Draining system and feeding rate during the initial development ofLophiosilurus alexandri(Steindachner, 1877),a carnivorous freshwater fish

Abstract

This study evaluated the efficiency of the drainage system during the larviculture of Lophiosilurus alexandri. Moreover, we assessed the best feeding rate after feed training for juvenile production. The study was performed in three phases over 87 days. In phase 1 (40 days), larvae were fed live food and posteriorly submitted to feed training in two drainage systems: water drained on the surface (DS), and water drained into a tank column (DI). In the second phase (30 days), using only the DS system juveniles were fed a formulated diet at feeding rates, 2, 4, 6 and 8% of body wet weight. In the third phase (17 days), the fish from the second phase were fed until apparent satiation. At the first phase, the animals in the DS system exhibited greater survival rates and growth. The best feeding rate for daily weight gain, specific growth rate (SGR) and mean body weights were similar: 5.57, 5.13 and 5.68% respectively. In the third phase, an increased SGR was observed in the treatment groups that received lower feeding rates in the second phase (2 and 4%), which could indicate a possible compensatory growth rate.

The effect of environmental colour on the growth, metabolism, physiology and skin pigmentation of the carnivorous freshwater catfish Lophiosilurus alexandri

“…The pacamã Lophiosilurus alexandri Steindachner 1876 is a Siluriformes much appreciated for its meat. The breeding and raising of its larvae can be successfully carried out under laboratory conditions (Luz & Santos, ; Guimarães‐Cruz et al , ; Santos & Luz, ; Santos et al , ; Melillo Filho et al , ; Costa et al , ). Pedreira et al (), however, stated the use of green tanks can compromise the use of live food during larval rearing of this species, but to date, the effects of how the environmental colour can influence the performance and well‐being of juveniles is unknown.…”

Effects of temperature on growth, survival and physiological parameters in juveniles ofLophiosilurus alexandri,a carnivorous neotropical catfish

“…Lophiosilurus alexandri belongs to the order Siluriformes and has already been listed as endangered (Lins, Machado, Costa & Herrmann ). Consequently, a series of studies has been developed to improve our knowledge base about the reproduction and larviculture of this species (Cardoso, Chiarini‐Garcia, Ferreira & Poli ; López & Sampaio ; Barros, Guimarães‐Cruz, Veloso‐Júnior & Santos ; Luz & Santos ; Pedreira, Luz, Santos, Sampaio & Silva ; Santos & Luz ; Luz, Santos, Pedreira & Teixeira ; Melillo Filho, Takata, Santos, Silva, Ikeda, Rodrigues, Santos, Salaro & Luz ). However, no information exists about the effect of temperature on the growth, survival, nutrient utilization and metabolic parameters in the blood of L. alexandri juveniles.…”

Toxicidade aguda ao sal comum e larvicultura intensiva do jundiá Rhamdia quelen em água salobra

“…Para o bocudo (Steindachneridion scripta), foram utilizadas menores concentrações de presas, 100 náuplios/larva (Adamante et al, 2007), assim como para o suruvi (Steindachneridion scriptum) (Schütz et al, 2008). Outras espécies podem necessitar de concentrações ainda mais altas, como o pacamã, cuja recomendação inicial é em torno de 1000 náuplios/larva (Melillo-Filho et al, 2014 Médias seguidas da mesma letra (maiúscula na horizontal em cada subquadro e minúscula na vertical) não diferem entre si pelo teste de Tukey (P>0,05).…”

“…A larvicultura de peixes neotropicais é um assunto que está em pauta no cenário científico internacional (Jomori et al, 2012;Melillo-Filho et al, 2014;Portella et al, 2014). As larvas das espécies reofílicas de interesse comercial são altriciais, que possuem reserva vitelínica reduzida e cujo trato digestório não está totalmente desenvolvido no início da alimentação exógena (revisado por Portella et al, 2014).…”