158 BULLETIN OF THE BUREAU OF FISHERIES 



Food. — "Mummies" are omnivorous, feeding on all sorts of edible things, 

 vegetable as well as animal. They have been found full of diatoms, eelgrass and 

 other vegetable matter, foraminifera, shrimps and other small Crustacea, small 

 mollusks, and even with small fish in their stomachs. 83 At spawning time they 

 greedily eat their own or each other's eggs. They soon congregate about any dead 

 fish or other bit of carrion, to prey either upon it or upon the amphipod scavengers 

 that gather on such dainties. 



Breeding habits.- — Spawning probably takes place at the same season in the 

 Gulf of Maine as on the southern coast of New England — that is, June, July, and 

 early August. As sexual activity approaches, the males, now brilliantly tinted, 

 court and pursue the females, rivalry among them being very keen, those most 

 highly colored or most excited usually driving off the others. Sometimes they fight 

 fiercely. At the moment of spawning the male clasps the female with his anal and 

 dorsal fins just back of her anal and dorsal, usually forcing her against some stone 

 or against the bottom, the bodies of both being bent into an S and their tails 

 vibrating rapidly while the eggs and the milt are being extruded. 84 Occasionally, 

 however, pairs clasp and spawn free in the water without coming in contact with 

 any object, and sometimes a female is seen to pursue and court a male. They 

 have been seen spawning in a few inches of water, seeking shady spots. 



The eggs, which are about 2 mm. in diameter, colorless or pale yellowish and 

 surrounded by a firm capsule, sink and become so sticky on contact with the water 

 that they mass together in clumps or stick fast to sand grains or to anything they 

 chance to rest upon. Incubation occupies from 9 to 18 days, the exact duration 

 probably depending on temperature, this being the factor that governs the rate of 

 development for most fishes. The larva is about 7 to 7.7 mm. long at hatching, its 

 yolk absorbed already, its pectoral and caudal fins fully formed. By the time the 

 little fish has grown to 11 mm. the dorsal and anal fin rays are present in full 

 number, and the first trace of the ventrals is to be seen. At 16 mm. the ventrals 

 are apparent, and fry of 20 mm. resemble the adult not only structurally but in form. 



The mumrnichog is of some little commercial value as bait, but only locally. 



58. Striped niuinmickog {Fundulus majalis Walbaum) 



Mummichog; Mummy; Killifish 



Jordan and Evermann, 1S96-1900, p. 637. 



Description.- — This fish closely resembles the more common mummichog in 

 general form, in its sexual dimorphism, in the form of its dorsal and anal fins, and 

 in the development of "contact organs" on the scales of the breeding male; but it 

 is more slender, its snout is more pointed in side view, its body more definitely 

 fusiform, tapering toward both head and tail, and its caudal peduncle is less stout. 

 The most striking point of difference between the two, however, is to be seen in the 

 color pattern, both sexes of Fundulus majalis being definitely barred with black 



» Lists of stomach contents are given by Field (1907, p. 29). 



81 Newman (Biological Bulletin, Marine Biological Laboratory, Woods Hole, Mass., Vol. XII, No. 5, April, 1907, p. 315) 

 gives an interesting account of the courtship and spawning from which the preceding is condensed. 



