Freshwater biodiversity is highly threatened and is decreasing more rapidly than its terrestrial or marine counterparts; however, freshwaters receive less attention and conservation investment than other ecosystems do. The diverse group of freshwater megafauna, including iconic species such as sturgeons, river dolphins, and turtles, could, if promoted, provide a valuable tool to raise awareness...

The pattern of age-specific fecundity is a key component of the life history of organisms and shapes their ecology and evolution. In numerous animals, including humans, reproductive performance decreases with age. Here, we demonstrate that some social insect queens exhibit the opposite pattern. Egg laying rates of Cardiocondyla obscurior ant queens increased with age until death, even when the ...

A test of the hypothesis that the members of the order Acipenseriformes (sturgeons and paddlefishes) possess a slowed rate of molecular evolution was carried out by conducting relative-rate comparisons with representatives of four groups of teleost fishes (Cypriniformes, Elopomorpha, Salmonidae, and Percomorpha) using 21 nuclear or mitochondrial protein loci and the nuclear and mitochondrial sm...

Migratory fishes are important components of the rich wildlife our waters. Amongst them there certain species which spend vast majority their lives in fresh water (catadromous) and migrate to sea for spawning, instance eel species. Others other way around (anadromous), spending main growth period reaching sexual maturity sea, then spawning freshwaters. Notable representatives this group salmoni...

Suitable physiological condition in fishes for the selection of broodfishes can be achieved through hematological studies. The present study aimed to examin the hematological indices in Juvenile Sturgeons at different stages of growth. Total albumin content in blood serum, hemoglobin concentration, the erythrocyte and leukocyte count of 54 sturgeon specimens (Persian sturgeon Acipenser persicus...

The objective of this study was to compare the biological parameters such as length, weight, age, caviar production indices, caviar/weight, condition factor and sex ratio of Persian sturgeon (Acipenser persicus Borodin, 1897) and Russian sturgeon (A. gueldenstaedtii Brandt & Ratzeburg, 1833) in the Caspian Sea during 1990-2014. All these characteristics (except condition factor) of Persian stur...