• Family: Cyprinidae (Minnows and Carps)
• Other Names: None
• Ohio Status: No special status
• Adult Size: Usually 2-3 inches, can reach 4 inches.
• Typical Foods: Organic debris, aquatic insects, and zooplankton.
The fathead minnow has stout half ray in front of the usual 8 rays on the dorsal fin and the scales on the back between the head and dorsal fin are small and squished together. There is a dark spot of pigment on the first two or three dorsal rays about mid way up the fin. Fathead minnows have terminal (ending at tip of snout) mouth. Young, females, and non-breeding adult males have a faint stripe down their side which gets wider and more visible as it gets closer to the tail. Fathead minnows are the only Pimephales species in Ohio (there are three total) that do not have a complete lateral line. Breeding males have a nearly black head with lighter copper colored cheeks. They also have a light copper colored ring that goes the entire way around their body just behind the head and gills. A second such ring is found just below the dorsal fin. The rest of their body is darker colored and can be almost black. Breeding males also have two rows of large pointed tubercles (horn like bumps) on their head, along with several smaller ones in the middle of their head and two on either side of their lower jaw. They also have a large spongy pad on their back from the back of the head to just in front of the dorsal fin. Fathead minnows differ from both the bluntnose and bullhead minnows by having an incomplete lateral line.
Habitat and Habits
Historically the fathead minnow widely populated only in the western part of Ohio. They prefer small low gradient streams, as well as ponds and small lakes. They are very tolerant of a wide range of conditions in both water clarity and pH. The largest populations are found in streams or bog ponds where the conditions are rather poor for most other species of fish. They do not compete well with the closely related bluntnose minnow.
Reproduction and Care of the Young
Fathead minnows spawn repeatedly starting in May and continue into August. Males select the spawning site, usually under logs, branches or rocks in shallow water. They will also use artificial spawning sites in old tiles or pipes. Females lay adhesive eggs on the underside of whatever the male has chosen to spawn under. The male then aggressively defends the spawning site from other fish. Males also use the large spongy pad on the top of their body to clean the eggs the female has laid on the underside of the select object.