Class Gastropoda Research Articles

Biodiversity of symbiotic gastropods (Mollusca, Eulimidae) in Vietnamese waters barcoded

ABSTRACT Eulimidae is a prominent group within the class Gastropoda, comprising 1087 species that have developed specialised symbiotic relationships with all extant echinoderm classes. At least 47 species of eulimids can be found in the waters of Vietnam. Representatives of the genus Pulicicochlea, the species Vitreobalcis tripneusticola, and four new undescribed species were observed for the first time. In this study, we update the existing checklists of Vietnamese eulimids, emphasising the use of molecular barcoding to determine the phylogenetic relationships among the collected species. The classical taxonomy of molluscs relies heavily on the morphology of the shell and radula. The family Eulimidae presents challenges as in many species these features are poorly developed, and molecular phylogenetic methods have proven to be more informative for the taxonomy and systematics of this family. To understand the evolutionary pathways in Eulimidae, we constructed a COI-based phylogenetic tree, which included original sequences primarily from Vietnam and all available sequences for Eulimidae from GenBank. The newly obtained genetic information is crucial for enhancing our understanding of this family of gastropod mollusсs, as well as for any future revisions that may be necessary.

MACROZOOBENTHOS ABUNDANCE IN THE MANGROVE AREA OF TANAH MERAH SAMBOJA KUTAI KARTANEGARA EAST KALIMANTAN

Tanah Merah Beach is a coastal area of Samboja in East Kalimantan, which is a local tourist destination. The association of coastal ecosystems can be shown by macrozoobenthos, as one of the biota components in coastal areas to mangroves. This study identifies the species, calculates the abundance, and analyses the ecological index of macrozoobenthos, as well as looking at the relationship between nutrients and sediment texture with the number of macrozoobenthos found. The purpose of this research is to determine the condition of nutrients in the sediment substrate to its abundance in the mangrove ecosystem area. Sampling was conducted at three points based on the percentage of mangrove canopy cover in the Monmang version 2.0 application, with each point represented by 3 quadrant points measuring 0.25 m2. The results showed that the percentage of mangrove canopy cover was categorised as slight-moderate, the abundance of individuals was dominated by the Gastropoda class with 9 species and a small proportion of the Bivalve class. The ecological indices in order are the Diversity Index (H') in the low category, Diversity (E) in the low category, and dominance (C) found Cerithidae sp species dominating each point. The highest abundance was found at radius 2 canopy cover 77.24 - 83.13%. Nutrient content in sediment, nitrate (1.00-16.25 mg/L), phosphate (29.01-83.94 mg/L), organic carbon (2.23-3.24%) with confirmed sediment texture of sandy loam. Nitrate content ranged from 1.00-16.25 mg/L, Phosphate 34.65 - 44.51 mg/L and Organic carbon 2.23-3.24% (per mg) in the sediment and a significant effect of phosphate content on Macrozoobenthos abundance was found in the correlation test results.

Complete mitochondrial genome and phylogenetic analysis of Mancinella alouina.

The Muricidae family in the Class Gastropoda comprises numerous species with a vast range of morphological features and a worldwide presence. The phylogeny of the Muricidae has been analyzed in previous studies; however, the evolutionary relationships among the main branches of the Muricidae remain unknown. In the present study, the mitochondrial genome of Mancinella alouina was sequenced. The mitochondrial genome was found to be 16,671bp in length and made up of 37 genes (13 protein-coding genes, 22 transfer RNA and 2 ribosomal RNA genes). The genome has an A-T-rich region (66.5% A + T content) and all of the PCGs use the ATN start codon and the TAG or TAA stop codons. The mitochondrial gene arrangement of Mancinella alouina is similar to that of other Muricidae, except for Ocinebrellus inornatus and Ceratostoma burnetti. On the basis of a flexible molecular clock model, time-calibrated phylogenetic results indicate that the genus Mancinella diverged roughly 18.09Mya, and that the family Muricidae emerged in the Late Cretaceous. This study reveals the structural and sequence information features of the mitochondrial genome of Mancinella alouina. This study provides evidence for the relationships within the family Muricidae at the molecular level, and infer the divergence time. The results of phylogenetic analyses strongly support the current classification.

The Families of Non-LTR Transposable Elements within Neritimorpha and Other Gastropoda.

Repeated sequences, especially transposable elements (TEs), are known to be abundant in some members of the important invertebrate class Gastropoda. TEs that do not have long terminal repeated sequences (non-LTR TEs) are frequently the most abundant type but have not been well characterised in any gastropod. Despite this, sequences in draft gastropod genomes are often described as non-LTR TEs, but without identification to family type. This study was conducted to characterise non-LTR TEs in neritimorph snails, using genomic skimming surveys of three species and the recently published draft genome of Theodoxus fluviatilis. Multiple families of non-LTR TEs from the I, Jockey, L1, R2 and RTE superfamilies were found, although there were notably few representatives of the first of these, which is nevertheless abundant in other Gastropoda. Phylogenetic analyses of amino acid sequences of the reverse transcriptase domain from the elements ORF2 regions found considerable interspersion of representatives of the four neritimorph taxa within non-LTR families and sub-families. In contrast, phylogenetic analyses of sequences from the elements' ORF1 region resolved the representatives from individual species as monophyletic. However, using either region, members of the two species of the Neritidae were closely related, suggesting their potential for investigation of phyletic evolution at the family level.

Macrozoobenthos Community Structure at Teluk Marunggai Beach, Nagari Sungai Nyalo, Pesisir Selatan District, West Sumatera Province

Teluk Marunggai Beach, Nagari Sungai Nyalo, is one of the new tourist areas in Pesisir Selatan Regency which, over time, will begin to be in demand by tourists, which will have an impact on the life of the biota on the beach, one of which is macrozoobenthos. This research was conducted in March 2023 in the Intertidal Zone of Teluk Marunggai Beach, Sungai Nyalo Village, Koto Ampek Tarusan District, Pesisir Selatan Regency, West Sumatra Province. The purpose of this study was to determine the type and abundance of macrozoobenthos species in the coastal waters of Marunggai Bay and to determine the diversity, uniformity, dominance and distribution patterns of macrozoobenthos in the coastal waters of Marunggai Bay. The research method used is the survey method, where the sampling using the quadrant transect method is carried out at three stations. The research results found 40 species of macrozoobenthos. The most common species found at all stations were Turbo cinereus from the Turbinidae family and the Gastropod class. The macrozoobenthos abundance values ​​obtained ranged from 6.44–6.67 ind/m2. Species diversity index values ​​ranged from 3.06–3.52, namely high. Uniformity index values ​​ranged from 3.02 to 3.14, high uniformity, dominance index values ​​ranged from 0.10 to 0.15; no species dominated, and the value of the distribution pattern ranged from 2.959 to 2.962 with a group distribution pattern

Freshwater Malacofauna and Distribution of Trabzon, Türkiye

In this study, freshwater molluscs and their zoogeographical distributions in Trabzon were investigated. During the period of June-December 2021, samples were collected from 38 freshwater river localities. From the study area, Ancylus fluviatilis from Gastropoda class, Planorbidae family, non-native species Physella acuta from Physidae family, and Dreissena polymorpha from Bivalvia class and Dreissenidae family were identified. While A. fluviatilis specimens were found from all freshwater systems in Trabzon region, the non native P. acuta could be identified from Fol Stream, Yıldızlı Stream, Sera Lake and Manahoz River. Empty shells belonging to the D. polymorpha species were identified from the area where Çatalzeytin Stream joins the sea. P. acuta and D. polymorpha are new records for the freshwater streams of Trabzon region.

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.

The genome of the rayed Mediterranean limpet Patella caerulea (Linnaeus, 1758).

Patella caerulea (Linnaeus, 1758) is a mollusc limpet species of the class Gastropoda. Endemic to the Mediterranean Sea, it is considered a keystone species due to its primary role in structuring and regulating the ecological balance of tidal and subtidal habitats. It is currently being used as a bioindicator to assess the environmental quality of coastal marine waters and as a model species to understand adaptation to ocean acidification. Here, we provide a high-quality reference genome assembly and annotation for P. caerulea. We generated ∼30 Gb of Pacific Biosciences high-fidelity data from a single individual and provide a final 749.8 Mb assembly containing 62 contigs, including the mitochondrial genome (14,938 bp). With an N50 of 48.8 Mb and 98% of the assembly contained in the 18 largest contigs, this assembly is near chromosome-scale. Benchmarking Universal Single-Copy Orthologs scores were high (Mollusca, 87.8% complete; Metazoa, 97.2% complete) and similar to metrics observed for other chromosome-level Patella genomes, highlighting a possible bias in the Mollusca database for Patellids. We generated transcriptomic Illumina data from a second individual collected at the same locality and used it together with protein evidence to annotate the genome. A total of 23,938 protein-coding gene models were found. By comparing this annotation with other published Patella annotations, we found that the distribution and median values of exon and gene lengths was comparable with other Patella species despite different annotation approaches. The present high-quality P. caerulea reference genome, available on GenBank (BioProject: PRJNA1045377; assembly: GCA_036850965.1), is an important resource for future ecological and evolutionary studies.

Mollusca Biodiversity as A Quality Bioindicator Waters in Central Lombok Gerupuk Bay Coastal Area

Various natural resource utilization activities on the coast of Gerupuk Bay can potentially affect the quality of the aquatic environment, both biotic and abiotic, one of which is mollusc biodiversity. This study aimed to determine the relationship between the existence of Mollusca biodiversity and water quality and substrate in Gerupuk Bay. This study used a quantitative descriptive method of determining stations using the purposive sampling method based on differences in community activities at each station. Sampling was conducted at three stations, including Mollusca samples and water quality measurements: salinity, pH, temperature, and substrate. Molluscs in Gerupuk Bay found 55 species of Mollusks representing three classes, namely the Gastropoda class, with as many as 44 species incorporated in 22 Families; the Bivalve class, as many as ten species contained in 6 Families; and the Scaphopoda class, with as many as one types incorporated in 1 Family. The composition of Mollusca classes found on the Gerupuk Bay Coast is Gastropoda class at 62%, Bivalve class at 35%, and Scaphopoda class at as much as 3%. Mollusca diversity is calculated using the Shannon-Wienner diversity index (H'). The diversity index results ranged from 2.890-1.998, with moderate categories at all stations. Bioindicators of water quality using the diversity index show that stations I and III categorize the Gerupuk Bay area as lightly polluted. In contrast, at station II, it is moderately polluted.

A Study on the Biodiversity of Aquatic Invertebrate Fauna of Nizamsagr Irrigation Reservoir, Kamareddy District, Telangana, India

Nizamsagar reservoir constructed across the river Manjeera between Achampeta and Banjapalli villages of newly formed Kamareddy district of Telangana State. The River Manjeera is a tributary river of the Godavari. The height of the dam is 96 meters and length is 3 km having water capacity 30 TMC. The study revealed that a total of 27 invertebrate species belonging to three phyla: Arthropoda, Mollusca, and Annelida. Among these, the Arthropoda phylum species dominated, followed by Mollusca and Annelida. In the Mollusca phylum, the Gastropoda class exhibited rich abundance, with species like Bithynia transsilvanica, Bellamya bengalensis, Perrysisfavidens, and Pila globose being prominent. Within the Annelida phylum, Tubifex tubifex in the Clitellata class showed the highest abundance compared to Limnodrillus hoffmeisteri. In the Arthropoda phylum, specifically in the Insecta class, there were a diverse range of species, including Chironomus Sps., Anophelus mosquito larvae, Culex mosquito larvae, Sympetrum vulgatum, and Orthetrum cancellatum, with the highest diversity observed.

The occurrence and density of some molluscs species in different areas of Basrah province, southern of Iraq and first record of The invasive golden mussel Limnoperna fortunei (Dunker, 1857).

The study was conducted to compare the distribution and composition of the Molluscs community in 4 ecosystems (4 sites) in southern of Iraq, namely: (Site 1)- in Euphrates River at Al-Madinah city, (Site 2)- in Shatt Al-Arab at Al-Sharsh area, (Site 3)- in the Garmat Ali River at Al-Mashib area and Site 4- in the Al-seba area. Samples were collected from study sites during a period of January to August 2019. (11) species from the class Gastropoda and (4) species from the class Bivalves, species were predominated in most of the study months which are species: Melenodies nodosa, Bellamya bengalensis and Melanopsis turbculata from Gastropoda and two of the species are bivalve: Corbicula fluminalis and Limnoperna fortunei (Dunker, 1857), and the last species, L. fortunei, was recorded in the current study for the first time in freshwater of Iraq. The total biodiversity values of Molluscs at the Euphrates River at Al-Madinah area (Site. 1), Al-Sharsh area (Site 2), Al-Mashib area (Site 3) and Al-seba area (Site 4) were 3.1, 2.9, 2.4, 1.8, respectively, and It was noted that the highest seasonal densities of the species in the current study were recorded in the winter season, reaching 1013, 905, 762 and 639 individuals / m2 in four sites, 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.

IDENTIFIKASI MAKROZOOBENTOS SEBAGAI BIOINDIKATOR KUALITAS PERAIRAN DI PANTAI TELUK BENOA, BADUNG

Utilization of coastal waters for aquaculture activities or for other activities provides positive value for human welfare but can also provide the potential for reducing water quality. The decline in environmental quality can be seen from changes in components such as biology, chemistry, and beach physics. Changes in chemical and physical components cause sediment to decrease, which will affect the life of marine biotas, such as the community structure, especially the slow-moving and relatively settled biota on the bottom of the waters (macrozoobenthos). Macrozoobenthos are very appropriate to be used as an indicator of changes in water quality due to their benthic nature which is relatively silent or has low mobility so it is strongly influenced by the environment. The purpose of the study was to determine the structure of the macrozoobenthos community and the condition of seawater quality. There were 25 species of gastropods and 3 other classes. The macrozoobenthos species diversity index on the Benoa Bay Coast showed a moderate level of diversity with the highest value of 2.4576. The uniformity index at each station ranges from 0.0894 – 0.5337. The value of the dominance index ranges between 0.000004-0.7656. Based on the relative abundance, the macrobenthos community is dominated by the Gastropod class. The temperature values ??at each station were relatively the same, ranging from 29.3°C– 30.8°C, and the pH was in accordance with quality standards for macrozoobenthos growth. Some indicators of water quality are still below the quality standard threshold, but the concentration of phosphate (PO4) at all locations is already above the predetermined quality standard of 0.015 mg/L?.
 Keyword: Macrozoobenthos; Bioindicator; Benoa Bay; Bali

Macroinvertebrate assessment in seagrass ecosystem in Sinacaban Municipality, Misamis Occidental, Philippines

Abstract. Mahilac HMO, Tandingan JP, Torres AG, Amparado JRR, Roa-Quiaoit HA. 2023. Macroinvertebrate assessment in seagrass ecosystem in Sinacaban Municipality, Misamis Occidental, Philippines. Biodiversitas 24: 5586-5597. Marine ecosystems such as seagrasses are economically and ecologically important in tropical coastal areas like Sinacaban municipality, southern Philippines. This study assessed the macrobenthic species and water quality (e.g., pH, salinity, temperature, Dissolved Oxygen (DO), and total suspended solids (TSS) in three seagrass areas in the municipality. The study showed the seagrass habitats with 40 macrofaunal species from the classes Gastropoda (27), Bivalvia (11), and Crustacea (2), with Clibanarius longitarsus as the most abundant species (77 individuals or 24% relative abundance). The Strombidae family holds the highest dominance within the Gastropoda class, whereas the Arcidae family is the most dominant within the Bivalvia class. However, there is no dominant family within the Crustacea class. Water quality showed pH at 7, 30 ppt salinity, and 28? within their standard limits, while DO (8 mg/L) and TSS (127 mg/L) exceeded their range. This study recorded eight economic important species and five least concern International Union for Conservation of Nature (IUCN) species. Among the three (3) sites, the seagrass area in Libertad has the highest species richness (28), Shannon’s Index (2.92), and species evenness (0.66). The Chao estimation result revealed that Libertad (37.17) and Poblacion (18.5) have lower uncertainty in their species estimates than Colupan (39.60), which has a wider range of potential species richness. The Canonical Correspondence Analysis (CCA) proved that there are species that can adapt to a certain level of environmental parameters, like Angaria delphinus, while Decatopecten radula is one of the species that does not correlate with the water parameters in the study. The findings are critical for biodiversity conservation, ecosystem management, sustainable resource use, and adaptation to changing environments in order to maintain ecological balance and the long-term health of the seagrass ecosystem.

A Classification and the Life Cycle of Snail Monacha cartusiana (O.F. Müller, 1774) in Iraq/ Baghdad

Most species of Mollusca lives in salts water, on the shores of seas and lakes and some in fresh water, others are found in deserts, forests and forms and there are 45,000 species . They are invertebrate animals with lateral symmetry, slow-moving and a few of them are fast, like Octopus and Squid and some of them are economic importance. The class Gastropoda are considered the largest class belonging to the Phylum-Mollusca, as it contains more than 80%. Its importance follows from its great diversity and spread in all environments. It has an ecological importance because it plays an great role in ecosystems due to the diversity of its food methods between herbivorous and predatory. Studies on snails in Iraq are very few and modest. Hence the idea of identifying these animals and study there classification and life cycle, and when collecting samples in the early morning hours in home gardens and public gardens. A group of these snails was found and most prevalent in these sites in Baghdad was chosen. It was classified and took pictures of it, then it was raised in industrial environment, and after all the appropriate condition were created for it. It found that in Baghdad this snail does not live more than approximately 150 days on average, and that the average duration off eggs hatching is approximately 14 days, and that the resulting larvae survive form only 40% of resulting larvae after hatching, and that those succeed in reaching puberty do not exceed 14% of the individuals. It is diameter ranges at puberty at an average of 11 mm and the number of turns of shell of the shell is 5.5. This snail is characterized by the edge of opening of shell is red lip. These animals like others are affected by its environment. It was found that this species does not live more than a year, with an average of 195 days. As well as that it bears temperatures from (13-37)°C and that it produces eggs 4-5 times and 21-29 eggs each time.

Malacofaunal diversity (Gastropods and Bivalves) along the mangrove forest area of the Gulf of Mannar marine biosphere region, South India

The mangrove ecosystem is one of the most distinctive biospheres, and it is under threat from habitat loss, aquaculture expansion, overharvesting, and pollution, all of which impact the malacofaunal diversity. This study aimed to investigate the malacofaunal diversity along the mangrove region of the Gulf of Mannar (GoM) and Physico-chemical properties of the sediments were measured to correlate the malacofaunal diversity. The diversity of the molluscs along the Thoothukudi coast was investigated from December 2020 to September 2021, documenting 84 mollusc species, represented by 45 gastropods and 39 bivalves. The class Gastropoda represented 7 orders, 15 families, and 30 genera, with Caenogastropoda having the highest species (19), followed by Neogastropoda with 7 species, while in bivalves, Venerida had the most species (14 species), followed by Cardiida (9 species). Palayakayal had the greatest number of species (68), followed by Punnakayal (63), Karapad Bay (32), and Machoda Bridge (33). Palayakayal has the highest Shannon–Wiener diversity index (H’) and Margalef species richness (d) at 4.11 and 10.81, followed by Punnakayal at 4.05 and 10.16; Karapad at 3.39 and 5.65; and Machoda Bridge at 3.55 and 3.55 respectively. The BC (Bray–Curtis)​ similarity index identified the most similarity (86.91%) between Palayakayal and Punnakayal. Palayakayal has the greatest (H’) and (d) values due to its pristine mangrove habitat and low anthropogenic activity. The Physico-chemical results showed that salinity and diversity were positively correlated, while hydrogen sulfide, organic matter, and molluscan diversity were negatively correlated. The malacofaunal diversity has been documented to provide useful baseline data for conservation management. Additionally, the findings showed that salinity is a crucial factor in favoring diversity. The anthropogenic activities in the ecosystem first alter the salinity of the soil, directly impacting malacofaunal diversity. Such studies might increase knowledge among the public and policy-makers, enabling them to develop legislation adequately.

Diversity of Gastropods and Bivalvia in Jukung Bay Waters, Pemongkong Village, Jerowaru District, East Lombok Regency

Several activities affect the distribution of gastropods and bivalves, one of which is the activity of the community around the coast which is thought to affect water quality. The entry of organic and inorganic contaminants into coastal waters is thought to cause a decrease in water quality followed by changes in physics, chemistry and biology. The purpose of this study was to determine the diversity of gastropods and bivalves in the waters of Jukung Bay, Ujung Betok Hamlet, Pemongkong Village, Jerowaru District, East Lombok Regency. This research was conducted in Ujung Betok Hamlet (Tukung Bay Waters), Pemongkong Village, Jerowaru District, East Lombok Regency. the study was conducted from October 2022 to July 2023. The results showed that the highest species abundance was found in the Gastropoda class Nassarius sp with an abundance of 31 individuals/m2. The highest gastropod and bivalves diversity index value was obtained at point 3, namely 0.42 individuals/m2. The highest gastropod and bivalves uniformity index value was obtained at point 2 with a uniformity index value of 0.28. The dominance index value obtained was 0.1-0.56 individuals/m2 included in the moderate dominance category. Based on the results and discussion it is known that the abundance of gastropods and bivalves in the coastal waters of Jukung Bay which were analyzed totaled 108 individuals. The diversity index (H') obtained in this study ranged from 0.41-1.39 individuals/m2. The uniformity found ranged from 0.14 to 0.28 individuals/m2. The dominance index obtained ranged from 0.1 to 0.56 individuals/m2.

PROXIMATE ANALYSIS AND ESSENTIAL MINERALS CONTENT OF GASTROPODA Turbo setosus FROM LEMUKUTAN ISLAN, WEST KALIMANTAN

PROXIMATE ANALYSIS AND ESSENTIAL MINERALS CONTENT OF GASTROPODA Turbo setosus FROM LEMUKUTAN ISLAND, WEST BORNEO. Turbo setosus is a species of the gastropod class that has a wavy shell with circular lines on its surface. Because it is easy to find, this type of snail is widely used in the food sector. The nutritional value of Turbo setosus is also high so it has economic value. Proximate analysis and essential minerals are useful to determine the nutritional value contained. Gastropods were extracted using Soxhlet at a certain temperature to measure moisture content, fat content, ash content, and carbohydrates. To find out the number of carbohydrates, the by difference method is used. Meanwhile, to find out the amount of minerals contained using the Atomic Absorption Spectrophotometry (AAS) method.

Identification of Mollusca Types Around Bungus Beach Padang

Mollusca animals have a soft body, not segmented, most of the shell is made of calcium carbonate. Taxonomic identification is carried out to find out the types of Mollusca animals as well as for collections. This research aims to determine the types of Mollusca animals around Bungus Beach Padang. This type of research is descriptive with roaming method. The cruising method is carried out by tracing the beach as far as the tides are ± 1 km long and 8 meters wide. Molluscs were taken directly for three times, and tested the water with physical and chemical factor parameters. The results obtained from the identification of Mollusca species found in the form of shells consisting of two classes, namely the Bivalvia class and the Gastropod class. The total number of individuals is 202 individuals. The most commonly found molluscs are the class Bivalvia with 17 species. The most abundant species and always found in each repetition was Soletellina diphos with 29 individuals, at least Meretrix lyrata, Barbatia fusca with 1 individual. Class Gastropods found as many as 14 species. The species most commonly found was Cypraea vitellus with 15 individuals, the least found were Cypraea leviathan, Murex trapa, Bufonaria rana, Turbo setosus, Pomacea sp., Phenacolepas sp. amounted to 1 individual. Identification of the types of Mollusca animals can be identified based on the morphology of their shells and can also match the Mollusca images that have been obtained with the identification book. From the results of this study it can be concluded that the identification of the types of Mollusca animals can be known based on the morphology of their shells and can also match the Mollusca images that have been obtained with identification books. The results of the research are recommended for further researchers to find the types of Mollusca animals as a whole, especially on the beach.

RETUSA CANALICULATA (SAY,1822) AS A SEDIMENTARY ENVIRONMENTAL INDEX FOR SAND DEPOSITS IN THE IRAQI COAST

The aim of the research is to determine the sedimentary environment and estimate the geological period of the rocky islands (solidified sand deposits) and shoals in the Iraqi coast, by studying a type of gastropod class known to be present in the region, which is Retusa canaliculata (Say,1822). Only eight sand sediment samples were used for this purpose. The particle size distribution showed that sediment was formed of Clayey sand, Silty sand, sand and Muddy sand. By checking the species Retusa canaliculata (Say,1822) in the sandy samples, it was observed that the percentage of species individuals increased with the rise in the percentage of sand in the samples. From the shells nature of the individuals of this species, their age is probable to date back to the late Holocene period (less than 4,000 years ago). Which means that the solid sandy sediments were within the aforementioned period, where the estuarine environment was, which represents the ideal environment for the species Retusa canaliculata (Say,1822).