Thursday, 27 September 2007

Thursday gastropod: Temporena whartoni (Cox 1871)

It might look dull and ordinary but this is one of the shortest of short range endemic snails in Australia. Temporena whartoni (Cox 1871) is restricted to a single small island off the Queensland coast.

Temporena whartoni is a mid-sized snail — average shell width is 36 mm, shell height 25 mm.


Its home — Holbourne Island — is a granite outcrop that was formerly mined for guano. The 34 ha island is now a national park, so the species is presumably doing all right.




Its taxonomy is another matter. It has been shifted around from one genus to another. Originally described as Helix whartoni (in the 1800s, Helix was the catch all genus for large, rounded shells), it was later moved into Temporena, Iredale's (1933) subgenus of Gnarosophia. Then Iredale (1937) elevated Temporena to genus with H. whartoni as type species. Subsequently, it's been shoved into another catch all — Sphaerospira (Smith, 1992). It almost certainly belongs in a different corner from that genus. It shares some conchological and anatomical characteristics with three other species on the adjacent mainland, including the smaller Varohadra macneilli Iredale 1937, which also occurs on granite islands.

So there's a nice little investigation for someone. A bit of DNA analysis, some historical biogeography ... Oh, and Varohadra — another can of taxonomic worms.


References

Cox, J.C. (1871) Descriptions of seven new species of Australian land shells. Proceedings of the Zoological Society of London 1871: 53–55.

Iredale, T. (1933) Systematic notes on Australian land shells. Records of the Australian Museum 19: 37–59.

Iredale, T. (1937) A basic list of the land Mollusca of Australia. Pt II. Australian Zoologist 9: 1–39.

Smith, B.J. (1992). Non-marine Mollusca. In Houston, W.W.K. (ed.) Zoological Catalogue of Australia. Vol. 8. Canberra: Australian Government Publishing Service.

5 comments:

AYDIN ÖRSTAN said...

How would one get to Holbourne Island?

Snail said...

Sorry, Aydin. I missed your comment.

I haven't been to Holbourne Island but I know people who have. They've travelled by boat. (I suppose that one could charter a seaplane from Shute Harbour, which is down near Airlie Beach, but I'm not sure how close you could get with a plane.)

That figured specimen is from a museum collection. IIRC, it was picked up when the island was still a guano mine.

restoration_rake said...

Just obtained a specimen of what I believe is T. whartoni. It's from the Strecker collection at Baylor University and was accompanied by a shelf tag that identified it as Papuina xanthochila (I know, right? No explanation for that element of the tag). Locality given as "Solomon Islands", and the shell is marked with the same sequence that is typed on the card -- SM32239. The collection date is given as August 4, 1923. The FLMNH has a specimen interpreted as T. whartoni (209158-Mollusca) with a location of New Ireland Province, PNG.

T. whartoni is an insular species and is unlikley to have ever been found in places other than on Holbourne Island, but it seems that there are Camaenidae in nearby places that look quite a bit like T. whartoni. Also, many have written that it was in the past quite common for unidentified specimens to be delivered in boxes labeled (quite generally) "Papua", for example, which really was the locale at which someone got around to aggregating them and boxing them up. The Prys-Jones article ("...the reliability of museum specimen data") provides many examples of this.

So I wonder if what I have here is something like T. whartoni, if someone could have confused Holbourne for the Solomons (which seems impossible in 1923), or if T. whartoni is one of those animals, like Noctepuna/Papuina poiretiana, that's more wide ranging than we have suspected. It's not a dead on match for anything in Stanisic, and putting images aside, there is no single shell whose description is a dead on match, either. In Stanisic, it most resembles the image of T. whartoni, but is a bit lighter in all respects.

amanda starkey said...

I have been to Holbourne Island many times and have seen these shells on the beach.I have even brought an empty one home so I could double check that this is the Thursday Gastropod.It is! You get to Holbourne Island by boat.It is 37klms from Bowen in North Queensland.We are very concerned at the moment as The Abbott Point expansion(if it is approved) allows for toxic dredged material to be dumped very close by here.One would think besides the other obvious environmental impacts this would have around this Island,the Thursday Gastropod would also be in danger.And as this is the only known location they are found well it should be stopped at all costs!

Snail said...

Hi Amanda. I still find it amazing that somewhere like Holbourne has its own species. And I am totally envious of your visit!

A lot of things are happening at the moment (and are likely to keep happening), which have the potential for unintended consequences. :(