Dadagulella browni semulikiensis, Rowson & Tattersfield, 2013

Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the “ Gulella radius group ” (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, European Journal of Taxonomy 37, pp. 1-46 : 14

publication ID	https://doi.org/ 10.5852/ejt.2013.37
publication LSID	lsid:zoobank.org:pub:ADF6394E-77B5-4309-87FE-4097FDE0A3FD
DOI	https://doi.org/10.5281/zenodo.3815747
persistent identifier	https://treatment.plazi.org/id/4511E41D-D829-FFC9-FDAE-FC8DF3A5FD8C
treatment provided by	Carolina
scientific name	Dadagulella browni semulikiensis
status	subsp. nov.

Treatment

Dadagulella browni semulikiensis View in CoL subsp. nov

Figs 22 View Figs 6-26 , 55 View Figs 51-64 , 84 View Fig ; Table 1 View Table 1

Etymology

From Semuliki.

Type material examined

UGANDA: holotype NMW.Z.1997.009.00004 : 1 ad., Semuliki National Park (00.82°N, 30.16°E), Bwamba County, Bundibugyo District, lowland Guineo-Congolian rainforest (site IIR), approx. 760 m alt., leg. PT & J.A. Allen , 14 Jul. 1996. GoogleMaps Paratype NMW. Z.1997.009.00005: 1 ad., data as holotype.

Other material examined

UGANDA: NMW. Z.1997.009.00006: 1 juv., data as holotype.

Description

SHELL ( Figs 22 View Figs 6-26 , 55 View Figs 51-64 ). Small (3.20 - 3.30 mm high x 1.90 mm wide), of 6.0 - 6.5 whorls. Ovate-acuminate, spire broadly acuminate (spire angle around 67°). Apex pointed. Embryonic whorls smoothly granulate. Later whorls with relatively coarse ribs (around 12 per mm on penultimate whorl). Sutures relatively shallow. Umbilicus closed. Peristome complete. Outer palatal surface of aperture with a depression corresponding to the palatal tooth, and another much weaker one corresponding to the basal tooth. Dentition 8-fold, consisting of: one lamella-like parietal tooth and one additional parietal denticle; one slab-like palatal tooth, forming a long, narrow parieto-palatal sinus; two basal denticles; a deepset columellar baffle and two shallower columellar denticles. Juvenile shell with 3-fold dentition: one parietal lamella; one bifid basal tooth; and one baso-columellar tooth. Anatomy unknown.

Range and habitat

Lowland Guineo-Congolian forest at the type locality in the valley of the Albertine Rift.

Remarks

This subspecies is very similar to D. b. browni comb. nov. and, if found together, the two might not at first glance be distinguished. However, D. b. semulikiensis subsp. nov. is approximately 10% taller and wider, has shallower sutures and a more complete peristome. Its parieto-palatal sinus is longer and narrower than that of D. b. browni comb. nov., and does not widen appreciably towards its inner end. The type localities of D. b. browni comb. nov. and D. b. semulikiensis subsp. nov. are over 3000 km apart, in very different biogeographic and climatic regions. Although several snail species are known to range between South and East Africa, most are either species of the coastal strip, or are widely distributed throughout the entire area. Dadagulella gen. nov. has not been recorded from much of the intervening area of East Africa and is represented in the Albertine Rift otherwise only by D. selene (van Bruggen & Van Goethem, 1999) comb. nov. It remains possible that the Semuliki population has descended from D. b. browni comb. nov., introduced by man from Tanzania or further to the south, and that the morphological differences are mainly ecophenotypic. However, in the light of these differences and the great geographic separation, we treat it as a subspecies of D. browni comb. nov. as we do with D. b. mafiensis subsp. nov.