Mussel of the

Page last updated
29 October 2004

Mussel of the Month

The November 2004 Mussel of the Month is Haasodonta fannyae. Haasodonta is an odd genus of freshwater mussel endemic to the island of New Guinea.

Haasodonta fannyae
MCZ 160663. Marco River, Merauke, New Guinea.

Two species of freshwater mussels are currently placed in the genus Haasodonta, and one of them is H. fannyae. The interesting thing about Haasodonta is that we aren't sure what family it belongs to. Richard Johnson originally described fannyae as a Hyridella, which belongs to the family Hyriidae. But Don McMichael, who revised the Australasian freshwater mussels and had seen his share of hyriids, thought fannyae was more like a unionid, and he made up the genus Haasodonta for it. For the time being, since we haven't seen (or even heard of) soft parts for this animal, we will just have to go along with McMichael that Haasodonta belongs in the Unionidae.

If Haasodonta is a unionid genus, that would be interesting. It would be the only genus of the Unionidae to cross Wallace's Line. There are a bunch of mussels on the rest of the Indonesian archipelago, but no other member of the Unionidae makes it as far out as New Guinea. And, there are other freshwater mussels on New Guinea, but they are all hyriids similar to those found in nearby Australia.


Phylum Mollusca
Class Bivalvia
Subclass Palaeoheterodonta
Order Unionoida

Superfamily Unionoidea Rafinesque, 1820 ??

Family Unionidae s.s. ??

Genus Haasodonta McMichael, 1956

Species Haasodonta fannyae (Johnson, 1948)

For more information about Haasodonta:
  • McMichael, D.F. & I.D. Hiscock. 1958. A monograph of the freshwater mussels (Mollusca: Pelecypoda) of the Australian region. Australian Journal of Marine and Freshwater Research 9(3): 372-508 + 19 plates.
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