Influence of interspecific hybridization on fitness-related traits in Siberian sturgeon and Russian sturgeon

Abstract

Polyploidy in sturgeons makes them highly susceptible to interspecific hybridization, and these interspecific hybrids have been described in nature as well as in captivity. Nevertheless, the fitness-related traits between sturgeon hybrids and pure species have been poorly compared as yet. In the present study, we compared the reproductive parameters such as fertilization rate and hatching rate, growth traits and genetic polymorphism in the artificially produced hybrids of the Siberian sturgeon (Acipenser baerii) and Russian sturgeon (A. gueldenstaedtii) with their purebreds. Fertilization and hatching rates were found to be significantly higher in Siberian sturgeon (♀) × Russian sturgeon (♂) hybrid group compared to purebreds. The highest cumulative survival rate was determined in purebred groups until 151 days post-hatch (dph); however, this trend changed and Russian sturgeon purebred showed the lowest cumulative survival rate (0.21%) by 913 dph. Similarly, the lowest average body weight was recorded in Russian sturgeon purebred group (264 g). In contrast, the highest average body weight was recorded in Russian sturgeon (♀) × Siberian sturgeon (♂) hybrids (435.3 g) and the highest cumulative survival rate was recorded in Siberian sturgeon (♀) × Russian sturgeon (♂) hybrids (12.32%) by 913 dph. No significant differences were found at heterozygosity levels among studied crosses. Our results showed that studied sturgeon hybrids had higher survival and growth if compared with the purebreds under provided hatchery conditions.

Ploidy Levels and Fitness-Related Traits in Purebreds and Hybrids Originating from Sterlet (Acipenser ruthenus) and Unusual Ploidy Levels of Siberian Sturgeon (A. baerii)

“…The observed heterosis levels in the F1 generation hybrids changed depending on the trait or the time period considered in the present study. However, these levels were quite comparable with other studies dealing with heterosis in sturgeons [ 29 , 30 ]. The perspectives on the influence of hybridization on evolution have changed from time to time.…”

“…Overall, it implies the common speculation of sterility of the hybrid sturgeon with abnormal ploidy can be fallacious and more importantly, the ploidy status and fitness characteristics of the produced F1 generation can be seriously questionable. While the importance of hybridization in the sturgeon breeding has been substantially studied [ 18 , 28 , 29 , 30 ], extensive research has not been conducted yet on the influence of polyploidy in cultured sturgeon. Today, sturgeon farming is a rapidly growing branch of aquaculture for the production of black caviar and boneless meat [ 31 ].…”

Intraspecific Hybrids Versus Purebred: A Study of Hatchery-Reared Populations of Sterlet Acipenser ruthenus

“…Our results are also in agreement with the results of studies exploring sturgeon hybridization to increase the growth rate and improve productivity through hybrid vigor [21,41,[48][49][50]. We found a dramatic effect of hybridization on cumulative survival, both negative and positive.…”

“…Our analysis showed the intraspecific hybrids to perform better than the purebreds, similar to our previous results on interspecific sturgeon hybrids [41]. There were significant differences in the mean BW and cumulative survival of the reciprocal hybrids in this study.…”

“…Hybridization is commonly used in aquaculture to increase fitness, manifested as an improvement in relevant physiological traits compared to the parent species [40,41]. The reproductive characteristics of many interspecific sturgeon hybrids have been widely studied [41][42][43], but similar aspects of intraspecific hybrids are not well-documented. However, in aquaculture reproductive factors may be of secondary concern, with growth being the primary interest [40].…”