The effects of stocking density, prey concentration and feeding on Rhinelepis aspera (Spix e Agassiz, 1829) (Pisces: Loricariidae) larviculture

Abstract

ABSTRACT. The aim of this study was to evaluate three stocking densities (20, 40 and 60 larvae L -1 ), and two daily prey concentrations (400 and 700 Artemia nauplii larvae -1 ) during the first seven days of active feeding (first phase). In the second phase was evaluate the effect of the different feeding regimes: fasting, dry diet (55% crude protein), Artemia sp. and mixed feeding (Artemia sp. plus dry diet), after 17 days of active feeding on Rhinelepis aspera larviculture. In the first phase, growth was affected only by prey concentration. In the second phase, the dry diet induced higher growth rates than fasting, but lower growth rates than the other treatments. The acceptance of the dry diet was evidenced by an increase in the growth rate from 4.6% day -1 in the first five days to 10.7% day -1 in the following five days of feeding. Survival was similar among dry diet, mixed feeding and Artemia nauplii treatments. R. aspera larvae can be reared during the first seven days of active feeding at a density of 60 larvae L -1 , after which they can be fed with a commercial dry diet.

Effect of prey concentrations and feed training on production of Hoplias lacerdae juvenile

“…In the present study, H. lacerdae larvae showed higher SGR during the early life followed by a tendency of decreasing rates as the animal grows, a pattern also registered with L. alexandri (Santos and Luz 2009), and R. aspera larvae fed with different prey concentrations (Santos et al 2012). However, a more drastic drop in the SGR was found after the introduction of semi-moist diet (beginning of the feed training), reflecting the period of feed transition and the reluctance of fish to accept and ingest the new source of food.…”

“…It can be expected, up to a certain point, that different prey concentrations may have an effect upon fish growth, especially in the first days of active feeding, as observed (Santos and Luz 2009), and Rhinelepis aspera (Santos et al 2012). However, in another species like P. maculatus (Luz and Zaniboni Filho 2001), and P. corruscans (Santos and Luz 2009) this effect was not detected.…”

“…During the larviculture, food quantity can affect growth (Rabe and Brown 2000, Santos and Luz 2009, Santos et al 2012, cannibalism (Luz and Zaniboni Filho 2001), and reduce mortality when the optimal level is determined (Lee and Ostrowski 2001), optimizing the food use.…”

Feed management and stocking density for larviculture of the Amazon ornamental fish L333 king tiger pleco Hypancistrus sp. (Siluriformes: Loricariidae)

“…nauplii obtain satisfactory results when given from the first feeding, promoting larval growth and development (Jomori et al., 2008; Leitão et al, 2011; Luz et al., 2011; Takata et al, 2014). This has been observed for the Amazon ornamental fish species Nannostomus beckfordi (Abe et al., 2019), Pyrrhulina brevis (Abe et al., 2016), Heros severus (Abe et al., 2018), Astronotus ocellatus (Jomori et al., 2013) and others, such as pacu Piaractus mesopotamicus (Jomori et al., 2012; Leitão et al., 2011; Portella et al., 2014), Rhinelepis aspera (Santos et al., 2012), Lophiosilurus alexandri (Santos et al., 2016), tambaqui Colossoma macropomum , matrinxã Brycon amazonicus (Barros et al, 2019) and piau Leporinus macrocephalus (Jomori et al., 2013). However, it is necessary to evaluate the capacity of fish larvae to adapt to this kind of live food, as it is not a natural food source of freshwater fish (Jomori et al., 2012).…”

“…However, it is necessary to evaluate the capacity of fish larvae to adapt to this kind of live food, as it is not a natural food source of freshwater fish (Jomori et al., 2012). Moreover, the amount of live food offered should be evaluated, since it is an important parameter of larval growth and development (Abe et al., 2019; Luz et al., 2011; Santos et al, 2012, 2015).…”