Effects of salinity on sexual maturity and reproduction of Poecilia velifera

Abstract

Poecilia velifera is a popular fish in freshwater aquarism that naturally inhabits aquatic habitats with a wide range of salinities. Nonetheless, the effects of different salinities on the reproductive success and sex ratio of the species remain unknown. Male sex characters, sex ratio and reproductive success of P. velifera were evaluated by maintaining 160 juveniles (0.078 ± 0.011 g) in four different salinities (0; 12; 24; 36 g/L), with four replicates. The only modification observed in males was the formation of a copulatory organ from the anal fin, which was used to distinguish them from females. Timing of the formation of the male copulatory organ, and the weight and total length of males when it occurred, were recorded. Twenty‐eight fish from each treatment were euthanized after 150 day to examine the gonads and confirm sex. Eight females and four males from each treatment were then kept in their respective salinity treatments for 65 days to examine the effects of salinity on reproduction. Males were kept with females in the different treatments for 15 days, at which point they were removed. Salinity was negatively correlated with male weight and length. Salinity also affected the sex ratio, with the percentages of males and females being 32.5 and 67.5%, and 27.5 and 72.5% in the salinities of 24 and 36 g of salt/L, respectively. Fifty percent of the females kept in freshwater reproduced, while there was no reproduction in the other treatments. The maintenance of P. velifera in freshwater promoted greater reproductive success and precocity, as well as larger males.

Phenotypic plasticity in the sailfin molly III: Geographic variation in reaction norms of growth and maturation to temperature and salinity

“…There are differences among geographically separated groups of populations within P. latipinna and differences between P. latipinna and its close relatives. For example, whereas lower salinity induced slower growth in NF P. latipinna , lower salinity induced more rapid growth in P. velifera (Neves et al., 2019) and in the all‐female Amazon molly, P. formosa , which shares half its genome with P. latipinna (Makowicz & Travis, 2020). Females from SC matured at younger ages at the warmer temperature regardless of salinity, whereas, in P. formosa , females matured at younger ages at the warmer temperature only in moderate and high salinity, not at low salinity.…”

The fish community in Gulf of Mexico mangroves, a response to hydrological restoration

“…After two years, the sites under restoration showed an increase in the abundance of resident species, G. yucatana and P. velifera. Although both are freshwater species, they can tolerate euryhaline conditions (30-40 ups) due to their broad osmoregulatory capacity (Carter 1981, Neves et al 2019. These species typically constitute the resident fish in estuarine systems (Arceo-Carranza & Vega-Cendejas 2009) and petenes (Torres-Castro et al 2009).…”

“…However, the response of the ichthyofauna to the restoration process is varied, and it depends on the species analyzed (Vose & Bell 1994, Trexler & Gross 2009. In this work, we expected that the response of resident species is reliable because these livebearers have similar tolerances, osmoregulatory capacities (Carter 1981, Neves et al 2019, feeding strategies, and life cycles (Miller 2009). We detected changes in fish composition and abundance related to hydrological reconnection with the Terminos Lagoon in the short term.…”

Toxicity, physiological, histopathological, handling, growth and antiparasitic effects of the sodium chloride (salt) in the freshwater fish aquaculture

“…NaCl has been used in fish aquaculture for various purposes, including treatment of fungus in fish and eggs (El‐Gawad et al, 2016; Khodabandeh & Abtah, 2006; Singhal et al, 1986; Weirich & Tiersch, 1997), bacteria (Akinola & Olakunbi, 2019; Fathollahi et al, 2020), proliferative kidney disease in fish caused by the myxozoan Tetracapsuloides bryosalmonae (Enevova et al, 2018), fertilization, reproduction and early developmental stages of fish (Mahrosh et al, 2014; Neves et al, 2019), and in combination with anaesthetics (Davis et al, 1982) because it reduces stress and facilitates osmoregulation (Burgdorf‐Moisuk et al, 2011). NaCl has also been used for several other purposes in fish aquaculture.…”