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A new labrid fish species, Halichoeres sanchezi n. sp., is described from eight specimens collected in the Revillagigedo Archipelago in the tropical eastern Pacific Ocean, off the coast of Mexico. The new species belongs to the Halichoeres melanotis species complex that is found throughout the region, differing by 2.4% in the mtDNA cytochrome c oxidase I sequence from its nearest relative, H. melanotis from Panama, and 2.9% from Halichoeres salmofasciatus from Cocos Island, off Costa Rica. The complex is distinguished from others in the region by having a black spot on the opercular flap and a prominent black area on the caudal fin of males. The juveniles and initial phase of the new species closely resemble those of H. salmofasciatus and Halichoeres malpelo from Malpelo Island of Colombia, differing in having an oblong black spot with a yellow dorsal margin on the mid-dorsal fin of initial-phase adults as well as on juveniles. In contrast, the terminal-phase male color pattern is distinct from other relatives, being vermilion to orangish brown with dark scale outlines, a white patch on the upper abdomen, and a prominent black band covering the posterior caudal peduncle and base of the caudal fin. The new species adds to the list of endemic fish species for the isolated archipelago and is an interesting case of island endemism in the region. The discovery was made during the joint 2022 collecting expedition to the archipelago, which featured a pioneering collaborative approach to an inventory of an island ichthyofauna, specifically including expert underwater photographers systematically documenting specimens in situ, before hand-collection, and then photographed fresh, tissue-sampled, and subsequently vouchered in museum collections.
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Cavidade Abdominal , Perciformes , Masculino , Animais , México , Oceano Pacífico , Peixes/genéticaRESUMO
Coral reefs, vital and ecologically significant ecosystems, are among the most jeopardized marine environments in the Atlantic Ocean, particularly along the northeastern coast of Brazil. The persistent lack of effective management and conservation has led to fragmented information on reef use and pressures, hindering the understanding of these ecosystems' health. Major difficulties and challenges include inadequate data, diverse anthropogenic pressures, and the complex interaction between marine species. This study sought to bridge this knowledge gap by conducting a comprehensive analysis of marine diversity and anthropogenic pressures, specifically focusing on Seixas coral reef near João Pessoa city, an area notably impacted by tourism. Utilizing 25 monitoring transects, subdivided into 1 m2 quadrants, the marine diversity was meticulously evaluated through innovative procedures including (a) sedimentological and geochemical field surveys, (b) application of Shannon-Weaver diversity and Simpson dominance indices, (c) cluster analysis, (d) species identification of macroalgae, coral, and fish, and (e) an examination of anthropogenic interactions and pressures on the coral reef. The assessment encompassed three distinct zones: Back Reef, Reef Top, and Fore Reef, and identified a total of 25 species across 15 genera and 10 fish families. The findings revealed the prevalence of brown macroalgae, fish, and coral, with heightened abundance of red macroalgae in the Fore Reef, which also exhibited the greatest diversity (2.816) and dominance (0.894). Original achievements include the identification of specific spatial variations, recognition of the anthropogenic factors leading to ecological changes, and the formulation of evidence-based recommendations. The study concludes that escalating urbanization and burgeoning daily tourist visits to the reef have exacerbated negative impacts on Seixas coral reef's marine ecosystem. These insights underscore the urgent need for strategic planning and resource management to safeguard the reef's biodiversity and ecological integrity.
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Antozoários , Alga Marinha , Humanos , Animais , Recifes de Corais , Ecossistema , Efeitos Antropogênicos , Brasil , Biodiversidade , PeixesRESUMO
Biodiversity conservation has been a critical challenge faced by environmental managers worldwide. From 2020 to 2022, a total of 576 underwater visual censuses focused on reef fishes, marine litter (ML), and non-native species were performed in the newest Brazilian Hope Spot, to understand the distribution, characteristics, and effects of ML and Tubastraea spp., on the reef fish community. Plastic was the main category recorded (34.54 %), followed by Metal and Line (mostly fishing gear within a Marine Protected Area). Tubastraea spp. was widely distributed, especially between 10-20 meters deep. The t-test analysis showed that fish abundance and richness were significantly higher at low Tubastraea cover areas. Our efforts present the baseline of ML (mean 1.92 ± 1.5 items/100 m2) and non-native species occurrence (15) and distribution (including three new records) showing their negative impacts on rocky reef ecosystems and provide managers support in the elaboration of marine conservation strategies.
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Conservação dos Recursos Naturais , Recifes de Corais , Peixes , Brasil , BiodiversidadeRESUMO
En este trabajo se registra a Anthias noeli Anderson & Baldwin, 2000 por primera vez en el Perú. Entre el 2016 y 2019, se capturaron 15 ejemplares en el litoral del departamento de Tumbes, en el extremo norte del Perú. Los ejemplares fueron fotografiados en fresco, se realizaron los análisis merísticos y morfométricos para su identificación. Además, de cinco individuos se obtuvieron tejido muscular para determinar las secuencias del gen COI. Los análisis filogenéticos confirmaron su identificación como A. noeli. Las secuencias fueron depositadas en la base de datos públicos BOLD Systems, siendo las primeras secuencias depositadas de esta especie. Con este registro se amplía la distribución sur de A. noeli.
This work documents the first record of Anthias noeli Anderson & Baldwin, 2000 in Peru. Between 2016 and 2019, fifteen specimens were captured from the littoral of the Tumbes Department, located in the northernmost of Peru. Fresh photographs were taken of the specimens and meristic and morphometric analyses were conducted for species identification. Additionally, muscle tissue was extracted from five individuals to determine COI gene sequences. Phylogenetic analyses confirmed the specimens' identity as A. noeli, and the sequences were deposited in the public database BOLD Systems, representing the first deposited sequences for this species. This record expands the southern distribution of A. noeli.
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[This corrects the article DOI: 10.3897/zookeys.1103.83795.].
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The vulnerability of a fish stock to becoming overfished is dependent upon biological traits that influence productivity and external factors that determine susceptibility or exposure to fishing effort. While a suite of life history traits are traditionally incorporated into management efforts due to their direct association with vulnerability to overfishing, spawning behavioral traits are seldom considered. We synthesized the existing biological and fisheries information of 28 fish stocks in the U.S. Gulf of Mexico to investigate relationships between life history traits, spawning behavioral traits, management regulations, and vulnerability to fishing during the spawning season. Our results showed that spawning behavioral traits were not correlated with life history traits but improved identification of species that have been historically overfished. Species varied widely in their intrinsic vulnerability to fishing during spawning in association with a broad range of behavioral strategies. Extrinsic vulnerability was high for nearly all species due to exposure to fishing during the spawning season and few management measures in place to protect spawning fish. Similarly, several species with the highest vulnerability scores were historically overfished in association with spawning aggregations. The most vulnerable species included several stocks that have not been assessed and should be prioritized for further research and monitoring. Collectively, the results of this study illustrate that spawning behavior is a distinct aspect of fish ecology that is important to consider for predictions of vulnerability and resilience to fisheries exploitation.
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Here we describe massive spawning aggregations and seasonal changes in the large-scale distribution of the Patagonian grouper Acanthistius patachonicus in the Southwest Atlantic based on three sources of information: (a) data from bottom trawl research surveys covering the distributional range of the species within the Argentine continental shelf; (b) folk ecological knowledge gathered from experienced captains of the Argentine industrial trawl fisheries; and (c) sampling of an artisanal trap fishery targeting the Patagonian grouper in a specific location off the coast of Buenos Aires Province. The trawl surveys showed a general pattern of aggregation of Patagonian grouper towards the coast during the reproductive period (September-December). Captains described massive aggregations of the species at specific near-shore locations, where trawl catches of up to 15 t in a single haul were registered during the reproductive season. At a local scale, the artisanal trap fishery described operates exclusively during the reproductive period, targeting near-shore aggregations with a high proportion of individuals releasing gametes onboard. These three sources of information provide evidence of the existence of massive transient spawning aggregations of Patagonian grouper in the Argentine shelf. This is the first report of a reef fish spawning aggregation in the southern region of the Southwest Atlantic. Anecdotal information gathered in this study points to the depletion of many of the aggregations targeted during the 1980s and 1990s by the industrial fleet. At the same time, the spawning aggregation site off Buenos Aires Province has been productive for the last 34 years, being exploited exclusively by traps. The Patagonian grouper is classified as Data Deficient by the International Union for Conservation of Nature, which highlights the need for further research to determine its stock status. Mapping its current spawning aggregations should be a priority to inform the design of a targeted monitoring program and management plan for this species.
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Bass/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Oceano Atlântico , Pesqueiros , Reprodução , Estações do AnoRESUMO
There are increasing global concerns of the alarming pollution impacts on marine life, thus it is becoming essential to generate reliable tools to monitor and understand the effects of these impacts on aquatic organisms. We performed a field study assessing how exposure to anthropogenic pollution impacts immunological and health-state parameters and parasite infection of a wild marine fish, the Brazilian sandperch Pinguipes brasilianus. Then we compared this information to previously published data of a sympatric species, the Patagonian rockfish Sebastes oculatus inhabiting the same polluted and pristine areas. The field study revealed that exposed P. brasilianus showed chronic stress, poor immune condition and higher prevalence and abundance of acanthocephalan parasites. By comparing these former results with already published in S. oculatus, we concluded that, although both species exhibited physiological alterations associate to inhabiting sites exposed to pollution, their specific immunological and health-state responses differed. Our results demonstrate that Patagonian reef-fish assemblages inhabiting sites exposed to pollutant are being affected in their immune and heath condition, which could potentially result in higher susceptibility to disease and in turn population decline. These findings highlight the necessity of more studies incorporating interspecific comparisons to assess variation in fish susceptibility in an ecoimmunotoxicological context and get a more profound understanding of anthropogenic impacts on wildlife.
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Bass , Parasitos , Perciformes , Animais , Brasil , Poluição Ambiental , PeixesRESUMO
A series of small emergent coral reefs and shallow, submerged coralliferous banks are scattered along the western edge of Campeche Bank (southwest Gulf of Mexico), 150-200 km offshore from the Yucatán Peninsula, Mexico. Here a reasonably comprehensive, annotated checklist of reef-associated fishes for one reef, Cayo Arcas (expanded from 162 to 209 species) is presented, with preliminary checklists of such fishes from three other emergent reefs (Cayo Arenas, Triángulo Oeste, Triángulo Este) and four submerged bank reefs (Banco Obispo Norte, Banco Obispo Sur, Banco Nuevo and Banco Pera). During 2017-18 a total of 260 species was observed or collected from those reefs, and previous studies and georeferenced museum records in the global aggregator Fishnet2 added another 101 shallow-living species recorded on or adjacent to those reefs. Some coral-reef fishes are thought to be strongly dependent on seagrass and mangrove areas as nursery habitats for maintenance of their local populations on reefs near to those habitats. The abundance of a number of such "nursery" species on these Campeche reefs indicates otherwise, as there are no seagrass- or mangrove habitats for reef fishes within ~ 150 km of the study reefs. Other isolated Caribbean-area reefs that lack mangroves and, in some cases, seagrasses, also support many such nursery species of reef-fishes.
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Habitat discontinuities, temperature gradients, upwelling systems, and ocean currents, gyres and fronts, can affect distributions of species with narrow environmental tolerance or motility and influence the dispersal of pelagic larvae, with effects ranging from the isolation of adjacent populations to connections between them. The coast of the Tropical Eastern Pacific (TEP) is a highly dynamic environment, with various large gyres and upwelling systems, alternating currents and large rocky-habitat discontinuities, which may greatly influence the genetic connectivity of populations in different parts of the coast. Elacatinus puncticulatus is a cryptic, shallow-living goby that is distributed along the continental shore of virtually the entire TEP, which makes it a good model for testing the influence of these environmental characteristics in the molecular evolution of widespread species in this region. A multilocus phylogeny was used to evaluate the influence of habitat gaps, and oceanographic processes in the evolutionary history of E. puncticulatus throughout its geographical range in the TEP. Two well-supported allopatric clades (one with two allopatric subclades) were recovered, the geographic distribution of which does not correspond to any previously proposed major biogeographic provinces. These populations show strong genetic structure and substantial genetic distances between clades and sub-clades (cytb 0.8-7.3%), with divergence times between them ranging from 0.53 to 4.88 Mya, and recent population expansions dated at 170-130 Kya. The ancestral area of all populations appears to be the Gulf of Panama, while several isolation events have formed the phylogeographic patterns evident in this species. Local and regional oceanographic processes as well as habitat discontinuities have shaped the distribution patterns of the genetic lineages along the continental TEP. Large genetic distances, high genetic differentiation, and the results of species-tree and phylogenetic analyses indicate that E. puncticulatus comprises a complex of three allopatric species with an unusual geographic arrangement.
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Evolução Biológica , Ecossistema , Peixes/fisiologia , Clima Tropical , Animais , Teorema de Bayes , Bases de Dados Genéticas , Evolução Molecular , Haplótipos/genética , Oceano Pacífico , Panamá , Filogenia , Filogeografia , Análise de Sequência de DNA , Especificidade da Espécie , Fatores de TempoRESUMO
A large fish-count dataset from the Brazilian province was used to describe spatial patterns in standing biomass and test if total biomass, taxonomic and functional trophic structure vary across nested spatial scales. Taxonomic and functional structure varied more among localities and sites than among regions. Total biomass was generally higher at oceanic islands and remote or protected localities along the coast. Lower level carnivores comprised a large part of the biomass at almost all localities (mean of 44%), zooplanktivores never attained more than 14% and omnivores were more representative of subtropical reefs and oceanic islands (up to 66% of total biomass). Small and large herbivores and detritivores varied greatly in their contribution to total biomass, with no clear geographical patterns. Macrocarnivores comprised less than 12% of the biomass anywhere, except for two remote localities. Top predators, such as sharks and very large groupers, were rare and restricted to a few reefs, suggesting that their ecological function might have already been lost in many Brazilian reefs.
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Recifes de Corais , Peixes/fisiologia , Animais , Biodiversidade , Biomassa , Brasil , Comportamento Alimentar , Geografia , Ilhas , Dinâmica PopulacionalRESUMO
The damselfish Chromis limbata is native to the Macaronesian Archipelagos (Azores, Madeira and Canaries) and the western coast of Africa between Senegal and Angola. During the austral summers of 2008 and 2009 the species was recorded for the first time in the south-western Atlantic Ocean around Campeche and Xavier Islands, in Florianópolis, Santa Catarina State, Brazil. Here, the progression of C. limbata in southern Brazilian waters is described using visual counts and genetic surveys and changes in the density of the native congener Chromis multilineata were also investigated. Underwater visual censuses of both Chromis species were carried out from 2009 to 2014. Chromis limbata tissue samples were collected and the mtDNA control region was sequenced and compared with mtDNA haplotypes from the natural range to confirm species identity, compare genetic diversity and to infer connectivity between newly established Brazilian populations. The Brazilian population of C. limbata increased significantly over the past 5 years and the effect on C. multilineata is still an open question, longer time-series data will be necessary to clarify possible interactions. The molecular analyses confirmed species identity, revealed strong haplotype connectivity among Brazilian study sites and showed a low genetic diversity in Brazil when compared with the native populations, suggesting few individuals started the invasion. Four hypotheses could explain this colonizing event: C. limbata was released by aquarium fish keepers; larvae or juveniles were transported via ship ballast water; the species has rafted alongside oil rigs; they crossed the Atlantic Ocean through normal larval dispersal or naturally rafting alongside drifting objects. The rafting hypotheses are favoured, but all four possibilities are plausible and could have happened in combination.
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Peixes/fisiologia , Espécies Introduzidas , Animais , Oceano Atlântico , Sequência de Bases , Brasil , DNA Mitocondrial/química , Peixes/genética , Variação Genética , Haplótipos , Filogenia , Densidade DemográficaRESUMO
The Abrolhos Bank is an area of high ecological, socio-economic importance and harbour the richest and most-extensive coral reefs in the South Atlantic. Here we report the discovery of shallow (12-25m depth) reef complex with ten large biogenic structures, intermediate between the typical mushroom-shaped pinnacles of the northern Abrolhos Bank (17°-18° S) and the small patch reefs found on the central/southern coast of the Espírito Santo State (19°-20° S). The newly discovered reefs harbour a relatively rich and abundant reef community, with 73 fish and 14 benthic cnidarian species, including endangered and commercially important ones. We discuss on urgent needs of properly mapping and understanding the ecological functioning of this reef system. Information provided here is a baseline for future impact evaluations, particularly considering the recent worst environmental disaster of Brazil from a dam collapse in Doce river that affected the region.
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Conservação dos Recursos Naturais , Recifes de Corais , Animais , Antozoários/crescimento & desenvolvimento , Brasil , Ecologia , Meio Ambiente , Peixes , Poluição da Água/prevenção & controle , Poluição da Água/estatística & dados numéricosRESUMO
Cayo Arcas is a small, offshore reef complex on the southwest corner of Campeche Bank, Gulf of Mexico. The only published information (from 2000) on the fishes of that reef refers to 37 species. Here additional information is added, some from unpublished observations during the 1980s, as well as author observations made during 2013 and 2016. These bring the checklist of that reef's fishes up to 162 species. The possible effects of the limited number of fish habitats available at Cayo Arcas on the composition of its fish fauna are discussed. The Indo-Pacific damselfish Neopomacentrus cyanomos (Bleeker, 1856) was first recorded in the Atlantic in mid-2013, on shoreline reefs in the southwest corner of the Gulf of Mexico. Recently reviewed underwater photographs show that Neopomacentrus cyanomos also was present at Cayo Arcas in mid-2013, 350 km from the first-record site. Hence it evidently had a substantial population in the southwest Gulf of Mexico in 2013, and must have arrived in there long before that year.
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Pinguipes brasilianus is a conspicuous and abundant rocky-reef fish inhabiting the Northern Patagonian gulfs of Argentina, Southwest Atlantic. This study describes its reproductive biology in this region. We made macroscopic and histological descriptions of the testis and ovary development, analyzed the evolution of the gonadosomatic index (GSI) in both sexes throughout the year, and estimated fecundity and length at 50% maturity for females. Pinguipes brasilianus is a multiple spawner with indeterminate annual fecundity and an extended reproductive season, encompassing austral spring and summer. Low GSI values in males (monthly means ranged between 0.11% and 0.75%) and low relative fecundity in female fish (between 2 and 44 oocytes/g) are consistent with a need of close proximity between male and female during oocyte fertilization, sexual courtship and with spawning in pairs and/or within reef crevices. The estimated length at 50% maturity (± SD) for females was 15.22 ± 0.43 cm total length. Although P. brasilianus shares the main reproductive features of its congeneric species Pinguipes chilensis , male GSI and female length at 50% maturity in P. brasilianus were markedly lower than those reported for P. chilensis , while relative and batch fecundity were greater in fish of the same size.
Pinguipes brasilianus es una especie abundante en los arrecifes rocosos de los golfos norpatagónicos de Argentina, en el Atlántico Sudoccidental. En este trabajo estudiamos su biología reproductiva, incluyendo la descripción macroscópica e histológica del desarrollo de testículos y ovarios, el análisis de la evolución del índice gonadosomático (IGS) para ambos sexos a lo largo del ciclo anual, y la estimación de la fecundidad y la talla de primera madurez para las hembras. Pinguipes brasilianus es un desovante múltiple con fecundidad indeterminada y una estación reproductiva extensa que abarca la primavera y el verano australes. Los bajos valores de IGS en machos (el promedio mensual varió entre 0,11% y 0,75%), y la baja fecundidad relativa en las hembras (entre 2 y 4 oocitos/g) son consistentes con un sistema de apareamiento que involucra una estrecha proximidad entre machos y hembras durante la fertilización de los oocitos, cortejo y desove en parejas y/o en áreas confinadas (ej .: refugios). La talla de primera madurez (± DE) estimada para las hembras fue de 15,22 ± 0,43 cm de largo total. Aunque P. brasilianus comparte los principales rasgos reproductivos con Pinguipes chilensis , tanto los valores promedio de IGS en machos como la talla de primera madurez en hembras fueron menores que los reportados para P. chilensis , mientras que la fecundidad (parcial y relativa) fue mayor.
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Animais , Comportamento Sexual Animal/classificação , Comportamento Sexual Animal/fisiologia , Medicina Reprodutiva/classificaçãoRESUMO
Pinguipes brasilianus is a conspicuous and abundant rocky-reef fish inhabiting the Northern Patagonian gulfs of Argentina, Southwest Atlantic. This study describes its reproductive biology in this region. We made macroscopic and histological descriptions of the testis and ovary development, analyzed the evolution of the gonadosomatic index (GSI) in both sexes throughout the year, and estimated fecundity and length at 50% maturity for females. Pinguipes brasilianus is a multiple spawner with indeterminate annual fecundity and an extended reproductive season, encompassing austral spring and summer. Low GSI values in males (monthly means ranged between 0.11% and 0.75%) and low relative fecundity in female fish (between 2 and 44 oocytes/g) are consistent with a need of close proximity between male and female during oocyte fertilization, sexual courtship and with spawning in pairs and/or within reef crevices. The estimated length at 50% maturity (± SD) for females was 15.22 ± 0.43 cm total length. Although P. brasilianus shares the main reproductive features of its congeneric species Pinguipes chilensis , male GSI and female length at 50% maturity in P. brasilianus were markedly lower than those reported for P. chilensis , while relative and batch fecundity were greater in fish of the same size.(AU)
Pinguipes brasilianus es una especie abundante en los arrecifes rocosos de los golfos norpatagónicos de Argentina, en el Atlántico Sudoccidental. En este trabajo estudiamos su biología reproductiva, incluyendo la descripción macroscópica e histológica del desarrollo de testículos y ovarios, el análisis de la evolución del índice gonadosomático (IGS) para ambos sexos a lo largo del ciclo anual, y la estimación de la fecundidad y la talla de primera madurez para las hembras. Pinguipes brasilianus es un desovante múltiple con fecundidad indeterminada y una estación reproductiva extensa que abarca la primavera y el verano australes. Los bajos valores de IGS en machos (el promedio mensual varió entre 0,11% y 0,75%), y la baja fecundidad relativa en las hembras (entre 2 y 4 oocitos/g) son consistentes con un sistema de apareamiento que involucra una estrecha proximidad entre machos y hembras durante la fertilización de los oocitos, cortejo y desove en parejas y/o en áreas confinadas (ej .: refugios). La talla de primera madurez (± DE) estimada para las hembras fue de 15,22 ± 0,43 cm de largo total. Aunque P. brasilianus comparte los principales rasgos reproductivos con Pinguipes chilensis , tanto los valores promedio de IGS en machos como la talla de primera madurez en hembras fueron menores que los reportados para P. chilensis , mientras que la fecundidad (parcial y relativa) fue mayor.(AU)
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Animais , Medicina Reprodutiva/classificação , Comportamento Sexual Animal/classificação , Comportamento Sexual Animal/fisiologiaRESUMO
Spawning aggregations of red hind Epinephelus guttatus, tiger grouper Mycteroperca tigris and yellowfin grouper Mycteroperca venenosa were identified at two coral-reef systems: Arrecife Alacranes (emergent bank reef) and Bajos del Norte (submerged bank reef) on the continental shelf of the Yucatan Peninsula (Campeche Bank), Mexico. At both reefs, E. guttatus forms large spawning aggregations between February and March. At Bajos del Norte, M. tigris reproduces in a small, low-density aggregation in May, while M. venenosa aggregates at high densities for spawning between March and May. Multi-species use of an aggregation site by E. guttatus and M. venenosa was observed at Bajos del Norte. The identified spawning aggregations are apparently stable in location over time, and all three species were commonly observed to spawn within 1 week following the full moon. Development and survival of the larvae spawned in these aggregations are probably aided by a seasonal (spring-summer) upwelling in the north-east Campeche Bank. A permanent area closure at Bajos del Norte, currently outside any specific fisheries management area or regulations, would provide protection needed for the spawning aggregations of these three species.
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Recifes de Corais , Perciformes/fisiologia , Reprodução , Comportamento Sexual Animal , Animais , Conservação dos Recursos Naturais , Feminino , Golfo do México , Masculino , Densidade Demográfica , Estações do AnoRESUMO
The marine managed areas (MMAs) of the U.S. Caribbean are summarized and specific data-rich cases are examined to determine their impact upon fisheries management in the region. In this region, the productivity and connectivity of benthic habitats such as mangroves, seagrass and coral reefs is essential for many species targeted by fisheries. A minority of the 39 MMAs covering over 4000km(2) serve any detectable management or conservation function due to deficiencies in the design, objectives, compliance or enforcement. Fifty percent of the area within MMA boundaries had no-take regulations in the U.S. Virgin Islands, while Puerto Rico only had 3%. Six case studies are compared and contrasted to better understand the potential of these MMAs for fisheries management. Signs of success were associated with including sufficient areas of essential fish habitat (nursery, spawning and migration corridors), year-round no-take regulations, enforcement and isolation. These criteria have been identified as important in the conservation of marine resources, but little has been done to modify the way MMAs are designated and implemented in the region. Site-specific monitoring to measure the effects of these MMAs is needed to demonstrate the benefits to fisheries and gain local support for a greater use as a fisheries management tool.
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Conservação dos Recursos Naturais , Pesqueiros , Animais , Ecossistema , Porto Rico , Ilhas Virgens AmericanasRESUMO
Three decades ago, Acropora palmata was one of the main reef-building coral species throughout the Caribbean, forming an essential component of the structural complexity of shallow coral reef habitats. These colonies still provide microhabitats for settlement, food and shelter to many vertebrates and invertebrates. The recent decline of A. palmata has been followed by a significant loss in spatial heterogeneity and possibly in species diversity. Studies addressing whether dead and living stands of Acropora hold different fish and benthic assemblages are scarce. The status of Acropora colonies and their associated species were assessed in October 2012, at two reef zones of Cayo Sombrero, Venezuela. Visual censuses of fish abundance and the number of macrofaunal individuals were recorded for both live and dead zones. Living Acropora colonies had the lowest abundance (˂31%). In both zoned the fish community was dominated by damselfishes (˂53%) and wrasses (˂36%), the benthic macrofauna by peracarid crustaceans (˂40%) and polychaetes (˂38%). Fish and benthic communities were not correlated with the condition (live or dead) of the Acropora habitats; possibly branching structures provide the necessary shelter and protection no matter if they are dead or alive. More replication is necessary to test this unexpected result.
Hace tres décadas, Acropora palmata fue una de las principales especies de coral constructoras de arrecifes a lo largo del Caribe, formando un componente esencial de la complejidad estructural disponible en los hábitats arrecifales someros. Estas colonias todavía proveen microhábitats para el asentamiento, alimentación y refugio de muchas especies de vertebrados e invertebrados. El declive reciente de A. palmata ha sido precedido por una pérdida significativa de heterogeneidad espacial y se piensa que ésta reducción ha producido una disminución importante en la diversidad de especies. Los estudios señalan que las colonias muertas o vivas de Acropora que sostienen diferentes comunidades de bentos y de peces son escasas. El estado de las colonias de Acropora y sus especies asociadas fueron evaluadas en Octubre de 2012, en dos zonas arrecifales diferentes de Cayo Sombrero, Venezuela. Censos visuales de la abundancia de especies de peces y el número de individuos de la macrofauna fueron también registrados para ambas zonas, tanto vivas como muertas. Las colonias vivas presentaron la menor abundancia (˂31%). En ambos sitios la comunidad de peces fue dominada por los peces damiselas (˂53%) y lábridos (˂36%); la macrofauna bentónica por crustáceos peracáridos (˂40%) y poliquetos (˂38%). Las comunidades de peces y bentos no mostraron correlación con la condición (vivo o muerto) de los hábitats de Acropora; posiblemente las estructuras ramificadas proveen el refugio y protección necesario sin importar si están vivos o muertos. Una mayor replicación es necesaria para probar este resultado inesperado.
RESUMO
Movement and exchange of individuals among habitats is critical for the dynamics and success of reef fish populations. Size segregation among habitats could be taken as evidence for habitat connectivity, and this would be a first step to formulate hypotheses about ontogenetic inter-habitat migrations. The primary goal of our research was to find evidence of inter-habitat differences in size distributions and density of reef fish species that can be classified a priori as habitat-shifters in an extensive (~600km²) Caribbean shelf area in NW Cuba. We sampled the fish assemblage of selected species using visual census (stationary and transect methods) in 20 stations (sites) located in mangrove roots, patch reefs, inner zone of the crest and fore reef (12-16m depth). In each site, we performed ten censuses for every habitat type in June and September 2009. A total of 11 507 individuals of 34 species were counted in a total of 400 censuses. We found significant differences in densities and size compositions among reef and mangrove habitats, supporting the species-specific use of coastal habitats. Adults were found in all habitats. Reef habitats, mainly patch reefs, seem to be most important for juvenile fish of most species. Mangroves were especially important for two species of snappers (Lutjanus apodus and L. griseus), providing habitat for juveniles. These species also displayed well defined gradients in length composition across the shelf. Rev. Biol. Trop. 62 (2): 589-602. Epub 2014 June 01.
El movimiento e intercambio de individuos entre hábitats son aspectos críticos para la dinámica y el éxito de las poblaciones de peces arrecifales. La segregación de tallas entre hábitats puede ser considerada como evidencia para la conectividad de hábitats y esta podría ser el primer paso para la formulación de hipótesis sobre migraciones ontogenéticas entre hábitats. El objetivo principal de nuestra investigación fue encontrar evidencia de diferencias entre hábitats en la distribución de tallas y densidad de especies de peces de arrecifes, las cuales pueden ser clasificadas, a priori, como especies con cambios ontogénicos en el hábitat, en una área extensa (~600 km²) de plataforma en el Caribe. Se realizaron censos visuales (métodos estacionario y de recorrido) de especies de peces seleccionadas en 20 sitios localizados en raíces de mangle, arrecifes de parche, la zona interna de la cresta arrecifal y el arrecife frontal (12-16m de profundidad). Se hicieron diez censos en cada sitio de los cuatro tipos de hábitat y se repitió este esquema en junio y septiembre 2009. Fueron contados un total de 11 507 individuos de 34 especies en un total de 400 censos. Se encontraron diferencias significativas en la densidad y composición por tallas entre los hábitats de arrecife y manglar. Estas diferencias, indicaron un uso variable de los hábitats costeros dependiendo de la especie. Los adultos fueron encontrados en todos los hábitats. Los hábitats de arrecifes, principalmente los arrecifes de parche, parecen ser muy importantes para los juveniles de peces de la mayoría de las especies en nuestra área de estudio. Los manglares fueron especialmente importantes para dos especies (L. apodus y L. griseus), que a lo largo de la plataforma fueron las únicas que mostraron gradientes bien definidos en las tallas.