Crescimento do niquim ( Lophiosilurus alexandri Steindachner 1876), em diferentes condições de luminosidade e tipos de alimento

Abstract

Niquim 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 significant difference 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 did not obey the luminosity criterion. The conclusions pointed that by using carnivore's ration, the growth of Niquim was influenced only by luminosity.