Asteroids of the genus Echinaster are key predators in several benthic coastal ecosystems. Despite their ecological importance, little is known about the population biology of these species, including the response to coastal environmental heterogeneity. This manuscript aims to describe population features (spatial distribution, abundance and density) and reproductive traits of Echinaster (Othilia) paucispinus in a hypersaline wetland under the hypotheses of potential effects of the environmental gradient. Along the gradient, the densities of E. (O.) paucispinus were far higher than any previously reported for this genus. Strong zonation patterns were detected for size, fertility and abundance; however, instead of spatial variation associated with the environmental gradient, the differences were detected between the center and the extremes of the gradient. The extremes were inhabited by more dispersed, larger, mature organisms, while the intermediate region was characterized by high densities of aggregated, small, immature individuals. Temporal variability in reproductive characteristics was considerably lower than spatial variability. Based on these results, it seems that the population of E. (O.) paucispinus at Laguna de La Restinga is governed by pre-settlement processes, rather than by environmental variability along the gradient.
Asteroidea Reproductive effort Population structure Caribbean Sea RAMSAR site
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This work was funded by Consejo de Investigación, Universidad de Oriente, Venezuela, under grant No. CI 06-030601-1926-14. Special thanks to Prof. Juan Bolaños (1954-2015) and Régulo López for facilitating almost every aspect of the laboratory and field logistics. Comments from Dr. Roger Sepúlveda, Dr. Iván Hernandez, and Dr. Juan J. Cruz-Motta helped improve this article substantially. Our gratitude is also extended to M.Sc. Rodrigo Lazo and Prof. Sheila Marques.
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