BACKGROUND More fish have been afforded US Endangered Species Act protection than any other vertebrate taxonomic group, and none has been designated as recovered. Shortnose sturgeon (Acipenser brevirostrum) occupy large rivers and estuaries along the Atlantic coast of North America, and the species has been protected by the US Endangered Species Act since its enactment. METHODOLOGY/PRINCIPAL ...

Sturgeon spermatozoa maturation during their passage through the kidney is a prerequisite for initiation of motility. Samples of sterlet () testicular sperm (TS) were matured in vitro by incubation in seminal fluid (SF) or in SF supplemented with carbonyl cyanide -chlorophenyl hydrazone (CCCP; a respiration uncoupling agent). Sperm was diluted in activation medium (AM) containing 10 m Tris-HCl ...

The elucidation of the cDNA sequence for sturgeon proorphanin provides a unique window for interpreting the evolutionary history of the opioid/orphanin gene family. The molecular "fossil" status of this precursor can be seen in several ancestral sequence characteristics that point to its origin as a duplication of either a prodynorphin- or proenkephalin-like gene. The sturgeon proorphanin cDNA ...

Otoliths, calcium carbonate (CaCO3) ear bones, are among the most commonly used age and growth structures of fishes. Most fish otoliths are comprised of the most dense CaCO3 polymorph, aragonite. Sturgeon otoliths, in contrast, have been characterized as the rare and structurally enigmatic polymorph, vaterite-a metastable polymorph of CaCO3. Vaterite is an important material ranging from biomed...

the late sexual maturity in sturgeon and the absence of morphological differences between males and females makes sex discrimination difficult. identification of sex at an early life stage is of high interest in caviar production because it allows efficient selection of females. in this study, the genome of 10 mature male and 10 mature female specimens of persian sturgeon (acipenser persicus...

Scott Sturgeon has recently challenged Pollock’s account of undercutting defeaters. The challenge involves three primary contentions: (1) the account is both too strong and too weak, (2) undercutting defeaters exercise their power to defeat only in conjunction with higher-order beliefs about the basis of the lower-order beliefs whose justification they target, and (3) since rebutting defeaters ...

Newly hatched white sturgeon (Acipenser transmontanus) yolk-sac larvae are negatively phototactic, photokinetic and geotactic--seeking cover in the substrate during daylight hours. If cover is unavailable and the light intensity is low, they move into the water column and alternate periods of rapid, upward swimming with periods of quiescence during which they sink. In the dark they swim almost ...

lactic acid bacteria are characterized as gram-positive, usually non-motile, non-sporulating bacteria that produce lactic acid as a major or sole product of their fermentative metabolism. in this study, the presence of lactobacilli were investigated in the intestines of beluga ( huso huso) and persian sturgeon ( acipenser persicus ), inhabiting caspian sea. the obtained data showed that various...

In the present study, we examined the insulin-like growth factor receptor 1(IGF-1R) transcription using real-time PCR at different stages of oocytes of Russian sturgeon (Acipenser gueldenstaedtii) at age 8-9 years and weight 25 kg that were grown under aquaculture conditions. Compare to the pre-vitellogenesis stage, the transcription of IGF-1R increased at the vitellogenesis stages (yellow, gra...

world production of caviar from the farmed sturgeon has recently so increased that in addition to compensate reduction of natural resources of sturgeon, it has also increased its share in the world market for caviar and its substitutes. although belarus, china and norway are currently considered as the main exporting countries of caviar and its substitutes but, iran solely exports caviar from s...