Laboratory studies on food intake, growth and conversion efficiency of Palaemon lamarrei in relation to body size

Abstract

The effects of body size on the food intake, growth and conversion efficiency of the freshwater prawn Palaemon lamarrei have been studied. In captivity, fed on a restricted diet of the muscles of the fish Gambusia affinis, moulting in these prawns occurred once in 18 + 5 days at a temperature of 26 f 1°C. The importance of these cast moults, contributing a sizable amount of organic matter to the detritus deposit of freshwater habitats has been indicated. In a log-log system, both food intake and growth per day, represented as a percentage of body weight, showed an inverse relationship to the body size. Animals in the size range of 600-800 mg exhibited the highest conversion efficiency. The present study indicates that these prawns can be successfully reared and grown under laboratory conditions.

Effects of different feeding levels on moulting, growth and conversion efficiency of Palaemon lamarrei

“…Thus, with unrestricted supply of food, these prawns consume nearly 2 '/2 times more food than when the feeding schedule is restricted . On a restricted diet the conversion efficiency exhibited by P. lamarrei is also very low (2 .41% : recalculated from Katre, 1974) as compared to the present values (average : 8 .27%) . However, the conversion efficiency value of 1 .98% obtained at the highest feeding level is comparable to the conversion efficiency values (range : 0 .43 -1 .25%) of adult Daphniapulex reported by Richman (1958) .…”

“…An average moulting frequency of 18 t 5 days and an average moult dry weight of 14% of the animal's dry weight was reported earlier for Palaemon lamarrei (Katre, 1974) . Size of the animal was also shown to have no effect on the moulting frequency .…”

“…P. lamarrei of a comparable body size (463 .35 mg), fed only for 4 h/day, was reported to consume only 39 .59 mg food/g/day, which is equivalent to 7 .96% of the animal's body weight (Katre, 1974) . Thus, with unrestricted supply of food, these prawns consume nearly 2 '/2 times more food than when the feeding schedule is restricted .…”

Effects of eyestalk ablation on growth and food conversion efficiency of the freshwater prawn Macrobrachium lanchesteri (de Man)

“…At the end of the experimental period, the water in the aquarium ablated was filtered to collect faecal matter and the absorption efficiency was determined following the procedure of Katre (1977). Food intake, moulting frequency, growth and conversion efficiency were determined as detailed by Katre & Reddy (1977).…”

“…The values decreased to 5.24% in normal individuals. Katre & Reddy (1977) have reported a conversion value of 5.30% for P.…”