Feeding habits of the seahorse Hippocampus patagonicus (Actinopterygii: Syngnathiformes: Syngnathidae) on the southern coast of Brazil

Abstract

The feeding habits of the seahorse Hippocampus patagonicus Piacentino et Luzzatto, 2004 on the southern Brazilian coast was evaluated through the gut content analysis of 82 individuals (28–110 mm in height, HT) obtained through a fish landing monitoring program (July 2011 to November 2012). Results showed that H. patagonicus feed mainly on small benthic and pelagic zooplankton organisms, mainly amphipods, decapods post-larvae (megalopa), and isopods. In the warm season (>20°C, from November to April) the diet was dominated by amphipods, and in the cold season (<19°C, from May to October) by decapods post-larvae and isopods. No significant differences were observed on the diet composition of juveniles (<48.5 mm HT) and adults (>48.5 mm HT) and also among sites. The importance of amphipods and decapod larvae as a food source is well known for seahorses, all explained by their highly specialized prey-capture mechanism and foraging behaviour.

Keywords

• Crustacea
• diet
• South-western Atlantic
• threatene