Kellia becki (W. H. Turton, 1932 )

Valentich-Scott, Paul, Griffiths, Charles, Landschoff, Jannes, Li, Ruiqi & Li, Jingchun, 2024, Bivalves of superfamily Galeommatoidea (Mollusca, Bivalvia) from western South Africa, with observations on commensal relationships and habitats, ZooKeys 1207, pp. 301-323 : 301-323

Kellia becki (W. H. Turton, 1932)

Fig. 4 A – H

Erycina becki W. H. Turton, 1932: 238.

Material examined.

Two specimens from at Glencairn , South Africa (34.162 ° S, 18.432 ° E) .

Description.

Shell ovate, thin, fragile, highly inflated, semi-translucent; subequilateral; umbos broad, moderately inflated; anterior and posterior ends broadly rounded; shell margins not gaping; periostracum thin, adherent, yellow, iridescent; external sculpture of fine commarginal striae; hinge plate narrow; right valve with one small cardinal tooth and one thin posterior lateral tooth, with large gap between them; left valve with two very small cardinal teeth and one posterior lateral tooth; ligament oblique, broad, in shallow resilifer. Length up to 6 mm.

Mantle. Translucent, reflected, extending well past shell margin dorsally, forming an extended facultative siphon posteriorly (Fig. 4 H ).

Foot. Long, thin, translucent, without heel (Fig. 4 H ).

Ctenidia. Specimens for internal examination not available.

Type.

ZC - M 003209, Port Alfred, South Africa.

Commensal relationship and habitat.

Found on the undersides of rocks in intertidal pools. Although the errant polynoid polychaete, Polynoe scolopendrina Savigny, 1822 , is also visible in some of the images provided herein, we do not suspect any commensal relationship between the Kellia becki and this polychaete and consider it to be a free-living, nestling species.

Comparisons.

Huber (2015) considered Kellia becki to be the only member of this genus to be present in the Cape Town region. The Australian Kellia rotunda ( Deshayes, 1856) had been recorded from South Africa by Bartsch (1915), W. H. Turton (1932), Barnard (1964 a), and Kilburn and Rippey (1982), but these records were considered erroneous by Huber (2015), although he did mention the need to genetically compare these two species.

The specimens illustrated by Cosel and Gofas (2019: 486) in tropical West Africa as Kellia suborbicularis ( Montagu, 1803) are very similar conchologically to our specimens from the Cape Peninsula. Genetic studies on these two populations, as well as other Atlantic species of Kellia , are needed.

Locality information.

Collected intertidally from beneath boulders at Glencairn, on the east coast of the Cape Peninsula, South Africa (34.162 ° S, 18.432 ° E). Voucher specimens deposited as SBMNH 666951 and SAMC-A 096819.

Figures

Figure 4. Kellia becki A – F SBMNH 669951, length = 5.6 mm, height = 4.9 mm A exterior of right valve B exterior of left valve C interior of left valve D interior of right valve E hinge of left valve F hinge of right valve G living animal on rock adjacent to polynoid polychaete, Polynoe scolopendrina H living animal with mantle and foot fully extended.