Abstract:
The red spotted grouper Epinephelus akaara is a marine species of economic importance and also at risk of extinction. This study investigated the effects of high water temperature on the growth and maturation of juvenile E. akaara females. From 160-420 days post-hatching (dph), the fish were maintained under natural water temperature (NT) and a constant high-water temperature (HT). From 240 dph, both the total length and body weight in the HT group were greater than in NT group. After 360 dph, the gonadosomatic index was also increased in the HT group compared to NT group. Mature oocytes were only observed in the HT group at 330, 360, and 390 dph. Both kiss1 and kiss2 levels increased at 240 and 270 dph in both groups; however, they were greater in the HT group at 240 dph. Similarly, gpr54 levels after 360 dph were greater in the HT group, suggesting that kisspeptin is related to maturation via its receptor gpr54. Levels of fshβ and lhβ were greater in the HT group after 360 dph. Estradiol-17β (E2) levels after 160 dph (except 300 dph) were greater in the HT group than in the NT group, suggesting that the higher E2 levels trigger maturation, and is related to increased fshβ and lhβ. This study provides evidence that high water temperature is effective in accelerating growth and triggering early maturation of juvenile E. akaara, via regulating gpr54, fshβ, lhβ, and E2 levels.
摘要:
红色斑点石斑鱼Epinephelusakaara是具有经济重要性的海洋物种,也有灭绝的危险。本研究调查了高水温对幼年阿卡拉雌性生长和成熟的影响。孵化后160-420天(dph),鱼保持在自然水温(NT)和恒定的高水温(HT)下。从240dph,HT组的总长度和体重均大于NT组。360dph之后,与NT组相比,HT组的性腺指数也增加。仅在330、360和390dph的HT组中观察到成熟卵母细胞。两组的kiss1和kiss2水平均增加到240和270dph;然而,在240dph的HT组中,它们更大。同样,360dph后的gpr54水平在HT组中更高,表明kisspeptin通过其受体gpr54与成熟有关。360dph后,HT组的fshβ和lhβ水平更高。160dph(300dph除外)后,HT组的雌二醇-17β(E2)水平高于NT组,表明较高的E2水平会触发成熟,与fshβ和lhβ增加有关。这项研究提供了证据,表明高水温可有效地加速幼年E.akaara的生长并触发其早期成熟。通过调节gpr54,fshβ,lhβ,E2水平。