Due to early sexual maturity and its economic impor-tance sterlet has become one of the most commonlycultured sturgeon species in many countries Although basic procedures for artificial fertilization havebeen described very few empirical studies have been conductedwith respect to standardization of fertilization protocols bypre-incubation of eggs for this species.
In general, sturgeon eggs contain numerous micropy-les (reviewed in. Furthermore, eggmorphology, the structure of egg envelopes, as well asthe adhesive properties of the eggs (when in contactwith fresh water) are similar among all sturgeon species. Additionally, the ultrastructureof sperm, sperm density, and osmolality of the seminalplasma are similar amongst males. In the hatchery, sturgeon gametes arecollected into dry containers and then sperm is dilutedwith water at a 1:200 ratio, to provide the highest prob-ability of monospermic insemination. Thus, fertilization strategies and rearing techniques dur-ing artificial spawning are comparable amongst all species.As a result, standardization of the fertilization protocolfor sterlet can be useful for other hatchery-reared stur-geon.
Male fertility is predicted to increase when moresperm are incorporated into the fertilization environ-ment. However, in case of sturgeon, an excessivevolume of sperm increases the chance of polyspermy,which can impair embryonic development. Therefore, quantificationof sperm density is important for standardizing fertil-ization protocols under controlled conditions for anyspecies Unfortunately, thereis currently no data on the optimal sperm to eggratio for sterlet; limited data is available for stur-geon species, in general