Outside br eeding season both sexes similarin color with a green back, silvery flanks and belly. Agreenish-blue stripe along the lateral line. In spawningseason males colorful, top of head and back olive tobright green, reddish or dark violet. Iris bright red. Peritoneumdark. Pharyngeal teeth elongated and compressed,with a hooked tip. Gut with numerous coils.Males develop a patch of tubercles on each side of snoutand above eyes. Female develops a long ovipositor. Favorsheavily vegetated areas of slow waters. Bottom usuallya fine sand or a thin layer of mud. Mussels or clamsnecessary for reproduction. Maximum age 5 years andtotal length 7 cm. Maturity during second year, at about43 mm total length. Sex ratio 1.5males:1female. Reproductionin April-May inside the clams and males defendit. Female deposits 1-2 eggs at a time and male shedssperm sucked into clam on its feeding current. Absolutefecundity up to 350 eggs of up to 3.1 mm in diameter.Food include diatoms, detritus, aquatic insects, crustaceans,plants, filamentous algae and eggs of other fish.