Macrochlamys leggeae, Chandra & Sivakumar, 2019

Sajan, Sheikh, Basudev Tripathy, Chandra, Kailash & Sivakumar, Kuppusamy, 2019, A new species of the genus Macrochlamys Grayı 1847 (Stylommatophora: Ariophantidae) from Western Himalayaı India, Journal of Natural History 53 (13), pp. 797-813 : 800-808

publication ID	https://doi.org/ 10.1080/00222933.2019.1615566
DOI	https://doi.org/10.5281/zenodo.3680524
persistent identifier	https://treatment.plazi.org/id/4F272B5C-FF84-FF9D-A089-FA4FF3E9FA06
treatment provided by	Valdenar
scientific name	Macrochlamys leggeae
status	sp. nov.

Treatment

Macrochlamys leggeae View in CoL sp. nov.

( Figures 2 View Figure 2 aı 3a – bı 4a – b; Table 1 View Table 1 )

Type material

Holotype: 1 ex. (SL 10.28 mmı SW 7.08 mm) ( NZSI M.31208/8)ı 300 m north-east of the Pushpawati River (30.72573°Nı 079.59150°E) 3544 mı Chamoli Districtı Uttarakhandı Western Himalayaı India; coll. S.K. Sajanı 28 August 2016.

Paratypes: 4 ex. dry/ 7 ex . wet ( NZSI M.31209/8)ı 300 m north-east of the Pushpawati River (30.72573° Nı 079.59150°E) 3544 mı Chamoli Districtı Uttarakhandı Western Himalayaı India ( Figure 5 View Figure 5 )ı 5 ex . ( NZSI MO.147)ı 300 m north-east of the Pushpawati River (30.72573° Nı 079.59150°E) 3544 mı Chamoli Districtı Uttarakhandı Western Himalayaı India deposited at Northern Regional Centreı Zoological Survey of Indiaı Dehradunı Uttarakhandı India; 2 ex . ( NZSI M.316 – 319) 300 m north-east of the Pushpawati River (30.72573° Nı 079.59150°E) 3544 mı Chamoli Districtı Uttarakhandı Western Himalayaı India deposited at High Altitude Regional Centreı Zoological Survey of Indiaı Solanı Himachal Pradeshı Indiaı same date as holotype.

Diagnosis

The new species Macrochlamys leggeae has the following combination of characters: spire height is lowı the body whorl globose and largeı aperture width is greater than heightı lower whorl countı embryonic shell largerı smooth radial stair in protochonch and external shell surfaceı fewer teeth in each rowı penis very small ( Figures 2 View Figure 2 aı 3a – bı 4a – bı 7a – gı 8; Tables 1 – 2 View Table 1 View Table 2 ).

Description

The shell is medium (SL 8.66 – 10.28 mm)ı thin and smoothı convex and sub-globosely depressed; apex is obtuse and depressedı shell surface has smooth lirae over the whole bodyı shell pale in colour and horny; body whorl broad and globsely rounded at periphery and whorl largeı about two-thirds of shell height and convexı slightly descending in frontı spire is low (SH 1.16 ± 0.01 mm); whorls 4 ¼ – 5; peristome simple and thinı aperture is broadly ovate-lunate in shape; howeverı the width of the aperture is greater than its height (AH 4.76 ± 0.28 mm and AW 5.02 ± 0.33 mm)ı columellar region is straight and reflected at the perforationı umbilicus of shell narrowly perforate.

Radula

Each row of the radula consists of 73 teeth with the formula 22-1-13-1-13-1-22 (36-1-36). Central tooth (c) triangular tricuspid with large mesoconus (m). Lateral teeth (lt) asymmetric tricuspid with very small ectoconus (ec) and larger endoconus (et). Rachidian tooth central cusp base width 10.19 µm and rachidian tooth central cusp height 29.49 µm ( Figure 7a – g View Figure 7 ).

Genital organ

Atrium (at) very shortı penis (p) short and cylindrical and corresponding to penial verge (pv)ı length of penis 1.20 mmı epiphallus (e) long and slender tubeı double length of penisı epiphallic caecum (epc) having one coiled circle located at middle of epiphallus and attached with penial retractor muscle (prm). Flagellum (fl) slightly larger then penis lengthı with single fold. Vas deferens (vd) thin slender tube connected between distal end of epiphallus and free oviduct (fo). Vagina (v) smaller than penis in length (0.8 mm) and cylindrical in shape. Dart apparatus (da) 4 times as long as penisı stout and cylindrical in shape and attached to proximal end of vaginaı tip of da attached with dart retractor muscle (drm). Gametolytic sac (gs) prolonged and bulbousı around 1 mm in diameter. Gametolytic duct (gd) long (double penis length)ı stout and cylindrical in shapeı free oviduct (fo) as long as penis and a cylindrical tube. Oviduct (ov) with large lobulesı with prostate gland (pg) running alongside. Hermaphrodite duct (hd) coiled and approximately 5 mm in length ( Figure 8 View Figure 8 ).

External features

Animal about 4 – 5 mm in length with reticulated skinı the shell is pale yellowı with a large and globose body whorl. The body surface is dark chocolate brown in colourı while the tentacle is darker. The caudal horn is raised and same colour as the body. The posterior left dorsal lobe is short and slightly visible. The animal secretes a very light slime during locomotion.

Distribution. The specimens were collected from 300 m north-east of the Pushpawati River (30.72573°Nı 079.59150°E) 3544 mı Chamoli Districtı Uttarakhandı Western Himalayaı India ( Figures 4c View Figure 4 – fı 5).

Habitat. The new species was usually found more than 3500 m above sea level on the ground surface and on small bushes (vegetation) of Meconopsis aculeata and Aconitum sp. in the sub-alpine zone of the main valley. This species is probably endemic to this particular region and known only from the type locality ( Figure 5 View Figure 5 ). The species is mostly active during the monsoon and post-monsoon season.

Etymology. The specific epithet ‘leggeae’ is named after Joan Margaret Leggeı Botanist of the Royal Botanical Gardensı Kewı who came to India to study flora of the Valley of Flowersı and lost her life there on 4 July 1939.

Remarks. The new species M. leggeae sp. nov. is compared with M. nuda (Pfeifferı 1852) ( Figure 2e View Figure 2 ). In M. nuda the shell is thickı larger and less globose and the spire is highı and the aperture is shortı while in the new species the shell is thin and sub-globoseı and the aperture is wider than long. Howeverı the height of the body whorl is greater than in M. nuda and the number of whorls is also fewer (4 ¼ – 5)ı whereas in M. nuda the whorl number is 5 – 5 ½. In M. vesicula (Bensonı 1838) the shell is larger in size (SL 13.05 ± 1.38 mm)ı whereas the ratio of the aperture height to shell height is also greater (4.48 mm). In M. glauca (Pfeifferı 1846) the shell is also large in size (SL 16.64 ± 3 mm)ı and the height to width ratio of the aperture is also less (0.93 mm) than in M. leggeae (0.95 mm). In comparison to M. kuluensis Blanfordı 1904 the shell length and width are also greater (SL 11.28 ± 2.02 mmı SW 8.41 ± 1.49 mm)ı and the aperture ratio is greater than in M. leggeae . In M. leggeae the diameter of the spire without the last whorl is also less than in all the compared species (4.80 ± 0.28 mm) (see Tables 1 View Table 1 and 2 View Table 2 ; Figure 2b – d View Figure 2 ). The unique large body whorlı aperture openingı and morphometric measurements are reliable characters to distinguish the species.

Statistical species differentiation. For morphometric differentiation among five individuals of Macrochlamys leggeae sp. nov. (paratype NZSI M.31ı209/8ı n = 5) and five individuals each of the congeneric species M. vesicula ı M. glauca ı M. kuluensis and M. nuda (n = 5)ı a PCA was performedı using Past3. The variables SL/SW – shell length/shell widthı AH/AW – aperture height/aperture widthı AW/SH – aperture width/spire heightı HBW/AH – height of the body whorl/aperture heightı and HBW/SH – height of the body whorl/spire height were calculated. PC1 explained 93.7% of the total variance and PC2 explained 5% of the variance in th eshell ratio ( Figure 6 View Figure 6 ). The most significant variance was observed in the ratios AW/SH (0.822) and HBW/SH (0.567) which are significantly different from those of the closely related species ( Tables 1 View Table 1 and 3 View Table 3 ; Figure 6 View Figure 6 ).