de hembras ovadas. Una correlación fue aplicada para evaluar la influencia de los factores abióticos limitantes (salinidad, pluviosidad, temperatura del aire y del agua) en la época de crianza. La población se reproduce continuamente con picos estacionales en el período seco, lo que no fue asociado a las variaciones mensuales de salinidad, precipitación y temperatura del aire y del agua. Por lo tanto, nuestra hipótesis fue refutada. Sin embargo, la reproducción se intensificó en el período seco, cuando la salinidad y las temperaturas fueron más altas y la precipitación fue menor. Se concluye que, a pesar de que la reproducción no está relacionada con la variación mensual de los factores ambientales limitantes, ella ocurre en períodos de mayor salinidad y temperatura, y baja precipitación.
Subject(s)
Animals , Female , Male , Brachyura/physiology , Brazil , Breeding , Brachyura/classification , Reproduction/physiology , SeasonsABSTRACT
Spatial distribution of Ocypode quadrata (Decapoda: Ocypodidae) in eight beaches of NorthEastern Cuba. Studies on the ecology of Ocypode quadrata have been mostly carried out in the Northern and Southern part of its distribution range. In despite that this species is common in Cuban beaches, there are no quantitative studies regarding its abundance and spatial distribution. The aim of this study was to report some aspects about the spatial variation of O. quadrata density in sandy beaches, with different levels of human influence, in the North coast of Eastern Cuba. For this, on May 2010, eight beaches with different levels of human influence were surveyed. On each beach, the number of crabs burrows were counted in 45 quadrats of 4m2 located in three different strata (P1, P2 and P3). According to burrow opening diameter, crabs were separated into young and adults forms. To determine the existence of statistical differences in the density of crab burrows among beaches and strata, a two-way ANOVA was developed with a Scheffé-procedure post hoc test. A total of 355 burrows were counted in 360 sample units. The composition by size classes was 237 burrows for young and 118 for adults. From the total of burrows, 74% were located in P1, 20% in P2 and 6% in P3. The higher concentration of burrows was found at Jiguaní beach (0.52±0.08 burrows/m2) while the lesser concentration was found at Estero Ciego beach (0.06±0.01 burrows/m2). Most of the beaches did not present significant differences in the burrows density (Scheffé, p>0.05), according to ANOVA results, in despite their different human influence level. Density of individuals was significantly higher in the upper intertidal (P1) areas (Scheffé, p<0.05) with predominance of young crabs. Total density diminished in P2 and P3 strata where a predominance of adult individuals was observed. The interaction term of beach and strata evidenced that the pattern of variation among strata was not the same for all beaches. The general pattern of adults and young specimen spatial distribution in the beaches was very similar to those reported in the literature. In the present study, the first conducted in Cuban beaches, we did not find evidence of direct relationship between the level of human impact and the density of ghost crab burrows.
Uno de los organismos más comunes en las playas arenosas son los miembros del género Ocypode conocidos como cangrejos fantasmas, están ampliamente distribuidos en las regiones tropicales y subtropicales; además tienen un importante papel en la transferencia de energía en diferentes niveles tróficos. El objetivo del presente trabajo es dar a conocer aspectos relacionados con la variación espacial de la densidad de O. quadrata en playas con diferente nivel de influencia humana en la costa norte oriental de Cuba. En mayo de 2010, fueron contadas un total de 355 galerías en 360 unidades de muestreo. La composición por clases de tallas fue de 237 galerías de jóvenes y 118 de adultos. Del total de galerías contadas el 74% ocuparon el nivel P1, 20% el nivel P2 y 6% el nivel P3. La densidad varió entre 0.06-0.52galerías/m2. A pesar del nivel de influencia humana, la mayoría de las playas no mostró diferencias significativas en la densidad de galerías (Scheffé, p>0.05). La densidad de individuos en la zona superior de resaca del oleaje es mayor (Scheffé, p<0.05), predominando los jóvenes y en el resto de los estratos la densidad total va disminuyendo y predominan los individuos adultos. El patrón de variación entre los estratos no fue el mismo para todas las playas. En el presente estudio no se encontró evidencia directa entre el nivel de turismo y la densidad de galerías del cangrejo fantasma.
Subject(s)
Animals , Humans , Brachyura/classification , Environment , Cuba , Population Density , Population Dynamics , Seasons , SeawaterABSTRACT
Dana Swimming crab growth Callinectes danae (Decapoda: Portunidae) from Margarita Island, Venezuela. Callinectes danae is a common species captured with crab traps in nearby areas of coastal lagoons in Margarita Island. Although its considerable economic importance as a fishery resource, few studies have been done on population dynamics and its fishery potential in local coastal environments to support decision making in fishery administration. We present growth pattern details of Callinectes danae to better estimate its population size and exploitation feasibility. For this, we analyzed a total of 3 623 specimens that were Wonthly captured in crab pots by artisanal fishermen in Las Marites lagoon, from October 2007 to September 2008. The length-weight ratio was determined, and growth parameters estimated from both length and weight curves of the von Bertalanffy model. The general sex ratio showed no significant difference between males and females (χ2=0.04, p>0.05). However, values of slopes b between males and females were significantly different (ts=2.75, p<0.05), as well as intercepts a (ts=2.44, p<0.05). Thus, the length-weight ratio was determined separately: W=7.48e-5*L2.98 for males and W=1.21e-4*L2.87 for females, indicating a negative allometric growth in both sexes. Growth parameters were established as: L∞=134.80mm, W∞=166.04g and k=0.86/yr for males; L∞=122.35mm, W∞=118.45g and k=0.63/yr for females. Lifespan was estimated at 3.05 years for males and 4.24 years for females. We concluded that Callinectes danae is a species with short lifespan and moderately rapid growth. The coefficient of variation values (CV), of the phi-prime growth performance index (Ø), showed a different growth pattern compared to those obtained in other regions. We propose that a management strategy will be the periodical review of the minimum capture size for fishing area, after the great variability found in growth parameters. Rev. Biol. Trop. 59 (4): 1525-1535. Epub 2011 December 01.
Las especies del género Callinectes sostienen pesquerías importantes en varias partes del mundo. En el occidente de Venezuela, Callinectes sapidus es capturado con palangre y sostiene una pesquería artesanal importante en el Lago de Maracaibo; mientras que en la Isla de Margarita, Callinectes danae es capturado con nasa en zonas cercanas a lagunas costeras y su pesca está limitada por la oferta y la demanda. Estos recursos son de considerable importancia económica entre los crustáceos comestibles; sin embargo, pocos estudios han sido reportados sobre la dinámica poblacional y potencialidad pesquera en ambientes costeros de Venezuela que contribuyan a la toma de decisiones en la administración pesquera. En este documento se presenta información de los parámetros de crecimiento del cangrejo Callinectes danae Smith, 1869, con el fin de obtener un conocimiento detallado del patrón de crecimiento y lograr estimaciones más precisas sobre el tamaño de la población y su disponibilidad para la explotación. Se analizó una muestra constituida por 3 623 ejemplares capturados con nasa cangrejera por la flota artesanal, entre octubre 2007 y septiembre 2008. Se estableció la relación longitud-peso y se estimaron los parámetros de crecimiento de las curvas en longitud y peso del modelo de von Bertalanffy. La proporción sexual global mostró que no existe diferencia significativa entre machos y hembras (χ2=0.04, p>0.05). Los valores de las pendientes b entre machos y hembras presentaron diferencias significativas (ts=2.75, p<0.05) igualmente los interceptos a (ts=2.44, p<0.05); por lo que se estableció la relación longitud-peso por separado: P=7.48e-5*L2.98 para machos y P=1.21e-4*L2.87 para hembras, evidenciándose un crecimiento alométrico negativo en ambos sexos. Los parámetros de crecimiento quedaron establecidos en: L∞=134.80mm, P∞=166.04g y k=0.86/año para machos; L∞=122.35mm, P∞=118.45g y k=0.63/año para hembras. La longevidad fue de 3.05 años para machos y 4.24 años para hembras. Se concluye que Callinectes danae es una especie de vida corta con crecimiento moderadamente rápido, y los valores del coeficiente de variación (CV) del índice de crecimiento phi prima (Ø) demostraron diferencia de los patrones de crecimiento obtenidos en otras regiones. Como medida de manejo se recomienda considerar la talla mínima de captura por zona de pesca y revisar periódicamente las normativas, debido a la gran variabilidad en el crecimiento.
Subject(s)
Animals , Female , Male , Brachyura/growth & development , Brachyura/anatomy & histology , Brachyura/classification , Population Density , Seasons , VenezuelaABSTRACT
Biodiversity, morphometry and diet of Callinectes crabs (Decapoda: Portunidae) in Santiago de Cuba. On the basis of fishery intensity and proximity to river mouth, a total of 257 swimming Callinectes crabs were collected from March 2007 to April 2008 in eight localities. Captures were made with hanging nets, to a maximal depth of 1.5m, establishing a top time of 2 hr. The genus was widely distributed, and it is represented at least by four species: C. sapidus, C. similis, C. rathbunae and C. larvatus, the last two not included in the last list of Cuban crustaceans (Crustacea: Decapoda). The size and shape of the gonopods were very useful as taxonomical criteria, considering the prevalence of males. The most abundant species were C. sapidus (47.08%), and C. similis (30.35%). C. rathbunae, which was identified at 75% (6) of the localities, showed a better distribution, followed by C. sapidus, which appears in the 63% (5). Sex rate (Rs) by species (male:female) was 6.20 for C. rathbunae, 3.58 for C. similis, 1.40 for C. larvatus and 0.40 for C. sapidus. The most abundant species had a lower Rs value. Morphometrical analysis and weight allowed us to know the average carapace width (CW) and weight (W). C. sapidus had an average CW = 110.57 mm (DS 21.55, n = 121) and W = 84.46 g (SD 43.25, n = 121); C. rathbunae a CW = 115.50 mm (DS 14.94, n = 36) and W = 140.44 g (DS 55.02, n = 36); C. larvatus a CW = 76.04 mm (DS 10.88, n = 22) and W = 31.70 g (DS 14.67, n = 22); and C. similis had the minimal parameter values, with a CW = 59.77 mm (DS 14.09, n = 78) and W = 13.80g (DS 10.00, n = 78). These are the first records of the coastal crabs in the area. All values are lower than in previous reports. The largest individuals (CW>140 mm: C. rathbunae and C. sapidus) were captured in localities with adequate environmental characteristics. The stomach content suggests nine dietary categories, mainly fishes and macroalgae. The genus Callinectes has a diversified trophic spectrum. These crabs eat the available food, but they have a preference for the most abundant items. Rev. Biol. Trop. 57 (3): 671-686. Epub 2009 September 30.
El objetivo del presente trabajo es el estudio del género Callinectes en la zona costera del municipio de Santiago de Cuba. Se realizó una recolecta de 257 ejemplares durante marzo de 2007 a abril de 2008, en ocho estaciones a lo largo de la costa. El género resultó estar ampliamente distribuido en el litoral y representado al menos por cuatro especies: C. sapidus, C. similis, C. rathbunae y C. larvatus, las dos últimas no incluidas en la lista publicada de crustáceos (Crustacea: Decapoda) cubanos. Las especies más abundantes resultaron ser C. sapidus y C. similis. C. rathbunae fue la más ampliamente distribuida. El análisis del contenido estomacal permitió identificar nueve categorías alimentarias, siendo las más importantes los peces y las macroalgas. Las especies de Callinectes tienen un amplio espectro trófico; comen no sólo lo disponible, sino también lo más abundante.
Subject(s)
Animals , Female , Male , Biodiversity , Brachyura/anatomy & histology , Brachyura/classification , Feeding Behavior , Brachyura/physiology , Cuba , Gastrointestinal Contents , Population DensityABSTRACT
Observations on the larvae of the tropical marine crab Petrolisthes armatus in the Gulf of Nicoya, Costa Rica. During October and November 1998 (rainy season), and December, February and March 1999 (dry season), larvae distribution of Petrolisthes armatus and associated decapods were sampled in three different sites at the Punta Morales peninsula, Gulf of Nicoya, Costa Rica. A total of 6014 decapod larvae were collected, and 73 belonged to the genus Petrolisthes spp. No significant total larval density differences were found between seasons (p>0.05); but there was a greater density of P. armatus and other decapod larvae (p>0.05) during the dry season. In addition, no significant variations on temperature and oxygen concentration were observed. P. armatus larval abundance was higher during low tide, in contrast with other decapod larvae. Significant differences among sites were found for other decapod larvae, but not for P. armatus. The only parameter that varied significantly between seasons was salinity and results demonstrate that this factor regulates temporal concentration of larvae. Moreover, flow-tide oscillations were the most important spatial factor in larval dynamics. We propose this mechanism: P. armatus liberates larvae during high tide; these larvae leave the coastal area during low tide and return to the rocky intertidal ecosystem during high tide, when they are ready to settle as megalopa (pre-juvenile stage). Parallel laboratory observations showed higher survival rates at lower salinities (15 ups against 35 ups) and that the duration of the period from zoea I to megalopa was, in average, 19 days. Rev. Biol. Trop. 56 (3): 1209-1223. Epub 2008 September 30.
Durante octubre y noviembre de 1998 (estación lluviosa) y diciembre, febrero y marzo de 1999 (estación seca) se muestreó la distribución de la larva de Petrolisthes spp, así como la densidad del total de las larvas de decápodos en superficie y a 3 metros de profundidad. Los muestreos se realizaron en tres sitios de la zona de Punta Morales, Golfo de Nicoya, Costa Rica, por medio de arrastres con una red de plancton de 280 µm. Se recolectaron un total de 6014 larvas de decápodos de las cuales 73 (1.21%) pertenecían al género Petrolisthes spp. No se encontraron diferencias significativas entre estaciones (p > 0.05), sin embargo fue posible observar una mayor densidad tanto de P. armatus como de larvas de decápodos en estación seca. Temporalmente el único parámetro físico-químico que varió significativamente fue la salinidad. En cuanto a la variación espacial no se encontraron diferencias significativas por profundidad, ni para Petrolisthes spp. ni para larvas de decápodos asociados (p > 0.05), a pesar de que la variación de algunos parámetros como la temperatura y el oxígeno si lo fue. Entre mareas se encontraron diferencias significativas para las larvas de Petrolisthes spp., no así para larvas de decápodos. Para la especie estudiada se observó un mayor número de larvas en marea baja. Entre los sitios hubo diferencias significativas para las larvas de decápodos, pero no para Petrolisthes spp.; físico-químicamente estos sitios son muy parecidos y solo difieren en penetración de luz, lo que parece no afectar a la larva de Petrolisthes. spp. Los resultados demuestran que el principal factor que regula la concentración temporal de las larvas es la salinidad, mientras que espacialmente las oscilaciones en el flujo mareal son de mayor importancia. Debido a las diferencias observadas marealmente para la concentración de larvas se propone el siguiente mecanismo: P. armatus libera sus larvas en el máximo de marea, éstas salen hacia fuera de la costa con la marea baja y se reincorporan con la marea alta, cuando están cerca de la fase previa al asentamiento (la megalopa). Adicional a los resultados en el medio natural para esta especie también se estudió en el laboratorio la duración del periodo larval y la supervivencia de las larvas a salinidades extremas utilizándose los valores máximos y mínimos registrados en el medio natural (15 ups y 35 ups). Este ensayo demostró que las larvas presentan un mayor porcentaje de supervivencia en salinidades menores (15 ups) y que la duración del período de desarrollo es de 19 dias.
Subject(s)
Animals , Brachyura/growth & development , Brachyura/classification , Brachyura/physiology , Costa Rica , Larva/classification , Larva/growth & development , Larva/physiology , Population Density , Population Dynamics , Seasons , Seawater , Tropical ClimateABSTRACT
Los "cangrejos porcelana" Petrolisthes haigae Chace 1962 y P. nobilii Haig 1960, son especies de aguas poco profundas distribuidas a lo largo de las costas del Pacífico Este Tropical. Recolectamos larvas de ambas especies, de ocho y cuatro hembras, en las islas de Taboga y Naos, respectivamente. Las criamos en el laboratorio para describir e ilustrar los primeros estados de zoea de estas especies fueron, hasta ahora desconocidos. Las comparamos con los primeros estadios de zoea de otras especies del género en el oeste de Panamá y concluimos que las características de la primera zoea de ambas especies se asemejan a las del grupo 4 de larvas propuesto por Osawa en 2002.
Subject(s)
Animals , Female , Male , Brachyura/anatomy & histology , Brachyura/classification , Larva/anatomy & histology , Pacific IslandsABSTRACT
Eight species of Brachyura and two species of Anomura were registered for the first time on the Santa Catarina coast, in the waters around the Arvoredo Marine Biological Reserve. The animals were collected by scuba divers, between 3 and 22 meters depth, from September 2001 to February 2003. A total of 31 decapod species were collected, and most of the new occurrences had already been registered in the adjacent northern waters.
Oito espécies de Brachyura e duas espécies de Anomura foram registradas pela primeira vez na costa de Santa Catarina, em águas no entorno da Reserva Biológica Marinha do Arvoredo. Os animais foram coletados por meio de mergulho autônomo, entre 3 e 22 metros de profundidade, de setembro 2001 a fevereiro de 2003. Um total de 31 espécies de Decapoda foram coletadas e a maioria das novas ocorrências já haviam sido registradas em águas adjacentes ao norte da Reserva.
Subject(s)
Animals , Anomura/classification , Brachyura/classification , Conservation of Natural Resources , Brazil , SeawaterABSTRACT
Information on size frequency distribution, the width-weight relation and growth parameters of the crabs Callinectes arcuatus and C. bellicosus is presented. The data comes from samples taken with a trawl net both day and night on a monthly basis from March 1998 to February 2000 in a coastal lagoon from Gulf of California. C. bellicosus (n=878) was more abundant than C. arcuatus (n=357) and its size frequency distribution presented carapace width CW ranges of 8.4-166 mm and 9-130 mm respectively. Both populations were mainly represented by juveniles (75 mm in CW) ranging from 37 to 75 mm in CW, and adults (>75 mm in CW) between 76 and 90 mm in CW. In both species the width-weight relation showed that males grow more than females, with an isometric growth tendency being observed. The growth parameters for C. arcuatus estimated using the von Bertalanffy Model, were: K = 0.84 year(-1), L infinity = 140 mm to = -0.12 for C. arcuatus, and K= 0.9 year(-1), L infinity = 169 mm to = -0.11 for C. bellicosus. These results showed that the relative age at which maximum growth is attained is between three and four years for both species.
Subject(s)
Animals , Male , Female , Brachyura/growth & development , Brachyura/anatomy & histology , Brachyura/classification , Population Density , Population Dynamics , MexicoABSTRACT
In order to determine temporal and spatial distribution patterns of Callinectes sapidus, samplings were carried out during the cold-front (January-February), dry (May-June) and rainy (August-September, 2002) climatic seasons, in 30 sampling stations of Chetumal Bay, grouped in sectors A (14 stations), B (eight stations) and C (eight stations). In each sampling station crabs were collected from two transects parallel to the coast, each with three traps, separated by 30 m. Sediments were calcareous coarse and medium sand, white or lightly gray. A total of 1 031 specimens were collected. CPEU (Capture Per Effort Unit) differed spatially and temporally. Highest CPEU was found in sector C with 1.3 ind.trap(-1), and in the rainy season with 1.1 ind.trap(-1). Population was predominantly composed of male individuals. The male:female ratio was 15:1. Males and adults (group II) CPEU was significant different between sectors and climatic seasons. Both males and adults (group II) had a greater CPEU in sector C (1.2 ind.trap-) and in the rainy season (1.1 ind.trap(-1)). Abundance of female and juvenile individuals (group I) was low during the sampling period whereas group 0 juvenile individuals were not found. A greater relative frequency between sectors and climatic seasons were observed in 130-139 mm and 140-149 mm size interval (CW). C. sapidus occurred on sandy sediments in Chetumal Bay. Pearson product moment correlations exhibited significant relationships between CPEU and temperature, salinity and dissolved oxygen. In Chetumal Bay, the spatial and temporal distribution of C. sapidus can be related to salinity, temperature, habitat quality, food availability, recruitment and reproduction events of individuals.
Subject(s)
Animals , Male , Female , Brachyura/physiology , Ecosystem , Brachyura/classification , Population Density , Population Dynamics , Seasons , MexicoABSTRACT
Two new species of freshwater crabs of the genus Hypolobocera from Serranía de Los Paraguas, Cordillera Occidental, Colombia, are described. Hypolobocera solimani n. sp. is closely related to H. alata Campos 1989, but can be distinguished from it by smooth upper margin of third maxilliped merus, the size and shape of apex of first gonopod, and the internal lobe or papilla of spermatic channel, which is concave, raised, with ends with minute papillae or rounded tubercles. Hypolobocera triangula n. sp. is very similar to H. rotundilobata Rodríguez 1994, but differs from it by the shape and size of the lateral lobe, an oblique basal ridge of tubercles and by the apex of first gonopod. With the two new species, the total number of valid members of the genus Hypolobocera known from western Colombia or biogeographic Chocó is 20.
Se describen dos nuevas especies de cangrejos de agua dulce del género Hypolobocera de la Serranía de Los Paraguas, Cordillera Occidental de Colombia. H. solimani n. sp. está estrechamente relacionada con H. alata Campos 1989, pero se puede distinguir de ésta por el margen superior del mero del tercer maxilípedo, el cual es liso; por la forma del ápice del primer gonópodo y la forma del lóbulo interno o papila del canal espermático, la cual es cóncava, levantada y termina bordeada por diminutas papilas o tubérculos redondeados. H. triangula n. sp. es muy similar a H. rotundilobata Rodríguez 1994, pero se diferencia de ésta por el tamaño y la forma del lóbulo lateral, una cresta basal de tubérculos y la superficie apical del gonópodo. Con estas dos nuevas descripciones se incrementa a 20 el número de miembros válidos del género Hypolobocera conocidos del occidente de Colombia o del Chocó biogeográfico.
Subject(s)
Animals , Male , Brachyura/classification , Brachyura/anatomy & histology , Colombia , Fresh Water , Species SpecificityABSTRACT
The box crabs, genus Calappa, are important crab species landed by the industrial trawl fleet in Venezuela. These crabs have a wide distribution in the country, from the Gulf of Venezuela to the Orinoco River, but major landings take place in such gulf, near Margarita Island and northern Sucre State. Average annual landing in the eastern region was 69 t during 1970-2001, with a maximum of 221 t. For this study a sample of 2 398 box crabs was collected by observers on board of industrial trawl vessels, which operated in eastern Venezuela from 1994 to 2000. Three species were found in the landings, Calappa sulcata and C. flammea, each represented 47% of the sample, and C. nítida, which accounted for 5% of the sample. Sex ratio was strongly biased towards males in C. sulcata (2.8:1) and in C. flammea (1.9:1), while it was only slightly biased in C. nitida (1.4:1). Due to its large size, C. sulcata is of great commercial interest, with average weight 290 g and a maximum weight of 720 g; C. flammea showed an average weight of 140 g and a maximum weight of 418 g, while C. nitida is the smallest species, with average weight 46 g and maximum weight not beyond 113 g. Box crabs were captured by day and night in similar proportions, and were found in a wide depth range, from a few meters to 126 m deep; however, the largest captures were obtained in the interval 38 - 54 m. Regressions between weight of chelae and total weight were linear, and significantly different between sexes. The relation between total weight and carapace width was allometric, with a power exponent ca. three in C. sulcata, and less than three in C. flamea and C. nítida. Females of C. sulcata and C. nitida showed power exponents significantly smaller than males. Since claws are removed from the animal to be commercialized, while the rest of the...
Los cangrejos moros, del género Calappa, constituyen las principales especies de cangrejos desembarcados por la flota arrastrera industrial en Venezuela. Su distribución es amplia en el país, desde el Golfo de Venezuela hasta el delta del Río Orinoco, pero las mayores capturas provienen de dicho golfo, los alrededores de la Isla de Margarita y norte del estado Sucre. Las capturas en la región oriental alcanzaron 221 t por año, con un promedio de 69 t en el período 1970-2001. Para este estudio se procesó una muestra de 2 398 cangrejos moros recolectada por observadores científicos a bordo de las embarcaciones de arrastre industrial que operaron en el oriente del país entre 1994 y 2000. Tres especies componen las capturas, Calappa sulcata y C. flammea, ambas en proporción de 47%, y C. nítida, que representó 5% de la muestra. La proporción de sexos estuvo fuertemente sesgada hacia los machos en C. sulcata (2,8:1) y en C. flammea (1,9:1), y ligeramente sesgada en C. nitida (1,4:1). Calappa sulcata es la especie con mayor interés comercial para la flota, alcanzando un peso promedio de 290 g y máximo de 720 g; C. flammea alcanzó un peso promedio de 140 g y máximo de 418 g, mientras que el peso promedio de C. nitida fue 46 g y su peso máximo no superó los 113 g. Los cangrejos moros son capturados de noche y de día en similar proporción en la región oriental. Aunque la distribución batimétrica de estas especies es amplia, desde pocos metros a 126 m de profundidad, las mayores capturas tuvieron lugar entre 38 y 54 m. Las relaciones entre el peso de las quelas y el peso total fueron lineales y difirieron significativamente entre sexos. La relación entre el peso total y el ancho del caparazón fue alométrica, con exponente ca. 3 en C. sulcata, y menor que 3 en C. flamea y C. nítida. Las hembras de C. sulcata y C. nitida presentaron exponentes significativamente menores que los machos. Motivado a que las quelas son separadas a bordo para ser...
Subject(s)
Animals , Male , Female , Biometry , Brachyura/anatomy & histology , Fisheries , Brachyura/classification , VenezuelaABSTRACT
O caranguejo-uçá (Ucides cordatus) é um crustáceo (Decápoda: Brachyura) de grande valor cultural, biológico e comercial em todo Espírito Santo. Contudo, ainda há uma grande lacuna de conhecimentos acerca de sua biologia. Com o intuito de minimizar essa carência, o presente trabalho realizou um estudo sobre a caracterização morfológica de três populações do caranguejo-uçá (Ucides cordatus L.) em manguezais do Espírito Santo. Foram analisadas quatro características morfométricas em 172 indivíduos machos, coletados nas cidades de São Mateus (N=62), Vitória (N=60) e Anchieta (50). Foi observada diferença significativa entre as três populações (p<0,01) por meio de uma Análise de Variância Multivariada. O maior grau de similaridade foi encontrado entre as populações de São Mateus (Norte) e Anchieta (Sul), de modo que a população de Vitória (Centro) foi agrupada separadamente, evidenciando-se divergência entre essa população e as demais. Os resultados sugerem pressões de seleção diferentes nas populações do interior em relação à população da capital, o que pode estar relacionado a uma maior ação antrópica nas populações da capital.
Subject(s)
Animals , Male , Brachyura/anatomy & histology , Analysis of Variance , Brachyura/classification , BrazilABSTRACT
Potamonautes loveni (Colosi) is the valid name for the species also described as P. granviki; P. harvardi and P. loveni longimerus; and incorrectly identified as P. berardi berardi. Potamonautes jeanelli and P. idjwiensis may be allied to P. loveni; but are geographically separated and show sufficient morphological distinction not to be considered conspecific. Potamonautes loveni occurs in the upper reaches of rivers on the highlands of western Kenya and eastern Uganda. Its replacement by other species; principally P. niloticus; at lower altitudes is probably determined by the temperature range of the water. Potamonautes loveni has been observed to coexist with P. niloticus within the range of altitude 1280-1950 m. Distinct forms of P. loveni; differing in colour; size and the expression of the post-frontal crest; occur on the western side of Mt. Elgon and in the former ochocerciasis foci of Kenya. Hybridization is evident in populations from between these areas. Morphological divergence within P. loveni may be the result of past climatic change. Periods of generally lower temperature have been accompanied by increased aridity and reduction of forest cover. It is suggested that these conditions are such as to promote a disjunct distribution of P. loveni; and in particular the isolation of the Mt. Elgon population