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 ...

  The salinity tolerance, hematological and hydromineral regulation capabilities of juvenile Russian sturgeon (Acipenser gueldenstaedtii) were investigated in different ages and sizes in freshwater (FW: <0.5‰), estuary water (EW: 9.5‰) and Caspian Sea water (CSW: 12.5‰). The fish were directly transferred from FW to EW and CSW. The possible repercussions of ion-osmoregulatory processes on some ...

Hypophysectomy was performed on sexually mature sterlets, Acipenser ruthenus L., in summer and autumn. The operation usually lasted about 45 sec, but never longer than 90 sec. After the parasphenoid was stripped, an ellipsoid hole was trepanated at the level of the eyes. The hypophysis was ablated by catching its rostral end with a pincer. As the result of the extirpation of the hypophysis the ...

The specific stimulatory effect of sturgeon Acipenser güldenstädti Br. gonadotropic hormone (GTH) on frog Rana temporaria L. oocyte maturation in vitro was investigated in relation to humic acid (HA) concentrations from 12.5 to 50 mg/l. HA was observed to bind to both the follicular membrane of the oocytes and the GTH molecule, reducing the oocytes' hormone sensitivity and maturation ability. I...

Acipenser fulvescens, the lake sturgeon, belongs to one of the few extant non-teleost ray-finned (bony) fishes. The sturgeons (family Acipenseridae) have a phylogenetic history that dates back about 250 million years. The study reported here is the first investigation of peripheral coding strategies for spectral analysis in the auditory system in a non-teleost bony fish. We used a shaker system...

Standardization of fertilization protocols for sterlet Acipenser ruthenus is crucial for improving reproductive techniques and for conservation purposes. Our objectives were to determine the number of sperm (tested 430,000:1, 43,000:1, 4300:1, 430:1 sperm to egg) required to fertilize eggs and explore how pre-incubation of eggs in freshwater for 0min, 0.5min, 1min, and 10min interacts with diff...

A rapid quantitative method of ultra performance liquid chromatography (UPLC) has been developed for the analysis of 17 amino acids in fish eggs from Acipenser schrenckii, Huso dauricus and Acipenser ruthenus. The analytes were hydrolyzed with 6 0 mol/L HCI. The extraction solution was concentrated under low pressure and neutralized with NaOH solution before derivatization with 6-aminoquinolyl-...

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...