Gastrocopta margaretae (Cox, 1868)

Whisson, Corey S. & Koehler, Frank, 2013, Gastrocopta (Mollusca, Gastropoda, Pupillidae) in the Pilbara region of Western Australia, ZooKeys 261, pp. 15-39 : 25-26

3. Gastrocopta margaretae (Cox, 1868) Fig. 2F

Pupa margaretae Cox 1868: 80, pl. 14, figs 20,20a.

Pupa wallabyensis Smith 1894: 97.

Gastrocopta margaretae Pilsbry 1917 [in 1916-1918]: 160-161, pl. 26, figs 7-8; Solem 1986: 99-101, figs 8 –9,11– 12, 1991: 249; Pokryszko 1996: 1096-1099, figs 6, 8-10.

Gastrocopta tatei Pilsbry 1917 [in 1916-1918]: 165-166, pl. 26, figs 9-10, pl. 30, fig. 12; Solem 1989: 491-492, figs 56-59; 1991: 249.

Gastrocopta wallabyensis Pilsbry 1917 [in 1916-1918]: 171-172; Solem 1986: 101-102, figs 13-15; 1991: 249.

Australbinula margaretae Iredale 1937a: 302, 1937b: 11, pl. 1, fig. 4.

Australbinula wallabyensis Iredale 1937a: 302.

Australbinula tatei Iredale 1937a: 302, 1937b: 10.

Gastrocopta pilbarana Solem 1986: 103-104, figs 16-20; 1991: 249.

Type locality.

Wallaroo, South Australia.

Material studied.

Western Australia: Bateman Sanctuary: 23.0552°S, 113.8234°E (WAM S42834). ~18km N of Boolathana Homestead: 24.4133°S, 113.7445°E (WAM S64708). Boolathana Station: 24.4127°S, 113.7631°E (WAM S64709). Bush Bay: 25.1175°S, 113.8063°E (WAM S42806); 25.1316°S, 113.7681°E (WAM S60355); 25.1136°S, 113.7311°E (WAM S64575); 25.1175°S, 113.8063°E (WAM S64577). Carrarang Station: 26.1666°S, 113.3500°E (WAM S34378). Cy Creek: 23.1000°S, 113.8000°E (WAM S34380). Dirk Hartog Island: 25.7166°S, 113.0667°E (WAM S 14439); 25.8333°S, 113.0500°E (WAM S34398). Francois Peron National Park: 25.9760°S, 113.5707°E (WAM S60269); 25.9758°S, 113.5706°E (WAM S64706); 25.8752°S, 113.5497°E (WAM S61127). Lake Macleod area: 24.3449°S, 113.5194°E (WAM S65084); 24.3668°S, 113.5145°E (WAM S65093); 24.3544°S, 113.5098°E (WAM S65102); 24.4760°S, 113.5257°E (WAM S65108); 24.4598°S, 113.5013°E (WAM S65110); 24.3544°S, 113.5098°E (WAM S65121). 0.25 miles W of Nichol Springs: 24.1333°S, 118.4167°E (WAM S60270). ~25 miles N of turn off to Shark Bay on NW Coastal Highway: 26.0647°S, 114.3353°E (WAM S34459, WAM S60271, WAM S64585). 0.5 miles W of 512 mile peg on NW Coastal Highway: 26.1966°S, 114.3758°E (WAM S34379). Quobba Station: 24.4758°S, 113.4166°E (WAM S42829); 24.2448°S, 113.5353°E (WAM S61125); 24.1927°S, 113.4548°E (WAM S64576); 24.2233°S, 113.5036°E (WAM S64707). Salutation Island: 26.5333°S, 113.7667°E (WAM S34377). Winderabandi Point: 22.4929°S, 113.7258°E (WAM S60474). Zuytdorp: 27.2636°S, 114.0703°E (WAM S64710).

Distribution.

This species has previously been recorded fromthe western and southern coastal areas of Western Australia, the southern regions of South Australia and the area near Alice Springs in the Northern Territory. There is also an isolated record from the King Leopold Range in the north of Western Australia ( Pokryszko 1996). In the Pilbara it is confined to the near west coast with an isolated inland record from the Ashburton River (Figure 3).

Comparative morphology.

Shells of Gastrocopta margaretae are easily distinguished from other Gastrocopta species in the Pilbara by the presence of (1) a moderately to strongly folded columellar tooth (2) a generally large and transverse basal tooth (3) a high and long lower palatal tooth (4) an upper palatal tooth that is moderately to strongly convergent with the lower palatal (5) a weak to strong infraparietal tooth present.

Remarks.

Solem (1986) maintained the separation of the west coast species Gastrocopta wallabyensis from the south coast Gastrocopta margaretae based on size (smaller) and length of apertural barriers (longer). He also described a new species, Gastrocopta pilbarana , from the west coast but his separation of it from Gastrocopta wallabyensis was vague. Solem later ( 1989) maintained the separation of the central Australian Gastrocopta tatei from the above species but remarked it was somewhat similar to the west coast Gastrocopta wallabyensis . Pokryszko (1996) later disagreed, synonymising all species with Gastrocopta margaretae .

The few specimens sequenced from the south coast of Western Australia (WAM S32048, WAM S32052) could represent genetic isolation by distance or perhaps a different species from those on the west coast (WAM S42834) but more molecular data are required. The southern specimens are (1) much larger with reduced apertural barriers (2) more strongly rounded whorls (conical) and (3) consistently lack an infraparietal tooth. Specimens resembling the smaller west coast form (ie. long apertural barriers and weak to strong infraparietal tooth) have also been recorded from the south west area of Western Australia (Whisson, pers. comm.) where it is often sympatric with Gastrocopta bannertonensis (Gabriel, 1930). It is not known whether there is a continuous distribution between the two areas. Until more detailed molecular work is undertaken we have maintained Pokryszko’s ( 1996) systematic positions.