Tail of Acipenser ruthenus
Species: A. ruthenus
The tail of is Acipenser ruthenus is strong and rigid. The tail is bifurcated, that is it divides into two, having two fork like branches. The upper part is longer and having pointed end. The lower branch is smaller and more broader. There is a single dorsal fin near the tail. another fin also near the ventral side of the tail, one anal fin and one pectoral fins are also present in the tail.
About the Animal
These are highly endangered freshwater fishes. Overharvesting and habitat destruction have caused dramatic population declines worldwide. This is a large growing prehistoric-looking fish with a slender elongated snout, mouth on the underside, with spiked bony ridges running down the body, including down the spine. When young the Sterlet also has a white line along the back and down both sides. It Occurs in large rivers, usually in the current and in deep water. Moves to flooded areas to feed. Chiefly potamodromous. Like other sturgeons, it aggregates in bottom holes in winter and exhibits little activity. In spring, when ice breaks, it rises from the bottom holes and moves upstream for spawning. Spawns in habitats with strong-current on gravel, rarely on gravel-sand bottom or in flooded sites. Juveniles stay in riverine habitats during their first summer. Classified as endangered species. Anadromous populations are now extirpated; local populations are still surviving in most parts of range.