Morphological variation in seven species of catfishes of the genus Glyptothorax in Iranian inland waters using traditional and geometric morphometric methods

  In the present study, the morphological variation in seven catfish species of the genus Glyptothorax in the inland waters of Iran was studied using traditional and geometric morphometric methods.

For this purpose, 182 specimens including 32 G. alidaeii, from the Seimare in the Karkheh drainage, 54 G. galaxies, from the upper Karun drainage, 12 G. hosseinpanahi, from the Zohreh drainage, 16 G. shaperi, from Shapur in the Helleh drainage, 30 G. silviae, from the Jarrahi drainage, 26 Glyptothorax sp. from the Gamasiab drainage, 12 G. pallens, from the Sirvan drainage, totally from 12 sampling sites in inland waters of Iran were analyzed. The sampling was done using electrofishing during 2009-2021. Morphological traits were measured. The geometric morphometric comparison based on 15, 13, and 10 landmark indicators respectively from lateral view with 106, ventral 79, and dorsal 46 distance between these points were digitized and analyzed. The landmark method was used to determine the general body shape of the populations and related analyzes including DFA, CVA, PCA, and hierarchical dendrogram were performed to determine the differences between the Glyptothorax populations

The PCA results of the studied Glyptothorax showed that in lateral, dorsal, and ventral views, 37.375%, 51.164%, and 38.228% of body shape changes are related to two main components, respectively. The traits that had the greatest impact on the separation of the studied species were related to the position of the snout, body length, body depth, head depth, and caudal peduncle length. In addition to the previously reported differences, this morphological-analysis showed a significant interspecific morphological diversity among the studied Glyptothorax.

The obtained results showed a well separation between the studied Glyptothorax species, also suggest the Glyptothorax sp. Population from Gamasiab River as undescribed species, which needs further molecular studies to confirm.