Daily age, growth rate, and pelagic larval duration of commercially important snapper species in Abrolhos National Marine Park.

The age and daily growth of fish are registered through the deposition of increments in their otoliths, which are concretions formed by the precipitation of substances present in the endolymphatic fluid, mainly calcium carbonate (CaCO3). Faced with the need to fill some of the gaps in the knowledge on the occurrence and duration of the initial stages of snapper species' life cycles in the Abrolhos Bank, this study aimed to describe the growth rates, age, and period of pelagic larval duration (PLD) of three snapper species during the larval pre-settlement phase, in the Abrolhos Bank region. The post-larvae were captured using light traps. Otoliths were removed from 117 samples of snapper species; however, only 69 were viable for age estimation, of which 15 were Lutjanus analis, 25 were Lutjanus jocu, and 29 were Lutjanus synagris. Together, the samples presented individuals with total lengths ranging from 16.14 to 24.76 mm and ages from 21 to 39 days. Settlement marks were found for all three species, and the average PLD was ~25 days. The somatic growth of the snapper species was positively correlated with otolith growth. L. jocu presented the greatest daily growth compared to the other species. The three species use the Abrolhos Bank as a larval settlement site, demonstrating plasticity by using different habitats throughout their lives.

Bidirectional sex-change behavior and physiological aspects in the Gorgeous goby Lythrypnus pulchellus (Gobiidae).

The Gorgeous goby Lythrypnus pulchellus shows extreme sexual plasticity with the bidirectional sex-change ability socially controlled in adults. Therefore, this study describes how the hierarchical status affects hormone synthesis through newborn hormone waste products in water and tests the influence of body size and social dominance establishment in sex reversal duration and direction. The associated changes in behavior and hormone levels are described under laboratory conditions in male-male and female-female pairs of similar and different body sizes, recording the changes until spawning. The status establishment occurred in a relatively shorter time period in male and female pairs of different sizes (1-3 days) compared to those of similar size (3-5 days), but the earlier one did not significantly affect the overall time of sex change (verified by pair spawning). The changes in gonads, hormones, and papilla occurred in sex-changer individuals, but the first one was observed in behavior. Courtship started at 3-5 days in male pairs and from 2 h to 1 day in female pairs of both groups of different and similar sizes. Hormones did not gradually move in the new sexual phenotype direction during the sex-change time course. Nonetheless, estradiol regulated sex change and 11-ketotestosterone enabled bidirectional sex change and was modulated by agonistic interactions. Cortisol is associated with status and gonadal sex change. In general, similar mechanisms underlie sex change in both directions with a temporal change sequence in phases. These results shed new light on sex-change mechanisms. Further studies should be performed to determine whether these localized changes exist in the steroid hormone synthesis along the brain-pituitary gonad axis during social and bidirectional sex changes in L. pulchellus.

Biology and ecology of the lionfish Pterois volitans/Pterois miles as invasive alien species: a review.

The lionfish is an exotic invasive fish native to the Indo-Pacific, which is established in the western Atlantic Ocean and the Caribbean Sea. Lionfish can affect native fishes and invertebrates through direct predation or competition for food. The present review aims to analyze the most relevant characteristics of the biology and ecology of lionfish as an invasive alien species, with an emphasis on Cuba. We provide a current view of the well-known lionfish as a successful invasive fish, and we put in this context the information regarding lionfish in Cuban waters, enriching the background knowledge, and giving novel and relevant information. The compilation of numerous publications on the subject has allowed for a more complete analysis of essential aspects of this invader in the Cuban archipelago. The consulted literature records that the first report of lionfish in Cuba occurred in 2007; subsequently, sightings of lionfish were reported in numerous localities. In 2010, the lionfish was considered an invasive alien species, which currently is established in various habitats, at depths up to 188 m, throughout the Cuban archipelago (e.g., coral reefs, mangroves, seagrass beds, submerged artificial structures). In addition, it has reached very high densities (12.42 ind./100 m2), which exceed those reported in the Indo-Pacific as well as in many locations in the Western Atlantic. It has been confirmed that the lionfish in Cuba also presents numerous characteristics that guarantee its success as an invader, among them: less quantity and diversity of parasites than other Atlantic fishes found in similar environments, a high number of gametes in the gonads, reproductive activity during all year and wide diet. The most important fish families for the lionfish diet in Cuba have been Pomacentridae, Gobiidae, Scaridae, Holocentridae, Mullidae, Labridae and Acanthuridae; and the most important crustacean orders are Decapoda, Mysida, Stomatopoda and Isopoda. In Cuba, as in the entire invaded region, numerous investigations have been directed to evaluate the impact of this invader on ecosystems, and although there is enough information, their results differ. Additional studies are required to assess the impact of lionfish as a predator after several years of invasion on a larger geographic scale in Cuba and other areas of the region. This knowledge will allow the development of more effective control strategies. Periodic lionfish culling have been carried out in Cuban MPAs as a control strategy, and some positive results have been observed, such as the average size reduction; however, further efforts are still required. Due to the importance of the study of lionfish as an invader, this review is a necessity as it provides, for the first time, a comprehensive analysis of lionfish information and results from Cuba, which is adequately contrasted with previous studies of other areas, particularly, from the Greater Caribbean.

Diel feeding activity of Abudefduf saxatilis (Perciformes: Pomacentridae) on southwestern Atlantic reefs

Feeding ecology studies are crucial for understanding energy flow in reef ecosystems. In this study, we used an integrative approach to investigate the diel-feeding ecology of the sergeant-major Abudefduf saxatilis. To examine the possibility of diel-periodicity and size-class differences in foraging behaviour, we tracked fish individuals until their first bite on two subtropical reefs. During each observation, we recorded the substratum that was bitten and estimated the individual's total length. To assess the diet, we analysed the stomach contents of five individuals from each location. In total, we observed 2,703 individuals biting seven substrates. Our results showed no significant differences in substrate use for diel-periodicity. However, we found significant differences between two size classes. Despite this, both populations tended to forage near the surface in the water column in the morning and on the benthos in the afternoon, although this tendency was not statistically significant. Smaller individuals fed mostly in the water column, while larger individuals foraged on all substrates, likely due to their different energetic demands. Our findings indicate this species has an omnivorous, generalist diet, comprising 12 items from both benthos and plankton. The lack of differences in diel-periodicity is likely due to the sergeant-major's opportunistic behaviour.

Estudos de ecologia alimentar são cruciais para entender o fluxo de energia em ecossistemas recifais. Neste estudo, usamos uma abordagem integrativa para investigar a ecologia alimentar do sargentinho Abudefduf saxatilis. Para responder se há periodicidade ou diferenças relacionadas a classes de tamanho no substrato forrageado, acompanhamos indivíduos deste peixe até a primeira mordida, em dois recifes subtropicais. Durante cada observação, registramos o substrato mordido e estimamos o comprimento total do indivíduo. Para estudar a sua dieta, analisamos o conteúdo estomacal de cinco indivíduos em cada recife. No total, observamos 2.703 indivíduos mordendo em sete substratos diferentes. Nossos resultados não mostraram diferenças significativas no uso de substrato para a periodicidade diária. No entanto, encontramos diferenças significativas entre duas classes de tamanho. Apesar disso, ambas as populações tenderam a forragear próximo à superfície na coluna d'água pela manhã e no substrato bentônico à tarde, embora essa tendência não tenha sido estatisticamente significativa. Indivíduos menores forragearam principalmente na coluna d'água, enquanto os indivíduos maiores forragearam em todos os tipos de substratos, provavelmente devido às suas diferentes demandas energéticas. Nossos resultados corroboram que o sargentinho tem uma dieta onívora e generalista, composta por 12 itens de ambos os compartimentos, bentônico e planctônico. A falta de diferenças na periodicidade diária é provavelmente devido ao comportamento oportunista do sargentinho.

Host-parasite Interactions between a Copepod (Pharodes tortugensis) and Small Reef-associated Gobies (Coryphopterus) in the British Virgin Islands.

The effects of parasitic copepods on free-living hosts are infrequently documented, and the copepod Pharodes tortugensis has remained virtually unstudied since described. For the first time, we document its host range in the British Virgin Islands (BVI), the prevalence and intensity of infections on wild hosts, and its impacts on host morphology and performance. Infections were observed on four benthic gobies in the BVI (Coryphopterus glaucofraenum, C. venezuelae, C. dicrus and C. eidolon) but not on other host species previously reported from other parts of the western Atlantic. Infected gobies were widespread in the BVI (detected at 33 of 52 sites, prevalence from 1-25%) but extremely rare elsewhere in the Caribbean (detected at 2 of 16 sites, prevalence < 0.006%). As is typical of macroparasite infections, P. tortugensis was over-dispersed in BVI host populations (mean intensity = 4.7, range = 1-17). Infections were most common in juvenile and female hosts, and rarely found in larger male hosts. The copepods attach in the branchial chamber of the goby; female copepods show high attachment fidelity to the ventral surface of the chamber, while male copepods attached most often to the first two gill arches and in the branchial chamber adjacent to the female. Infections caused substantial damage to the host's branchial chamber and gill filaments. Parasitized gobies also had larger livers and smaller gonads than unparasitized individuals of similar length. The changes in organ mass of infected gobies were not sizeable enough to affect total body mass, and host condition (the body-length vs. body-mass relationship) was similar for gobies with and without infections. Parasitized gobies were, however, significantly smaller in body mass at a given age, reflecting slower overall growth. Effects of P. tortugensis on individual hosts were broadly similar to those of other parasitic copepods that infect fish gills and, for unknown reasons, the BVI appears to be a persistent hotspot of infections on these goby hosts.

Neobenedenia melleni from reef ornamental fish species in a retailer of Southeastern Brazil and its possible role as a mechanical vector of bacterial infection.

Annually, more than 2500 ornamental fish species are traded worldwide. Forty percent of these are from marine water. Some 98% of marine species are wild-caught from their natural habitat, and the majority subsequently exported. Wild fish frequently carry pathogens, which could induce diseases after the stress of capture. Neobenedenia melleni is a platyhelminth that mainly attaches to the skin and eyes of the host. It provokes dermal inflammation, epidermal loss, skin depigmentation, reduction in the number of mucous cells, and, consequently, decreased mucus protection, and declining immunological barriers. This makes fish susceptible to secondary infections. A total of 47 wild reef fish from a retailer were examined, suspected to be infected with ectoparasites. The morphological identification revealed N. melleni as a monogenean agent. One monogenean specimen was collected from the eye of each of the 40 fish analyzed to evaluate possible bacterial secondary infections using the matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) technique. The MALDI-TOF MS identified that 59% of monogenean collected from the eyes had bacteria, including some pathogenic to fish. This led us to believe that the ectoparasite can be a possible mechanical vector of pathogenic bacteria for fish culture and maintenance. The use of praziquantel as an antiparasitic agent is also discussed.

Recent dispersal and diversification within the clingfish genus Acyrtus (Actinopterygii: Gobiesocidae), with the description of a new western Atlantic species

The genus Acyrtus (Gobiesocidae) is represented by four valid species distributed in the western Atlantic, and a recently described fifth species from the eastern Pacific. Here, we describe a new species endemic to Trindade Island, Brazil, and provide the first phylogenetic inference for the genus including all representatives. The new species can be distinguished from all its congeners by meristic and morphometric characters, as well as genetic differences. It presents low genetic diversity and, contrarily to other Trindade Island endemic fishes, shows no evidence of recent population growth. Our phylogeny reveals cryptic species and the paraphyletic nature of Acyrtus, which included Arcos nudus (western Atlantic) in a clade that separated from Arcos erythrops (tropical eastern Pacific) around 20 Mya. The three species found in the Brazilian Province, including one that remains undescribed, form a monophyletic clade which colonized the western South Atlantic around 2.6 Mya. Our study suggests that Arcos nudus should be placed in Acyrtus, and that the relationships among the closely-related Gobiesocidae genera Acyrtus (mostly from the Atlantic Ocean) and Arcos (from the Pacific Ocean) need further investigation.(AU)

O gênero Acyrtus (Gobiesocidae) é representado por quatro espécies válidas encontradas no Atlântico ocidental e uma recentemente descrita do Pacífico oriental. Aqui descrevemos uma nova espécie endêmica da Ilha da Trindade, Brasil, e apresentamos a primeira inferência filogenética para o gênero incluindo todos os representantes. A nova espécie pode ser distinguida de suas congêneres por caracteres merísticos e morfométricos, bem como por diferenças genéticas. A espécie apresenta baixa diversidade genética, entretanto, diferentemente de outras espécies endêmicas da Ilha da Trindade, não mostra evidência de expansão populacional recente. A filogenia obtida revelou a existência de espécies crípticas e a natureza parafilética de Acyrtus, o qual inclui Arcos nudus (do Atlântico ocidental), e que é separado de Arcos erythrops (do Pacifico tropical oriental) por cerca de 20 milhões de anos. As três espécies encontradas no Brasil, incluindo uma ainda não descrita, formam um clado monofilético que colonizou o Atlântico Sul ocidental há cerca de 2,6 milhões de anos. Nosso estudo sugere que Arcos nudus deva ser alocado no gênero Acyrtus, e que as relações entre os gêneros Acyrtus (em maioria do Oceano Atlântico) e Arcos (do Oceano Pacífico) precisam ser estudadas em mais detalhes.(AU)

Agonistic Behavior Is Affected by Memory in the Dusky Damselfish Stegastes fuscus.

The ability to discriminate familiar from unfamiliar conspecifics has been demonstrated in several species of fish. Agonistic interactions are among the most frequent behaviors exhibited by territorial species and could offer useful information for the individual recognition process. In agonistic situations, memory may modulate the behavioral response and affect social dynamics, but few studies have explored the memory retention acquired during aggressive encounters. The present study investigated the memory retention of an agonistic encounter in the dusky damselfish Stegastes fuscus. The experimental procedure was divided into three parts: (1) Familiarization; (2) Recognition test; and (3) Memory test. During the familiarization phase, the fish were visually exposed to the same conspecific for 5 days (10 min per day) and the behavior was recorded. On the following day (conspecific recognition test), half of the animals were paired with the same conspecific and the other half with a different conspecific for 10 min, and the behavior was recorded. The fish were retested 5, 10, and 15 days after the test to evaluate memory retention. In the memory test, they were exposed to the same conspecific as before or to a different conspecific. We found that the damselfish reduced their agonistic displays when the stimulus fish was familiar, but when it was unfamiliar, the animals were more aggressive and only reduced their mnemonic response after 10 days. These results suggest that the recognition ability of damselfish can be affected by time and that it modulates agonistic response.

A new species of the genus Acyrtus on the eastern Pacific: A cornerstone for the evolution and biogeography of the genus.

The genus Acyrtus Schultz, 1944 currently includes four species distributed in the western Atlantic (WA), three occurring from the Bahamas to the southern Caribbean, and one endemic to the Fernando de Noronha Archipelago in north-east Brazil. We describe a new species of Acyrtus based on morphology and genetics from several individuals caught at artificial hard substrates deployed between 10 and 16 m deep at Malpelo Island, Colombian Pacific. The Malpelo clingfish, Acyrtus arturo new species, differs from all its WA congeners by a combination of morphology, meristics and genetics. This species is unique within Acyrtus in having the greatest number of caudal rays (12-13). It can also be distinguished by the greater body height (19.8-27.8% standard length), its longer disc (34.0-39.1% standard length) and the greater distance between anus and disc (13.9-18.1% standard length). A. arturo sp. nov. is the first Acyrtus so far recorded from the eastern Pacific and adds to the already high number of fishes endemic to Colombia's remote oceanic territory of Malpelo.

A new species of viviparous brotula genus Pseudogilbia (Ophidiiformes: Dinematichthyidae) from Brazilian reefs, with an updated diagnosis of the genus.

In this study, a new species of Pseudogilbia Møller, Schwarzhans & Nielsen 2004 is described based on two male specimens (40-44 mm LS ) from shallow reefs of Bahia, Brazil. Pseudogilbia australis sp. nov. is distinguished from its only congener, Pseudogilbia sanblasensis Møller, Schwarzhans & Nielsen 2004 from Caribbean Panama, by having: two lower preopercular pores (vs. one); dorsal-fin rays 65-67 (vs. 69); anal-fin rays 51-53 (vs. 56); pectoral-fin rays 18 (vs. 20); caudal vertebrae 27-28 (vs. 30); pectoral-fin length 15.0%-15.9% LS (vs. 14.3); pelvic-fin length 13.5% LS (vs. 16.4) and a different morphology of the male copulatory organ. Pseudogilbia australis sp. nov. is the only dinematichthyid so far recorded in the South Atlantic. An updated diagnosis for the genus is also provided.

Does acidification lead to impairments on oxidative status and survival of orange clownfish Amphiprion percula juveniles?

The nitrification process in recirculating aquaculture systems can reduce water pH. Fish can also be exposed to water acidification during transport, an important feature in the aquarium industry, as live fish can be kept in a closed environment for more than 24 h during overseas aerial transportation. Therefore, it is important to study the responses of fish to acidic environments. We investigated the impacts of acute exposure to decreasing pH levels in orange clownfish Amphiprion percula juveniles on their survival and oxidative stress status. Fish were exposed to pH 5, 6, 7, and 8 for 96 h. We observed a significant reduction in survival (85%) and protein damage as measured by P-SH (protein thiol) for fish maintained at pH 5. Despite no effects on survival or oxidative damage, fish exposed to pH 6 showed an increase in their antioxidant defense systems, demonstrating this pH level could not be suitable for them as well. Furthermore, there were no negative effects for fish kept at pH 7, compared to those maintained at pH 8 during this short-term evaluation.

Drivers of damselfishes distribution patterns in the southwestern Atlantic: tropical and subtropical reefs compared

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)

Drivers of damselfishes distribution patterns in the southwestern Atlantic: tropical and subtropical reefs compared

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)

NOTAS SOBRE LA REPRODUCCIÓN, MORFOLOGÍA Y ECOLOGÍA DE Pareques acuminatus (TELEOSTEI: SCIAENIDAE), EN LA REGIÓN DE SANTA MARTA, CARIBE COLOMBIANO / Notes on the reproduction, morphology and ecology of Pareques acuminatus (Teleostei: Sciaenidae), in the region of Santa Marta, Colombian Caribbean

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.

Review of the genus Malacoctenus (Actinopterygii: Labrisomidae) from the Southwestern Atlantic, with description of two new species.

The labrisomid genus Malacoctenus from Southwestern Atlantic is reviewed. Two new species of scaly blennies formerly reported by several authors as Malacoctenus triangulatus are described. One is found at the oceanic islands Fernando de Noronha Archipelago and Atol das Rocas, and the other is distributed along the Brazilian coastline. The two new species differ from other species of the genus and from each other by different combinations of the number of lateral-line scales, number and size of head cirri, and color pattern. Molecular data also support species' distinctiveness between M. triangulatus and the species described herein. Two additional recognized Brazilian species, M. delalandii and M. brunoi are described and illustrated and an identification key to all recognized Atlantic species is provided.

Diversity patterns of reef fish along the Brazilian tropical coast.

Causal mechanisms for broad-scale reef fish diversity patterns are poorly understood and current knowledge is limited to trends of species richness. This work compared the effects of ecological drivers on components of fish diversity across reefs spanning over 2.000 km of the tropical Brazilian coastline. A quarter of communities' diversity is accountable to common and dominant species, while remaining species are rare. Low-latitude sites were more diverse in rare species. Communities along the coast share common and dominant species, which display high densities across all reefs, but differ in rare species that show abundance peaks in particular reef morphotypes. The disproportionate distribution of rare species reveals a higher vulnerability of these communities to impacts and stochastic density fluctuations. Uneven conservation efforts directed to these morphotypes pose a threat to the maintenance of a paramount component of the reef fish diversity represented by rare species.

Fish biodiversity of Saint Peter and Saint Paul's Archipelago, Mid-Atlantic Ridge, Brazil: new records and a species database.

Saint Peter and Saint Paul's Archipelago (SPSPA), one of the smallest and most isolated island groups in the world, is situated on the Mid-Atlantic Ridge, between Brazil and the African continent. SPSPA has low species richness and high endemism; nonetheless, the diversity of fishes from deep habitats (>30 m depth) had not been previously studied in detail. Several expeditions conducted between 2009 and 2018 explored the shallow and deep reefs of SPSPA using scuba, closed-circuit rebreathers, manned submersibles, baited remote underwater stereo-videos (stereo-BRUV) and fishing between 0 and 1050 m depth. These expeditions yielded 41 new records of fishes for SPSPA: 9 in open waters, 9 in shallow waters (0-30 m), 8 in mesophotic ecosystems (30-150 m) and 15 in deeper reefs (>150 m). Combined with literature records of adult pelagic, shallow and deep-reef species, as well as larvae, the database of the fish biodiversity for SPSPA currently comprises 225 species (169 recorded as adult fishes and 79 as larvae, with 23 species found in both stages). Most of them (112) are pelagic, 86 are reef-associated species and 27 are deep-water specialists. Species accumulation curves show that the number of fish species has not yet reached an asymptote. Whereas the number of species recorded in SPSPA is similar to that in other oceanic islands in the Atlantic Ocean, the proportion of shorefishes is relatively lower, and the endemism level is the third highest in the Atlantic. Twenty-nine species are listed as threatened with extinction. Observations confirm the paucity of top predators on shallow rocky reefs of the island, despite the presence of several pelagic shark species around SPSPA. Because all of the endemic species are reef associated, it is argued that the new marine-protected areas created by the Brazilian government do not ensure the protection and recovery of SPSPA's biodiversity because they allow exploitation of the most vulnerable species around the archipelago itself. This study suggests a ban on reef fish exploitation inside an area delimited by the 1000 m isobath around the islands (where all known endemics are concentrated) as the main conservation strategy to be included in the SPSPA management plan being prepared by the Brazilian government.

Caribbean reefs of the Anthropocene: Variance in ecosystem metrics indicates bright spots on coral depauperate reefs.

Dramatic coral loss has significantly altered many Caribbean reefs, with potentially important consequences for the ecological functions and ecosystem services provided by reef systems. Many studies examine coral loss and its causes-and often presume a universal decline of ecosystem services with coral loss-rather than evaluating the range of possible outcomes for a diversity of ecosystem functions and services at reefs varying in coral cover. We evaluate 10 key ecosystem metrics, relating to a variety of different reef ecosystem functions and services, on 328 Caribbean reefs varying in coral cover. We focus on the range and variability of these metrics rather than on mean responses. In contrast to a prevailing paradigm, we document high variability for a variety of metrics, and for many the range of outcomes is not related to coral cover. We find numerous "bright spots," where herbivorous fish biomass, density of large fishes, fishery value, and/or fish species richness are high, despite low coral cover. Although it remains critical to protect and restore corals, understanding variability in ecosystem metrics among low-coral reefs can facilitate the maintenance of reefs with sustained functions and services as we work to restore degraded systems. This framework can be applied to other ecosystems in the Anthropocene to better understand variance in ecosystem service outcomes and identify where and why bright spots exist.

BRUVS reveal locally extinct shark and the way for shark monitoring in Brazilian oceanic islands.

Here we present records of sharks obtained using baited remote underwater stereo-video systems (stereo-BRUVS) at two Brazilian oceanic islands. Fourteen of the 60 deployments recorded 19 sharks in Trindade Island. In Saint Peter and Saint Paul Archipelago (SPSPA), two pelagic and two demersal deployments recorded two and one shark, respectively, including the locally extinct Galapagos shark Carcharhinus galapagensis. Stereo-BRUVS should be considered as adjuncts to other non-invasive methods to monitor shark populations.

Vulnerable sandstone reefs: Biodiversity and habitat at risk.

Sandstone reefs may be considered a unique geomorphologic feature within the subtropical Southwestern Atlantic Ocean region; however, biodiversity on these reefs has received little to no attention. Herein, we recorded the fish assemblage and benthic cover of sandstone reefs between 23 and 29 m depth in Southern Brazil and evidenced potential threats to habitat health. Video analysis and underwater censuses recorded 30 fish species. The unexpected high biomass of Epinephelus marginatus indicated that sandstone reefs may contain suitable habitats for the recovery of this endangered species. A rich benthic coverage including bryozoans, algae, hydrozoans, sponges, and octocorals increased local habitat structural complexity. However, a wide diversity of tangled fishing gear and broken sandstone slabs suggested that a valuable feature from Southern Brazil seascape is being lost by cumulative fishing impacts. An extensive mapping of sandstone reefs is urgently needed for better delineation of marine protected areas network in Southeast and Southern Brazil.