Milt
production and sperm quality in European eel (Anguilla anguilla) in relation to hormonal treatment
P. Koumpiadis, D.E. Sganga, S.N. Politis, V. Gallego,
I.A.E. Butts, J.F. Asturiano, I.E. Batjakas, J. Tomkiewicz
Abstract
Aquaculture production relies on controlled management
of gametogenesis, especially in species where assisted reproduction is needed for
obtaining high-quality gametes in captivity. The present study used hormonal
treatments to induce and sustain spermatogenesis in European eel (Anguilla anguilla), focusing on the
effect of strip-spawning timing (12 vs.
24 h) after weekly administration of human chorionic gonadotropin and the
necessity of a primer injection (in addition to weekly hormonal treatment),
prior to strip-spawning (primer vs.
no-primer). Sperm quality parameters included sperm density, assessed by
hemocytometer counting and spermatocrit, as well as sperm kinematic (motility
and velocity) parameters at three time points after onset of hormonal treatment
(Weeks 9, 11, and 13). All males responded to hormonal treatment and
spermiation was observed by Week 5. During the experimental timeline from Weeks 9 to 13, milt production and sperm kinetic parameters increased, while sperm density decreased.
Variability in sperm kinetic traits was observed depending on strip-spawning
timing (12 or 24 h) after hormone injection and the primer treatment did not
show a significant effect on sperm quality. Moreover, spermatocrit values and
hemocytometer counts were highly correlated. Overall, the hormonal treatment
and stripping at two-week intervals provided suited milt production and
high-quality sperm. Considering that each male may be stripped 4-5 times over the
2-3 months spawning season, handling and hormone administration can possibly be
reduced by eliminating the primer.
Reproduction in Domestoc Animals 56(12): 1497-1505 (2021)
Disponible en: http://doi.org/10.1111/rda.14011
