Selection of meiobenthic prey by juvenile spot (Pisces): an experimental study

Meiofauna are known to be important components of the diet of many juvenile fish, but whether these fish actively select certain taxa has yet to be fully determined. Harpacticoid copepods account for 70 % of the visible prey items in juvenile spot Leiostomus xanthurus collected from North Inlet Estuary, South Carolina, USA. The sediment fauna in North Inlet, however, is numerically composed of 70 % nematodes and only 17 % copepods. Controlled feeding experiments were conducted to determine if spot select copepods in preference to nematodes and whether prey motility is a factor in the selection. Spot were allowed to feed for 1 h in aquaria containing azoic sediment seeded with live (i.e. motile) and freshly-killed (i.e. immobile) copepods and live and freshly-killed nematodes. Spot selected live copepods over all other prey types. Greater copepod motility compared to nematodes is probably the primary factor in copepod selection by spot.