Many hydroelectric dams have been in place for 50 - >100 years, which for most fish species means that enough generations have passed for fragmentation induced divergence to have accumulated. However, for long-lived species such as Lake Sturgeon, Acipenser fulvescens, it should be possible to discriminate between historical population structuring and contemporary gene flow and improve the broad...

Veronaea botryosa is a melanized mold and cause of systemic fungal infections in cultured sturgeon (Acipenser spp.). Mortality in adult female sturgeon caused by this emergent pathogen results in significant economic losses for the caviar industry. Little is known regarding environmental conditions conducive to V. botryosa infection. This study evaluated the effect of temperature on V. botryosa...

The sturgeon is a primitive actinopterigian fish that, unlike modern teleosts, possess a portal vascular system that connects a true median eminence with the anterior pituitary as in mammals. The occurrence and localization of corticotropin and corticotropin releasing factor-like immunoreactivies were examined in the brain of the sturgeon (Acipenser ruthenus L.) by immunocytochemistry with anti...

Acipenser persicus is one of the economically valuable fishes in the Caspian Sea. Due to the economical and cultural importance of sturgeons in the world, understanding of sturgeon reproduction is necessary for successful management of their populations in aquaculture and nature. To improve the culture methods and to facilitate captive breeding programs to support restocking, it is necessary to...

Approximately 8 weeks after a chlorine insult associated with the city water supply, shortnose sturgeon, Acipenser brevirostrum (L.), from one group presented with small (3-4 mm) irregular foci of cutaneous pallor that involved the dorsocranial integument with progressive ulceration of the nascent lesions. Various bacterial organisms were isolated from the cutaneous lesions, but not from the in...

Twenty four farmed great sturgeon, Huso huso (including 8 males and 16 females) over 6 years old were used to develop a method for determination of sex and maturity stages. Seasonal gonadal tissue and blood samples were collected from farmed great sturgeon for three years. The sex and stages of maturity were determined by histology and laparoscopy at the beginning and end of experiment. Plasma ...

Sturgeon aquaculture is an emerging worldwide industry both for human consumption as well conservation. Several transmissible diseases limit this including mycosis by dematiaceous fungi such Veronaea botryosa . This study reports the first diagnosis of phaeohyphomycosis in a beluga sturgeon ( Huso huso ) Italy.

Rich intraspecific diversity in traits that shape responses to environmental conditions implies effects of climate change will differ within species or even populations. Nevertheless, few studies investigate how different groups respond climatic fluctuations, and most risk assessments rely upon species-wide generalizations. We studied among-year variation air temperature on the spring migratory...

The structures of the pyruvate kinases isolated from rabbit and sturgeon muscles were compared. Both enzymes are composed of subunits of 56000 mol.wt. Amino acid compositions of the two enzymes are similar, but not identical. Examination of the peptides produced by CNBr cleavage demonstrated that there are at least some highly homologous regions in the two proteins. There are only two replaceme...