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COSEWIC Assessment and Update Status Report on the Banded Killifish, Newfoundland population in Canada

COSEWIC Status Report
on the
Banded Killifish
Fundulus diaphanus
Newfoundland Population
in Canada

Species Information

Name and Classification









Scientific Name:

Fundulus diaphanus (Lesueur 1817)

Common Name:

Eng. - Banded killifish; Fr. – fondule barré



The Banded Killifish, Fundulus diaphanus (Lesueur 1817) is a member of the family Fundulidae containing 5 genera and approximately 48 species (Nelson 1994). Sometimes referred to as egg-laying toothcarps, adult killifish are usually small, reaching between 5-10 cm in length. The largest known killifish of the family Fundulidae, Fundulus grandissimus, have been found to measure 18 cm (Berra 1981). Many killifish are slender and pike-like in shape to aid in rapid swimming (Riehl and Baensch 1991) and some species have a flattened head and terminal mouth adapted for surface feeding, hence the name topminnows (Leim and Scott 1966; Scott and Crossman 1973; Houston 1990). Three species of the family Fundulidae, Fundulus diaphanus, F. heteroclitus, and F. notatus have been recorded in Canadian waters (Houston 1990). Of these three, only Fundulus diaphanus and F. heteroclitus are found in Newfoundland (Scott and Crossman 1964,1973; Houston 1990).

Fundulus diaphanus, the Banded Killifish, is described as having olive colored sides with numerous vertical bands and a contrasting dark coloration across the dorsal region. The number of bands anterior to the dorsal fin are useful as a means of determining the sex of live fish as a greater number of “anterior” bands (approximately >9) are evident in male Banded Killifish. Bands in females usually appear black in color, are thin and distinct, and often do not appear to span the full width of the body. Males, however, have pale, grey bands that are less distinct and closer together. Figure 1 provides an illustration of a Banded Killifish.

Figure 1: Illustration of the Banded Killifish

Illustration of the Banded Killifish.

From Scott and Crossman (1973), by permission.

Fundulus diaphanus is distinguished from F. heteroclitus by having a relatively thin caudal peduncle, larger gill rakers, usually numbering 5 or 6 (9-11 in F. heteroclitus), and having brachiostegal rays most often numbering 6,6 (5,5 in F. heteroclitus) (Scott and Crossman 1973). Fundulus heteroclitus is also most often associated with brackish waters whereas F. diaphanus, although euryhaline, is usually found in fresh water (Houston 1990).

Fundulus diaphanus (Lesueur, 1817) is divided into two subspecies; Fundulus diaphanus diaphanus (Lesueur), the eastern Banded Killifish, and F. d. menona (Jordan and Copeland), the western Banded Killifish. The eastern Banded Killifish differs from the western subspecies in several ways including a more anterior positioning of the dorsal fin, a greater number of anterior bars in males (9-15 diaphanus vs. 5‑0 menona) and more intense bars along the side that remain intact over the anterior back, a greater number of scale rows (45-49 diaphanus vs. 40-44 menona), and a combination of dorsal dorsal and anal fin rays totaling 24 to 26 (23 to 24 menona), as well as being much larger in size (110mm maximum diaphanus vs. 74mm maximum menona) (Trautman 1957; Hubbs and Lagler 1974). The eastern form occurs in the Atlantic drainage west to the Upper St. Lawrence and eastern Lake Ontario where it intergrades with the western form (Scott and Crossman 1973).