Spawning performance, serum sex steroids, and ovarian histology in wild-caught Levantine scraper, Capoeta damascina (Valenciennes, 1842) treated with various doses of sGnRHa + domperidone

Abstract

As global aquaculture continues to expand, increasing efforts are focusing on assisted reproductive technologies. This study sought to test whether salmon GnRH [D-Arg 6 , Pro 9 NEt]) analogue (sGnRHa) + domperidone injection at 0.25 mL/body weight (BW; 5-μg sGnRHa + 2.5-mg domperidone), 0.5 mL/kg BW (10-μg sGnRHa + 5-mg domperidone), or 1.0 mL/kg BW (20-μg sGnRHa + 10-mg domperidone) affects spawning performance and gamete quality in wild-caught Levantine scraper, Capoeta damascina. The ability of these treatments to elicit a response was further examined by in vivo stimulation of estradiol (E2) and 17α,20β-dihydroxy-4pregnen-3-one (DHP) and by its in vivo potency to induce oocyte maturation (OM). Females that received saline injection (control) did not spawn, whereas sGnRHa + domperidone induced ovulation and spawning across the hormonal gradient.Spawning success was highest with the 0.5 mL/kg dosage (80%) and female latency period decreased with increasing dosage. Females treated with 0.5 mL/kg had a significantly higher fecundity than those injected with 0.25 or 1.0 mL/kg. Mean oocyte diameter significantly increased in females treated with 0.5 or 1.0 mL/kg. Fertilization success, hatching rate, larvae morphology, and survival were not affected by hormonal treatment. At 12 h postinjection, E2 levels significantly declined in females treated with 0.5 or 1.0 mL/kg, whereas DHP levels significantly increased across the hormonal gradient. This steroidogenic shift is supported by histological analyses, where OM was accelerated by administration of sGnRHa + domperidone in a dose-dependent manner. In conclusion, the 0.5 mL/kg dosage of sGnRHa + domperidone is recommended for assisted reproduction of Levantine scraper.

Effects of human chorionic gonadotropin and gonadotropin releasing hormone analogue on plasma steroid hormones and spawning performances in golden rabbitfish Siganus guttatus

“…The hatching rate is percentage of number of newly hatch larvae divided by number of spawned eggs. The duration of embryogenesis was defined as the time between fertilization and hatching (Zadmajid & Butts, ; Zadmajid, Mirzaee, Hoseinpour, Vahedi, & Butts, ).…”

Outcomes of in vitro fertilization with frozen‐thawed sperm: An analysis of post‐thaw recovery of sperm, embryogenesis, offspring morphology, and skeletogenesis for a cyprinid fish

“…Straws were frozen and thawed, as above. To obtain ovulated oocytes, wild‐caught females (n = 6) were induced by Ovaprim injections at 0.50 mL/kg BW . After hormonal induction (~20‐25 hr), the genital region was thoroughly cleaned with tissue to avoid gamete contamination with faeces or urine.…”

“…To obtain ovulated oocytes, wild-caught females (n = 6) were induced by Ovaprim injections at 0.50 mL/kg BW. 37 After hormonal induction (~20-25 hr), the genital region was thoroughly cleaned with tissue to avoid gamete contamination with faeces or urine. Eggs (1.88 ± 0.06 mm in diameter) were obtained by applying slight pressure to the abdomen.…”

“…Due to overfishing, pollution, and habitat destruction, Levantine scraper populations are experiencing population declines. As such, studies are now being conducted to promote aquatic diversification/conservation, by means of artificial reproduction and captive rearing, for this societal and economically important species . Storage of germplasm using cryopreservation will be an important step for supporting these initiatives.…”

Reproductive performance of lambari ( Astyanax altiparanae ) in a seminatural system using different protocols

“…Exogenous hormones such as CPE and analogue of salmon gonadotropin‐releasing hormone (sGnRHa) have been shown to induce maturation, ovulation and spawning performance in both wild and cultured fish species (Souza et al., 2020; Vazirzadeh et al., 2011; Zadmajid, 2016; Zadmajid et al., 2018; Zohar & Mylonas, 2001). However, the efficiency of exogenous hormones for induction of spawning exhibits considerable variation between species and may be species‐specific, for either dose of hormonal treatment, administration method, or degree of sexual maturity at time of treatment (DiMaggio et al., 2014; Zadmajid & Butts, 2018; Zohar & Mylonas, 2001). For Neotropical fishes, the physiological effects of synthetic hormones used to induce spawning remain poorly understood, and they can vary according to the nature of the molecule and the species of fish (Acuña & Rangel, 2009; Carneiro & Mikos, 2008; Felizardo et al., 2012; Ittzés et al., 2014; Paulino et al., 2011; Pereira et al., 2016; Souza et al., 2018; Viveiros et al., 2013).…”