taxonID	type	description	language	source
03D287BCFFD2F1044822FF0BFE9E0FDC.taxon	description	Subclass: Pulmonata	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD2F1044822FEAFFDEB0C23.taxon	description	Physidae is the family of freshwater pulmonates and is found world-wide. The shells of this family are always sinistral (coiling to the left or anticlockwise spirally coiled), comparatively small with an acute and posteriorly directed spire and distinguished by lack of an operculum. In India, the family is represented by only one genus, Physa. Physa acuta (Draparnaud, 1805) Taxonomic description- Shell sinistral, non-operculate, elongate-ovate, thin, light fawn coloured, smooth, moderately lustrous and translucent; fine, close set lines of growth; protoconch distinct; number of whorls 5, regularly and rapidly decreasing in size; apex pointed; spire short; sutures slightly impressed; aperture large, about three-fourth of shell’s total length; outer lip thin, slightly deflected out; umbilicus closed; parietal callus wide, columella well-marked.	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD2F1044822FCE4FE9608CF.taxon	description	The Planorbids are hermaphroditic and non-operculate. The shells of this family may be discoidal or planispiral, dextral or sinistral. They inhabit clear freshwater (stagnant or slow running), live on aquatic vegetation and feed on minute algae and fine organic deposits. Few species are also reported as the intermediate hosts for several trematode parasites. Gyraulus convexiusculus (Hutton, 1849) Taxonomic description- Shell dextral, non-operculate, discoidal, very small, greatly depressed, smooth, glossy, pale horny brown coloured, periphery subangulate; number of whorls 4, rounded, widely coiled, last whorl covers the shell; body whorl not ribbed; spire sunken; sutures well defined; aperture oblique, oval shaped; lips simple; umbilicus wide and deep. Gyraulus euphraticus (Mousson, 1874) Taxonomic description - Shell dextral, non-operculate, discoidal, very small, thin, greatly depressed, narrow, peripheral angle slightly keeled, more compressed and strongly carinate, more opaque and coarser than G. convexiusculus; number of whorls 3; sutures deep; irregularly sculptured with longitudinal and spiral stripes, striations very fine but visible; umbilicus narrow. Indoplanorbis exustus (Deshayes, 1834) Taxonomic description - Shell sinistral, non-operculate, discoidal, thin, dorso-ventrally flat, creamish-brown coloured, surface transpirally ridged; body whorl large and greatly expanded; penultimate whorl very narrow; number of whorls 4; spire depressed; sutures deeply impressed; aperture ear shaped; umbilicus wide; callus developed; inner peristome fused with body whorl, outer peristome reflected outwards, rounded at periphery.	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD2F1034822F858FDBB0D2C.taxon	description	Lymnaeidae family is having world-wide distribution. Its maximum diversity is found in the northern part of North America. The shells of this family are dextral showing varied sizes, from small to medium and variable shapes, globular to attenuate. They live in shallow waters, where temperature is generally found high and more food for them is available. Few exceptional species are known to inhabit deep lakes. They also act as vectors of helminths parasites that severely affect human and livestock as well. Lymnaea mimetica (Annandale, 1918) Taxonomic description- Shell dextral, non-operculate, small, thin, fragile, oblong, pale or cream coloured; number of whorls 3; body whorl narrow; spire short; apex blunt; columellar callus absent; aperture oblong, outer lip thin and sharp. Radix persica (Issel, 1865) Taxonomic description - Shell dextral, non-operculate, large, inflated, whitish to creamish, sculptured with transpiral striae; number of whorls 4, body whorl large, inflated; spire short, sunken, pointed and acuminated; aperture large, obliquely placed, greatly expanded; columellar fold highly developed, twisted, fold occludes umbilicus, callus well developed, gets sharply narrowed below twist. Radix acuminata (Lamarck, 1822) Taxonomic description- Shell dextral, non-operculate, thin, fragile, oblong-ovate, glossy, smooth, sculptured with fine and feeble vertical lines without spiral ridges; number of whorls four and half, body whorl inflated; spire short, acuminate, apical whorls somewhat flattened, forming an acute spire, separated by a very oblique suture; aperture large, wide; number of whorls 4 - 5; umbilicus imperforate; columellar fold prominent, twisted; callus whitish and well developed. Radix biacuminata (Annandale and Rao, 1925) Taxonomic description- Shell dextral, non-operculate, thin, large, fragile, narrow, elongate, spindle shape, sculptured with curved longitudinal striae, pale luteous colour; number of whorls three and half; aperture large, ovoid; columellar callus well developed, slightly twisted with a broad fold; umbilicus completely occluded. Radix luteola (Lamarck, 1822) Taxonomic description- Shell dextral, non-operculate, small, ovate, smooth, glossy, pale yellow colour with whitish bands; number of whorls three and half, body whorl inflated, broad at anterior end; spire conical, less pointed placed little laterally to body whorl; sutures traverse, length of suture at base of spire almost equal to height of spire; aperture ovate, narrow, rounded below; umbilicus closed; callus very less developed, translucent; inner peristome fused with body whorl, outer peristome thin. Radix luteola ovalis (Gray, 1822) Taxonomic description- Shell dextral, non-operculate, thin, ovate, brownish coloured, broad base; number of whorls 4; spire small, exerted, acuminated; body whorl large, quite inflated; apex pointed; sutures transverse; aperture oval, peristome thin, simple; columella spirally twisted. Galba truncatula (Müller, 1774) Taxonomic description- Shell dextral, non-operculate, small, elongate-oval, slender, conical, smooth, nearly twice as high as broad, light brownish or straw coloured, more or less transparent, striae transpiral, fine, closely arranged; number of whorls 4, convex, oblique, slightly shouldered; spire gradually increasing in size; body whorl not much inflated; sutures, deep, impressed; aperture narrow, almost equally long as body whorl, rounded at the base with little reflected peristome; umbilical pore prominent; columellar callus not much developed, callus formation after the twist.	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD5F1034B7AFA22FBA10AC7.taxon	description	Subclass: Paleoheterodonta	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD5F1034822F87BFA660C7F.taxon	description	Thiaridae is a family of tropical freshwater snails with an operculum and are commonly named as thiarids or trumpet snails. The shells of this family are dextral, elongated, conical, and turreted and are micro sculptured with spiral ridges. They inhabit both lotic and lentic freshwater bodies, though some taxa are also found tolerating brackish conditions. They bury themselves in mud or sandy bottoms or are found attached to rocks. Melanoides tuberculata (Müller, 1774) Taxonomic description - Shell dextral, operculate, slender, turreted and conical, dark reddish-brown dots and flames distributed irregularly and longitudinally arranged on the shell surface; body whorl large and swollen, sculptured with vertical ribs and spiral striae, sculpturing more prominent on upper whorls than lower; number of whorls 10; spire high; aperture pyriform, pointed above and rounded below; umbilicus imperforate, outer peristome red rimmed; columellar callus translucent anteriorly and whitish posteriorly; operculum paucispiral, nucleus placed near the base of operculum. Thiara rudis (Lea, 1850) Taxonomic description- Shell dextral, operculate, turreted to sub cylindrical, thick, cream or brownish cream colored, sculptured with axial ribs and spiral ridges often in the beaded form; spire high; number of whorls 8; aperture pear shaped.	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD5F1034822FD3CFDF708B1.taxon	description	Viviparidae is a family of freshwater, operculate snails from rivers, ponds and lakes. The shells of this family are thick, globose, and dextral with size varying from medium to large. They live in still or slow moving waters and are usually nocturnal. The members of this family are found amongst vegetation, in sand or mud. Many species during drought conditions burrow themselves in mud and seal their operculum. Filopaludina bengalensis typica (Lamarck, 1822) Taxonomic description- Shell dextral, operculate, medium sized, conical in outline, yellowish brown colour; number of whorls 6, plano-convex, dark bands spirally arranged, irregular pattern of thick and thin bands; sutures impressed; body whorl evenly convex, greatly swollen; penultimate whorl broad; spire pointed, height equal to body whorl; aperture sub circular with narrow black margin; umbilicus widely open; operculum horny, deep brown, eccentric nucleus, deep red area around the nucleus; columellar callus developed; inner peristome clearly visible, thick rim like, not fused with body whorl, outer peristome thick. Filopaludina bengalensis mandiensis (Lamarck, 1822) Taxonomic description- Shell dextral, operculate, medium sized, more conical than typica, greenish brown colour, number of whorls 6, more convex than typica, broad and narrow dark spiral bands arranged alternately; sutures less impressed than typica; body whorl evenly convex; penultimate whorl less broader than typica; spire with pointed apex, height almost equal to body whorl; aperture ovoid; operculum horny, deep brown, eccentric; umbilicus narrowly open; columellar callus well developed; inner peristome not distinct, thin fused with body whorl, outer peristome thin. Idiopoma dissimilis (Müller, 1774) Taxonomic description- Shell dextral, operculate, ovately conical, small, dirty olive green coloured; spire broadly conical and swollen; sutures deeply impressed; whorls inflated, number of whorls four and half; body whorl with slightly elevated ridge, without dark spiral bands; aperture ovate; umbilicus narrow; operculum thick.	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD5F1024B7AFA46FE480C9C.taxon	description	Unionidae family is commonly referred as pearly mussels or unionids, and are found in freshwater habitats globally. These bivalves are the inhabitants of permanent freshwater sources like lakes, streams and rivers. The shells of this family are internally nacreous having equilateral valves with raised umbones and well developed radial sculptures. They are the key members of aquatic ecosystems and plays very vital ecological role like nutrient cycling, bio-turbation, water purification etc. Lamellidens marginalis (Lamarck, 1819) Taxonomic description- Shell oblong-ovate, twice as long as high, thin, smooth, somewhat inflated, inner surface of shell pearly and iridescent; periostracum blackish-brown and shinning; valves equilateral; umbones placed nearer to anterior end; dorsal margin behind the umbones almost straight, extends into a more or less well defined wing expansion; anterior margin narrower than posterior margin, anterior end evenly rounded; ventral margin slightly contracted in the middle; right valve with hinge with two cardinals, upper one poorly developed, a single lateral and a trace of second one; left valve with one cardinal and two curved lateral teeth; adductor impression and non-sinuate pallial line typical. Lamellidens corrianus (Lea, 1834) Taxonomic description- Shell narrowly elliptical, longer in proportions to height; valves equilateral, relatively thin; umbones slightly inflated; periostracum smooth, dark or greenish brown; anterior margin rounded, posterior margin more or less sub-angular; posterior wing expansion thin, ventral margin evenly curved; cardinal teeth thin, lamina like, two in each valve or one in left and two in right valve; lateral teeth elongated, thin, straight; nacre bluish white or pearly white and iridescent; adductor scars and pallial line fairly marked. Parreysia caerulea (Lea, 1831) Taxonomic description- Shell elongate, internally nacreous, sculpture restricted to the upper half of the valves in the adult, young shells with whole shell surface sculptured; posterior umbonal carina very distinct.	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD4F1024822FA22FEDB08CF.taxon	description	Ariophantidae is the largest family of Indian land pulmonates. The shells of this family are dextral or sinistral and their size varying from small to large with no operculum. They are usually depressedly globose and broader than high. Macrochlamys indica (Godwin-Austen, 1883) Taxonomic description- Shell perforate, depressed, smooth, polished throughout, translucent, pale brownish, striations not distinctly and coarse, all whorls have microscopic longitudinal impressed lines, striations slightly flexuous, not close together; spire low, conoid; suture slightly impressed; number of whorls five and half, slightly convex above, last whorl not descending, rounded at the periphery and moderately convex beneath; aperture slightly oblique and broadly lunate; peristome thin dorsally; columellar margin curved, oblique, quite vertical, carried forward and briefly reflected above.	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD4F1024822FA9EFE9D0A6B.taxon	description	Subclass: Pulmonata	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD4F1024822F858FA710DE4.taxon	description	Subulinidae is a family of most diverse terrestrial gastropods. The shells of this family are elongate, turreted to cylindrical and their size varying from small to medium. They are uniformly coloured, whorls are smooth or with indistinct sculpture on apical whorls and in sutural region on lower whorls. Opeas gracile (Hutton, 1834) Taxonomic description- Shell small to large, thin walled, turreted, uniformly dull pale brown colored; spire gradually tapering; apex rounded; body whorl conspicuous, equal to two preceding whorls; number of whorls 10; aperture semi-ovate, slightly narrowed above, longer than broad; columellar lip slightly reflected, almost straight, outer lip thin, sharp edged. Zootecus insularis (Ehrenberg, 1831) Taxonomic description- Shell pupiform, sub cylindrical, thin, corneous white; number of whorls 7, moderately convex; body whorl slightly bigger, little above the aperture; aperture semi-oval, pointed above; columellar margin strongly reflected, thickened, partially covering umbilicus; umbilicus narrow, sculptured with fine closely set sub ventral striae.	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
03D287BCFFD4F1014B7AFCA6FCBB0821.taxon	description	Cerastuidae is a family of air-breathing land snails. The shells of this family are ovate or oblong with size varying from small to medium. They are narrowly perforate or deeply umbilicate with fine sculpture or coarse striae. Rachis punctatus (Anton, 1839) Taxonomic description- Shell ovately conical, smooth, glossy; number of whorls 6, feebly convex to almost flattened; spire elevated, cone like; apex obtuse; aperture slightly oblique, ovate; outer lip sharp, columellar lip reflected. 3.4 Seasonal variations in molluscan fauna diversity Amongst the collected gastropod species Physa acuta was found ubiquitous and dominant species as well. In the hierarchy of dominance it was followed by Melanoides tuberculata, Gabbia travancorica, Filopaludina bengalensis typica and Filopaludina bengalensis mandiensis. The other species were found showing erratic occurrence and in lesser number. The species diversity, species richness and evenness of the collected molluscan fauna was found showing temporal or seasonal variations. (Figure 2). The site S 1 was found inhabited by only three molluscan species and their maximum richness was observed in summer season (3 Sp.) followed by monsoon while the winter season witnessed the presence of a single species i. e. Physa acuta. In the post monsoon season no molluscan shell was recovered from this site. The maximum abundance was also observed in summer season (237) followed by monsoon (22) and winter (20). Despite of the maximum abundance and higher species richness in summer season, the values of Simpson’s Dominance Index (0.92) indicated the dominance of any one species. The site S 2 was found inhabited by only 4 species. The maximum species richness was observed in winter season (4 Sp.) followed by monsoon (3 Sp.), summer (2 Sp.) and post monsoon season (1 Sp.). Maximum abundance at this site was also observed in winter season (122) followed by monsoon (118), summer (77) and post monsoon season (1). In all seasons P. acuta was found as a dominating species. From site S 3, total 7 molluscan species were collected during the entire study period of two years. The maximum species richness was observed in summer season (6 Sp.) followed by winter (4 Sp.), post monsoon (4 Sp.) and monsoon season (2 Sp.). Maximum abundance was also recorded in summer season (468), followed by winter (389), monsoon (73) and post monsoon (30). Despite of the maximum species richness and abundance in summer season the value of Simpson’s Diversity Index (0.34) and H ̍ index (0.66) in summer indicated less diversity as compared to other seasons. This was due to the dominance shown by two species i. e. P. acuta and M. tuberculata while other species contributing towards the community diversity were represented in comparatively less number. Both the post monsoon and winter season witnessed equal number of species but the more abundance was observed in winter season in comparison to the post monsoon. From site S 4 three species i. e. P. acuta, M. tuberculata and G. truncatula were collected. P. acuta was found as a dominating species and was recovered in all four seasons. Only 2 specimens of M. tuberculata were collected in summer and winter season. A single shell of G. truncatula was found in summer season. P. acuta was found as a sole representative in monsoon and post monsoon season with 9 individuals in each season. A total of 22 molluscan species were collected from the site S 5. The summer and monsoon season were found supporting the maximum species richness (17 sp.) followed by winter (13 Sp.) and post monsoon (9 Sp.). Maximum abundance was observed during monsoon season (293) followed by summer (280), winter (239) and post monsoon (93). Though the monsoon season witnessed the maximum species richness and abundance still the values of Simpson’s Diversity Index (0.76) and H ̍ index (1.83) indicated less diversity as compared to other seasons. This was due to dominance shown by a few species. The same was supported by the higher values of Simpson’s Dominance Index (0.23) and lower values of Evenness Index (0.64) in the monsoon season. The other species were found in meager number hence were not contributing towards the species diversity. Similarly the summer season witnessed the maximum species diversity with highest values of Simpson’s Diversity Index (0.89), H ̍ index (2.42) and Evenness Index (0.85). The post monsoon season was found least favorable for the molluscan species to flourish and diversify. The site S 6 was found having very poor molluscan fauna with only two representatives i. e. Physa acuta and Galba truncatula. The maximum species richness was observed in winter season along with higher value of the Evenness Index (0.99) indicating the presence and equal distribution of both species followed by summer and monsoon season representing only single species (P. acuta), while no shell was found in the samples collected during the post monsoon season. The maximum abundance was observed in summer season (154) followed by winter (28) and monsoon season (12).	en	Jindal, Rajinder, Wats, Meenu (2021): Systematic descriptions and seasonal variations of mollusc in Chandigarh (U. T., India) and its surrounding freshwater bodies. International Journal of Fisheries and Aquatic Studies 9 (3): 165-173, DOI: 10.22271/fish.2021.v9.i3c.2470, URL: https://doi.org/10.22271/fish.2021.v9.i3c.2470
