Striped mummichog Fundulus majalis (Walbaum) 1792

MUMMICHOG; MUMMY; KILLIFISH

Description—

This fish resembles the common mummichog closely in general form, in the shape of its dorsal and anal fins, in its sexual dimorphism, and in the development of "contact organs" on the scales of breeding males. But it is more slender, its snout more pointed, its body more definitely fusiform, tapering toward both head and tail, and its caudal peduncle not so stout. But the color pattern is the most striking difference between the two, both sexes of Fundulus majalis being definitely barred with black at maturity as well as when young. In the male the barring is transverse throughout life, the stripes increasing [page 165] in number from 7 to 12 in the young to 14 to 20 in adult fish. When the females reach a length of about two inches, however, the original 7 to 12 transverse bars are transformed with growth into two or three longitudinal stripes on each side, the upper stripe running uninterrupted from gill opening to tail, the lower stripes in two segments, the one from close behind the pectoral to above the ventral, the other thence backward to close behind the rear edge of the anal fin. One or two transverse bars persist however on the caudal peduncle, even on the oldest females.

Color—

This is a decidedly paler fish than the other "mummy." Apart from the black bars the male is dark olive green above with silvery sides, a greenish-yellow belly, and a black spot on the rear part of the dorsal fin; his pectorals and caudal are pale yellowish. The male becomes more brilliant at breeding time, the back turning almost black, the lower sides and belly changing to orange or golden, and the fins to bright yellow. The female is olive green above and white below, striped as described above.

Size—

This is a larger fish than the common mummichog, occasionally growing to a length of 7 inches and often to 6 inches.

Habits—

The striped mummie parallels the common mummie in being restricted to the immediate neighborhood of the land, and in its way of life, except that it keeps more strictly to salt water, and is found more often along open beaches. Its most interesting habit is its ability to flop back into the water if it becomes stranded with the receding tide, jumping unerringly toward the water in almost every instance, and progressing from several inches to several feet at each jump.^[97] And so noted are they for this peculiar ability that a special article has been devoted to it.^[98] Their diet consists of small animals including mollusks, crustaceans, fish, insects, and insect larvae. Westward and southward from Cape Cod they spawn from late spring to late summer.

General range—

Coast of the United States, from the vicinity of Boston, Mass., to Florida.

Occurrence in the Gulf of Maine—

The striped mummie is very abundant along the southern shores of New England, westward from Cape Cod. But the only published records for it in the gulf are for the vicinity of Boston and Salem, many years ago, and we had not seen it north of Cape Cod before 1937. In that autumn, however, B. Preston Clark brought in four specimens that he had taken at Cohasset, on the southern shore of Massachusetts Bay; it was reported to us as in numbers there in 1939,^[99] and we have seen small schools of them in recent summers in the salt marshes at the entrance to Cohasset Harbor, as well as nearby. If this little fish actually has extended its regular range northward and if its dispersal-route has been via the Cape Cod Canal, as has been suggested,^[1] it is to be expected anywhere in the marshes around Cape Cod Bay and along the southern shore of Massachusetts Bay, and we suspect that a resident population is to be found in the Nauset Marshes and in Pleasant Bay, on the outer shore of Cape Cod.