Acta Scientiarum: Biological Sciences (Oct 2006)
Crescimento do niquim (Lophiosilurus alexandri Steindachner 1876), em diferentes condições de luminosidade e tipos de alimento = Niquim (Lophiosilurus alexandri Steindachner 1876) growth, in different luminosity conditions and types of food
Abstract
O niquim Lophiosilurus alexandri é um peixe endêmico do rio São Francisco e foi prejudicado após o represamento das águas, sendo uns dos peixes mais valorizados na região do Submédio e apresentando potencial para a piscicultura. O trabalho teve por objetivo avaliaro seu crescimento durante as fases ontogênicas iniciais, em diferentes condições de luminosidade e tipos de alimento, fornecendo subsídios técnicos à piscicultura e aos programas de propagação da espécie. O experimento foi realizado em incubadoras com luminosidades de 100% (L), 50% (ML) e 0% (SL) com quatro repetições e dois critériosalimentares: plâncton+ração e Dendrocephalus brasiliensis+ração. A Análise de Variância (Anova) foi realizada para verificar o efeito de diferentes condições de luz e de alimento sobre o comprimento dos niquins. O teste de Tukey (PNiquim Lophiosilurus alexandri is an endemic fish from the San Francisco River and was harmed after the damming up of the waters, being one of the most valuable fish in the Sub-medium region and presenting potential for pisciculture. This study aimed to evaluate its growth during the initial ontogenic phases, under different luminosity conditions and types of food, supplying technical subsidies to the pisciculture and to the species propagation programs. The experiment was conducted in incubators with luminosity at 100% (L), 50% (ML) and 0% (SL) with four repetitions and two alimentary criteria: plankton+ration and Dendrocephalus braziliensis+ration. The variance analysis (ANOVA) was carried out to verify the effect of different light conditions and food on the Niquins' length. The Tukey test (P<0.05) was used to verify the differences between the treatment's averages. There was a significantdifference for the light treatment (ANOVA LUZ: P=0.0030) and the Tukey test indicated the smaller average measurement for the L treatment. The greatest average of the last biometric taken was 74.70±5.95 mm much superior to 25 mm taken for the one that didnot obey the luminosity criterion. The conclusions pointed that by using carnivore's ration, the growth of Niquim was influenced only by luminosity.
