MUD DARTER 



Etheostoma fu.si forme (Girard) 



Bruce B. Collette 



Research Assistant, Cornell University 



The mud darter is the smallest species of freshwater fish found in 

 Maine. It is widely distributed along the Gulf and Atlantic coastal plains 

 but extends only into the southernmost tip of Maine, in York County, 

 where it has been taken in the Ogunquit and Cape Neddick Rivers, it is 

 the only darter found in Maine. 



The mud darter is a member of a very interesting group of North 

 American freshwater fishes. This small fish, having lost its air bladder 

 during the course of evolution, must spend its life resting on the bottom 

 or in clumps of aquatic plants. From its resting place it moves out in 

 short, rapid dashes that have given rise to the common name of darter. 



Unlike other species of darters which prefer clear, running water, 

 the mud darter is usually found in muddy, swampy areas. It occurs 

 rarely in faster streams and then only in clumps of vegetation. However, 

 when the mud darter gains access to ponds or small lakes, it frequently 

 multiplies rapidly and can become quite numerous. 



Virtually nothing was known of the Hfe history of the mud darter 

 until recently. Sexual dimorphism is apparent, especially before and 

 during the spawning season which includes May and June. Females 

 possess an enlarged genital papilla which projects outward from the 

 genital orifice. Males develop a concentration of black pigment in the 

 dorsal and anal fins and, to a lesser extent, upon the body. 



During courtship, the male swims up behind the female, and then 

 "beats" her with his pelvic fins. The female swims into a clump of 

 plants and projects her genital papilla forward into the plants when ready 

 to spawn. The eggs are laid and fertilized while the pair undergo a 

 quivering motion. The young hatch in about 8 to 10 days at a tem- 

 perature of 70 F. At first they are free-swimming but soon settle down 

 to a life on the bottom. 



Collections made throughout the year on Cape Cod and Long 

 Island indicate the presence of only one major size class. However, col- 

 lections made in the Ogunquit and Cape Neddick Rivers of Maine on 

 September 18, 1957 show two distinct size classes. This indicates that 

 the mud darter in Maine may live for two years while southern popula- 

 tions only live for one. The reason for this may be the slower growth 

 and later spawning season as a result of the colder waters of Maine. 



Mud darters probably feed mainly on small aquatic insects and 

 other invertebrates, although few food studies have been made. This 

 species relies mainly on vision in food detection, and in aquariums it 

 darts forward quickly at the slightest movement. 



In Maine the mud darter has been taken along with the creek 

 chub, American eel, white sucker, golden shiner, chain pickerel, pump- 

 kinseed sunfish, and brown bullhead. Although a very small fish, seldom 

 more than IVi inches in total length, it may be important locally as a 

 forage fish. Studies in New Jersey and Florida have indicated it to be of 

 some importance in the diet of pickerel and bass. 



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