Effects of delayed first feeding on growth of the silver catfish larvae Rhamdia voulezi (Siluriformes: Heptapteridae)

Ariane F De Lima,Suelen Fernanda R Pini,Maristela C Makrakis,Sergio Makrakis,Fernanda F Andrade

doi:10.1590/1982-0224-20160027

Ariane F De Lima, Suelen Fernanda R Pini + Show 3 more

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https://doi.org/10.1590/1982-0224-20160027

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Abstract

ABSTRACT The effects of the timing of first feeding on the point-of-no-return (PNR) and growth of laboratory reared silver catfish Rhamdia voulezi larvae were studied. The experiment began immediately after the complete absorption of the yolk sac, 3 days after hatching (DAH). The food was provided for the first time on 3rd, 4th, 5th, 6th, 7th, 8th, and 9th DAH. Zooplankton and newly-hatched Artemia spp. were used to feed the larvae. To evaluate the effect of food deprivation on growth, the standard length and weight of 594 larvae were assessed. Larval growth was significantly affected by the time of first exogenous feeding. The larvae fed from 3rd to 5th DAH showed a significantly higher development than those fed from 6th DAH. The larvae reached the PNR on 6th DAH. Survival and larval growth strongly depended on the timing of initial feeding. In order to avoid potential mortality by starvation and obtain good growth, the silver catfish larvae R. voulezi must establish successful initial feeding within 5 days after hatching.

Highlights

Many fish larvae depend exclusively on the nutritive reserves of the yolk sac as soon as they hatch (Geurden et al, 2007)
Once the endogenous reserves are exhausted, the larvae need to make a successful transition from endogenous to exogenous feeding to assure their survival and growth in that phase (Blaxter, Ehrlich, 1974). Some factors, such as availability and composition of the food (Sánchez-Velasco, 1998), temperature, photoperiod (Paul, 1983; Porter, Bailey, 2007), development of the digestive tract, visual acuity, and the swimming ability of the larvae (Makrakis et al, 2005), are important for a successful feeding transition. When these factors do not comply with the actual larval stage, the larvae may not succeed in their initial feeding, and become vulnerable to starvation (Gisbert et al, 2004; Zhang et al, 2009)
This study investigates the effects of delayed first feeding on biological parameters in silver catfish larvae, Rhamdia voulezi Haseman, 1911, an endemic species from Iguaçu River Basin in South America, in order to better understand its larval growth during starvation and provide information for feeding management in larval rearing

Summary

Introduction

Many fish larvae depend exclusively on the nutritive reserves of the yolk sac as soon as they hatch (Geurden et al, 2007). Once the endogenous reserves are exhausted, the larvae need to make a successful transition from endogenous to exogenous feeding to assure their survival and growth in that phase (Blaxter, Ehrlich, 1974) Some factors, such as availability and composition of the food (Sánchez-Velasco, 1998), temperature, photoperiod (Paul, 1983; Porter, Bailey, 2007), development of the digestive tract, visual acuity, and the swimming ability of the larvae (Makrakis et al, 2005), are important for a successful feeding transition. When these factors do not comply with the actual larval stage, the larvae may not succeed in their initial feeding, and become vulnerable to starvation (Gisbert et al, 2004; Zhang et al, 2009). Food deprivation affects other biochemical parameters and weight (Hung et al, 1997)

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