The effects of salinity on reproductive performance and plasma levels of sex steroids in Caspian kutumRutilus frisii kutum

Abstract

Sexually mature kutum, Rutilus frisii kutum, captured from its natural habits, the Caspian Sea and the Khoushkrood River, reared at 0.5 g L−1 and 8–13 g L−1 for approximately 1 year in experimental condition, for assessing the effect of salinity on reproduction. Plasma concentrations of sex steroid hormones (17β‐estradiol, testosterone and 17α‐hydroxyprogestrone) were measured in the three stages of gametogenesis. Female kutum held at <0.5 g L−1 or 8–13 g L−1 had no ovulated oocytes in their ovaries. In contrast, males held in captivity were spermiated, similar to their wild counterparts. The average sperm volume of males held at <0.5 g L−1 (2.36 ± 0.46 mL) was lower than males held at 8–13 g L−1 (3.65 ± 0.73 mL) at the end of the experimental period. The highest concentration of testosterone was observed in mid‐gametogenesis in wild fish that was significantly higher than the concentration seen in fish held in either <0.5 g L−1 or 8–13 g L−1. Female kutum showed suppressed steroid hormones in captivity, resulting in failure in the gonad development. However, male kutum adapt well to captivity and showed synchrony in steroid hormone variations with the wild fish, resulting in the testicular development. Results of this study also indicate that salinity plays a minor, but vital, role in reproduction of kutum, a factor that needs to be considered for keeping broodstock of brackish water fish species like kutum.

A Deep Insight of Spermatogenesis and Hormone Levels of Aqua-Cultured Turbot (Scophthalmus maximus)

“…In the present study, the contents of T and 11-KT in serum both increased, while only T prominently changed during the mature stages [IV(2200 g) -V(2500 g)], which was highly consistent with the situation at the stages of spermiogenesis, indicating that T might be crucial during the mature period of turbot. Similar profiles were also found in halibut (Hippoglossus hippoglossus), kutum roach (Rutilus frisiikutum), gilthead seabream and walleye (Stizostedion Vitreum) (Malison et al, 1994;Weltzien et al, 2002;Bani et al, 2015;Boj et al, 2015). For halibut, both T and 11-KT contents increased at the stages of haploid germ cells, including spermatozoa (Stage III and IV) (Weltzien et al, 2002), which corresponded to the stages of IV(2200 g) and V(2500 g) in our study.…”

Fish sperm motility assessment as a tool for aquaculture research: a historical approach

“…; Bani et al . ). Although the effect of salinity has been mainly studied regarding the sperm activation process, there are only a few reports about the effect of rearing salinity on breeders and the quality of gametes that they produce.…”

Transcriptional Changes in the Ovaries of Perch from Chernobyl

“…The prgr gene encode the progesterone receptor protein previously found involved in oocyte maturation in the fish, Nile tilapia (Oreochromis niloticus) . A depletion of progesterone (and subsequent receptor activity) resulted in failure of gonad development in female fish kutum (Rutilus frisii kutum) . Therefore, these results suggest a potential role played by vegfc and prgr genes in the inhibition of gonad development of perch.…”

“…47 A depletion of progesterone (and subsequent receptor activity) resulted in failure of gonad development in female fish kutum (Rutilus frisii kutum). 48 Therefore, these results suggest a potential role played by vegfc and prgr genes in the inhibition of gonad development of perch. Finally, some genes involved in cytoskeletal changes such as k1C18 were found downregulated in the undeveloped phenotypes, which is consistent with the upregulation described in mature oocytes (vitellogenic) as compared to previtellogenic oocytes in the Senegalese.…”