Using Copepods in Aquaculture

Many marine fishes produce tiny larvae following an abbreviated hatching cycle. These exceedingly small larvae necessarily require even smaller prey to fit in their developing mouth and gut. Unlike the brine shrimp, Artemia salina, and the marine rotifers, Brachionus spp., marine fish larvae regularly encounter Acartia nauplii in the wild, and many species are adapted to digest these nauplii and similar organisms. Due to the abundant populations, size, and nutritional profile of calanoid copepod nauplii, they are the primary first-feed for many marine species, both vertebrate and invertebrate (Lee et al. 2005). Additionally many adult vertebrate and invertebrate species of great economic value, such as the seahorses (an ornamental and medicinal commodity) or the corals (national treasures and tourist commodities) readily consume copepods.

Studies have shown that for a number of marine fish species, diets including copepod nauplii result in better development, growth, nutritional content, and survival of the first-feeding larvae compared to diets consisting solely of rotifers and Artemia (Watanabe et al. 1983; Støttrup et al. 1986; Kraul et al. 1992; Støttrup and Norsker 1997; Schipp et al. 1999; Shields et al. 1999; Støttrup 2000; Payne et al. 2001; Evjemo et al. 2004). Copepods have been shown to have a natural omega-3 profile, which exceeds that provided by enriched rotifers or enriched Artemia (Sargent et al. 1997).

The recent publication of Copepods in Aquaculture by Lee, O’Bryen, and Marcus (2005) consolidates much of the recent information on copepod culture and use. To quote Blackwell Publishing:

“(It)… includes review articles and papers presented by leading international experts in copepod biology and aquaculture. It … integrates the most up-to-date information on selecting copepod species, effects of algal species on reproduction, ways to increase production, the nutritional value of copepods, behavioral characteristics of copepods, potential use of copepod nauplii and eggs, and their application to larval rearing of various marine finfish species.”

While the majority of aquaculture of Acartia is for early feeds for fish larvae and, to a lesser extent, adult feeds for ornamental species; there also exists a niche market for bioassay Acartia tonsa. These protocols, as presented, do not conform to bioassay production standards; but only slight modifications would be required to achieve bioassay standards.