Selectivity of preys of Coralliophila abbreviata and C. caribaea in coral reefs of the National Park Morrocoy, Venezuela: an experimental approximation
Selectividad de presas de Coralliophila abbreviata y C. caribaea en arrecifes coralinos del Parque Nacional Morrocoy, Venezuela: una aproximación experimental
Author
del Mónaco, Carlos
Villamizar, Estrella
Narciso, Samuel
Full text
http://lajar.ucv.cl/index.php/rlajar/article/view/vol38-issue1-fulltext-610.3856/vol38-issue1-fulltext-6
Abstract
Coralliophila abbreviata and C. caribaea are tropical gastropods of the Caribbean Sea. These gastropods have shown to be important corallivores. The objective of this work was to evaluate in situ the prey selectivity of C. abbreviata and C. caribaea in some coral reefs of Morrocoy National Park by means of experimental and descriptive methods. We used quadrats of 1 m2 to estimate coral abundance and richness, number of Coralliophila specimens, and coral species preyed on by Coralliophila sp. in three sites at each locality. For the experiment, we enclosed in cages five coral colonies of different species together with 10 individuals of C. abbreviata located in the center of the cages and equidistant to all colonies. A total of 8 exclusion cages of 1 m3 were evaluated. We observed in situ a higher relation predator-prey between C. abbreviata and the hexacoral species M. annularis, representing 56.8% of the total interactions at all localities, followed by D. strigosa (19.3%), A. agaricites (12.2%), C. natans (4.6%) and A. tenuifolia (3.1%). C. caribaea presented a higher relation predator-prey with the octocoral species E. caribaeorum (42.6%), followed by those with the hexacoral species C. natans (24.1%), M. faveolata (11.1%), P. porites (7.4%) and D. strigosa (11.1%). The experiment showed a major relation between C. abbreviata and M. annularis, with 53.3% of total interactions, followed by those of C. natans (17.8%), A. tenuifolia and D. strigosa (11.1%) and A. agaricites (6.7%). According to the outcomes C. abbreviata is thought to generate a larger impact than C. caribaea on Morrocoy National Park because its more common preys are mainly coral reef building species while C. caribaea predate mainly on E. caribaeorum, which is a competitive species of hexacorals. Se evaluó la selectividad de presas de Coralliophila abbreviata y C. caribaea en seis arrecifes coralinos del Parque Nacional Morrocoy (PNM), Venezuela, mediante métodos descriptivos y experimentales. Se estimó la abundancia y riqueza coralina, el número de Coralliophila spp. y su presa coralina mediante cuadratas aleatorias de 1 m2 en tres sitios por cada arrecife . Se utilizaron ocho jaulas de exclusión de 1 m3 en cuyo interior se colocaron cinco colonias coralinas de diferentes especies, equidistantes a 10 individuos de C. abbreviata. Se observó una estrecha relación depredador-presa entre C. abbreviata y la hexacoralina Montastraea annularis, representando el 56,8% de todas las interacciones en todas las localidades, seguida por Diploria strigosa (19,3%), Agaricia agaricites (12,2%), Colpophyllia natans (4,6%) y A. tenuifolia (3,1%). C. caribaea exhibió una mayor afinidad con el octocoral Erythropodium caribaeorum (42,6%) y las hexacoralinas C. natans (24,1%), Montastraea faveolata (11,1%), Porites porites (7,4%) y D. strigosa (11,1%). De igual forma, el experimento mostró mayor asociación de C. abbreviata con M. annularis 53,3%, seguida por C. natans (17,8%), A. tenuifolia y D. strigosa (11,1% cada una) y A. agaricites (6,7%). Según estos resultados, C. abbreviata debería generar un mayor impacto que C. caribaea sobre el PNM debido a que sus presas más frecuentes están entre las principales formadoras de arrecife mientras que C. caribaea depredó mayormente a E. caribaeorum, la cual es competidora de hexacorales.