Wild Leporinus friderici induced spawning with different dose of mGnRHa and metoclopramide or carp pituitary extract

Abstract

How to cite: Souza TG, Kuradomi RY, Rodrigues SM, Batlouni SR. Wild Leporinus friderici induced spawning with different dose of mGnRHa and metoclopramide or carp pituitary extract. Anim Reprod. 2020;17(1):e20190078. AbstractBreeding technology is of utmost importance for reproduction of wild fish in captivity for the reintroduction and selective breeding programs purposes. The main challenge is that when applied to wild undomesticated specimens, conventional protocols often cause breeders and/or embryo mortality and spawning failure. In this study, we evaluated the reproductive performance of wild Leporinus friderici, a great importance fish for subsistence fishing in South American rivers, applying conventional and lower-dose hormonal therapies by means of two consecutive experiments. In the first, a conventional (0.5 and 5.5 mg/kg) and a lower carp pituitary extract (CPE) dose (0.5 and 1.0 mg/kg) were applied. In the second, a conventional mammalian GnRH analogue associated with metoclopramide (mGnRHa + MET) (40 µg mGnRHa + 20 mg MET/kg) and a lower dose (4 μg mGnRHa + 2 mg MET/kg and 8 µg + 4 mg of mGnRHa + MET/kg) were applied. Ovulation was observed in all treatments, however, only lower CPE protocol provided viable embryos. High levels of 17α,20β-dihydroxy-4-pregnen-3-one (DHP) and 17β estradiol (E 2 ) detected in conventional, but not in lower CPE dose, at ovulation, might be associated to the mortality of the embryos. The use of lower CPE dose applied here was the best way to obtain L. friderici viable embryos. These results directly contribute to the knowledge about poorly explored effects of reproductive management and hormonal therapies in wild-type breeders, showing that the use of reduced doses may be an alternative to reproductive success.

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

“…Moreover, the intermediate reproductive performance obtained using 1,000 μg sGnRHa/kg highlights that future approaches testing dopamine inhibitors together with sGnRHa may change the current scenario. Even unusual and much higher than that the doses used for hormonal induction for neotropical (Acuña & Rangel, 2009; Pereira et al., 2016, 2018; Souza et al., 2018, 2020; Viveiros et al., 2013), cyprinids (Podhorec et al., 2016; Podhorec, Socha, Sokolowska‐Mikolajczyk, Policar, Svinger, Drozd, et al., 2012; Podhorec, Socha, Sokolowska‐Mikolajczyk, Policar, Svinger, Gosiewski, et al., 2012) and salmonids fishes (Arabaci et al., 2004), the 1,000 μg sGnRHa/kg treatment resulted in fertility and hatching rates above 90%, indicating that the use of this synthetic treatment is not a problem for this species in this concern.…”

“…Concerning possible reasons for ovulation failures, we observed that only the unspawned females of the fractioned CPE group (and all individuals) retained GVBD oocytes (meiosis resumption) in the ovaries, while all unspawned females from other groups retained only oocytes with intact germinal vesicles. This specific type of failure, which causes GVBD but not ovulation, was in deep studied using fractioned CPE doses in common carp (Jalabert et al., 1977) and in some tropical reophilic species, such as matrinxã ( Brycon amazonicus ) (Hainfellner et al., 2012), piau ( Leporinus friderici ) (Souza et al., 2020), piapara ( Leporinus elongatus ) (Pereira et al., 2018) and piaçu, ( Leporinus macrocephalus ) (Pereira et al., 2016). All of these descriptions mentioned unovulated GVBD oocytes retained in the ovaries, but it is still unknown the reasons for such partial failure.…”

“…In that regard, some studies showed a negative effect of synthetic hormones on the production of viable embryos in neotropical species at doses much lower than the doses used in the present study. A dose of 8 µg of mGnRHa/kg in Leporinus macrocephalus (Pereira et al., 2016) and doses of 40 µg of mGnRHa/kg and 12 µg of mGnRHa/kg for Leporinus friderici (Souza et al., 2020) resulted in embryos death, and a dose of 10 µg of sGnRHa/kg in Colossoma macropomum resulted in low fertility and hatching rates (Acuña & Rangel, 2009). Moreover, for South American reophilic tropical species, the action of dopamine inhibitors remains misunderstood due to the controversial results found in the literature.…”

“…(2017). After this identification, an analysis of the volume density of the ovaries of a spawned female and a unspawned female per replicate from all treatments and four females before hormonal induction using a light microscope and a grid of 352 points of intersection (Criscuolo‐Urbinati et al., 2012; Pereira et al., 2016; Souza et al., 2020). The grid was applied and counted in three fields in the middle region of the ovary for a total of 1,056 points for each female using a 5× objective.…”

“…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).…”