Author: Heckel, 1840
Cottus poecilopus Heckel, 1840
Diagnosis: body naked except for a small patch of prickles under the pectoral fin. Pelvic fins long, reaching to beyond anus, innermost finray much less than half length of outer one. D (VI) VIII-IX (X) + (13) 17-19 (20); A (11) 13-14 (15); P (12) 13-15 (16). Lateral line above midline of body, short, to below hind part of soft dorsal fin, with 20 pores. Vertebrae (32) 34-35 (36). Colour: overall olive-green, with 4-5 large and many small brown blotches, lighter on flanks and belly; edge of first dorsal fin yellow-orange, pelvic fins with 5-15 narrow transverse bars, a dark patch at base of caudal fin; dorsal, pectoral, anal and caudal fins usually with a few darker bars. Size: to 15 cm SL, usually 8.5-10.0 cm.
Habitat: benthic in fast-flowing waters of coastal streams, rivers, also inland lakes, usually on stony bottoms; moves downstream to estuaries and tolerates brackish waters. Food: algae (diatoms, desmids, blue-green algae), polychaetes, crustaceans, aquatic insect larvae and nymphs (Ephemeroptera, Trichoptera, Plecoptera, Chironomidae), also fish eggs and larvae. Reproduction: spawns May-June; eggs about 200-1,000, less than 1.5 mm diameter, orange, deposited in adhesive masses on underside of rocks and guarded by males; first spawning at 3 years. Lifespan: 8 years at most.
Distribution: North Sea basin (south-eastern Norway, western Jutland), Baltic Sea basin (Denmark, Oder and Vistula Rivers, Sweden, Neva River), Black Sea basin (Danube and Dneister Rivers). Elsewhere, eastward in Siberian and Far eastern rivers.
Eggs, larvae and young stages. No data.
Otolliths (larvae). No data.