Dusky Grouper Epinephelus marginatus Growth and Survival When Exposed to Different Photoperiods

Paulo Henrique R Aride,Caterina Faggio,Gilson R Sangali,Henrique D Lavander,Douglas C Mattos,Lucas A Bassul,Marcelo F Polese,Maria Fernanda S Gomes,André B Souza,Darlan G Azevedo,Ana Cláudia F Silva,Leonardo D Cardoso,Adriano T Oliveira

doi:10.3390/fishes6030031

Paulo Henrique R Aride, Caterina Faggio + Show 11 more

Open Access

https://doi.org/10.3390/fishes6030031

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Abstract

Photoperiod is considered an environmental factor that influences reproduction and the growth processes of fish throughout the year. In the present study, we subjected dusky grouper Epinephelus marginatus to different photoperiods in order to evaluate growth and survival. Juvenile dusky grouper were randomly distributed in twelve 100 L tanks containing four fish per aquarium. The fish were exposed to continuous light, normal photoperiod or continuous darkness for 50 days. Fish were fed 3% of their total biomass, twice a day, and the diet consisted of ground commercial dry pellets (42% crude protein, 12% humidity, 9% ether extract, 15% mineral matter, 4% crude fiber, 3.5% calcium and 3% vitamin C, in accordance with the manufacturer’s instructions). There was no mortality during the experiment. After 50 days, the best performance was found for exposure to continuous light (24 h artificial light). The final weight of the fish reared under continuous light was significantly higher than that of the fish exposed to continuous darkness. The specific growth rate of the fish exposed to continuous light was significantly higher than that of the fish exposed to the natural photoperiod and to continuous darkness. Modifications to the photoperiod can be a key factor in increasing the efficacy of current production and the improvement of current aquaculture protocols.

Highlights

The species Epinephelus marginatus (Lowe, 1834), popularly known as the dusky grouper, occurs in the eastern and southwestern Atlantic, the Mediterranean, the western Indian Ocean and south of the Bay of Biscay to the southern tip of Africa [1]
There was no mortality during the experiment with E. marginatus exposed to different photoperiods
The data show that juvenile E. marginatus exposed to continuous light grew better than those exposed to the natural photoperiod and to continuous darkness

Summary

Introduction

The species Epinephelus marginatus (Lowe, 1834), popularly known as the dusky grouper, occurs in the eastern and southwestern Atlantic, the Mediterranean, the western Indian Ocean and south of the Bay of Biscay to the southern tip of Africa [1]. Its geographical distribution includes the coast of South America, from Rio de Janeiro to Argentina [1]. In Brazil, the dusky grouper is caught in artisanal fisheries in the southern and southeastern states of São Paulo and Rio de Janeiro [3]. Young fish are common in lagoons near mangroves [4], can exceed one meter in length and 40 kg in weight and are considered to be an important resource in Brazil [5]

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