An insight into the evolutionary history of Indoplanorbis exustus (Bulinidae: Gastropoda)at the scale of population and species

The history of a lineage is intertwined with the history of the landscape it resides in. Here we showcase how the geo-tectonic and climatic evolution in South Asia and surrounding landmasses have shaped the biogeographic history of Indoplanorbis exustus, a tropical Asian, freshwater, pulmonated snail. We amplified partial COI gene fragment from all over India and combined this with a larger dataset from South and Southeast Asia to carry out phylogenetic reconstruction, species delimitation analysis, and population genetic analyses. Two nuclear genes were also amplified from one individual per putative species to carry out divergence dating and ancestral area reconstruction analyses. The results suggest that Indoplanorbis dispersed out of Africa into India during Eocene. Furthermore, molecular data suggests Indoplanorbis is a species complex consisting of multiple putative species. The primary diversification took place in Northern Indian plains or the Northeast India. The speciation events appear to be primarily allopatric caused by a series of aridification events starting from late Miocene to early Pleistocene. None of the species seemed to have any underlying genetic structure suggestive of high vagility. All the species underwent population fluctuations during the Pleistocene likely driven by the Quaternary climatic fluctuations.

Diversity and Damage Assessment of Snail in Cultivated Crops of Neelabut Bagh Azad Jammu And Kashmir (Pakistan)

The present study was conducted to study diversity and damage assessment of snails in cultivated crops and ornamental plants. The study revealed two types of snail species Macrochlamys indica and Indoplanorbis exustus in the study area. The sampled plots of tomato, Karam, Palak, Dhania, Maize, Fresh beans, Sunflowers, Aloe Vera, Loki, Pumpkin, Bitter guard, Kheera, Kachmach, Hund were taken. The study revealed that at Neelabut, when 39 plants of Fresh beans were examined out of them 18 were found damaged and the damage percentage was 46%, 38 plants of sunflowers were examined and 17 (45%) were found damaged, 85 plants of tomato were examined and 11 (12.94%) were found damaged, 82 plants of Karam were examined and 12 ( 15%) were found damaged, 62 plants of Palak were examined and 16 (25%) were found damaged, 51 plants of maize were examined and 15 (29%) were found damaged. The snail is pest in the study area and measures should be taken to manage them through ecofriendly programs.

Distribution of freshwater Mollusca in Koothaippar wetland ecosystem Tiruchirappalli District Tamil Nadu

Freshwater Mollusca form an important animal group of the wetland ecosystems. The distribution and availability in terms of number of species needs scientific attention. Present study is an attempt to document the available Molluscan forms in Koothaippar wetlands of Tiruchirappalli District. This study was carried out between summer 2013 to post-monsoon 2017. Nine species were recorded and among them 6 species belong to Gastropoda representing 2 orders, 3 families, 3 genera while 3 species were bivalves representing 1 order, 1 family and 2 genera. Bellamya bengalensis, Lamellidens marginalis and Pila globosa were the predominantly present molluscan fauna and are distributed throughout the year. Five species of Molluscan fauna (Pila virens, Pila scutata, Bellamya dissimilis, Indoplanorbis exustus and Lamellidens corrianus) are less abundant and Parreysia favidens was found to be rare species of the ecosystem. These Molluscan forms, representing different families ranging from 34% of Ampullariidae, 33% of Unionoida, 22% of Viviparoidae and 11% of Planorbidae. Percent distribution of these shelled organisms indicate that they represent 3 orders viz., 56% of Architaenioglossa, 33% of Unionoida and 11% of Hygrophila.

Choosing exotic over the familiar taste: habitat-specific preferences of a malacophagous leech for freshwater snails as prey gastropod establishment?

The spread of freshwater invasive species through aquarium trade poses a threat to the ecosystem, economy and human health. The availability of the exotic freshwater gastropod mollusc, Planorbarius corneus (Linnaeus, 1758) (Gastropoda: Planorbidae), in pet shops in Kolkata, West Bengal, India, raises concern for its potential establishment as an invasive species. Assuming the role of the native predators as a potential biotic barrier for invasion, observations on the predation pattern of the malacophagous leech, Glossiphonia weberi (Blanchard, 1897) (Clitellata: Glossiphoniidae) against P. corneus was made in single as well as in combination with the native snail Indoplanorbis exustus (Deshayes, 1834) (Gastropoda: Planorbidae). Using varying size classes and densities of P. corneus, the predation potential of G. weberi was estimated after a 24 hour period. In another set of experiments, the predation of G. weberi against the snail P. corneus was observed in the presence of I. exustus under four different habitat conditions. The purpose was to justify - (1) the effect of conspecific and heterospecific conditions of the prey availability and (2) the effect of habitat complexity on the predatory efficacy of G. weberi. The results indicated that G. weberi consumed varied numbers of P. corneus, depending on the size and the densities of the prey and predator. Although the prey heterogeneity and complex habitats caused significant reduction of predation on both of the prey species, G. weberi significantly preferred P. corneus over I. exustus in open (P < 0.0001), macrophyte (P = 0.002) and pebbles and macrophyte containing habitats (P < 0.0001). Apparently, G. weberi preferred the exotic snail P. corneus in presence of alternative prey snail I. exustus, under different habitat conditions. Therefore, G. weberi may act as a significant biotic resistance against the colonization and establishment of P. corneus in the Indian context. However, further studies including the multiple prey and predators are required to ascertain the food web level impact of the exotic snail P. corneus in invaded freshwater ecosystems.

Holocene Lacustrine Environment in the Western Eritrea-evidence from Freshwater Shells

This study focused on finding of freshwater molluscs in Holocene sediments outcropping in western Eritrea. Three species of gastropods were found in calcareous sediments at the bank of a tributary river named Shatera River, within the license of Bisha Mines, they are Melanoides tuberculate (O. F. Müller, 1774), Bulinus globosus (Morelet, 1866) and Indoplanorbis exustus (Deshayes, 1833). The 14C dating on the shells of I. exustus and B. globosus was also carried out. The age dating result showed (9326-9134 cal yr BP) and (9134-8999 cal yr BP) respectively, of which are in the mid-Holocene epoch (11,000–5000 yr BP). This epoch is best known for it was a time when the northern and eastern part of Africa experienced a warm and humid climate. Among the freshwater molluscs, the existence of Melanonids tuberculate makes it more significant, for its widespread occurrence in Quaternary deposits throughout Africa and Asia in both fresh and highly evaporated lakes. This is suggestive of the considerable development of the lacustrine environment in the western part of Eritrea, which at present has disappeared.

MOLLUSCAN BIODIVERSITY AND ITS SEASONAL FLUCTUATIONS IN TEEKAR TAAL, HARYANA, INDIA

Freshwater molluscs are the integral part of every aquatic ecosystem and help not only in the ecosystem’s functioning but also enable the ecologists to judge the health of their abode. These shelled animals are used as the best biomonitoring tools worldwide. Gradually declining water quality of freshwater bodies owing to multiple factors, their biodiversity is also facing threat. Majority of the freshwater bodies near human vicinities are facing anthropogenic interventions, habitat destructions and overexploitation and the same is being reflected by the elimination of sensitive molluscan species and survival as well as abundance of other tolerant ones. The current study has been undertaken to understand the Malacofauna biodiversity in Morni hills, Panchkula, Haryana. During the study, total 359 gastropods both aquatic and land snails were collected. Pre-monsoon season witnessed greater molluscan abundance, 8.46 times, than post-monsoon. The molluscan biodiversity, 7 species, 7 Genera and 5 families, namely Filopaludina bengalensis, Melanoides tuberculata, Radix luteola, Gyraulus ladacensis, Indoplanorbis exustus, Ariophanta interrupta and Macrochlamys indica.Shannon-Weiner Index (H) and Simpson Diversity Index (D) for both seasons indicated higher species diversity during post monsoon season. Melanoides tuberculata was found to be dominant during pre-monsoon while Filopaludina bengalensis during post monsoon season.

MOLLUSCAN DIVERSITY WITH PARTICULAR EMPHASIS TO SNAILS IN DISTRICT GAUTAM BUDH NAGAR (U.P.) INDIA

Present investigation reveals molluscan diversity of the 4 selected sites viz., Tilpata Karanbas, Manhcha, Latifpur and Atta Gujran in the vicinity of district Gautam Budh Nagar (U.P.). As many as 22 species of molluscs under 9 families were collected. There were 19 species of snails viz ., Bellamya bengalensis , B. dissimilis , B. crassa , Lymnaea ( Pseudosuccinea ) acuminata f. hians , L. luteola f. ovalis , L. acuminata f. patula , L . ( Radix ) auricularia , L . ( Lymnaea ) stagnalis , L . acuminata f. gracilior , Pila globosa , Indoplanorbis exustus , Gyraulus convexiculus , G. pankongensis , Planorbis planorbis var. tangitarensis , Hydrobioides nassa, Thiara ( Melanoides ) tuberculata , Thiara ( Thiara ) scabra, T. ( M .) trigrina and Brotia ( Antimelania ) costula under 6 families. The other molluscs were Parreysia ( Parreysia ) favidens , Corbicula striatella and Lamellidens marginalis . There has been a marked variation in the composition of molluscan species collected from different habitats.