Food production for juvenile seahorse culture

Abstract

The aim of this project was to find a reliable, cost effective food for production of Hippocampus spp. juveniles. The first feeding preferences in terms o f short term survival and growth were investigated. H. guttulatus juveniles had a significantly higher rate of survival of 55.5% when fed on Tisbe battagliai compared to Artemia or two other copepods to day seven. H. kudo juveniles had a significantly higher survival rate of 61 % when fed on enriched rotifers compared to Artemia or T. battagliai to day seven. Experiments feeding T. battagliai to H. reidi gave conflicting results. A survival and growth experiment with H. fuscus juveniles resulted in no significant differences in survival to day 17 when fed on enriched Artemia, newly hatched Artemia or Tisbe battagliai. The weight of the juveniles fed on enriched Artemia and newly hatched Artemia was significantly higher than juveniles fed on T. battagliai however. Due to the success of T. battagliai as a live food for some species of juvenile seahorses, investigations were carried out to find optimal culture conditions. In survival experiments, it was found that T. battagliai would survive and reproduce on a variety of diets such as yeast and SMA milk in both small and large culture systems. A loss of pigment in the copepods was associated with these diets however. In a life time study of the effects of SMA milk and yeast on T. battagliai it was found that algae as a food resulted in a longer life span, more fertile females and more brood sacs. However T. battagliai fed on SMA milk had a shorter development time and had more nauplii per brood sac than those fed on a mixture of algae. The maximum ingestion rate of a T. battagliai in a 24 hour period was investigated for the algae Tetraselmis suecica. The highest pellet production was 32 pellets female day at a concentration o f 3.74 x 10' cell ml*1.