Blenny darter Blenny darter The blenny darter ("Etheostoma blennius") is a poorly known species of fish in the family Percidae, from Alabama and Tennessee that inhabits swift riffles. The blenny darter lives a maximum of two to three years, grows to a maximum of 69 mm standard length, and is sexually mature at one year. It is reproductively active throughout March and April. Spawning occurs over gravel riffles with swift currents. Mature eggs are orange and translucent. The fish are insectivorous, with analyzed gut contents containing Nematocera larvae, more specifically black fly (Simuliidae) and midge (Chironomidae) larvae. Significant numbers of mayfly (Ephemeroptera)
Round goby Nord-Ostsee (Kiel) Canal. As of 2010, the westernmost site of round goby occurrence in Europe was the Lower River Scheldt, the tidal zone in the river mouth, and Albert Canal, Belgium. In 2011, the round goby began invading the fresh waters of France: the species appeared in the Rhine River (on the border between France and Germany), and in the French part of the Moselle River. In total, 52 parasite species are registered in the round goby in the native area. Most abundant parasites of the Black-Sea round goby are metacercariae of trematodes of Heterophyidae family, such as "Cryptocotyle concavum",