FISHES OF CHESAPEAKE BAY 
143 
This fish was taken only on the muddy marshes of Lynnhaven Bay. Our imperfect knowl- 
edge of the life history of this fish would indicate that the species is limited in its habitat to shallow, 
muddy, brackish-water swamps, where it is taken in company with F. heteroclitus. 
This fish is said to be rather common on the Gulf coast. On the Atlantic coast it has been 
recorded only from Beaufort, N. C. (Hildebrand, 1916, p. 306). The range is now extended 
northward to Lynnhaven Bay, Va. 
Habitat . — Coastwise from Chesapeake Bay to Louisiana. 
Chesapeake localities. — (o) Previous records: None. ( b ) Specimens in collection: Lynnhaven 
Marshes, May 9 to 16, June 10 to 17, September 26, 1921, and April 6, 1922. 
62 . Fundulus diaphanus (LeSueur). Killifish; Fresh-water killy. 
Hydrargyra diaphanus LeSueur, Journ., Ac. Nat. Sci., Phila., 1817, p. 130; Saratoga Lake. 
Fundulus multifasciatus Uhler and Lugger, 1876, ed. I, p. 150; ed. II, p. 127. 
Fundulus diaphanus Bean, 1883, p. 366; Smith, 1892, p. 65, PI. XIX; Jordan and Evermann, 1896-1900, p. 645, PI. CI1I, figs. 
275 and 275a; Smith and Bean, 1899, p. 184; Evermann and Hildebrand, 1910, p. 159; Fowler, 1912, p. 54. 
Head 3.3 to 4; depth 4.1 to 5.7; D. 13 or 14; A. 10 to 12; scales 41 to 46. Body rather elongate, 
compressed; depth of caudal peduncle 2.2 to 3.3 in head; head depressed; snout broad and rather 
long, 2.8 to 4 in head; ej^e 2.8 to 4; interorbital 2.4 to 3.4; mouth mostly transverse, slightly superior; 
teeth in villiform bands, rather fewer and stronger than in related species; scales rather small, 14 
to 18 oblique rows between upper angle of gill opening and origin of dorsal; dorsal fin rather long, 
scarcely higher in males than in females; inserted nearly an eye’s diameter in advance of origin of 
anal in both sexes; inserted about equidistant from tip of snout and tip of caudal in females; fully 
an eye’s diameter farther forward in adult males; caudal fin straight or slightly concave; anal fin 
shorter than the dorsal; the oviduct extending slightly above the base of the first anal ray; ventral 
fins of moderate size, inserted about an eye’s diameter nearer tip of snout than base of caudal; 
pectoral fins rounded, 1.3 to 1.7 in head. 
Color in life, female, olive above, silvery white on lower part of side, abdomen white; sides with 
about 16 to 20 narrow greenish bars, becoming dark in spirits; dorsal, caudal, and pectorals yellow; 
anal and ventrals plain translucent. Male, greenish olivaceous above, abdomen white; caudal 
peduncle bluish white underneath; sides with about 20 to 22 silvery iridescent vertical bars; dorsal 
more or less dusky, sometimes with small dark dots on the base; caudal dusky; anal and pectorals 
more or less yellowish; ventrals mostly bluish white, tinged with yellow. The young, as usual in 
this group of fishes, are similar in color to the adult female, the differentiation in color between 
the sexes taking place when the fish reach a length of approximately 50 millimeters. 
Numerous specimens, ranging from 32 to 111 millimeters (lb£ to 4^ inches) in length, were 
preserved. This fish is distinguished from related species by the elongate body, long depressed 
snout, small scales, and by the many narrow vertical bars on the sides, the latter being darker than 
the ground color in the female and silvery in the male. 
The food of this species, as indicated by the contents of 15 stomachs examined, consists of 
small crustaceans, insects, mollusks, annelid worms, and of miscellaneous unidentified vegetable 
matter. 
Gravid fish were taken from April until September. The eggs, when fully developed, are 
spherical and about 2 millimeters in diameter. The ovary is single, and it usually contains eggs 
of more than one size. The largest number of eggs of one size found in one ovary in a limited num- 
ber of specimens examined was 252. The males in this fish, as well as in the other species of the 
genus, are somewhat smaller than the female, the average difference in size being about one-half 
inch. Sexual maturity appears to be attained when the fish is about 2J4 inches in length. The 
largest individual of this species taken during the present investigation was a female 111 milli- 
meters (4% inches) in length, which appears to represent the maximum size attained by the species. 
This minnow is more fresh-water in its habits than are the other members of the genus discussed 
in the present report. It is common in bays, rivers, and coves where the water is only slightly 
brackish, and it runs up the streams tributary to Chesapeake Bay into fresh water. 
This killifish no doubt is of some value as an eradicator of mosquito larvae. It is said to be an 
excellent bait for the larger predatory fishes, and it also is valuable as a natural food for these larger 
fishes. 
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