Effects of stocking density and presence or absence of soil base on growth, weight variation, survival and body composition of pearlspot,Etroplus suratensis(Bloch) fingerlings

Abstract

With the objective to develop an indoor tank seed rearing system for pearlspot (Etroplus suratensis), effects of three stocking densities in presence or absence of soil base were evaluated on growth, weight variation, survival and body composition in a 60‐day trial. The experiment had a 3 × 2 factorial design with three levels of stocking density (150, 300 and 450 fish m−3) and two levels of soil base (with and without) in triplicates. Pearlspot fry (27.5 ± 0.5 mm/0.39 ± 0.02 g) were stocked in experimental tanks (Length×Breadth×Height: 0.65 × 0.50 × 0.48 m) and fed with a formulated diet containing 29.85% crude protein. Increasing the stocking density from 150 to 450 fish m−3 significantly decreased the growth (average body weight and total length), daily weight gain, specific growth rate and survival (P < 0.001) and increased the feed conversion ratio (P < 0.01). Significantly lower growth and survival were observed in treatment having soil base compared with that of without soil base (P < 0.001). However, coefficients of variation at harvest weight and body composition of fingerlings were independent to stocking density and presence or absence of soil base (P > 0.05). A significant positive interaction effect of stocking density and presence or absence of soil base was observed on average body weight (P < 0.05) and survival (P < 0.001) of pearlspot fingerlings. This study suggests that stocking density of 150 fish m−3 without soil base in tanks would be appropriate for raising pearlspot fingerlings in brackishwater indoor seed rearing system.

Feeding ecology, prey selection and growth performances of gold spot mullet, Liza parsia (Hamilton, 1822) in extensive brackish water farming system of Indian Sundarbans

“…Concentrations of toxic metabolites like nitritenitrogen (NO2-N)and ammonia-nitrogen (NH4-N) remained lower than the critical level and concentrations of nutrients like nitrate-nitrogen (NO3-N) and phosphate-phosphorous (PO4-P) was much lower than fertilized ponds reported from Sundarbans [4,28] and corroborated with those reported earlier by Mondal et al [29] from the same location. Lower nutrient concentrations in the studied extensive system may be attributed to complete dependence on natural productivity without any additional input.…”

“…Small fry can enter through traditional bamboo screen during water exchanges but exit of bigger fishes is restricted. As seeds of L. parsia remain available in north-east coast of India during the month of January-March [2,4,18], entry of gold spot mullet fry along with other species was anticipated. Following traditional practice, no fertilizer or supplementary feed was used and fishes grew depending on natural food.…”

“…The gold spot mullet Liza parsia(Hamilton 1822), belonging to the family Mugilidae is a catadromousfish and widely distributed in the coastal waters of tropic, sub-tropic and temperate regions extending from 42º N to 42º S [1].With its good market price and consumer preference, abundant availability of seeds, non-carnivorous food habit, gold spot mullet is easily cultivable in shrimp growing areas and forms commercially important candidate for polyculture with shrimp and other mullets [2][3][4][5].Gold spot mullet, popularly known as 'parsia' in Indian subcontinent, can tolerate wide range of environmental fluctuation [6].…”

Effects of stocking density on growth performance and welfare‐related physiological parameters of Atlantic salmon S almo salar L. in recirculating aquaculture system

“…It seems consistent with other trials in farmed fish, such as burbot Lota lota , Atlantic cod G. morhua and Pearl spot Etroplus suratensis (Wocher, Harsányi & Schwarz ; Björnsson et al . ; Biswas, Ghoshal, Natarajan, Thirunavukkarasu, Sundaray, Kailasam, De, Sukumaran, Kumar & Ponniah ). These results together suggest that CF and CV are less sensitive than SGR to stocking density.…”

Using ecology to inform physiology studies: implications of high population density in the laboratory

“…37), and Etroplus suratensis fingerlings (Pearlspot; Ref. 7), revealed that diminished stocking densities yielded fish with comparably Fig. 1.…”