Mussel of the

Page last updated
5 August 2019

Mussel of the Month

The August 2019 Mussel of the Month is Elongaria orientalis. Elongaria is a genus of two species from Java and Borneo.

USNM 86058. Java (type).

The genus Elongaria is endemic to the subregion of East Asia that we call Sunda-Philippines, a area that would benefit from further study. We currently know of 31 freshwater mussel species in the subregion, 23 of which are endemic (i.e., not found in other subregions). The genera Caudiculatus, Ctenodesma, Discomya, Elongaria, Pressidens, Prohyriopsis, Schepmania, and Simpsonella are endemic to the subregion, and Rectidens extends from the Sunda-Philippine islands to the Malay peninsula, which we include in the Indochina subregion of East Asia. If you click around those previous Mussels of the Month, you will probably notice a theme: we know little about those mussels except that they have been described (and can be digitally photographed).

The burst of recent phylogenetic revisionary work in Indochina and Myanmar* has not extended south to the large islands between Asia and Australia, and only a few new works are available that update our published checklist (Graf & Cummings, 2007) — which was based largely on Haas (1969), which mostly just updated the genera of Simpson (1914). The freshwater mussels of Java have been reported by van Benthem Jutting (1953) and Affandi et al. (2013), those of Sumatra by Marwoto (1987), and Zieritz et al. (2018a) reported on Borneo. The grand East Asia review by Zieritz et al. (2018b) covers the whole Sunda-Philippines region.

* Check out the discussions in Mussel of the Month posts from 2018 and earlier this year for more information.


Phylum Mollusca
Class Bivalvia
Subclass Palaeoheterodonta
Order Unionoida

Superfamily UNIONOIDEA Rafinesque, 1820
Family UNIONIDAE s.s.
Subfamily RECTIDENTINAE Modell, 1942

Genus Elongaria Haas, 1911

Species Elongaria orientalis (Lea, 1840)

To find out more about Elongaria and the mussels of the Sunda Islands and the Philippines, check out:
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