Carry-over effects of pre-breeding diets on seahorse (Hippocampus reidi) reproductive success

11 pages, 8 figures, 4 tables

The effects of diet on reproduction success in fishes are fairly well known for many species. In syngnathids (seahorses, pipefishes and seadragons), almost nothing is known about how diet quality supplied during the pre-breeding period might influence subsequent breeding performance and fry quality. In the present study, the influence of pre-breeding diet was assessed for the first time in seahorses. For that, adult seahorses Hippocampus reidi were submitted to three dietary treatments (based on Artemia alone or supplemented with mysidaceans) including different timing schedules. The assimilation of the diets by breeders and subsequent newborn batches were evaluated isotopically (δ13C and δ15N). The timing of brood release, brood size, and length, weight and survival at day 7 in newborn seahorses were also evaluated. The species followed a mixed capital-income reproduction strategy and showed a higher breeding performance and larger newborn when fed on a mixed diet (Artemia and mysidaceans) supplied during the whole pre-breeding period (5 months). The enhancements were also noticed on the second half of the breeding period. An isotopic steady-state in newborn batches was achieved beyond the second month of the breeding period (i.e., slow isotopic change rates), depending on the treatment and isotope considered. For the first time in syngnathids, this study also revealed an isotopic relationship between breeder's diet and newborn. This work highlights the importance of the pre-breeding diet on seahorse reproduction, and will contribute to the optimization of breeding performance in seahorse culture

This study was part of the project Hippoeco (CGL2015-68110-R), financially supported by the Spanish Government (Ministerio de Ciencia, Innovación y Universidades) and Fondos FEDER

Peer reviewed