Replacing Artemia Cuts Weaning Time For Flounder

The Fish Site
by The Fish Site
18 November 2010, at 12:00am

US - In a 2010 hatchery trial at GreatBay Aquaculture in the US larvae of summer flounder were weaned onto manufactured feed by day 24, without Artemia. This is close to half the usual time. The trial used Skrettings latest Gemma Micro formulation.

Gemma Micro has pre-digested proteins and phospholipids and a blend of marine micro algae that gives the feed its striking green colour. Conventionally, larvae of marine species such as flounder are first fed with live feed, rotifers then Artemia, before being weaned onto manufactured feed. For summer flounder at GreatBay Aquaculture this is at day 40.

Brian Gennaco, Hatchery Manager of GreatBay Aquaculture comments, “We were highly impressed with the speed at which the flounder transitioned onto the new diets. The overall pigmentation, growth, and quality of the flounder exceeded our expectations. The elimination of Artemia in this trial has significantly reduced the work load of the live feed staff.”

Nick King of Skretting supervised the trial. “We phased Gemma Micro in alongside rotifers starting on day 19. As larvae began taking the feed, rotifer feeds were progressively eliminated. In two days all larvae were readily taking Gemma Micro so we shortened the weaning time to five days. The larvae were completely weaned by day 24. The usual 40 days in this hatchery is already far earlier than many flatfish hatcheries.”

Mr King adds, "For this hatchery, these trials have demonstrated that Artemia replacement is indeed a viable option for producing quality summer flounder juveniles. Given the uncertainty of supply and erratic quality sometimes experienced with Artemia, we will also evaluate the new Gemma Micro with meagre, sole, turbot, seriola and tuna. I suspect we will be reporting more ‘never been seen before’ claims.”