Identification of Golden Shiner, Notemigonus crysoleucas, Spotfin Shiner, Notropis spilopterus, and Fathead Minnow, Pimephales promelas, Larvae

The various proportional length measurements and myomere counts for each larval phase of the cyprinid fishes golden shiner, Notemigonus crysoleucas, spotfin shiner, Notropis spilopterus, and fathead minnow, Pimephales promelas, are generally quite similar and typical of the family. Mean snout to vent lengths for protolarvae and mesolarvae ranged from 58 to 60% of total length and decreased to 54 to 59% for metalarvae. Mean total myomere counts for all phases overlapped among the species and ranged from 34 to 37.Identification of protolarvae and mesolarvae depends largely on melanophore distribution and patterns, while fin ray counts and position are applicable to metalarvae. Later protolarvae and mesolarvae of Notemigonus crysoleucas exhibit a distinctive midventral line of pigment anterior to the vent, while metalarvae are readily distinguished by an anal ray count of over 10 and pelvic fins well anterior to the dorsal fin origin. The later protolarvae, mesolarvae, and metalarvae of Notropis spilopterus are distinguished by a lack of melanophores on the ventral surface of the gill covers.These and other distinguishing features discussed are not necessarily unique to the cyprmids studied. Unless potentially similar species (undescribed or inadequately described) in a study area can be eliminated, identifications based on these characters should be considered tentative. Key words: Notemigonus crysoleucas, Notropis spilopterus, Pimephales promelas, Cyprinidae, fish, larvae, development, identification, taxonomy