Family CYPRINODONTIDAE 



THE KILLIFISH FAMILY 



Fishes of this family have somewhat elongate bodies, compressed 

 posteriorly. The head is considerably depressed. The cycloid scales are 

 rather large. The lateral line is very imperfect. The mouth is very 

 small. The lower jaw is projecting and the upper jaw protractile in all 

 American species. There are teeth in the jaws and sometimes on the 

 vomer. The gill-membranes are free from the isthmus; the gill-rakers 

 are short. The branchiostegal rays number 4-6. The pseudobranchiae 

 are not developed. The dorsal fin, composed of soft rays, is single and 

 usually inserted far back. The caudal fin is not forked. The ventral 

 fins are inserted on the abdomen. The air bladder is sometimes absent. 



Many genera and species, including topminnows, are known in the 

 brackish and fresh waters of the southern states, the Atlantic Coast, 

 Mexico, and Central America. Some species found in the southeastern 

 United States are ovoviviparous, i.e., give birth to living young. Only 

 one genus is found in Minnesota and neighboring states. 



Key to Common Species of Family CYPRINODONTIDAE* 



1. Dorsal fin originating distinctly in advance of anal; body with crossbands in 



both sexes 



Western Banded Killifish, Ftindulus diaphanus menona Jordan and Copeland 

 Dorsal fin originating distinctly behind front of anal; body with crossbands 

 in male only 2 



2. Body rather deep and compressed, depth 3.5-4.3; males with vertical bars, 



females with about 10 horizontal streaks; a black blotch below the eye 



Northern Starhead Topminnow, Fundulus dispar dispar (Agassiz) 



Body slender and scarcely compressed anteriorly, depth 4'.4 or 5.3; a purplish 

 black lateral band with irregular edges in the male; no black blotch below 

 eye Northern Blackstripe Topminnow, Fnndidiis notaitis (Rafinesque) 



*Modified from Hubbs and Lagler (1941). 



GENUS Fundiihis Lacepede 



This genus contains a number of southern and eastern species, some 

 of which live in brackish water. Only one species is known from Minne- 

 sota, though closely allied topminnows, Fundulus notatus (Rafinesque) 

 and Fundulus dispar (Agassiz) , are known from Wisconsin and Illinois. 



WESTERN BANDED KILLIFISH 



Fundulus diaphanus menona Jordan and Copeland 



The western banded kilhfish (Figure 33) is olivaceous with the sides 

 barred with olive and silver crossbands; the back is sometimes spotted. 



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