Research Training Program Smithsonian Institution National Museum of Natural History PROJECT SUMMARY 1995
Glenn R. Almany San Francisco State University San Francisco, California
G. David Johnson, Ph.D. Carole C. Baldwin, Ph.D. Supervising Scientists Department of Vertebrate Zoology
"Understanding the relationships that exist among groups of animals, like fishes, is fundamental to understanding other aspects of their lives, such as their ecology, physiology, and reproduction. This is perhaps the most valuable lesson I have learned as a participant in this program. The opportunity to work closely with research scientists and to attend the numerous informative workshops and lectures has left me with a clearer understanding of systematics and has impressed upon me the importance of institutions such as this."
A new Atlantic species of Acanthemblemaria (Teleostei: Blennioidei: Chacoopsidae): Morphology and Relationships
ABSTRACT

This study had two main objectives. The first was to describe a previously unknown species of blennioid fish in the genus Acanthemblemaria from the Caribbean island of Tobago. The second was to analyze the evolutionary relationships of this new species to the other species within the same genus.

Fishes of the genus Acanthemblemaria are small, between 12 and 60 mm, cryptic fishes which inhabit the vacated tubes of some invertebrate worms like polychaetes and sipunculids. They live in the shallow-water coral reef environments of, interestingly enough, the Caribbean sea and the tropical eastern Pacific. This distribution of the genus in both oceans is interesting because it would indicate that an ancestral population of these fishes was separated by the emergence of the Panamanian isthmus, then speciation occurred to produce the species which exist today. The description of the new species began by comparing the 6 known specimens to other members of the genus. A series of measurements, counts, and written descriptions of pigment patterns and external morphological features were then performed for each specimen to accurately describe the features of the new species which separate it from other members of the genus. This information was then synthesized into a single description.

The second phase of the project began by clearing and staining one specimen so that internal osteological characters could be examined. A total of 60 different features were characterized and compared to the same 60 characters in each of the other species in the genus. This information was then used to generate a phylogenetic tree which illustrated the hypothesized evolutionary relationships between all the species in the genus Acanthemblemaria. The results of this analysis showed that the new species was most closely related to members of the genus which occur in the tropical eastern Pacific. This interesting outcome provided yet another piece of the complicated biogeographical puzzle which defines this genus of blennioid fishes.

Letter of Gratitude