Gulella fraudator Connolly, 1939

Herbert, David G., 2006, Rediscovery of the type species of Euonyma (Subulinidae) and observations on South African species of Gulella (Streptaxidae), with description of two new species (Gastropoda: Eupulmonata), Journal of Natural History 40 (17 - 18), pp. 1063-1081 : 1077-1079

Gulella fraudator Connolly, 1939

( Figures 24–30 )

Gulella fraudator Connolly 1939, p 57 , Plate 2, Figure 3 ; Aiken 1995, p 10. Type locality: ‘‘Mbotyi Beach bush’’, E. Cape Province, South Africa.

Material examined

Type material. Holotype and two paratypes ( BMNH 1937.12.30.862-5), three paratypes ( NMSA T560 /W1574), ‘‘Mbotyi Beach bush’’, E. Cape Province, South Africa, leg. W. Falcon, 1934.

Additional material. South Africa, E. Cape: Mkambati Nature Reserve ‘‘ Super Bowl’ ’ forest at junction of Msikaba and Kwadlambu rivers, 31 u 17.7289S, 29 u 55.7529E, indigenous forest, in leaf-litter, leg. D. Herbert, 5 March 2001 ( NMSA V8965 ) ; Manteku area , 31 u 31.4229S, 29 u 40.35729’E, coastal scarp forest, in leaf-litter, leg. D. Herbert and M. Bursey, 30 April 2004 ( NMSA W1919 ) ; Mntafufu , south side of river, 31 u 33.01269S, 29 u 37.06629E, coastal scarp forest, amongst talus and leaf-litter at base of road cutting, leg. D. Herbert and M. Bursey, 29 April 2004 ( NMSA W1818 ) ; Hluleka Nature Reserve , 31 u 49.2169S, 29 u 18.1829E, coastal forest, sorted from leaf-litter leg. D. Herbert, L. Davis and M. Bursey, 20 April 2005 ( NMSA W3457 ) ; Xora River mouth area, Kumqolo Forest , 32 u 09.5539S, 28 u 59.1219E, coastal forest, in leaf-litter, leg. M. Bursey, 12 August 2003 ( ELM 14265) .

Distribution and habitat

Known only from the coastal hinterland of the Transkei region, E. Cape, South Africa; from Mkambati Nature Reserve in the north, to the vicinity of Xora River mouth in the south ( Figure 30 ); in leaf-litter of coastal forests.

Remarks

Connolly’s (1939) description of G. fraudator was based on a sample collected at Mbotyi by W. Falcon in March, 1934. The holotype and two paratypes are in the BMNH (1937.12.30.862-5), and three further paratypes are present in the NMSA (W1574/ T560), the latter recently returned from long-term loan. Although a second locality, ‘‘Hole in the Wall’’ (Transkei region, E. Cape), was recorded by Aiken (1995), for which there is no voucher specimen, no further material of the species has been collected and it has remained poorly known. In the absence of reference material, Herbert and Kilburn (2004) were unable to adequately discuss the taxon and tentatively postulated that it might represent a synonym of G. mariae (Melvill and Ponsonby, 1892) .

Recently, regular field visits to the Transkei region of E. Cape have brought to light much new streptaxid material ( Bursey and Herbert 2004), including specimens which are clearly referable to G. fraudator . This has been confirmed by comparison with the holotype and the recently returned paratypes. Connolly’s figure of the species, though accurate, is typically small and I take this opportunity to refigure the holotype ( Figure 24 ) and illustrate additional features using the recently collected material ( Figures 25–29 ). The original description of the species is adequate and redescription is unwarranted, although it is puzzling that Connolly treated the species in his Group 4iia, comprising species with five-fold dentition, when, as he himself indicated, the species has six-fold dentition ( Figure 27 ). He also did not comment on the weak but distinct subsutural riblets, noting only ‘‘growth wrinkles’’. He did, however, observe that the latter become more regular and stronger behind the outer lip ( Figure 28 ) and on the base, around the umbilical margin ( Figure 29 ). In side view the base itself shows a distinct concavity and basal heel behind the reflected basal lip ( Figure 28 ). Using the Gulella subdivisions proposed by Herbert and Kilburn (2004), G. fraudator belongs within Group 8B, but it should be noted that there is some variability in the shape of the labral and columella teeth. Connolly gave the dimensions of the species as length 2.75 mm, width 1.5 mm, but measurements of the additional material range as follows: length 2.53–3.05 mm, width 1.24–1.5 mm, length: width 1.86–2.17 (N 512).

The taxon is clearly distinct and not a synonym of G. mariae (cf. Herbert and Kilburn 2004). That species lacks subsutural riblets and has a much weaker labral tooth complex, a less oblique parietal lamella, and a less elongate columella tooth. This broad, flat-topped tooth in the middle of the columella lip is one of the more distinctive characters of G. fraudator . Few southern African Gulella species share this feature and those that do differ in other respects. Perhaps the most similar species are G. himerothales (Melvill and Ponsonby, 1903) , G. rumpiana Connolly, 1932 , and G. contraria Connolly, 1932 , but all are noticeably larger than G. fraudator . Gulella himerothales (length up to 4.2 mm), from southern KwaZulu-Natal and E. Cape, has a labral complex in the form of two clearly distinct teeth, a more ridge-like basal tooth which is situated nearer to the columella, and a mamillate columella lamella. Gulella rumpiana (length up to 5.5 mm), from the E. Cape/KwaZulu- Natal border, has an even broader columella tooth, and lacks subsutural riblets. Gulella contraria (length up to 4.8 mm), from afromontane forests in northern KwaZulu-Natal, Mpumalanga, and Swaziland, likewise lacks subsutural riblets and has a labral tooth complex of very different form.

Conservation

Gulella fraudator is an element of the endemic subtropical/warm-temperate subtraction zone fauna characteristic of the Transkei region, E. Cape. Such species typically have narrow distribution ranges and frequently meet the IUCN criteria for red-listing. Issues relevant to the conservation of these species have been discussed by Bursey and Herbert (2004). The distribution of G. fraudator is similar to that of G. latimerae Bursey and Herbert, 2004 , although it ranges slightly further northward than that species.

Figures

Figure 30. Gulella fraudator Connolly, 1939, distribution: black triangles represent site records; contour at 1000 m.

Figures 24–26. Gulella fraudator Connolly, 1939. (24) Holotype, apertural view, length 2.75 mm. (25) NMSA V8965, length 3.0 mm. (26) Side view, NMSA V8175, length 2.87 mm.

Figures 27–29. Gulella fraudator Connolly, 1939. (27) Detail of apertural dentition, NMSA V8965. (28) Side view of aperture, NMSA V8175. (29) Umbilical region, NMSA V8965. Scale bars: 250 mm (27); 300 mm (28); 400 mm (29).

Figures 1–3. Euonyma laeocochlis (Melvill and Ponsonby, 1896). (1) Lectotype, BMNH, length 30.4 mm. (2) Livecollected shell, NMSA V8572, length 32.5 mm. (3) Apex of previous, NMSA V8572.