Short-term variability of fish larvae assemblages in Malpelo island, an isolated oceanic island in the Eastern Tropical Pacific
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| Autores: | , , , |
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| Formato: | artículo original |
| Estado: | Versión publicada |
| Fecha de Publicación: | 2026 |
| Descripción: | Introduction: Oceanic islands are key biogeographic features that influence the distribution and diversity of marine organisms, particularly in tropical ecosystems. Malpelo Island, located 380 km off the Colombian Pacific coast, is the only oceanic island in the country and a strategic site for assessing ichthyoplankton dynamics in the Eastern Tropical Pacific (ETP). Objective: To characterize the taxonomic composition and spatial ecological structure of fish larvae assemblages associated with Malpelo Island in the Colombian Eastern Tropical Pacific under prevailing hydrographic conditions. Specifically, to assess differences in species richness, abundance, and diel vertical distribution between insular and adjacent offshore sites. These patterns are interpreted in the context of localized larval retention and vertical migratory behaviors, potentially shaped by insular oceanographic features. Methods: Short-term variability in larval fish assemblages was evaluated using vertical zooplankton trawls conducted in September 2012 and July 2016 across three depth strata. Fish larvae were identified to the lowest possible taxonomic level, and hydrographic profiles of temperature and salinity were obtained using CTD casts. Results: A total of 26 taxonomic units representing eight orders and twelve families were recorded. Assemblages near the island included epipelagic and reef-associated taxa such as Sardinops sagax and Anchoa spp., while offshore stations were dominated by mesopelagic species including Diogenichthys laternatus and Vinciguerria lucetia. Although larval abundance did not differ significantly between locations (MW; p = 0.38), assemblage similarity was low (45 %) and species turnover high (79 %). Larvae exhibited diel vertical migration, occupying deeper strata (50-100 m) during daylight and ascending to shallower layers (0-50 m) at night, influenced by local thermocline and halocline depth. Conclusions: These findings highlight the ecological distinctiveness of Malpelo Island and its role in supporting larval fish diversity in tropical oceanic environments. The results provide baseline data for future ecological monitoring and conservation planning in insular marine habitats of the ETP. |
| País: | Portal de Revistas UCR |
| Institución: | Universidad de Costa Rica |
| Repositorio: | Portal de Revistas UCR |
| Lenguaje: | Inglés |
| OAI Identifier: | oai:portal.revistas.ucr.ac.cr:article/184 |
| Acceso en línea: | https://revistas.ucr.ac.cr/index.php/rrbt/article/view/184 |
| Palabra clave: | ichthyoplankton; oceanic islands; assemblages; diversity; vertical migration ictioplancton; islas oceánicas; ensamblajes; diversidad; migración vertical |