A New Gobioid Fish, Microdesmus lanceolatus, from the Gulf of Mexico with Notes on M. longipinnis (Weymouth)

Abstract

THE known species of Microdesmus in the Gulf of Mexico have been M. floridanus (Longley) from the Dry Tortugas, Florida Keys, and the Bahamas, and M. longipinnis (Weymouth) known from the coasts of Texas, Louisiana, Mississippi, southern Florida, and Bermuda. Robins and Manning (1958) in reviewing the western Atlantic Microdesmidae, compiled the first comparative counts and proportional measurements of M. floridanus and M. longipinnis and synonymized M. woodsi Kanazawa with the latter species. Since that contribution, there has been no significant addition to the literature on this interesting but little known group of bottom fishes. The capture of an undescribed species of Microdesmus from the offshore waters of Louisiana prompted the examination of a rather large series of M. longipinnis, the common species of the northern Gulf. The present report describes the new species, demonstrates the degree of morphological variation in longipinnis over a broad size range and includes certain observations on the status of the family Microdesmidae. A tentative key to the Atlantic species of Microdesmus is provided. Measurements were made to the nearest