Molluscan Diversity Research Articles

Molluscan marvels of Gujarat: exploring species distribution and conservation strategies using a spatial approach.

This study delves into the Molluscan diversity along the Gujarat coast, India, focusing on the distribution and habitat suitability of four key species: Cerithium caeruleum, Lunella coronata, Peronia verruculata, and Trochus radiatus. Utilizing species distribution models (SDMs) integrated with machine learning algorithms, we assessed the impact of environmental variables on the distribution patterns of these molluscs. Our findings reveal a nuanced understanding of habitat preferences, highlighting the critical roles of salinity, chlorophyll concentration, and water temperature. The MaxEnt model, with the highest area under the curve (AUC) value of 0.63, demonstrated moderate discrimination capability, suggesting room for enhancement in capturing complex ecological interactions. The spatial distribution analysis indicated a random arrangement of species, with no significant spatial autocorrelation observed. This research underscores the significance of advanced modelling techniques in predicting molluscan distributions, providing insights crucial for the conservation and sustainable management of marine biodiversity along the Gujarat coast. The study examined the distribution and habitat suitability of four key molluscan species-C. caeruleum, L. coronata, P. verruculata, and T. radiatus-along the Gujarat coast, India. By integrating SDMs with machine learning algorithms, we assessed how environmental variables such as salinity, chlorophyll concentration, and water temperature influence their distribution patterns. The MaxEnt model was employed, achieving an AUC value of 0.63, indicating moderate discrimination capability and suggesting potential areas for model refinement to better capture complex ecological interactions. Our analysis revealed no significant spatial autocorrelation, suggesting a random spatial distribution of these species. The results highlight the importance of using advanced modeling techniques to predict the distribution of molluscs, which is essential for the conservation and sustainable management of marine biodiversity along the Gujarat coast.

Terrestrial mollusc diversity on dragon fruit (Selenicereus spp.) cultivation: a case study of Acusta tourannensis (Souleyet, 1842) (Gastropoda, Camaenidae) in southern Vietnam

ABSTRACT This study investigates the diversity of terrestrial molluscs associated with dragon fruit (Selenicereus spp.) cultivation in southern Vietnam, focusing on the primary pest, Acusta tourannensis. Field surveys in Binh Thuan and Tien Giang provinces identified eight pest species, including A. tourannensis and Lissachatina fulica, which were particularly prevalent. Morphological and biological assessment of A. tourannensis revealed its remarkable reproductive capacity, producing up to 389 eggs per pair during its short lifespan of approximately 45.7 days. Optimal growth and development were achieved when feeding A. tourannensis a combination of chicken feed and dragon fruit branches. The snail exhibited nocturnal activity patterns and a strong preference for high soil humidity. Greenhouse experiments confirmed the significant influence of soil moisture on snail density, with peaks observed following rainfall. Field observations revealed seasonal peaks in A. tourannensis populations on dragon fruit branches and fruits. These findings underscore the importance of understanding terrestrial mollusc diversity and the ecological impact of A. tourannensis on dragon fruit orchards to develop effective pest management strategies.

Application of the River Habitat Survey Method in the Assessment of the Human Pressure Within the Lowland River Catchment: The Mollusc Biodiversity Versus Habitat Features

The objectives of our study were to analyse the degree of human pressure within the lowland river catchment in relation to the mollusc communities and to assess the usefulness of the River Habitat Survey as a field method in determining the human pressure in the mollusc biodiversity context. The River Habitat Survey (RHS), an essential method for hydromorphological studies of rivers under the requirements of the European Union Water Framework Directive, was applied. This study showed that the diversity of molluscs was impacted by several environmental factors acting simultaneously, including pH, concentration of ammonium nitrogen in water, and the habitat features depending on the degree of human pressure on the river. The result of the RHS method confirmed that the occurrence of molluscs including Unio crassus and Pseudanodonta complanata, the endangered species on a global scale, was associated with the extensive presence of several natural habitat features in the river channel. The RHS method proved to be an indispensable tool for assessing the relationships between the diversity of aquatic organisms and the degree of habitat anthropogenic modification of river environments. It seems innovative and necessary, especially in restoring the natural character of rivers.

Abundance and Diversity of Mollusks and Related to Some Physicochemical Properties in Euphrates River in Al-Muthanna Province

Abundance and Diversity of Mollusks and Related to Some Physicochemical Properties in Euphrates River in Al-Muthanna Province

Diversity, Evenness, and Richness of Mollusc on the Peh Pulo Beach, Blitar Regency

Molluscs are one of the most abundant invertebrate animals and live on various substrates. Peh Pulo Beach has a wide coastline, on the edge of the beach there are coral rocks, the sand is white, and the waves are big. Molluscs like to live in coral rock substrates. This research aims to determine the diversity, evenness, and richness of molluscs on Peh Pulo Beach. Sampling was carried out at three different stations using plots measuring 1x1 m which were chosen randomly. Mollusc samples were identified based on morphological characteristics and validated using the WoRMS database. The results of mollusc identification at Peh Pulo Beach showed that there were 37 species belonging to 23 families. They are classified in the classes Gastropods (32 species), Bivalves (3 species), and Polyplacophora (1 species). The diversity of molluscs in the Peh Pulo Beach area is at a moderate level. The evenness of molluscs in Peh Pulo Beach is similar. And the richness of molluscs is at a semi-disturbed level so appropriate management and conservation strategies for the sustainability of molluscs are needed.

Potential role of gastro-intestinal microbiota in terrestrial snails

This review provides an overview of the potential impact of the intestinal microbiota of land snails on their survival and functioning in a constantly changing environment. The diverse communities of microorganisms that inhabit both the outside and inside of animals in unique ecosystems help them to survive in constantly changing environmental conditions. A diverse microbial community is critical for digestion and nutrient delivery, but it is also important for animals that are adapting to new ecological niches. Molluscs are stable, multicellular in vivo systems that can be used to study the symbiotic relationships between microorganisms and animals, as well as how microbes affect an animal???s physiology and ecology. Furthermore, because of the vast number of species and the ecological diversity of molluscs, they allow for a better understanding of the variability of the microbiota associated with both their location in the host organism and the host in the environment. The microbiome is critical to a body’s homeostasis and survival in changing environmental conditions. This is true not only for terrestrial molluscs, but also for freshwater and marine species, which use the properties of the microorganisms that inhabit them to counteract the effects of stress.

Mid-Holocene marine faunas from the Bangkok Clay deposits in Nakhon Nayok, the Central Plain of Thailand.

Based on several field investigations, many molluscan shells and chondrichthyan teeth, together with other invertebrate and actinopterygian remains were found from the marine Bangkok Clay deposits in Ongkharak, Nakhon Nayok, at a depth of ~ 5-7 m below the topsoil surface. Animal macrofossils recovered from these Holocene marine deposits were identified and their chronological context was investigated in order to reconstruct the paleoenvironments of the area at that time. The majority of marine fossils recovered from the site consist of molluscs, with a total of 63 species identified. Other invertebrate species include a stony coral, a mud lobster, barnacles, and a sea urchin. The vertebrates are represented by fish remains, including carcharhinid shark teeth from at least nine species, stingray and trichiurid teeth, and one sciaenid otolith. The molluscan fauna indicates that the paleoenvironments of the area corresponded to intertidal to sublittoral zones, where some areas were mangrove forests and intertidal mudflats. The fish fauna is dominated by the river shark Glyphis, indicating freshwater influences and possibly occasional brackish conditions. The carbon-14 analysis of mollusc and charcoal remains shows that deposition of the marine sediment sequence began during the mid-Holocene, spanning approximately from 8,800 to 5,300 cal yr BP. This study provides in-depth insights into the diversity of fishes, marine molluscs, and other invertebrates from the Bangkok Clay deposits, supporting the existence of a marine transgression onto the Lower Central Plain of Thailand during the mid-Holocene.

Assessment of molluscan diversity and their responses to heavy metal deposition in a river ecosystem of Bangladesh

Assessment of molluscan diversity and their responses to heavy metal deposition in a river ecosystem of Bangladesh

The Diversity of Mollusks (Bivalve and Gastropod) in the Intertidal Zone of Mutun Coastal, Padang Cermin, Lampung

Mutun Coastal has a diversity of biota species. Biota that are commonly found include the mollusk phylum (Bivalve and Gastropod classes). The purpose of this study was to determine the diversity of mollusks (Bivalves and Gastropods) on Mutun Coastal Lampung. This research was conducted on February 5-7, 2021. The method of data retrieval at both stations used the belt transect method by purposive sampling. Station I is substrated fine sand, while station II is substrated by coarse sand. Based on the research conducted, 26 individuals were found consisting of 7 families, namely 6 families of the Gastropod class (Trochidae, Strombidae, Cerithiidae, Muricidae, Potamididae and Pisaniidae) and 1 family of the Bivalve class, namely the family Mactridae. The value (H') at station I is 1.44. At station II it has an H' value of 0.86. The value of H' at station I belongs to the medium category. The H' value at station II belongs to the low category. The value of E at station I is 0.72. While at station II it has a value of 0.1. The evenness value at station I belongs to the high category. The value (E) at station II of the evenness index belongs to the low category. The value (D) at station I is 0.57. While at station II it has a value of 0.35. The value of D at station I belongs to the medium category. The value of D at station II belongs to the medium category. Based on data analysis, Mutun Coastal has suitable habitat for mollusk and it is also supported by abiotic parameter conditions.

Diversity of Freshwater Mollusks from Lake Pampulha, Municipality of Belo Horizonte, Minas Gerais, Brazil

The artificially created Lake Pampulha, within the metropolitan area of Belo Horizonte, Minas Gerais State, lacks detailed information about its freshwater mollusks, representing a challenge for the assessment and conservation of this ecosystem. In this study, conducted during June and August 2021, we collected specimens on four different occasions and at five sampling points around the lake, using different sampling equipment, such as a shovel and a scoop. During these collections, we identified, enumerated and measured 1538 species of mollusks and additionally examined the presence of trematode larvae. We identified twelve species of fresh water bivalves and gastropods: Biomphalaria straminea, Biomphalaria kuhniana, Biomphalaria occidentalis, Drepanotrema cimex, Pomacea maculata, Stenophysa marmorata, Physa acuta, Gundlachia ticaga, Melanoides tuberculata, Pseudosuccinea columella, Omalonyx matheroni and Corbicula largillierti. Echinostome and strigeocercaria types of larval trematodes were detected in B. straminea. Notably, some species of mollusks have not previously been recorded at Lake Pampulha. The analyses revealed differences in the composition and abundance of species, highlighting the higher number of mollusk species in areas more impacted by human actions. This study expands our understanding of mollusk diversity at Lake Pampulha, and provides valuable data for longitudinal comparisons of water quality and considerations of the conservation of native species. Furthermore, it highlights the importance of choosing appropriate sampling equipment, depending on the research objectives. The presence of invasive species of medical and veterinary relevance as intermediate hosts of parasites reinforces the need for efficient environmental protection strategies to preserve this artificial, aquatic environment widely used by the local population and by tourists.

A Comparative Study on the Molluscan Diversity in the Selected Beaches of Kollam and Thiruvananthapuram districts of Kerala ,India

Biodiversity of bivalves and gastropods at Pozhikkara and Kappil beaches of kollam and thiruvananthapuram Districts of Kerala was assessed in this study. A total count of 1130 molluscs were collected in which 24 species belonging to 19 families of two classes ; Class gastropods and Class bivalves were observed. Study was carried from December-2022 to May 2023 by using Beachcombing method in sandy areas and scrapping of molluscs in the Rocky areas selected for the study . In family of Muricidae three species were found and in Babylonidae ,Turitellidae and Bursidae two species of each was observed ,remaining families were included with one species each were recorded from the study areas .Perna perna and Donax scrotum were seen in large number during the study period. . Cymaticum perryi ,Natica marochinesis ,Faunus ater and Nipponaphera quasilla were least in number during study period KeyWords:Pozhikkara,Kappil,Mollusc,Beachcombing,Bivalves,Gastropods

Diversity of Molluscs (Gastropoda and Bivalve) associated with Mangrove species in Dondon Beach and Gerupuk Beach, Central Lombok

Mollusks are macrofauna found in mangrove environments. The aim of this research is to explain the association of mollusks with mangroves at Dondon Beach and Gerupuk Beach, Central Lombok. Furthermore, the research method uses transects and quadrants and determines transects using the purposive sampling method. Meanwhile, data analysis used descriptive statistics, the Shannon-Wienner diversity index, the Evenness uniformity index, the Simpson dominance index, and the Ludwig & Reynolds association index. Next, the relationship between mangroves and mollusks was analyzed using the Pearson correlation index. The results of this research found 2 mangrove species and 45 mollusk species at Dondon Beach, while 6 mangrove species and 21 mollusk species were found at Gerupuk Beach. Results of descriptive statistical analysis, Littorinidae was highest and Cardidae was lowest at Dondon Beach, Potamididae was highest and Muricidae was lowest at Gerupuk Beach. The mollusk species diversity index was the highest at station III Dondon Beach and 2.33 at station III Gerupuk Beach. The highest mollusk species uniformity index was 0.9 at station III Dondon Beach and 0.76 at station III Gerupuk Beach. The highest mollusk species dominance index was 0.12 at station II Dondon Beach and 0.16 at station II Gerupuk Beach. The relationship between mangroves and molluscs is based on Pearson correlation, at Dondon Beach, the r2 value = 0.9973 while at Gerupuk Beach, the r2 value = 0.2265. Mollusk and mangrove association types, 25 positive species and 17 negative species. Meanwhile, at Gerupuk Beach, 8 species had positive associations and 3 species had negative associations. The conclusion of this research is that the association between mollusks and mangroves is very strong at Dondon Beach and the correlation is weak at Gerupuk Beach.

Monospecific mangrove reforestation changes relationship between benthic mollusc diversity and biomass: Implication for coastal wetland management

Anthropogenic causes are overtaking natural factors to reshape patterns of biodiversity and ecosystem functioning. Mangrove reforestation aimed at reversing losses of mangroves has been conducted worldwide for several decades. However, how reforestation influences the link between ecological processes that shape community diversity and the consequent effects on ecosystem functions such as biomass production is less well known. Here we used data collected before and after mangrove planting to examine the effects of reforestation on molluscan species richness and biomass production by testing the changes in species richness, compositional similarities, distance-decay effects (community similarity decreases with increasing geographical distance) in metacommunity across a regional scale of 480 km (23–27 °N) in southeast Chinese coasts. Additionally, we further detected the impact of landscape configuration caused by different intensities of reforestation on the mollusc community. After the mangrove reforestation, mollusc species richness and biomass increased significantly. The increases in species richness and biomass of mollusc community were mediated by reducing distance-decay effect, indicating an increase in relationship strength between species richness and biomass might be associated with a decrease in distance-decay effect with rising mangrove habitat. We highlight the importance of considering the effects of anthropogenic changes on the relationship between biodiversity and ecosystem functioning. Quantifying the distance-decay effect of these influences enables management decisions about coastal restoration to be based upon ecological mechanisms rather than wishful thinking or superficial appearance.

Current Estimates of Philippine Marine Mollusks Taxonomic Diversity

Mollusks are among the most diverse and the most threatened invertebrate groups, with high records of recent extinctions. Yet, the assessment of mollusk diversity and records in megadiverse countries such as the Philippines greatly needs synthesis and updating. Here, we report on the current taxonomic diversity of the Philippine mollusk. Comprehensive records of mollusks in the Philippines from published literature, accessible museum records, and online databases were compiled and checked with the World Register of Marine Species. A total of 64,898 Philippine mollusk records were compiled, comprised of 14,482 distinct species. Of these distinct species records of Philippine mollusk, 51% have accepted names in WoRMS, whereas 35.8% had taxonomic name changes; 1.5% had unaccepted names in WoRMS but with no accepted names either (e.g. taxon inquirendum, nomen dubium, etc), and 11.7% did not have exactly matched records in WoRMS. After checking all Philippine mollusks records against WoRMS, there were 8,066 mollusk species in the Philippines belonging to 1,991 genera within 423 families and 51 orders, representing all molluscan classes. A total of 7,085 (88%) of the species records were marine (6,953 or 86% were strictly marine species) belonging to 1,780 genera, 368 families, and 50 orders, also representing all mollusk classes. This current account is the most comprehensive we know to date, but it certainly is an underestimate, as not all possible resources are accessible. A systematic national-scale survey of Philippine mollusk diversity is needed to improve the current account and to fill the gaps in [1] taxonomic status verification, and [2] the IUCN and conservation status of many Philippine mollusk species (which, to date, 96% of all species have no IUCN assessments).

Annual and decadal surveys of molluscs on intertidal platform reefs in a warming marine environment in the southeastern Indian Ocean provide a baseline for monitoring for future environmental changes

ABSTRACT Few data sets are available to evaluate short- and long-term perturbations and impacts of increasing anthropogenic stresses and a warming marine environment in coastal regions near cities. The Perth, Western Australia shoreline has extensive, depauperate sandy beaches interrupted by small, biodiverse intertidal reef platforms. We present transect data on mollusc diversity and density on three Perth platforms recorded from 1983 to 1987, and compare it to 2007 and 2021 to analyse assemblage modifications in response to increased anthropogenic pressures. NMDS multivariate analysis showed a consistent drift in assemblage composition in 2007 and 2021, but this is was not statistically significant from the 1980s baseline (PERMANOVA, P = 0.336). There was no significant long-term decline (or increase) in molluscan species richness. Most species were uncommon but eight were recorded on at least 20 of the 21 surveys. The endemic Western Australian mussel Brachidontes ustulatus (Lamarck, 1819) accounted for 71.8% of all individuals. Total mollusc density varied primarily with changes in B. ustulatus. Tropical species were a minor component of the molluscs that did not change in diversity with warming temperatures. These data provide a long-term baseline for monitoring future anthropogenic changes.

Comparative Study of Molluscan Diversity of Kelve and Shirgaon Beach, Palghar, Maharashtra (India)

Coastal ecosystems, encompassing various habitats such as mangroves, coral reefs, beaches, cliffs, lagoons, and estuaries, are vital for the diversity of life. Mollusks, belonging to the phylum Mollusca in the animal kingdom, play a significant role in coastal ecosystems. They serve as important members of the food chain and exhibit remarkable ecological adaptations to various habitats. This research aims to investigate the diversity of mollusks at Kelwa and Shirgaon beaches in Palghar district, Maharashtra. The study will reveal the molluscan diversity at these specific locations, providing insights into their biological classification through systematic arrangement and accompanying shell photographs.

Diversity and Status of Non-Marine Molluscs in Papikonda National Park

In the present study, an attempt has been made to investigate the Mollusc assemblages of Papikonda National Park, Andhra Pradesh during the years 2021-2022. Papikonda National Park is located in Andhra Pradesh state covering East Godavari and West Godavari districts and is one of the biodiversity rich regions in Eastern Ghats. Many studies have been conducted on fauna of the park. However, little or no attention is paid to malacofauna. In the current study, the authors recorded 44 species of non-marine molluscs constituting 20 freshwater and 24 terrestrial species. Among the freshwater species, Tarebia granifera, Melanoides tuberculata and Radix rufescens, and among terrestrial species, Glessulas ubtornensis and Macrochlamys indica were the most frequent species. Unionidae and Ariophantidae were found to be the most speciose families in freshwater and terrestrial habitats respectively.

Mollusks diversity to support mangrove tourism attractions in the mangrove forest of Nusa Lembongan, Bali, Indonesia

Research on the diversity of molluscs has been carried out in the mangrove forest of Nusa Lembongan. The purpose of this study was to determine the species of mollusks that interact in the mangrove habitat, to support a scientific interpretation of the existence of mollusks in the mangrove forest of Nusa Lembongan. The research was conducted in seven mangrove forest sites, from April to June 2022 using the quadratic method. At each research site determined five sampling squares. Identification of mollusk species based on morphological characters (shape, size, shell texture and shell color). The abundance of each species was calculated based on the number of individuals per unit area (m2). The diversity of molluscs was calculated using the Shanon-Wiener diversity index. The results showed that 24 species were found in the mangrove forest of Nusa Lembongan, 19 species from the gastropod class and 5 species from the bivalves class. Several species that were quite dominant were the mangrove periwinkle Littoria scabra, with a density of 28.4 individuals/5 m2, sulcate swamp Terebralia sulcata, a density of 10.2 individuals/5m2, mud creeper Cerithidea obtusa, with a density of 7.2 individuals/5m2. The diversity of mollusks species in the mangrove area of Nusa Lembongan is included in the moderate category with a diversity index of 2.79 and an evenness index of 0.88. Based on the diversity index, it shows that the condition of mangroves in Nusa Lembongan is still relatively good or steady. The diversity of mollusks, the abundance of each species, the unique characteristics of each species, and the presence of mollusks in the substrate or mangrove vegetation are scientific interpretations and attractive attractions for eco-friendly mangrove tours.

Mollusc Diversity of Hard Substrate Habitats of Gökçeada Island

In the present study, molluscs diversity between 0-0.5 m depths of the hard substrate habitats of Gökçeada coasts was investigated qualitatively and quantitatively, seasonally, and monthly in 2010 and 2011. In addition, in summer months of 2021, samples were taken to investigate the mucilage impact on the mollusc fauna, which occurred in the Marmara Sea in 2021 and affected Gökçeada coasts due to the currents. A total of 76 mollusc species were identified and 27 of the determined species are new records for Gökçeada. Among the found species, while Cardita calyculata (Linnaeus, 1758) was the most dominant species at the Yıldız Koy station sampled monthly, Musculus costulatus (Risso, 1826) was the dominant one at all other sampling stations. The Tepeköy station was found to has the highest number of species and individuals. As the main reason for this can be indicate the limited human access to the region and the presence of various habitats. Mollusc species diversity, which was detected in 2010 due to the pouring of sand for tourists by the municipality at Yıldız Koy station, was found to be increased greatly in 2021 after this practice was abandoned. It was also detected that the mollusc species distributed on the coasts of Gökçeada were not acutely affected by the mucilage event occurred in 2021. However, more detailed studies need to be monitoring and report the negative effects that may occur the mucilage event on the species diversity of the region in the coming years.

An updated checklist of non-marine molluscs of the western Himalaya

This paper presents the first comprehensive checklist of the non-marine molluscs from the western Himalaya, a region of high biodiversity and endemism. Based on faunistic surveys during 2019-2023 and published records, the paper reports 242 species belonging to 101 genera and 45 families of gastropods and bivalves, of which 168 species are endemic to the region. The paper also provides new distribution records and taxonomic notes for some species. Among the notable findings are the first records of Limax mayae, Oxyloma sp., Odhneripisidium kuiperi, Thiara aspera from India, and Bensonies jamuensis, Euaustenia cassida, Stagnicola sp. from the western Himalaya. The paper presents some species with substitutional illustrations and literature from the region for the past two centuries. Additionally, the paper also discusses the threats that non-marine molluscs face in the western Himalaya and suggests some conservation measures to protect them. The authors hope this paper will serve as a baseline for future studies on the diversity, distribution, ecology, and conservation of non-marine molluscs in the western Himalaya.