Stone Loach

Barbatula barbatulaThe body, somewhat compressed from the sides, is almost the same width head to tail. The caudal peduncle is high holding a truncated fin with a shallow indent. The species is fine-scaled, lacking a leathery keel past the dorsal fin. The body is spotted brown, but the spots are never grouped into lateral bars. It can grow up to 16-18 cm long, with the average of 12. This loach’s areal is vast. Usually it inhabits current water, predominantly small streams and brooks, but it also can be encountered in ponds formed by damming creaks or those man-dug. Most of the time the loach is lying still on the bottom, hiding in snags and roots. As a rule, these fish do not school, sticking to groups of several species or keeps solo. Fry keep in schools for the first few months, and then spread over a broader area. Young species feed on wrigglers, small dayfly larvae and other small invertebrates. The larger ones prey on bigger invertebrates – dayfly larvae, caddis worms, leeches and beetles. Sexually mature male and female loaches present with epithelial projection on their heads and bodies when spawning, with males also sometimes presenting a leathery crest past the dorsal fin and on the caudal peduncle. Males are larger and have longer pectoral fins. In Central Europe the species spawns in May. The roe spawned is small-sized, sticking to plants or just laid in the sand in spots not deep and in the current. Fry hatched emerge in sandy shoals and lie on the bottom with the big pectoral fins as support. When fry swim in mid-water, the pectoral fins support the front part of the body. Stone loach fry have downward mouths. They feed on microscopic organisms living in the sand. Most often, their diet consists of rotifers and protozoa. Stone loaches are regulars of trout brooks, where they partly use the food from the trout fry’s diet. But the larger trout readily prey on stone loaches.

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