• Fisheries and Aquatic Sciences
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• v.16 no.1
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• pp.25-34
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• 2013

Early ontogenic development in Siberian sturgeon Acipenser baerii was documented and the effects of different temperatures on embryonic and prelarval development were examined. Photograph-assisted data on morphogenesis in Siberian sturgeon prolarvae agreed well with published descriptions of their ontogeny and ecological behaviors, although certain aspects of differentiation, such as gill covering and scute development, could be rearing condition-sensitive. The present study provides the first characterization of the transient development of teeth during early larval stages; the pattern was congruent with the transition of prolarvae to exogenous feeding. From examinations of embryonic and prelarval development under different temperature conditions ($12-24^{\circ}C$), developmental speed was inversely related with temperature. Overall, hatchability was higher and hatching events were more synchronized at $20^{\circ}C$ than at lower temperatures. After hatching, similar patterns of temperature-dependency were observed in yolk sac absorption and the evacuation of the pigment plug. Our results suggest that the incubation of Siberian sturgeon embryos and prolarvae at temperatures close to $20^{\circ}C$ would be advantageous in hatcheries, based on reductions in the duration and uniformity of egg and prolarval developmental stages.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.3
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• pp.274-282
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• 2019

Female Siberian sturgeon Acipenser baerii were crossed with male Russian sturgeon A. gueldenstaedtii and the development, ontogenetic behavior, and phototactic characteristics of the resultant hybrid prolarvae were examined. The fertilization rate of the hybrid group was similar to that of Siberian sturgeon (the maternal species), and the overall developmental characteristics of hybrid embryos were not significantly different from those of either parental species. The time window from first hatch to the completion of hatching was wider in Russian sturgeon than in Siberian and hybrid sturgeon groups. The prolarval viability of the hybrid group was similar to that of the maternal species, and significantly higher than that of the paternal species. Hybrid prolarvae displayed ontogenetic behavioral patterns that were quite similar to those of Siberian sturgeon. In an illumination preference test, hybrid prolarvae displayed significant positive phototaxis, similar to the maternal species, and clearly distinct from the negative phototactic character of the paternal species. Taken together, our data indicate that the prolarval traits of hybrid sturgeon from this cross more closely resemble those of the maternal than the paternal species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.1
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• pp.41-52
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• 2024

Serotransferrin cDNA from the Siberian sturgeon Acipenser baerii was isolated and its expression patterns during early life intervals were characterized. It contained an ORF encoding a 708-aa-long polypeptide, including a 19-aa signal peptide. Bioinfomatic analysis and 3D modeling indicated a typical bi-lobal structure with conserved iron-coordinating residues. During embryonic development, the potential transition of maternally provisioned transcripts to zygotically de novo transcribed ones occurred around blastula stage. The transferrin mRNA levels peaked at stages responsible for pronephros, heart and erythropoietic component differentiation. After hatching, the transferrin mRNA expression gradually increased at early ontogenic phases (0 to 3 DPH) corresponding to the periods in which prolarvae exhibited increased blood circulation and liver differentiation. The expression decreased at subsequent stages in which prolarvae exhibited benthic movement. The tissue distribution assay indicated liver-predominant expression at fingerling stage. From the microinjection-based challenge with Aeromonas hydrophila at day-0 and day-7, the transcriptional response was modulated toward upregulation, in which the amounts induced at 6, 12 and 24 HPI were greater in prolarvae injected at day-7 than at day-0. Therefore, transferrin plays important roles in both early development and host protective responses to pathogens in the Siberian sturgeon.