THE LAND SNAILS OF SHARAVATHI WILDLIFE SANCTUARY

Leaf litter and soil of tropical rain forests have the earth's most diverse and endangered, yet least understood communities (Emberton et aI., 1996). Molluscs are an important constituent of this ecosystem, yet majority of them remain undiscover~d and under described, partly because of insufficient exploration and partly because of their often minute sizes (Emberton, 1995). In India, especially from the Western Ghats in Karnataka, land snails have been least worked out. The present report is from our collection from the Sharavathi Wildlife Sanctuary (I4°N & 74°24' E) with a total area of 431.23 sq. km, which includes the reservoir area (123.63 sq. lan.). The sanctuary was declared vide notification No. AFD. 70. FWL-71, in 1972 by the Govt. of Karnataka. The collection includes 22 examples 10 of which have been identified to the species level with the remaining been assigned to their generic name. The system of Classification followed is that given in "A Classification of Living Mollusca" (Vaught, 1989). The study assumes significance because of 10 out of the 23 families of land snails found in the Western Ghats (Madhyastha 2002) are present in this Sanctuary.


INTRODUCTION
Leaf litter and soil of tropical rain forests have the earth's most diverse and endangered, yet least understood communities (Emberton et aI., 1996).Molluscs are an important constituent of this ecosystem, yet majority of them remain undiscover~d and under described, partly because of insufficient exploration and partly because of their often minute sizes (Emberton, 1995).In India, especially from the Western Ghats in Karnataka, land snails have been least worked out.The present report is from our collection from the Sharavathi Wildlife Sanctuary (I4°N & 74°24' E) with a total area of 431.23 sq.km, which includes the reservoir area (123.63 sq.lan.).The sanctuary was declared vide notification No. AFD.70.FWL-71, in 1972 by the Govt. of Karnataka.The collection includes 22 examples 10 of which have been identified to the species level with the remaining been assigned to their generic name.The system of Classification followed is that given in "A Classification of Living Mollusca" (Vaught, 1989).The study assumes significance because of 10 out of the 23 families of land snails found in the Western Ghats (Madhyastha 2002)    Shell globose, sturdy, opaque, widely umbilicate, spire short, dark brownish, with distinct chestnut flame like streaks near the sutures, and with distinct spiral lirations criss crossed by transverse striations.Body whorl with an indistinct keel, with 3-5 lirations above the keel prominent.Whorls 5, rapidly increasing, with visible growth lines, sutures distinct.Apex prominent, chestnut coloured with the periostracum generally corroded.Aperture rounded, lips double, inner lip slightly protruded, continuous fonning a thick callus on the columellar margin.Outer lip, expanded and reflected, discontinuous at the point of attachment to the penultimate whorl.Operculum concentric, concave, retractable only up to the aperture.
Measurements: H = 32 mm, W = 36 mm.Remarks: This species has been reported earlier from Maharashtra only.This report marks the extension of the range of distribution.It measures a bit more than the measurements given in the Fauna of British India (Gude, 1921).The absence of any sinus in the columellar lip rules out the possibility of it being C. indicus.

Genus Alycaeus Gray, 1850
Alycaeus expatriatus (Blanford, 1860)  Shell globose, widely umbilicate, uniformly pink coloured, apex reddish, an accessory canal runs along the suture at the body whorl.Shell thin with distinct vertical striations, which are lacking near the aperture.Whorls 3Y2, body whorl much inflated, just before the constriction, after which it descends considerably towards the aperture forming a vertical keel like swelling.Sutural tube present just before the constriction.Body whorl near the aperture descending and rounded.Lips double, outer expanded, inner lip continuous.Operculum thin, concave, retracts completely up to the constriction.
Measurements: H = 3 mm, W = 4 mm.Remarks: This is an interesting genus, which is widely distributed in the north eastern Himalayas with only two species reported in South India.The keel after the constriction is not so thoroughly marked and also the sutural tube is considerably long which is the opposite in A. footei, the other species found in South India.
Measurements: H = 3 mm, W = 1.5 mm.Remarks: This is a widely distributed genus endemic to Sri Lanka and South India.The present is the first report of the species outside Khandalla.
Shell cylindrical, narrowly perforate, glossy, thin and translucent.Spire sunken, apex obtuse, sutures impressed.Whorls 5, apical two gradually increasing and sunken, third suddenly increases almost enclosing the former, the penultimate whorl is equal to the third, body whorl constricted and deflected inwards.Whorls sculptured with vertical lirations, which are prominent on the body whorl.Aperture reversed, triangularly rounded, slightly ascending touches nearly half of the penultimate whorl.Lips double, reflected, with a broad channel between them.Operculum thin, fully retractable much beyond the aperture.
Remarks: This remarkable micro gastropod species measures around 1.5 mm.When observed under the microscope it exhibits a distinct sculpture, with its unique contorted aperture.Collection of leaf litter is the only feasible method of collecting this species.
Remarks: This species is endemic to Western Ghats and is easily distinguishable from A. bajadera and A. intumescens by its descending body whorl and also being comparatively more solid and sturdy.
Shell sinistral, moderately umbilicate, thin, fragile, translucent.Spire moderate, apex obtuse, dark brown above with a whitish band at the periphery after which the colour fades into white nearing the umbilicus, whorls rapidly increasing, and sutures not impressed.Whorls 5, surface with smooth transverse striations, converging with lines of growth, body whorl distinctly angled, rounded nearing the aperture in mature forms'; it takes the appearance of a keel in younger forms.Body whorl near the aperture scarcely descending, with nacre just behind the slight pinkish aperture, lips slightly thickened.Upper lip flattened, basal lip inflated and rounded, columellar lip triangularly reflected, but does not cover the comparatively wider umbilicus.
Measurements: H = 32 mm, W = 38 mm.Remarks: This typical species is endemic to Western Ghats.It is quite commonly distributed in Karnataka.It has a marked resemblance to A. cysis from which it differs in size, colour pattern and deeper umbilicus.In A. cysis the upper lip is rounded whereas in this species it is flattened.

Genus Cryptozona Morch, 1872
Cryptozona solata (Benson, 1848)  Shell dextral, moderately umbilicate and translucent.Spire moderate, apex obtuse, pinkish turning to white as the shell grows.Shell with small specks all over the body whorl; with a chestnut coloured band at the periphery, coinciding with the sutures and another just below it visible only on the body whorl, both the bands end abruptly just behind the aperture.Whorls 5Y2, rapidly increasing, sutures impressed, surface with smooth transverse striations, body whorl, rounded.Aperture negligibly descending, lips thin, white but just behind, it is hay coloured, inside it has nacre.Shell internal, flat, solid in mature forms, with beak like apex, sides sharp, hay yellow in colour, spire indistinct.Animal is a slug; yellowish with dark brown spots present in the hind region in older forms, the spots are not distinct in the younger.Shell is internal, partly visible externally through the pore present on the top of the mantle.Mantle lobes united to form a shield enclosing the various systems, on the surface with two ridges running almost' parallel to each other, the right one from the respiratory orifice to the shell aperture the other round the left margin.Posterior portion sharply keeled behind the mantle, ending in the mucus pore.Foot tripartite, edges with short vertical black parallel lines.
Measurements: Animal at full stretch 46 mm.
Remarks: This endemic slug of Western Ghats and Sri Lanka is an agricultural pest.Farmers cultivating Vanilla, the widely used flavouring agent, reported that it is a voracious feeder of the leaves.At full stretch the specimen measured around 46 mm.