Dadagulella browni browni (van Bruggen, 1969 ) browni (van Bruggen, 1969

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 : 11-13

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.3815763

persistent identifier

https://treatment.plazi.org/id/4511E41D-D82E-FFCB-FE16-F960F0C8FB62

treatment provided by

Carolina

scientific name

Dadagulella browni browni (van Bruggen, 1969 )
status

comb. nov.

Dadagulella browni browni (van Bruggen, 1969) View in CoL comb. nov.

Figs 23-26 View Figs 6-26 , 47-48 View Figs 43-50 , 71, 74 View Figs 69-76 , 82 View Figs 77-83 , 84 View Fig ; Table 1 View Table 1

Gulella browni van Bruggen, 1969: 69-71 View in CoL , figs 25-26.

Gulella browni View in CoL – van Bruggen & Appleton 1977: 31-32. — Aiken 1981: 321-323, fig. 5. — Richardson 1988: 60. — Verdcourt 1990: 349. — van Bruggen & Van Goethem 1999: 40. — van Bruggen 2000: 233-234. — Herbert & Kilburn 2004: 212. — Rowson & Lange 2007: 31. — Muratov 2010: 277.

“a closely related species from Zululand” – Verdcourt 1985: 119.

Gulella cf. radius View in CoL – Tattersfield et al. 2006: 52, 54, 58.

Type material examined

SOUTH AFRICA: holotype RMNH.MOL.54894 : 1 ad., Lake Sibayi (approx. 27.34°S, 32.71°E), KwaZulu-Natal, dune forest on the east shore, leg. D.S. Brown, 12 Jun. 1966 (examined digital photograph only). GoogleMaps

Other material examined

TANZANIA: NMW.Z.2003.001.00008: 6 ads, 5 juvs, Mt. Mwanihana Forest Reserve (7.82°S, 36.83°E), Udzungwa Mts National Park, Kilombero District, lowland forest at approx. 600-900 m alt., leg. BR, PT, MBS & CFN, 29 Jan. 2003. NMW.Z.2003.001.00009: 4 ads, data as previous but 700 m alt. NMW.Z.1997.007.00003: 5 ads, 2 juvs, Mzelezi Forest Reserve (8.79°S, 36.72°E), Mahenge Mts, Ulanga District, forest on limestone, approx. 645 m alt., leg. PT, MBS & CFN, 6 Feb. 1997. NMW.Z.1997.007.00004: 1 ad., data as previous. NMW.Z.1997.007.00005: 2 ads, 6 juvs, data as previous.

MOZAMBIQUE: NMW.Z.2012.040.00001: 2 ads, Pomene Bay, Inhambane Province, near lighthouse S of old hotel (22.9417°S, 35.5913°E), degraded dune forest, in leaf-litter, leg. D. Herbert, Oct. 2002 (ex NMSA.L5797). NMSA.L5797: 2 ads, data as previous.

SOUTH AFRICA: NMW.Z. 2012.040.00002: 3 ads, Kosi Bay mouth, KwaZulu-Natal (26.89°S, 32.88°E), dune forest, in sandy leaf-litter, leg. D. Herbert & L. Davis, “11-41”, 13 Oct. 2011 (ex NMSA. W8517). NHMUK.20110173: 2 ads, Lake Sibaya area of Tongaland (approx. 27.35°S, 32.67°E), Zululand, S. Africa, leg. C.C. Appleton, Dec. 1972 - Nov. 1973.

Description

SHELL ( Figs 23-26 View Figs 6-26 , 47-48 View Figs 43-50 ). Small (2.60 - 3.20 mm high x 1.60 - 1.90 mm wide), of 5.5 - 6.0 whorls. Ovateacuminate, spire broadly acuminate (spire angle 66 - 76°). Apex pointed. Embryonic whorls smoothly granulate. Later whorls with relatively coarse ribs (11 - 15 per mm on penultimate whorl). Sutures relatively shallow. Umbilicus closed or narrowly open. Peristome incomplete parietally. Outer palatal surface of aperture with a depression corresponding to the palatal tooth and another much weaker one corresponding to the basal tooth. Dentition 7-fold to 8-fold, consisting of: one lamella-like parietal tooth and (almost always) one additional parietal denticle; one slab-like palatal tooth, forming a narrow parieto-palatal sinus; two basal denticles; a deep-set columellar baffle, sometimes folded, and one or two shallower columellar denticles. Dentition of 8-fold individuals alternatively recognisable as 7-fold, depending on the interpretation of the columellar and parietal denticles (van Bruggen 1969). Juvenile shells of D. browni comb. nov. were not known to van Bruggen (1969, 2000). Herbert & Kilburn (2004) describe them simply as dentate, but with dentition different from that of the adult. Juveniles from southern Tanzania ( Figs 47-48 View Figs 43-50 ) have dentition similar to, but weaker than, juveniles of D. r. radius comb. nov. ( Figs 43-45 View Figs 43-50 ).

CEPHALOPODIUM. Pale cream, with pink-orange tentacle retractors and a few purple-brown speckles in the mantle.

SALIVARY GLANDS ( Fig. 71 View Figs 69-76 ). United, soft, not tumid, elongate, bilobed; each duct leaving at the whitened apex of the lobe and evenly thick throughout.

RADULA. Described and figured by Aiken (1981) as having a unicuspid, ‘heart-shaped’ central tooth and nine laterals in each half-row, of which at least the inner six are tricuspid, diminishing gradually in size laterally. The outer cusps of most teeth are smaller than the inner cusp. According to Aiken (1981) the teeth are flexible when pressed by a cover slip and there are 47 rows.

GENITALIA ( Figs 74 View Figs 69-76 , 82 View Figs 77-83 ). Upper parts of spermoviduct not recovered. Vas deferens appearing thickened prior to insertion on penis but actually with a very short, broad parallel diverticulum. Penial sheath absent. Interior of penis with weak radial pilasters. Apical, muscular part of penis with a single large hook, associated with a spatulate “scoop” with microscopically serrated tip. Elsewhere in penis, a single longitudinal row of short, simple hooks.

Range and habitat

Coast of north-eastern South Africa: dune forest, coastal forest and bush; also central Mozambique: high forest in Chiluvo [Xiluvo] hills (19.24°S, 34.06°E) at 700 ft (approx. 213 m) elevation (van Bruggen 1969; van Bruggen & Appleton 1977; Herbert & Kilburn 2004). Also in lowland forest, up to 900 m, in southern Tanzania, as far north as 7.8°S.

Remarks

We agree with van Bruggen (1969) that the complex dentition of D. browni comb. nov. s.l. separates it from D. radius comb. nov. s.l., which never seems to have 8-fold dentition, in particular the extra parietal and basal denticles. The shells of D. browni comb. nov. s.l. are also much smaller, less elongate (i.e. have a lower height/width ratio), and have a much narrower and more horizontal parieto-palatal sinus than is usual for D. radius comb. nov. s.l. Although some specimens of D. r. radius comb. nov. approach D. browni comb. nov. s.l. in one or more of these respects (e.g. Figs 10, 14, 17 View Figs 6-26 ) all can be readily assigned to one or the other and the type specimens are morphologically quite different ( Figs 1-5 View Figs 1-5 , 11 View Figs 6-26 , 52 View Figs 51-64 vs. Fig. 26 View Figs 6-26 ). Material intermediate between D. browni comb. nov. and D. radius comb. nov. might be expected in the intervening area of southern Tanzania or northern Mozambique. However, all the relevant southern Tanzanian material here (e.g. from Mafia and Mahenge) is closer to D. browni comb. nov. s.l. in dentition and other aspects. A recent survey in northern Mozambique ( Muratov 2010) encountered only D. delgada comb. nov.

NMW

Naturhistorisches Museum, Wien

BR

Embrapa Agrobiology Diazothrophic Microbial Culture Collection

MBS

Manchester Banksian Society

CFN

Clifton College

NMSA

KwaZulu-Natal Museum

NHMUK

Natural History Museum, London

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Stylommatophora

Family

Streptaxidae

Genus

Dadagulella

Loc

Dadagulella browni browni (van Bruggen, 1969 )

Rowson, Ben & Tattersfield, Peter 2013
2013
Loc

Gulella cf. radius

Tattersfield P. & Seddon M. B. & Ngereza C. & Rowson B. 2006: 52
2006
Loc

Gulella browni

Muratov I. V. 2010: 277
Rowson B. & Lange C. N. 2007: 31
Herbert D. & Kilburn D. 2004: 212
Bruggen A. C. van 2000: 233
Bruggen A. C. van & Van Goethem J. L. 1999: 40
Verdcourt B. 1990: 349
Richardson C. L. 1988: 60
Aiken D. W. 1981: 321
Bruggen A. C. van & Appleton C. C. 1977: 31
1977
Loc

Gulella browni van Bruggen, 1969: 69-71

Bruggen A. C. van 1969: 71
1969
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