The lake sturgeon, Acipenser fulvescens, belongs to one of the few extant nonteleost ray-finned fishes and diverged from the main vertebrate lineage about 250 million years ago. The aim of this study was to use this species to explore the peripheral neural coding strategies for sound direction and compare these results to modern bony fishes (teleosts). Extracellular recordings were made from af...

–Growth rates of juvenile lake sturgeon (initial weight 8 to 9 g, temperature 17.5° C), fed twice a day on brown worms for 56 days increased from -1.5% BW/d (% body wet weight/day) at zero ration to 2.6% BW/d at a ration of 13.2% BW/d. Maintenance ration was 1.6% BW/d. Fish fed larger rations had higher energy densities and lower water content. Appetite (average volitional daily food consumptio...

abstract the present study was carried out to investigate the efficacy of two anesthetics, clove oil and ketamine, comparison of hematological parameters, and blood biochemical indices under optimum doses of the two anesthetics in juvenile sterlet acipenser ruthenus (n=276) with an average weight of 64.1 ± 3.4 g. clove oil was used in concentrations of 14, 35, 56, 77, 98 and 119 mg/l, and those...

A phylogenetic hypothesis is presented illustrating relationships among 23 extant sturgeon species based on nucleotide data from five mitochondrial genes (cytochrome b, NADH5, control region, 16S, and 12S). The tree supports our previous hypotheses regarding relationships among species of Acipenser and Huso. The introduction of Scaphirhynchus and Pseudoscaphirhynchus to the analysis does not ch...

Biological invasion is a pervasive negative force of global change, especially in its effects on sensitive freshwater ecosystems. Even protected areas are usually not immune. Ptychobarbus chungtienensis is a threatened freshwater fish now almost confined to Bita Lake, in the Shangri-La region of Yunnan province, China. Its existence is threatened by the introduction of non-native weatherfishes ...

Water projects designed to extract fresh water for local urban, industrial and agricultural use throughout rivers and estuaries worldwide have contributed to the fragmentation and degradation of suitable habitat for native fishes. The number of water diversions located throughout the Sacramento-San Joaquin watershed in California's Central Valley exceeds 3300, and the majority of these are unsc...

The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (har...

the effect of feeding frequency on growth performance, feed consumption and body biochemical composition of acipenser ruthenus juveniles was investigated. the trial was performed using 150 fish with a mean initial weight of 50±1 g randomly introduced in fifteen tanks. fishes were fed at a feeding frequency of twice daily (t1), three times a day (t2), four times a day (t3), five times a day (t4)...