Authors: Ajay Patel, Lawrence Page
Faculty Mentor: Lawrence Page
College: Florida Museum of Natural History
Schistura mahnerti and S. poculi are currently regarded as two species of stone loaches, in the family Nemacheilidae. Schistura poculi is distributed along much of Thailand’s northwestern border, while S. mahnerti is found along the same western border, but farther south. The species have overlapping distributions along the central western border with Myanmar. They are usually distinguished through differences in color pattern and 15 vs. 17 caudal-fin rays. However recent genetic data suggest that these characters may be intraspecifically variable and unreliable in separating species. Individuals morphologically identified as one species were genetically identified as the other. This situation comes as no surprise because coloration and fin-ray counts often show variation in other species of Schistura. To address the taxonomic question of whether the individuals examined represent one variable species or two species, I have gathered morphological data on 50 specimens from throughout the range of the species. These data will be analyzed using a sheared principal component analysis to see if individuals are separated into two groups, as well as to identify morphological characteristics other than caudal-fin rays that may be useful in distinguishing species. I also soon will be phylogenetically analyzing DNA sequence data from specimens throughout the range of the species to assess relationships among individuals as a test of the morphological results.