Improved survival and growth performances with stocking density manipulation and shelter availability in bagrid catfishMystus nemurus(Cuvier & Valenciennes 1840) larvae

Abstract

Manipulation of stocking densities (10, 20, 30, 40 and 50 larvae L À1 ), each with or without the presence of shelter was conducted to determine the effects on survival, cannibalism and growth performances of larval bagrid catfish Mystus nemurus (Valenciennes 1840) from 2 to 14 days after hatching. This study revealed that stocking density significantly affected survival, cannibalism, total length, feed intake, specific growth rate and final weight of bagrid catfish larvae. Significantly higher survival was observed at moderate stocking density of more than 20 but less than 50 larvae L À1 . Survival was significantly low beyond this threshold and was the lowest at 10 larvae L À1 , coincides with the highest cannibalism. Total length, feed intake, specific growth rate and final weight were significantly higher at 10 larvae L À1 . Shelter significantly improved total length and feed intake. No significant effects of stocking density and shelter were observed on the apparent feed conversion ratio and coefficient of variation. There was also no significant interaction between stocking density and shelter in all parameters. This study suggests that bagrid catfish larvae could be cultured at more than 20 but less than 50 larvae L À1 with the availability of shelter for optimal larviculture condition.

Effects of light and artificial fish shelter (PVC pipe) on some phenotypic traits of stinging catfish (Heteropneustes fossilisBloch, 1794)

“…Similar negative phototactic behaviour has also been reported in other catfish species (e.g. Heterobranchus longifilis : Kerdchuen & Legendre, ; Clarias gariepinus : Britz & Pienaar, ; Silurus glanis : Kozlowski & Poczyczynski, ; Mystus nemurus : Rahmah et al, ; Lophiosilurus alexandri : Kitagawa et al, ; Hatcheria macraei : Barriga, Espinos, Walter, & Miguel, ). Moreover, their elongated body shape along with flattened head having subterminal mouth and a prognathic upper lip, barbels and very small dorsal eyes enable them like other catfishes to use tactile techniques rather than visual sense for feeding (Alexander, ; Hardy, Steinworth, & Hale, ).…”

Environmental enrichment for fish in captive environments: effects of physical structures and substrates

“…), but not in juvenile Asian redtail catfish Hemibargus nemurus (Bagridae) (Rahmah et al . ). The function of shelter as light refuge in nocturnal sharptooth catfish has also been indicated, as growth in constantly lit tanks was enhanced with the addition of shelter, while no effect was observed in constantly dark tanks (Britz and Pienaar ).…”

“…The differing results could depend on the fact that shelter structures where different between the studies (entangled plastic strips in the former, half PVC cylinders in the latter), as well as number of fish, experimental time and rearing environment. Shelter structures (plastic mesh materials) reduced cannibalism in African sharptooth catfish Clarias gariepinus (Clariidae) (Hecht and Appelbaum 1988;Hossain et al 1998), but not in juvenile Asian redtail catfish Hemibargus nemurus (Bagridae) (Rahmah et al 2013). The function of shelter as light refuge in nocturnal sharptooth catfish has also been indicated, as growth in constantly lit tanks was enhanced with the addition of shelter, while no effect was observed in constantly dark tanks (Britz and Pienaar 1992).…”

“…Several studies on salmonids indicate negative effects Wagner et al 1996;Maynard et al 2004;Lema et al 2005;Fast et al 2008), others show no effects (Arndt et al 2001;Brockmark et al 2010;Roberts et al 2011;N€ aslund et al 2013), and a few point to positive effects (Brockmark et al 2007;Hyv€ arinen et al 2011). In catfishes (Siluriformes), there are several indications of positive effects, but they seem to be dependent of the size of the fish and environmental light levels (Britz and Pienaar 1992;Hossain et al 1998;Coulibaly et al 2007;Rahmah et al 2013 (Herbert et al 2003), although the latter species did increase in condition factor when shelters were present.…”

Optimization of the culture methods for nursing Chinese black sleeper (Bostrychus sinensis Lacépède, 1801) fry using an orthogonal array design

“…Similarly, the present study indicated that B. sinensis fry reared using PVC pipes and concrete bricks for shelters showed higher SGR and CF than those reared without shelters. Based on the different behaviors of fish, certain types of shelters are species‐specific (Rahmah et al., ). Some salmonids prefer rocks rather than sand substrates, because they can hide between the rocks and reduce daytime energy expenditure (Suttle et al., ), while the mud eel Monopterus cuchia prefers water hyacinth ( Eichhornia crassipes ) compared to PVC pipes and mud as shelters (Narejo et al., ).…”