Research Training Program

Kristina Louie
Colgate University
Hamilton, New York

Bruce Collette, Ph.D.
Project Advisor
Department of Vertebrate Zoology
Division of Fishes

"The RTP is an excellent opportunity to work on a research project with leaders in the field. That opportunity is invaluable and allows students to learn what lies ahead in the research discipline."

The Systematic Review of the Fish Genus Nomorhamphus

Nomorhamphus differs from all other halfbeaks in having a very much less pronounced beak, a lower jaw that only slightly extends beyond the upper jaw, and being confined to the fast flowing mountain streams of a single Indonesian island, Sulawesi. It shares low vertebral counts, a reduced nasal fossa with an elongated nasal barbel, and modification of the anal fin in males associated with courtship with three other related genera: Zenarchopterus, Dermogenys, and Hemiramphidon. Based on geographic proximity of their localities, dentition, and morphometric and meristic similarities in their data, these seven species form three species groups: 1) N. celebensis 2) N. hageni and N. towoeti as the second group, and 3) N. liemi, N. ravnaki, N. brembachi, and N. sanussi.

Three taxonomic groups are recognized herein: the species N. hageni, found exclusively from the central part of the eastern arm of Sulawesi; N. towoeti, found in the southern part of the eastern arm of the island; N. celebenis, found in the central part of the entire island. The liemi group, found in rivers of the southwestern arm of the island, N. liemi, N. ravnaki, N. brembachi and N. sanussi make up a group of fish that are very closely related. They have only slight differences in their dentition, meristics and pigmentation, however, whether these small distinctions are enough to designate separate species is questionable. In N. liemi females, the branching split of the anal rays first occurred on the seventh or eighth ray, while N. ravnaki females had it in the fourth. Also, dentition in the upper jaw of the N. liemi was uniform and in a curvy wave, while the N. ravnaki was irregular and peninsula in shape. This left the upper jaw structure of N. brembachi and N. sanussi as expressing a gradient between extremes of N. liemi and N. ravnaki. Seeming different separately, these four populations were very similar.

This research was supported by a grant from the National Science Foundation Research Experiences for Undergraduates (Award: BIR-9300225).