Fathead Minnow

Identification

The fathead minnow is a small, stocky fish to 10 cm with a short, round snout and blunt head. Color is olive-green to yellowish-brown with a dark lateral stripe. During spawning, males undergo a spectacular transformation: the head swells and turns dark black, with white tubercles (breeding nodules) on the snout. Behind the head, a light, spongy pad appears.

Ecology

The fathead minnow is an extremely tolerant species that thrives in still, turbid water with low oxygen levels — conditions many other fish cannot survive. Feeds on algae, detritus, and small invertebrates. Males guard eggs, which are deposited upside down on hard surfaces.

In the Netherlands

A North American species introduced to Europe through the aquarium trade and as bait fish. Our database holds 11 records. Feral populations exist in some European countries. In the Netherlands, records are scattered and it is unclear whether established populations exist.