The Breeding Behavior of the Bridled Shiner, Notropis bifrenatus

Abstract

T HE breeding habits of the bridled shiner, Notropis bifrenatus (Cope), blackchin shiner, Notropis heterodon (Cope), and blacknose shiner, Notropis heterolepis heterolepis Eigenmann and Eigenmann, have not been described. Their ranges overlap, notably in New York state, although the bridled shiner is a strictly eastern form (Fig. 1), whereas the other two species range westward into the upper Mississippi drainage. All prefer quiet, weedy waters, and none of them exceeds three inches in total length. They are so similar in appearance that they have been confused in the earlier literature. Their chief economic importance is as forage fish, especially, due to their small size, for the early stages of such game fishes as the pike, Esox lucius, and the pickerel, Esox niger. The following account of the breeding behavior of the bridled shiner may provide a clue to that of the other two species. The observations recorded here were made at the Oyster River in Durham, New Hampshire, on 60 days in 1946, from mid-February to mid-July, and on 33 days in 1942, from late June to mid-August. The bridled shiner seldom exceeds 2 inches in total length (Adams and Hankinson, 1928: 343). The largest one on record was 48 mm. in standard length or 2176 inches in total length (Bailey, 1938: 169). The largest one encountered by the author was 45 mm. in standard length. The following dates have been published as the breeding times for this species: May 2 to August for Ithaca, New York (Wright and Allen, 1913), mid-May to mid-