Two new genera and three new species of exceptionally rare and endemic freshwater mussels (Bivalvia, Unionidae) from the Mekong Basin
Issued Date
2024-01-01
Resource Type
ISSN
14351935
eISSN
18600743
Scopus ID
2-s2.0-105004379428
Journal Title
Zoosystematics and Evolution
Volume
100
Issue
4
Start Page
1333
End Page
1345
Rights Holder(s)
SCOPUS
Bibliographic Citation
Zoosystematics and Evolution Vol.100 No.4 (2024) , 1333-1345
Suggested Citation
Jeratthitikul E., Sutcharit C., Prasankok P. Two new genera and three new species of exceptionally rare and endemic freshwater mussels (Bivalvia, Unionidae) from the Mekong Basin. Zoosystematics and Evolution Vol.100 No.4 (2024) , 1333-1345. 1345. doi:10.3897/zse.100.130929 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/110130
Title
Two new genera and three new species of exceptionally rare and endemic freshwater mussels (Bivalvia, Unionidae) from the Mekong Basin
Author(s)
Corresponding Author(s)
Other Contributor(s)
Abstract
Two new genera and three new species of freshwater mussels in the tribe Pseudodontini (Bivalvia, Unionidae) are described from the Mekong Basin in Thailand based on an integrative taxonomic study involving morphology and multi-locus phylogenetic analyses (mitochondrial COI and 16S, and nuclear 28S genes). The monotypic genus, Lannanaia kokensis gen. et sp. nov., presents unique features of being rather compressed, sub-trigonal in outline with short and high shell, and with a distinct posterior wing. Another new genus, Isannaia gen. nov., is characterized by having a thin and moderately inflated shell, with rhomboidal to ovate outline. It includes two lineages that are genetically separated by 3.54% uncorrected COI p-distance, and are herein described as I. fortunata sp. nov. and I. occultata sp. nov. Phylogenetic analyses further revealed that these two new genera were nested within a clade of subtribe Pseudodontina, and with pairwise uncorrected COI p-distance to other genera ranging from 11.42 to 15.66%. Based on the present data, Lannanaia gen. nov. is known only from the Kok River in the north of Thailand, whereas the two species of Isannaia gen. nov. are restricted to tributaries of the Mekong River in the northeast of Thailand. The discovery of rare and probably endemic freshwater mussels in the Mekong Basin thus again highlights the importance of this region among freshwater biodiversity hotspots of the world.