blackspotted topminnow

blackspotted topminnow (Fundulus olivaceus)
Photo © Isaac Szabo/Engbretson Underwater Photography

The blackspotted topminnow may attain a length of two to three inches with the male growing to a larger size than the female. Dark spots are present on the upper one-half of the body.  A wide, dark stripe can be seen along the sides, around the snout and onto the tail fin. The edges of this stripe are straight in females but uneven in males. The back and upper sides are light brown while the belly and lower sides are white to yellow. The fins are yellow, and the dorsal, caudal and anal fins have many dark spots. The dorsal fin is placed directly above the anal fin. The life span is about three years.

The blackspotted topminnow may be found in the southern one-fourth of Illinois. This fish lives in clear water with many plants in creeks, rivers, ponds and lakes. The blackspotted topminnow spawns in summer. The male and female defend a small territory. The eggs are deposited singly on plants or algae. Swimming near the surface in the early morning, late afternoon and evening, the blackspotted topminnow eats small crustaceans and insects.

​Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cyprinodontiformes
Family: Fundulidae