The essential habitat role of a unique coastal inlet for a widely distributed apex predator.

Essential habitats support specific functions for species, such as reproduction, feeding or refuge. For highly mobile aquatic species, identifying essential habitats within the wider distribution range is central to understanding species ecology, and underpinning effective management plans. This study examined the movement and space use patterns of sevengill sharks (Notorynchus cepedianus) in Caleta Valdés (CV), a unique coastal habitat in northern Patagonia, Argentina. Seasonal residency patterns of sharks were evident, with higher detectability in late spring and early summer and lower during autumn and winter. The overlap between the residency patterns of sharks and their prey, elephant seals, suggests that CV functions as a seasonal feeding aggregation site for N. cepedianus. The study also found sexual differences in movement behaviour, with males performing abrupt departures from CV and showing increased roaming with the presence of more sharks, and maximum detection probability at high tide. These movements could be related to different feeding strategies between sexes or mate-searching behaviour, suggesting that CV may also be essential for reproduction. Overall, this study highlights the importance of coastal sites as essential habitats for N. cepedianus and deepens our understanding of the ecological role of this apex predator in marine ecosystems.

Rocky reef incursions: challenges faced by reef fishes in a Brazilian Hope Spot region.

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.

Coral reef degradation at an atoll of the Western Colombian Caribbean.

Coral reef decline is an issue of concern around the globe. Remote and uninhabited coral areas are not exempt from facing changes in species composition and functionality due to global drivers. Quitasueño is a remote atoll within the Seaflower Biosphere Reserve, in the Southwestern Caribbean Sea. To evaluate the current status of the coral reefs in Quitasueño we sampled 120 stations through Rapid Ecological Assessment and evaluated four stations through Planar Point Intercept to compare the current percent cover of benthic groups with previous studies in the area. We found pronounced changes in coral and macroalgae covers in time, and great conspicuousness of multiple conditions of deterioration along Quitasueño, including diseases, coral predation, and aggression and invasion of coral colonies by macroalgae and sponges. The reef ecosystem seems to be facing a phase shift, in which the benthic cover previously dominated by hard corals is currently dominated by fleshy macroalgae. It is essential to evaluate the possible drivers of the extent of degradation of Quitasueño to understand the process of deterioration and mitigate the impacts.

Embriogénesis, desarrollo larval y sobrevivencia post-asentamiento del coral Orbicella annularis (Scleractinia: Merulinidae)

Introducción: Las poblaciones del coral Orbicella annularis han mostrado bajo reclutamiento en el Caribe. Uno de los cuellos de botella demográficos es la alta mortalidad en las primeras etapas de desarrollo. El conocimiento detallado del ciclo y las tasas de supervivencia de estas fases nos permitirá ayudar en la recuperación de la población y la restauración de los arrecifes. Objetivo: Describir la embriogénesis y estadios larvarios obtenidos por fertilización asistida y medir las tasas de asentamiento y supervivencia de las larvas en sustratos artificiales, antes de ser trasplantadas al arrecife. Métodos: Seis días después de la luna llena de septiembre de 2021, se recolectaron bolsas de gametos de ocho colonias de O. annularis en el Parque Nacional Natural Los Corales del Rosario y San Bernardo, Colombia, y se llevaron al laboratorio. Se realizó fecundación cruzada, se siguió el desarrollo embrionario y larvario hasta el asentamiento larval y se registró supervivencia hasta el día 41. Las larvas se mantuvieron en tres tanques con agua de mar filtrada con 126 sustratos marcados, previamente acondicionados con algas coralináceas costrosas. Luego, los sustratos se trasplantaron al arrecife. Resultados: El inicio del desarrollo embrionario ocurrió 1.11 hAF (horas después de la fertilización), cuando las células mostraron signos de la primera división, y duró hasta 104.59 hAF cuando comenzaron a metamorfosearse. El asentamiento de larvas se observó al sexto día AF. Veintiún días después de la fecundación se encontraron zooxantelas. La supervivencia de las larvas después del asentamiento fue de 27.5 %. Conclusión: En este primer esfuerzo de propagación sexual utilizando O. annularis en Colombia, 1.4 % de larvas competentes completaron todo el proceso de desarrollo. Aunque la tasa de supervivencia fue baja, estos resultados se suman a los esfuerzos de restauración de corales en el Caribe en los que se ayuda a las especies a aumentar la supervivencia de los corales en sus primeras etapas de desarrollo.

Introduction: Populations of the coral Orbicella annularis have shown low recruitment in the Caribbean. One of the demographic bottlenecks is the high mortality in the early stages of development. Detailed knowledge of the cycle and survival rates of these phases will allow us to assist in population recovery and reef restoration. Objective: To describe the embryogenesis and larval stages obtained by assisted fertilization and measure the settlement and survival rates of larvae on artificial substrates, before being outplanted to the reef. Methods: Six days after the full moon in September 2021, gamete bundles were collected from eight O. annularis colonies in Los Corales del Rosario and San Bernardo National Natural Park, Colombia and brought to the laboratory. Cross fertilization was carried out and embryonic and larval development were followed until larval settlement and survival was recorded until day 41. The larvae were kept in three tanks with filtered sea water with 126 tagged substrates, previously conditioned with crustose coralline algae. The substrates were then outplanted to the reef. Results: The onset of embryonic development occurred 1.11 hAF (hours after fertilization), when cells showed signs of the first cleavage, and lasted until 104.59 hAF when they began to metamorphose. Larvae settlement was observed on the sixth day AF. Twenty-one days after fertilization, zooxanthellae were found. Post-settlement larval survival was 27.5 %. Conclusions: In this first sexual propagation effort using O. annularis in Colombia, 1.4 % of competent larvae completed the entire development process. Although low survival rate, these results add to coral restoration efforts in the Caribbean in which species are assisted to increase the survival of corals in their early stages of development.

Zooplankton exposure to microplastic contamination in a estuarine plume-influenced region, in Northeast Brazil.

This work describes the spatio-temporal distribution of suspected plastic and microplastic (MP) particles in estuarine plumes and analyzes the microplastic/zooplankton ratio. Subsurface hauls with a conical-cylindrical net were deployed in the coastal area of Tamandare (Pernambuco, Brazil), covering the plume of two rivers and a bay adjacent to coral reefs. A total of 2079 suspected plastic particles were detected, mostly fibers and fragments (>60%). Organic matter digestion was made using a 30% hydrogen peroxide solution, of which approximately 50% of suspected particles were validated as MPs. The average MP abundance was significantly higher during the high rainfall season (53.8 ± 89.6 and 18.8 ± 32.3 particles/m³, respectively), with higher values registered in the plume area (108.9 ± 158.5 and 44.6 ± 55.5 particles/m³). Polymer identification using FT-IR confirmed that suspected particles were mainly polypropylene, polyamide, and polyurethane. These results confirm the hypothesis of a temporal transport variation of MPs from the river to the coastal environments, particularly since the plume influences debris input. Eleven animal phyla were identified, and the subclass Copepoda was predominant (90%), particularly the nauplius stage (70%). Over 70% of verified MPs range between 20 and 2000 µm, equivalent to the most common size of zooplanktonic organisms. Results support that coastal areas near estuarine plumes are exposed to microplastic contamination, affecting species dependent on zooplankton in marine coastal food webs.

First record of mating behaviour and induced parturition of the Brazilian endemic Lutz's stingray Hypanus berthalutzae.

The recently described Lutz's stingray Hypanus berthalutzae is endemic to the Brazilian Province, including oceanic islands. Although it is expected to have life-history traits similar to the southern stingray H. americanus, little is known about its reproductive biology. Here we present the first observations of courtship behaviour (n = 4), copulation (n = 3) and an induced parturition of H. berthalutzae at the Fernando de Noronha Archipelago, an insular Marine Protected Area from the Equatorial Atlantic Ocean. The mating event records included (1) 'chasing/close following', (2) 'biting/precopulatory biting', (3) 'insertion/copulation' and (4) 'separation'. These results are especially relevant considering that records of reproductive behaviour in the wild are rare for elasmobranchs in general. Mating events occurred in different months, suggesting that the reproductive cycle of H. berthalutzae in this insular system is asynchronous, as observed for other stingray species in regions with favourable environmental conditions and abundant food throughout the year. The opportunistic documentation of the induced parturition allowed for direct nonlethal observation of the two pups at or near full term in late May. Although preliminary, these observations should be considered in future management plans as they provide relevant data about the life-history traits and mating behaviour of this endemic and threatened species.

Coral diversity matches marine park zonation but not economic value of coral reef sites at St. Eustatius, eastern Caribbean.

Stony corals play a key role in the marine biodiversity of many tropical coastal areas as suppliers of substrate, food and shelter for other reef organisms. Therefore, it is remarkable that coral diversity usually does not play a role in the planning of protected areas in coral reef areas. In the present study we examine how stony coral diversity patterns relate to marine park zonation and the economic value of reefs around St. Eustatius, a small island in the eastern Caribbean, with fisheries and tourism as important sources of income. The marine park contains two no-take reserves. A biodiversity survey was performed at 39 sites, 24 inside the reserves and 15 outside; 22 had a maximum depth >18 m and 17 were shallower. Data on economic value per site were obtained from the literature. Corals were photographed for the verification of identifications made in the field. Coral species richness (n = 49) was highest in the no-take reserves and species composition was mainly affected by maximum depth. No distinct relation is observed between coral diversity and fishery value or total economic value. Based on the outcome of this study we suggest that in future designs of marine park zonation in reef areas, coral diversity should be taken into consideration. This is best served by including reef areas with a continuous depth gradient from shallow flats to deep slopes.

Evaluation of the management of marine protected areas. Comparative study in Costa Rica.

Costa Rica is one of the most biodiverse countries in the world, and stands out for its commitment to conservation. Along its two coasts, it presents a great heterogeneity of ecosystems and social realities. Social factors, more than physical-natural factors, determine the success or failure of an MPA, so they must be urgently incorporated into all phases of MPA management. The objective of this work is to analyze the management of three marine protected areas, to establish improvements. These areas are Santa Rosa National Park, Marino Ballena National Park and Cahuita National Park. The methodology used assesses 26 indicators grouped into 4 key factotres: management body, planning subprocess, public participation, and implementation subprocess. The results of this evaluation are 5 possible scenarios. These scenarios have been termed (from the ideal situation to the least favourable): proactive (1), learning (2), interactive (3), centralized (4) and formal (5) management. The results of this study show that both Santa Rosa and Cahuita present a proactive scenario (1), with high citizen participation, although in practice the way the two MPAs are managed is very different. Marino Ballena, on the other hand, is in scenario 5 (formal), and a series of measures are presented that can move it towards scenario 2 (learning). In general, MPA management in Costa Rica tends to be adaptive, with high public participation, as determined by its public policies. However, the existence of a public policy favors but does not guarantee success in MPA management, as can be seen in the difference in results. Therefore, the periodic evaluation of its management, allowing for feedback, is essential.

Foraging ecology of critically endangered Eastern Pacific hawksbill sea turtles (Eretmochelys imbricata) in the Gulf of California, Mexico.

The Eastern Pacific hawksbill sea turtle population is one of the most endangered of all sea turtle species. Here, we examine the foraging ecology of 47 hawksbill turtles (40.5-90.3 cm CCL, mean = 54.1 ± 10.1 cm) around Isla San José, Gulf of California, Mexico by integrating information from passive acoustic telemetry, behavior recordings, fecal analysis, and habitat surveys. Tagged hawkbill turtles exhibited high site fidelity over months and years (tracking duration 1-1490 days, mean = 255 ± 373 days) to the location and benthic habitat where individuals were initially caught. Diet was dominated by benthic invertebrates and algae including sponges, algae, tunicates, and mangrove roots. The mean percent cover of these benthic food items was significantly greater in the mangrove estuary than in adjacent rocky and sandy reef habitats. The Isla San José foraging ground is a high-use area for hawksbills and should be granted national protection status.

The elasmobranchs of Malpelo Flora and Fauna Sanctuary, Colombia.

Management and conservation actions in marine-protected areas require baselines for monitoring threatened marine fauna such as elasmobranchs. This article provides evidence of the occurrence of 34 species of elasmobranchs (21 sharks and 13 batoids) in the Malpelo Flora and Fauna Sanctuary, Colombia, including five new records of sharks and three of rays. From 1987 to 2021, new records were obtained by underwater visual census using SCUBA, manned submersibles and deep-ocean cameras to depths of up to 2211 m. Of the recorded species, 21 are considered as threatened taxa (64%) by the IUCN, making the Malpelo Flora and Fauna Sanctuary an essential conservation area for this highly threatened group of species.

Conservation actions and ecological context: optimizing coral reef local management in the Dominican Republic.

Over the past few decades, coral reef ecosystems have been lost at accelerated rates as a result of global climate change and local stressors. Local management schemes can help improve the condition of coral reefs by enhancing their ecosystem recovery capacity. Caribbean conservation efforts include mitigation of local anthropogenic stressors, and integrating social participation. Here, we analyzed the case of the Bayahibe reefs in the Southeastern (SE) Dominican Republic to identify conservation actions and illustrate a conceptual example of local seascape management. We assessed reef health indicators from 2011 to 2016. Overall, our results show increases in total fish biomass, in both commercial and herbivorous fishes. Mean live coral cover was 31% and fleshy macroalgae was 23% after multiple disturbances such as Hurricanes Sandy and Isaac (2012), Mathew (2016) and heat stress presented in the study area in 2015. We also described actions taken by stakeholders and government institutions, including the implementation of a policy declaring an area of 869,000 ha as a marine protected area (MPA), enhanced water quality treatment, local restrictions to vessel traffic, enforcement of fishing regulations, and the removal of invasive lionfish (Pterois spp.). In addition, a restoration program for the threatened staghorn coral (Acropora cervicornis) was established in 2011, and currently has eight coral nurseries and six outplanting sites. Considering the biology and ecology of these reefs, we observed good results for these indicators (live coral cover, fish biomass, and water quality) in contrast with severely degraded Caribbean reefs, suggesting that optimizing local management may be a useful example for improving reef condition. Our results provide an overview of trends in reef condition in the SE Dominican Republic and could support current strategies to better protect reefs in the region. Given that Caribbean coral reefs face extreme challenges from global climate change, management measures may improve reef conditions across the region but stronger policy processes and increased scientific knowledge are needed for the successful management of coral reefs.

Drivers of coral bleaching in a Marine Protected Area of the Southern Gulf of Mexico during the 2015 event.

Here we report the bleached coral cover and its drivers observed at Alacranes Reef in 2015. Our results show that 2015 was an unprecedented heat stress event. However, we observed low coral bleaching, with the most substantial impact on sites with a 10-20% of coral cover with bleaching. Depth was the most relevant variable related to coral bleaching and the bleaching severity index, with deeper reefs being most affected. Further, our results show that reefs with higher structural complexity based on species composition were among the most affected. We identified that accumulated heat stress and thermal variation in the last 28 days were relevant drivers of coral bleaching. This work highlights the importance of multidimensional frameworks in assessing the spatial variation of coral bleaching, demonstrating the importance of structural habitat variables such as depth in high heat stress events and at a reef scale.

First evidence of polycyclic aromatic hydrocarbons in sediments from a marine protected area within Argentinean Continental Shelf.

This study evaluated for the first time, the distribution, sources, and ecological risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) in sediments collected along the northern Patagonian shelf in the Argentine Sea -included in a Marine Protected Area (MPA). Total concentration of the PAHs varied from 19.47 to 183.17 ng/g dry weight and low molecular weight compounds, such as Anthracene and Naphthalene were the dominants. The selected PAHs ratios suggested a predominance of petrogenic sources and ecotoxicological risk evaluation based on the sediment quality guidelines model, indicated that some PAHs might cause occasional adverse biological effects in the study area.

First evidence of microplastic pollution in the El Quetzalito sand beach of the Guatemalan Caribbean.

In Guatemala, assessment of the impacts of microplastic pollution in marine and coastal protected areas has not yet been carried out. Therefore, the main goal of this paper was to evaluate the abundance, composition, physical forms, and the possible sources of plastic debris in the El Quetzalito Beach. The area was intended for biodiversity conservation but has been excessively contaminated by plastic materials from land-based activities. The results state that plastic debris negatively impact the Caribbean coast of Guatemala and are released by storm water and riverine transport from the Motagua River. With a high abundance of 279 items/m2 (30 items/kg d.w.), composed mainly of polystyrene foam beads (66.8%) and polypropylene fragments (25.8%), the microplastic sources are the deterioration of large plastics. As these plastics are commonly used in industrial, commercial, fishing, and household activities, these findings reinforce the need to improve effective sustainable management actions of solid waste treatment and disposal in the Guatemalan cities.

Mesophotic ecosystems at Fernando de Noronha Archipelago, Brazil (South-western Atlantic), reveal unique ichthyofauna and need for conservation

Although several studies on the ichthyofauna of the Fernando de Noronha Archipelago have been carried out, its mesophotic fish diversity has never been surveyed before. Here we used SCUBA and technical rebreather diving, baited remote underwater videos and remotely operated vehicle to record shallow (≤ 30 m depth) and mesophotic (31 to 150 m depth) fishes. Nineteen fish species belonging to 14 families are reported here as new records, representing an increase of 8.2% in marine fish richness for the region, which now has a total of 250 species and 77 families. These new records include four potential new species and highlight the importance of surveying mesophotic ecosystems, even in well studied sites. Our results also emphasize the need for protection and attention to the unique ichthyofauna found at mesophotic depths.(AU)

Apesar de muitos estudos sobre a ictiofauna do Arquipélago de Fernando de Noronha terem sido realizados, sua diversidade de peixes mesofóticos nunca foi estudada antes. Neste estudo utilizamos mergulho autônomo e mergulho técnico, vídeos subaquáticos remotos com isca e veículo operado remotamente para registrar peixes de ecossistemas rasos (≤ 30 m de profundidade) e mesofóticos (31 a 150 m de profundidade). Dezenove espécies de peixes pertencentes a 14 famílias são apresentadas aqui como novos registros, representando um aumento de 8,2% na riqueza de peixes marinhos da região, que agora possui um total de 250 espécies e 77 famílias. Esses novos registros incluem quatro prováveis novas espécies e reforçam a importância de estudos em ecossistemas mesofóticos. Nossos resultados também enfatizam a necessidade de proteção e atenção à essa ictiofauna única encontrada nesses ecossistemas profundos.(AU)

Mesophotic ecosystems at Fernando de Noronha Archipelago, Brazil (South-western Atlantic), reveal unique ichthyofauna and need for conservation

Abstract Although several studies on the ichthyofauna of the Fernando de Noronha Archipelago have been carried out, its mesophotic fish diversity has never been surveyed before. Here we used SCUBA and technical rebreather diving, baited remote underwater videos and remotely operated vehicle to record shallow (≤ 30 m depth) and mesophotic (31 to 150 m depth) fishes. Nineteen fish species belonging to 14 families are reported here as new records, representing an increase of 8.2% in marine fish richness for the region, which now has a total of 250 species and 77 families. These new records include four potential new species and highlight the importance of surveying mesophotic ecosystems, even in well studied sites. Our results also emphasize the need for protection and attention to the unique ichthyofauna found at mesophotic depths.(AU)

Resumo Apesar de muitos estudos sobre a ictiofauna do Arquipélago de Fernando de Noronha terem sido realizados, sua diversidade de peixes mesofóticos nunca foi estudada antes. Neste estudo utilizamos mergulho autônomo e mergulho técnico, vídeos subaquáticos remotos com isca e veículo operado remotamente para registrar peixes de ecossistemas rasos (≤ 30 m de profundidade) e mesofóticos (31 a 150 m de profundidade). Dezenove espécies de peixes pertencentes a 14 famílias são apresentadas aqui como novos registros, representando um aumento de 8,2% na riqueza de peixes marinhos da região, que agora possui um total de 250 espécies e 77 famílias. Esses novos registros incluem quatro prováveis novas espécies e reforçam a importância de estudos em ecossistemas mesofóticos. Nossos resultados também enfatizam a necessidade de proteção e atenção à essa ictiofauna única encontrada nesses ecossistemas profundos.(AU)

Polychaetes from Burdwood Bank: "Namuncurá I" Marine Protected Area and slope, SW Atlantic Ocean

Introduction: The first open-sea (non-coastal) Marine Protected Area in Argentina, named "Namuncurá I" (NMPA), was created in 2013 at Burdwood Bank (BB), an undersea plateau located about 200 km south from Malvinas Islands (Falkland Islands) and 150 km east from Staten Island, SW Atlantic Ocean. It comprises three different management areas: the central one ("core", strict protection, only control and monitoring activities), surrounded by a "buffer" area (authorized activities, e.g. scientific research) and an external "transition" area (productive and extractive activities contemplated in the Management Plan). Beyond the transition area, only the southern shelf-break is protected, after the creation of the "Namuncurá II" MPA in December 2018. Objective: Provide the inventory of polychaetes collected during 2016 and 2017 at the core (98 m depth), buffer (128 m depth), transition (133 m-189 m depth) areas of the Namuncurá I MPA, together with slope areas (220 m-798 m depth). Methods: Taken with a trawl net used to characterize the faunal assemblages and to compare results with other Magellan areas. Multidimensional Scaling (MDS) and Cluster Analysis (CA) were applied to a Bray-Curtis similarity index to assess polychaete assemblages in the NMPA - BB slope and Magellan region respectively; SIMPER (Similarity Percentage Analyses) and ANOSIM (Analysis of Similarities) were performed. Results: A total of 918 individuals, which correspond to 39 taxa distributed in 22 families, were recorded in samples from NMPA and BB slope, mainly epibenthic or associated with the large corals collected. Ampharete kerguelensis McIntosh, 1885; Hyalinoecia artifex Verrill, 1880; Idanthyrsus macropaleus (Schmarda, 1861); Laetmonice producta Grube, 1877; Onuphis pseudoiridescens Averincev, 1972; Pista mirabilis McIntosh 1885 and Terebellides malvinensis Bremec & Elias, 1999 constitute new records for Burdwood Bank. A similar polychaete assemblage characterized the three areas of NMPA and slope locations, while H. artifex characterized locations at the NW deepest slope of the bank. Conclusions: These results indicate strong connections between the fauna collected at NMPA and the polychaetes assemblage in other Magellan areas dominated by soft bottoms. The biogeographic importance of the BB as connection for benthic polychaete species between South America and the Antarctic Peninsula merits future investigation.

Introducción: La primera Área Marina Protegida de mar abierto (no costera) en Argentina, llamada "Namuncurá I" (AMPN), fue creada en 2013 en el Banco Burdwood (BB), una plataforma sumergida ubicada unos 200 km al sur de las Islas Malvinas y 150 km al Este de la Isla de los Estados. En el Océano Atlántico SO. El área comprende tres diferentes áreas de manejo: la central ("el núcleo", con protección estricta, solo Control y actividades de monitoreo), rodeada por un área "de amortiguación" (solo actividades autorizadas, como investigación científica) y un área externa de "transición" (se contemplan actividades productivas y extractivas en el Plan de Manejo). Más allá del área de transición, el talud y las áreas adyacentes no presentan medidas de protección. Objetivos: Proporcionar un inventario de poliquetos colectados durante 2016 y 2017 en el Núcleo (98 m de profundidad), de Amortiguación (128 m), de Transición (133 m-189 m) y Talud (220 m-798 m). Métodos: Las muestras fueron obtenidas con una red de arrastre para caracterizar las asociaciones faunísticas y para compararlas con otras áreas Magallánicas. Análisis de Escalamiento Multidimensional y de agrupamiento aglomerativo jerárquico fueron aplicados a una matriz de similaridad de Bray-Curtis para determinar las asociaciones de poliquetos en el AMP - Talud del BB y región Magallánica, respectivamente. Resultados: Un total de 918 individuos, que corresponden a 39 taxones distribuidos en 22 familias, fueron registrados en las muestras del AMPN y talud del BB, mayormente epibentónicos o asociados a grandes corales. Ampharete kerguelensis McIntosh, 1885; Hyalinoecia artifex Verrill, 1880; Idanthyrsus macropaleus (Schmarda, 1861); Laetmonice producta Grube, 1877; Onuphis pseudoiridescens Averincev, 1972; Pista mirabilis McIntosh 1885 y Terebellides malvinensis Bremec & Elias, 1999 constituyen nuevos registros para el Banco Burdwood. Un ensamble de poliquetos similar caracteriza a las tres áreas del AMPN y talud, mientras que H. artifex caracteriza los sitios más profundos del talud del banco. Conclusiones: Estos resultados indican una fuerte conexión entre la fauna colectada en el NMPA y los ensambles de poliquetos de sustratos blandos de otras áreas Magallánicas. La importancia biogeográfica del BB como una conexión entre Sudamérica y la Península Antártica justifican futuras investigaciones.

Coordinated hunting behaviors of mixed-species groups of piscivores and associated species at Isla del Coco National Park (Eastern Tropical Pacific)

Studies of mixed-species groups of animals can reveal emergent complexities of collective behaviors. In this study we collected data on mixed-species hunting groups composed primarily of piscivorous fishes (species composition, abundance, behavioral interactions) and used both multivariate and network analyses to quantify pair-wise and guild level behavioral relationships. Our results indicate that such collective behaviors exhibit consistent patterns of associations (33 species with 282 pair-wise links within the observed network) with 10 dominant species accounting for 60% of pair-wise interactions. Species richness within groups varied (mean = 2.4, range 2-6 species) as did group size (mean = 8.1 individuals, range 2-80). Mixed-species groups, in general, were composed of species representing morphologically diverse forms that appeared to enhance access to shelter sites and implement diverse strategies for prey capture. It is noteworthy that the composition of groups did not reflect the relative abundances of their component species within the overall community of fishes, suggesting that group membership was an elective choice. The identification of these patterns, assuming they are persistent features of these communities, can be used as a foundation for studies to assess dynamics of mixed-species relationships, rates of predator success based on group membership, demographic consequences, and responses to variations in habitat attributes and associated prey resources. Such information could be used to interpret the nature of multispecies interactions within predator communities and potentially aid in conservation and management.(AU)

Estudios de grupos mixtos de animales puede revelar complejidades y sutilezas del comportamiento colectivo. En este estudio recolectamos datos sobre depredación de grupos mixtos de especies, compuestos principalmente por piscívoros (composición de especies, abundancia, interacciones) y usamos tanto análisis multivariado como de redes para cuantificar relaciones de comportamiento entre pares de especies y a nivel de gremios. Nuestros resultados indican que los comportamientos colectivos exhiben patrones consistentes de asociaciones (33 especies con 382 interacciones entre pares de especies dentro de la red) con 10 especies dominantes que constituyen el 60% de las interacciones entre dos especies. La riqueza de especies dentro de grupos varió (media = 2.4, ámbito 2-6 especies) cómo también el tamaño del grupo (media = 8.1, ámbito 2-80). Los grupos de especies mixtas, en general, estaban compuestos por especies con diversas morfologías que aparentemente aumentan el accesos a lugares estrechos y además, implementa diversas estrategias de captura de presas. Vale la pena resaltar que la composición de los grupos no reflejaba la abundancia relativa de las especies en la comunidad total de peces, sugiriendo que la membresía en el grupo era algo electivo. La identificaión de estos patrones, asumiendo que son características persistentes de la comunidad, se podrán usar en estudios para determinar la dinámica de las relaciones de grupos mixtos, tasa de éxito de depredación basado en la membresía del grupo, consecuencias demográficas y respuestas a varicaciones en las habitat y presas. Esta información servirá para interpretar la naturaleza de las interacciones multiespecíficas dentro de la comunidad de depredadores y potencialmente ayudar en la conservación y manejo de recursos.(AU)

Coordinated hunting behaviors of mixed-species groups of piscivores and associated species at Isla del Coco National Park (Eastern Tropical Pacific)

Studies of mixed-species groups of animals can reveal emergent complexities of collective behaviors. In this study we collected data on mixed-species hunting groups composed primarily of piscivorous fishes (species composition, abundance, behavioral interactions) and used both multivariate and network analyses to quantify pair-wise and guild level behavioral relationships. Our results indicate that such collective behaviors exhibit consistent patterns of associations (33 species with 282 pair-wise links within the observed network) with 10 dominant species accounting for 60% of pair-wise interactions. Species richness within groups varied (mean = 2.4, range 2-6 species) as did group size (mean = 8.1 individuals, range 2-80). Mixed-species groups, in general, were composed of species representing morphologically diverse forms that appeared to enhance access to shelter sites and implement diverse strategies for prey capture. It is noteworthy that the composition of groups did not reflect the relative abundances of their component species within the overall community of fishes, suggesting that group membership was an elective choice. The identification of these patterns, assuming they are persistent features of these communities, can be used as a foundation for studies to assess dynamics of mixed-species relationships, rates of predator success based on group membership, demographic consequences, and responses to variations in habitat attributes and associated prey resources. Such information could be used to interpret the nature of multispecies interactions within predator communities and potentially aid in conservation and management.(AU)

Estudios de grupos mixtos de animales puede revelar complejidades y sutilezas del comportamiento colectivo. En este estudio recolectamos datos sobre depredación de grupos mixtos de especies, compuestos principalmente por piscívoros (composición de especies, abundancia, interacciones) y usamos tanto análisis multivariado como de redes para cuantificar relaciones de comportamiento entre pares de especies y a nivel de gremios. Nuestros resultados indican que los comportamientos colectivos exhiben patrones consistentes de asociaciones (33 especies con 382 interacciones entre pares de especies dentro de la red) con 10 especies dominantes que constituyen el 60% de las interacciones entre dos especies. La riqueza de especies dentro de grupos varió (media = 2.4, ámbito 2-6 especies) cómo también el tamaño del grupo (media = 8.1, ámbito 2-80). Los grupos de especies mixtas, en general, estaban compuestos por especies con diversas morfologías que aparentemente aumentan el accesos a lugares estrechos y además, implementa diversas estrategias de captura de presas. Vale la pena resaltar que la composición de los grupos no reflejaba la abundancia relativa de las especies en la comunidad total de peces, sugiriendo que la membresía en el grupo era algo electivo. La identificaión de estos patrones, asumiendo que son características persistentes de la comunidad, se podrán usar en estudios para determinar la dinámica de las relaciones de grupos mixtos, tasa de éxito de depredación basado en la membresía del grupo, consecuencias demográficas y respuestas a varicaciones en las habitat y presas. Esta información servirá para interpretar la naturaleza de las interacciones multiespecíficas dentro de la comunidad de depredadores y potencialmente ayudar en la conservación y manejo de recursos.(AU)

Population structure and reproductive cycle of the commercial sea cucumber Holothuria mexicana (Echinodermata: Holothuroidea) in Belize / Estructura de la población y ciclo reproductivo del pepino de mar comercial Holothuria mexicana (Echinodermata: Holothuroidea) en Belice

Abstract The population and reproductive biology of the commercial sea cucumber Holothuria mexicana (Ludwig, 1875) was studied in Southern Belize (Caribbean Sea), including the sex ratio, size at sexual maturity and reproductive cycle, as well as the size structure among habitats located inside and outside protected areas. Individuals found inside marine protected areas were consistently larger than individuals found outside these boundaries. The male:female sex ratio was 1.1:1.0 with a unimodal size distribution composed mainly of sexually mature individuals (87 %). Size at sexual maturity was established to be ~10 cm based on measures of gamogenetically mature individuals during the peak of the gametogenic maturity period. Juveniles and small adults measuring ≤ 15 cm (13 %), were collected exclusively in sandy and muddy areas of seagrass habitats associated with mangroves. Larger adults were commonly found on hard substrates in both seagrass-associated and coral-reef-associated habitats. Based on histology and gonad indices, the first sign of early gametogenesis was detected in August in both sexes. Gametes developed and matured throughout the colder months between November and February. Decreases in gonad index in both years suggest annual spawning, starting in MarchApril 2014 (single major event) and March-April and July-August 2015 (two smaller events) for both males and females. The spawning periods were correlated with warmer or increasing temperatures, low rainfall and increasing or high chlorophyll-a concentrations. These data will hopefully guide management and protection of the natural populations of H. mexicana, which are already suffering from overfishing in Belize and neighboring countries.(AU)

Resumen La población y la biología reproductiva de pepino de mar comercial Holothuria mexicana (Ludwig, 1875) fue estudiado en el sur de Belice (Mar Caribe), incluyendo la proporción de sexo, talla de madurez sexual y el ciclo reproductivo, así como la estructura de tamaño entre hábitats situados dentro y fuera de áreas marinas protegidas. Los individuos dentro de las áreas marinas protegidas fueron siempre mayores que los individuos encontrados fuera de estos límites. La proporcion de machos a hembras fue de 1.1:1.0, con una distribución de tamaño unimodal compuesta principalmente de individuos sexualmente maduros (87 %). La talla de madurez sexual fue ~10 cm basada en medidas de individuos con gametos maduros durante el período del pico de maduracion de gametos. Los juveniles y adultos pequeños de medidas ≤ 15 cm (13.1 %), fueron recogidos exclusivamente en zonas fangosas y arenosas en pastos marinos asociados con los manglares. Los adultos mayores se encontraban comúnmente sobre substratos duros tanto en pastos marinos asociados como en los arrecifes de coral. Basada en la histología y gónada de índices, el primer signo de la gametogénesis temprana fue detectado en Agosto en ambos sexos. Los gametos en desarrollo y maduros se encontraron durante los meses fríos entre Noviembre y Febrero. Las disminuciones en el índice gonadal en ambos años sugieren desove anual, el cual comenzó en Marzo y Abril de 2014 (único gran evento) y en Marzo-Abril y Julio-Agosto de 2015 (dos pequeños eventos) tanto para ambos sexos durante temperaturas más cálidas, escasas precipitaciones y altas concentraciones de clorofila-a. Con estos datos esperamos orientar la gestión y la protección de las poblaciones naturales de H. mexicana, que ya están sufriendo los efectos de la sobrepesca en Belice y países vecinos.(AU)