Salinity and prey concentration on larviculture of killifish Hypsolebias radiseriatus (Cyprinodontiformes: Rivulidae)

Abstract

The aim of this study was to investigate the tolerance of Hypsolebias radiseriatus larvae to different salinities, and the effects of different prey concentrations and water salinities on the larviculture of this species. Salinity tolerance was tested by subjecting newly-hatched larvae to 96 hours of osmotic shock testing (experiment I) and gradual acclimatization (experiment II) of the following salinities: freshwater (control), 2, 4, 6 and 8 g of salt L-1. A third experiment (experiment III) evaluated three water salinities (S0 - freshwater, S2 - 2 g of salt L-1 and S4 – 4 g of salt L-1) and three initial daily prey concentrations (100, 300 and 500 artemia nauplii larva-1). In experiments I and II, survival was only influenced by the salinity of 8 g of salt L-1 (p < 0.01). After 35 days, weight was only influenced by prey concentration (p < 0.05), with the highest value being with 500 artemia nauplii larva-1. The lowest survival was for 4 g of salt L-1 and for 100 artemia nauplii larva-1. H. radiseriatus larviculture can be carried out in salinity of up to 2 g of salt L-1 and initial daily prey concentrations with 500 artemia nauplii larva-1.

Salinized water as a strategy for increase stocking density in Heros severus larviculture, an Amazonian ornamental fish

“…The H. severus larvae presented a WU and SR reduction when the salinized water increased from 3 to 6 g L -1 . Similarly, were registered for the larviculture of Pseudoplatystoma corruscans (Santos and Luz, 2009), C. macropomum, Brycon amazonicus, A. ocellatus (Jomori et al, 2013), Oreochromis niloticus (Luz et al, 2013), Pyrrhulina brevis (Abe et al, 2015), B. splendens (Dias et al, 2016) and H. radiseriatus (Araújo et al, 2021), when 5/8…”

“…The use of salinized water also provided better weight gain results in larviculture of other freshwater fish species that was fed with Artemia nauplii as live food. Such as Astronotus ocellatus (Jomori et al, 2013), Betta splendens (Dias et al, 2016), Lophiosilurus alexandri (Nascimento et al, 2020) and Hypsolebias radiseriatus (Araújo et al, 2021) kept in salinized water between 0 and 2 g L -1 ; and Piaractus mesopotamicus (Jomori et al, 2012), Colossoma macropomum, Leporinus macrocephalus (Jomori et al, 2013), B. splendens (Fabregat et al, 2017) and Arapaima gigas (Silva et al, 2019) kept in salinized water between 2 and 4 g L -1 .…”

“…Artemia is a marine microcrustacean naturally found in saline environments and when submitted to freshwater does not survive for long time (Jomori et al, 2012;Silva et al, 2019). This leads to reduce its availability during the feeding of freshwater fish larvae, impairing feed efficiency, larval development and water quality (Santos et al, 2015;Araújo et al, 2021). In this context, the larviculture in salinized water may have helped to increase the Artemia nauplii survival, extending the life time of the nauplii and making the live food available and attractive for longer.…”

“…The used of salinized water in larviculture of freshwater fish is considered a good strategy to improve larval growth and survival (Jomori et al, 2013;Araújo et al, 2021). The used of salinized water benefits the Artemia nauplii, once it makes possible the microcrustacean to remain alive longer than in freshwater and thus, improving its availability and attractiveness to the larvae (Silva et al, 2019).…”

Effect of feeding frequency and water salinization on early development of Pyrrhulina brevis, an Amazonian ornamental fish

“…Similarly, other studies that tested the effect of water salinization on post-larvae of P. brevis obtained best production parameters at 1 g L -1 (Oliveira et al 2020) and at 2 g L -1 (Abe et al 2015), although the latter did not test concentrations lower than 2 g L -1 and neither of the two studies related the salinized water with the feeding frequency of the fish. The use of salinized water at concentrations higher than 2 g L -1 also resulted in negative effects on growth and survival of post-larvae of Colossoma macropomum (Cuvier, 1816), Brycon amazonicus (Spix and Agassiz, 1829), Astronotus ocellatus (Agassiz, 1831) (Jamori et al 2013), Hypsolebias radiseriatus Costa, 2012 (Araújo et al 2021), Oreochromis niloticus (Linnaeus, 1758) (Luz et al 2013) and Brycon vonoi Lima, 2017(Coraspe-Amaral et al 2017. Therefore, our results confirm that freshwater fish species perform better when raised in slightly higher salinity levels compared to their natural conditions (Boeuf and Payan 2001), but generally lower than 2 g L -1 .…”