Prey selectivity and trophic behaviour of Patagonian seahorse Hippocampus patagonicus in captivity.

STORERO, LORENA P.; GONZÁLEZ, RAÚL

JOURNAL OF THE WORLD AQUACULTURE SOCIETY

Wiley-Blackwell

Año: 2009 vol. 40 p. 394 - 401

0893-8849

This study aims at evaluating the Patagonian seahorse, Hippocampus patagonicus, feeding behavior in captivity with regard to type and size of prey selectivity and time-investment-related activities for searching and capture. Experiments in aquaria were carried out under two different treatments, with and without refuge for prey. Different diets composed of amphipods (Melita palmata and Ampithoe valida), juvenile decapods (Neohelice granulata) from natural environments, and artificially cultured Artemia salina. The eaten prey’s size was analyzed and experiments with size-controlled prey were carried out. There were neither significant differences in the prey quantity ingested between males and females nor between treatments (with or without refuge). However, significant differences were found between the quantities of each prey consumed. Amphipods and A. salina were consumed in greater quantity (P , 0.05) when compared with juvenile decapods. Experiments with A. salina of different sizes did not show significant differences on seahorses’ preference. N. granulata was highly avoided and seahorses had lower capture efficiency over this prey. Behavioral observations showed that more than 50% of the times seahorses were resting and ambushing their prey. In captivity, with optimal conditions for predation, the Patagonian seahorse modifies its opportunistic behavior, feeding selectively, and bases its food preferences on prey size and shape.