Kalidos maryannae, Griffiths & Herbert, 2013

Griffiths, O. L. & Herbert, D. G., 2013, New species of land snails (Mollusca: Gastropoda) from two isolated karst formations in central western Madagascar: Tsingy Beanka and Antsingimavo, with additional notes on other regional endemics, African Invertebrates 54 (1), pp. 1-48 : 32-38

Kalidos maryannae sp. n.

Figs 23 , 24 , 25H

Etymology: Named for Mary-Ann Stanley, wife of Owen Griffiths.

Diagnosis: Shell globose-lenticular, periphery rounded, aperture weakly descendant, umbilicus narrow; sculpture of fine, uneven spiral lines crossed by growth-lines; lustreless, pale coffee-brown, with a bold white spiral band just above periphery, bordered above and below by thinner, dark brown spiral lines.

Description:

Shell: Medium sized, globose-lenticular with a relatively elevated spire (H:D=0.57– 0.67); periphery at mid-whorl, rounded in adults, somewhat angled in juveniles; suture indented but not strongly so, situated at whorl periphery, occasionally slightly descendant prior to aperture; umbilicus narrow. Protoconch of approx 1¼ whorls, smooth except for numerous, close-set, microscopic, spiral threads; junction with teleoconch often indistinct. Teleoconch of a further 3½–4 whorls; initially lustreless and smooth, save for weak growth-lines, but with fine, irregular spiral sculpture developing with growth; last adult whorl with surface cut by somewhat stronger, rather uneven spiral lines, crossed by irregular growth-lines, creating low, weakly and unevenly pustular spiral ridges ( Fig. 23K ), these more distinct toward periphery, but evanescing on base which is more glossy and sculptured only with close-set, microscopic, incised spiral threads, rendered irregularly undulant by growth-lines. Aperture ovate-reniform, peristome strongly oblique to vertical axis of shell, interrupted by base of penultimate whorl; outer lip simple and thin; upper part of columella lip reflected and partially covering umbilicus.

Shell strikingly coloured, with a bold white spiral band (1.0–2.0 mm wide) just above periphery, bordered above and below by thinner, dark brown spiral lines; white band and upper brown line visible on penultimate whorl, but generally absent on spire whorls; remainder of shell rather unevenly washed with buff to pale coffee-brown in fresh specimens, fading to dirty white with time and loss of periostracum. Colour bands often ceasing a short distance before lip edge, and clearly visible inside aperture. In the largest specimens, an additional ⅛ whorl is added to the mature lip ( Fig. 23I ). These may represent individuals that survive through the dry season after maturity has been reached and begin another phase of growth when the rains return the following year.

Dimensions: Holotype, max. diameter 27.3 mm, height 17.7 mm; largest specimen, max. diameter 29.4 mm, height 18.8 mm.

External features ( Fig. 25H ): Head-foot mostly pale, but somewhat darker anteriorly, with yellowish white tubercles contrasting with darker, brownish skin grooves; lateral pedal grooves and peripodial groove distinct; caudal pit and surmounting horn well developed; optic tentacles darker greyish brown; mantle lobes pale with numerous yellowish white pigment granules.

Distal genitalia ( Fig. 24 ): Penis of moderate length (approx. 12.5 mm), apical portion swollen and with a deep indentation; basal ¾ encased in a thin sheath; apical bulb of penis containing a well-developed verge; verge much contracted but possessing a deep longitudinal groove confluent with opening of epiphallus; lower portion of penis with 5 or 6 broad, low folds with a microscopically velvety texture; epiphallus cylindrical, with a sharp bend at insertion of penial retractor muscle and thus divided into proximal and distal limbs; proximal limb slightly shorter than distal one (distal limb might also be considered part of penis rather than epiphallus); a short flagellum, comprising just over one tight loop, arises at junction of vas deferens and epiphallus; flagellum and vas deferens wrapped in connective tissue, but flagellum not connected to penis by muscle bands; lumen of flagellum with a rod-like process extending from its blind end; vas deferens passes along vagina and free oviduct to its origin at base of sperm-oviduct; retractor muscle of right optic tentacle passes to right of penis, i.e. between penis and vagina; bursa copulatrix large, narrowing apically and with a short broad duct; wall of duct thick and muscular, lined internally with longitudinal folds, wall of bursa much thinner; bursa with one moderately fresh allospermatophore and the remains of at least one more; free oviduct swollen prior to its junction with vagina (peri-vaginal or oviducal gland); sperm-oviduct well developed, twisted and with numerous superficial folds. Spermatophore with well-developed capsule (head and body) and a looped tail piece corresponding with shape of flagellum; tail piece with prominent flange-like spiral ridge; a small ‘filling nipple’ present at level of vas deferens.

Holotype: MADAGASCAR: Central W Madagascar, ca 60 km E of Maintirano, S part of Tsingy Beanka , S side of Tana–Maintirano road, above N bank of Kimanambolo R., tall moist forest growing on limestone on south-facing slopes, 18.06325°S 44.52861°E, ca 345 m, ii.2010, R. Randalana, st’n R01/10 ( AMS C.474168) . Paratypes: Same data as holotype ( NMSA L8470 /T2904, 10 specimens, body of one in alcohol); 12/06 ( NMSA L7193 /T2944, 3 specimens, body of one in alcohol); st’n 8/10 ( NMSA L8471 /T2943, 1 specimen) ; st’n R01/09 ( NMSA L8475 /T2912, 1 specimen, body in alcohol); st’n 08/09 ( AMS C.469578, 12 specimens) ; st’n 03/10 ( MNHN IM-2010-20072, 3 specimens; NHMUK 20120015 , 3 specimens); st’n 07/09 ( TMAM T166 , 6 specimens) .

Additional locality data: Antsingimavo: st’n 04/06 (subfossil). Tsingy Beanka : st’ns 12/06, 14/06, 15/06, 18/06, 02/09, 06/09, 07/09, 08/09, 09/09, 11/09, 01/10, 04/10, 06/10, 07/10, 08/10, 09/10.

Distribution: Evidently now confined to the Tsingy Beanka , where it is moderately common; not recorded from the Tsingy de Bemaraha, but a single subfossil specimen was found at Antsingimavo.

Habitat: Fresh dead shells are found most commonly amongst limestone rocks, predominantly in the taller moister forests of the southern part of Tsingy Beanka . Living specimens are usually found in leaf-litter.Appears to aestivate sealed to limestone rocks or deep in tsingy slots.

Remarks: In its moderate size and pattern of peripheral banding (two dark brown spiral lines separated by a broader whitish band) this species resembles K. bathensis ( Robson, 1914) , K. bournei Robson, 1914 , K. ekongensis (Angas, 1877) , K. hova (Odhner, 1919) , and K. namorokae Emberton, 2007 . In K. bournei and K. namorokae , however, the shell is smaller and the upper brown spiral line is situated further from the whorl periphery. In contrast, K. bathensis is larger than the present species, paler in colour and the median spiral band between the brown spiral lines is not distinctly paler than the remaining shell. In addition, it has a third brown spiral line below the suture and the supra-peripheral spiral line is clearly present on the spire whorls.

Undoubtedly, the most similar species in terms of size and colour pattern are K. ekongensis and K. hova , both of which, as presently conceived, are poorly delineated species. In his description of K. hova Odhner (1919) noted a fawn peripheral band on an otherwise brownish shell, but he made no mention of this band being bordered above and below by dark brown spiral lines, neither are these clearly evident in his figure nor in the type material ( Fig. 26J–L , syntype, SMNH). He also stated that the shell was smooth and glossy and that the spiral microsculpture was more distinct on the base. This is not the case in K. maryannae in which the shell is lustreless and the spiral sculpture strongest above the periphery of the last whorl.

K. ekongensis is more difficult to assess since the type material is now missing. A paratype reportedly in the NHMUK (Fischer-Piette et al. 1966) is not in fact present there (Ablett pers. comm. Nov. 2011). The original description is not detailed, but the figure shows a shell closely resembling the present material. However, Fischer-Piette et al. (1966) noted, after examination of the NHMUK paratype, that the shell was thin and very glossy. Again this is not a description that would apply to the present material. Fischer-Piette et al. (1966, 1994) interpreted K. ekongensis very loosely, including in it a variety of different forms from widely disjunct localities with widely differing habitats. Almost certainly these are not conspecific and their true identity requires further investigation.

In addition to having relatively coarse spiral sculpture on the last adult whorl, rendering it lustreless, K. maryannae also differs from K. ekongensis and K. hova in having more rapidly expanding whorls. Another distinctive feature of K. maryannae is that the colour bands are evident only on the penultimate and final whorls, the spire whorls being of a uniform colour.

The genital anatomy of K. maryannae conforms to the common pattern evinced by Kalidos species (Fischer-Piette et al. 1975; Schileyko 2002) and is fully consistent with referral of the species to this genus. In this regard it is perhaps most similar to Kalidos oleatus (Ancey, 1902) as figured by Schileyko (2002), but in the present species the flagellum is shorter and more tightly coiled and it is not connected to the penis by muscle bands, and the bursa copulatrix duct is shorter and much broader.

Figures

Fig.23. Kalidos maryannae sp.n.:(A–C) holotype, max.diameter 27.3 mm,height17.7 mm,AMSC.474168; (D–J) paratypes, NMSA L8470/T2904: (D) specimen with bands of intermediate strength, max. diameter 29.3 mm; (E) specimen with broad brown bands and low spire, max.diameter 27.0 mm; (F) specimen spire of intermediate height, max. diameter 28.3 mm; (G, H) fresh subadult with unfaded colour pattern, max. diameter 24.8 mm; (I) large specimen with additional ⅛ whorl of growth, max. diameter 29.3 mm; (J) juvenile showing angular periphery, max. diameter 15.2 mm; (K) holotype, portion of last adult whorl showing sculpture of growth-lines and spiral threads.

Fig. 24. Kalidos maryannae sp. n., genitalia, paratype, NMSA L8470/T2904: (A) entire reproductive tract; (B) penis opened longitudinally to show well-developed penial verge extending from epiphallus; (C) allospermatophore from bursa copulatrix, head end missing.Abbreviations:ag – albumen gland, bc – bursa copulatrix, bcd – bursa copulatrix duct, ep – epiphallus, f – flagellum, ga – genital atrium, og – oviducal gland, p – penis, ps – penis sheath, pv – penial verge, prm – penial retractor muscle, sc – spermatophore capsule, sod – sperm-oviduct, st – spermatophore tail, v – vagina, vd – vas deferens.

Fig. 25. Living animals from Tsingy Beanka: (A) Acroptychia bathiei Fischer-Piette & Bedoucha, 1965, st’n 13/06, shell diameter 23.2 mm, NMSA L7315; (B) Tropidophora humbug sp. n., st’n 12/06, shell diameter 28.3 mm, paratype,NMSA L7204/T2984; (C) Tropidophora secunda Fischer-Piette & Bedoucha, 1965, st’n 03/06, shell diameter approx.19.0 mm; (D) Clavator griffithsjonesi Emberton, 1999, st’n 12/06, shell height 94.8 mm, NMSA L7192; (E) Ampelita milloti Fischer-Piette,1952,st’n 07/09, shell diameter 19.2 mm, NMSA L8502; (F) Ampelita namerokoensis Fischer-Piette, 1952, st’n 12/06, shell diameter 20.3 mm, NMSA L8442; (G) Kalidos griffithshauchleri Emberton, 2002, st’n 12/06, shell diameter approx. 60 mm; (H) Kalidos maryannae sp. n., st’n 12/06, shell diameter 22.5 mm, paratype, NMSA L7193/T2944.

Fig.26.Speciesillustrated for comparative purposes:(A–C) Tropidophora moulinsii, holotype of Cyclostoma moulinsii Grateloup, 1840, ‘Madagascar’, max. diameter 33.1 mm, NHMUK 1907.11.22.12; (D–F) Tropidophora thesauri Fischer-Piette, 1949, Orangea, Diego Suarez [= Antsiranana] district, max. diameter 38.0 mm, NMSA L8438; (G–I) Tropidophora reticulata, one of three syntypes of Cyclostoma reticulatum (Adams & Reeve, 1850), ‘Madagascar’, max.diameter 15.1 mm, NHMUK 1874.12.11.231; (J–L) Kalidos hova, syntype of Nanina hova Odhner, 1919, Catsèpe, Madagascar, max. diameter 24.4 mm (SMNH).