Evaluation of different stocking densities and carbon:nitrogen ratios on growth, body composition and production performance of Labeo rohita (Hamilton, 1822) spawn in biofloc based‐nursery system

Abstract

total finfish production (FAO, 2020). Still, higher production can be achieved, but the unavailability of fry as a result of high mortality during the nursery rearing phase has been one of the major impediments in expanding its production. Generally, nursing of carp from spawn to fry stage is undertaken in small earthen ponds. With proper nursery management, where survival of 30%-40% of fry is

Effect of C/N Ratio Levels and Stocking Density of Catla Spawn (Gibelion catla) on Water Quality, Growth Performance, and Biofloc Nutritional Composition in an Indoor Biofloc System

“…In the present study, a lower stocking density of SD3 resulted in improved growth performance as compared to other groups. Te results agree with the fndings of Dey et al [17] who observed enhanced growth of Labeo rohita spawn in terms of fnal length, fnal weight, and SGR at a lower stocking density (1, 2, and 3 spawn L −1 ) than at a higher stocking density (4 and 5 spawn L −1 ) in biofoc systems. Impaired growth of goldfsh larvae with an increase in the stocking density in the BFT system was recorded by Besen et al [8].…”

“…As bacteria need about 20 units of carbon per unit of nitrogen assimilated [27], in this study, it is confrmed that a C/N ratio of 20 : 1 favored biofoc promotion which acts as a supplemental food source available 24 hrs [33,[64][65][66]. Te improvement in growth of catla spawn at C/N 20 could be associated with the presence of adequate natural proteinlipid source and other nutrients at any time as observed for Carassius auratus larvae at C/N ratios of 20 and 25 : 1 and Labeo rohita spawn at C/N 15 and 20 [17], whereas the insignifcant diference in the C/N 10 and 15 groups might indicate the limited number of prey production as reduction in organic carbon addition can slow down the formation of foc as observed with lower foc volume at a lower C/N ratio in the present study [29,67], or consumption of biofoc does not contribute to growth of the fsh [12]. Biofoc is known to improve feed utilisation of fsh by supplementing essential amino acids, vitamins, lipids, and minerals and stimulates digestive enzyme activity resulting in improved digestion of nutrients in the fsh gut [68].…”

“…Catla spawn starts feeding on plankton (mainly zooplankton) from the third day after hatching. Defning the biofoc, it is the heterotrophic conglomeric aggregation of microbial communities, such as phytoplankton, bacteria, and living and dead particulate organic matter, and the presence of zooplankton species such as rotifers, moina, daphnia, copepods, and freshwater infusoria makes the BFT system prosper for rearing of spawn [17,63].…”

“…Biofoc technology is studied for its application in nurseries as an additional feed source for postlarvae, to provide extra essential nutrients [9][10][11] and improve water quality to support better larval survival and growth [12,13]. BFT has been applied successfully in the nursery phase in diferent fsh and shrimp species such as Oreochromis niloticus [12], Rhamdia quelen [13], Clarias gariepinus [14], Labeo rohita [15][16][17], Carassius auratus [8], Farfantepenaeus brasiliensis [18], and Penaeus vannamei [19].…”