Fish o' the Day - southern brook lamprey

OK, maybe a little bit of a stretch. But, in the eyes of most people, it's got fins, lives in the water, breathes with gills - fish. They're not bony fish, true. They're not even in the Chondrichthyes with the cartilaginous sharks and rays. But we're still gonna call 'em fish.

When most people think of lampreys, the one that comes to mind is the parasitic sea lamprey, Petromyzon marinus. The sea lamprey is an anadramous species that has become landlocked in the Great Lakes and rained down havoc on freshwater fish there. But not all lampreys are evil-doers like P. marinus, and the southern brook lamprey, Ichthyomyzon gagei, is a pretty unassuming member of the clan. It's a small, nonparasitic species that's actually fairly common in many of our streams. They reach a length of 7-8" and live in small to moderate streams, typically over sand or gravel bottoms. They spend most of their lives as a larval form known as the ammocoete, which burrows in the substrate and filter feeds on detritus and diatoms. After a three year larval period, the ammocoete metamorphoses into the adult form, which spawns and dies.

This comes up as the result of the efforts of a couple of my field guys, who returned from working a local stream today with the report of an escaped "eel". The little guy, it seems, slipped out through the mesh of the seine. Now, we certainly have eels in our rivers and streams. But the size of the escapee (a few inches), the location (a shallow riffle over a gravel bottom), and the time of year (most of the literature has Icthyomyzon spawning starting around this time), makes me think they probably had a close encounter with a newly metamorphosed lamprey. Sorry, guys.