Feeding of Farfantepenaeus paulensis (Pérez-Farfante, 1967) (Crustacea: Penaeidae) inside and outside experimental pen-culture in southern Brazil

PABLO JORGENSEN; CARLOS E. BEMVENUTI; CLARA M. HEREU

Pan-American Journal of Aquatic Sciences

Creative Commons

Año: 2009 vol. 4 p. 39 - 51

We assessed the value of benthic macroinvertebrates to the diet of Farfantepenaeus paulensis juveniles in experimental pen-cages after three independent rearing periods of 20, 40 and 60 days each. For each time period we initially stocked 3 pen-cages with 60 shrimps m-2 supplemented with ration (treatment RS), and 3 pen-cages with 60 shrimps m-2 without ration (WR). The diet of captive shrimps was compared with the diet of free shrimps (C). Shrimps fed preferentially on benthic preys. Captive shrimps extended their activity to daylight hours and consumed a significant amount of vegetation, likely in response to a severe decrease of macroinvertebrate density passed 20 and 40 days. After 60 days, the diet of the few survivors of F. paulensis in pen-cages without ration (WR) approached the diet of shrimps in the natural environment (C). These similarities were explained by the recovery of macroinvertebrates populations to relaxation from high predation pressure during the last 20 days of the experiment in WR pens. Considering the strong predatory control of F. paulensis over the benthic invertebrate assemblages we concluded that the value of natural production as food source for shrimps reared in pens is limited to the initial stage of the culture.