The biodiversity richness of Mollusk species in Lanaga waters, Meureubo Subdistrict, Aceh Barat Regency, Aceh Province

Mollusca are soft-bodied animals that are generally protected by shells, and have a variety of species richness in habitat, especially in Lanaga Waters, Mereubo Subdistrict, Aceh Barat Regency and need to be studied through research. The research objectives were (1) to assess the number of species of each class, and (2) to analyse the level of species richness of each class of molluscs, which are found in Lanaga Waters, Meureubo Sub-district, Aceh Barat district, Aceh Province. The research was carried out from January to March 2021, in Lanaga Waters. The research area was divided into three locations, each location was divided into five stations, and each station was assigned five sampling plots. Data were taken by using the purposive sampling technique. Data analysis of species richness level was analysed by richness formula, and analysis of data about the number of each species in each class was carried out descriptively. The results showed that (1) the species of Molluscs belonging to the Gastropod class were 9 species with a richness index, the Bivalvia class contained 2 species with a species richness index of 0.13 to 0.90 indicating that the level of species richness was low to high, in the Lanaga Waters area. Mereubo Subdistrict, Aceh Barat Regency, Aceh Province.

Keanekaragaman dan Pola Sebaran Moluska (Gastropoda dan Bivalvia) yang Berasosiasi Pada Ekosistem Mangrove di Pesisir Selatan Lombok Timur

Mangrove ecosystems have an important role in coastal areas. Mangroves have a function as a shelter, foraging for food, and breeding various aquatic biota. Damage to mangrove forests can cause the service of mangrove ecosystems to decrease, especially for mollusk life. Mollusks are one of the associated biotas of mangroves whose life is influenced by mangrove forests. Therefore, the purpose of this study was to determine the diversity of mollusks and the relationship between mollusk density and mangrove density in the mangrove ecosystem of the southern coast of East Lombok. A sampling of mollusks used the quadrate sampling method by purposive sampling by taking into account the mangrove species contained in the observation plot. The collected data were analyzed by diversity index, distribution pattern, association, and Pearson correlation coefficient. Then a simple linear regression analysis was performed with the independent variable (x) mangrove density and the dependent variable (y) mollusk density. The results of this study were the discovery of 22 species of mollusks consisting of 17 species of gastropods and five species of bivalves. The density of mollusks in the mangrove ecosystem of the southern coast of East Lombok is 44.50±2.63 ind./m2. The diversity index at the study site was classified as moderate, with a value ranging from 1.99 to 2.46. The distribution pattern of mollusks at the research site is clustered with an Id value > 1. There are eight mollusk species associated with three mangrove species from 22 mollusk species found. The linear regression equation y = 0.084x – 0.2963 with a Pearson correlation coefficient (r) 0.95 describes a strong relationship between the independent variable (x) mangrove density and the dependent variable (y) mollusk density. This study concludes that there is a significant relationship between mangrove density and mollusk density as indicated by F-hit(41.01) > F-table (7.70) and P-value (0.003) < (0.05).

Crustacean and mollusk species diversity and abundance in the mangrove communities of Mimika District, Papua, Indonesia

Setyadi G, Rahayu DL, Pribadi R, Hartati R, Wijayanti DP, Sugianto DN, Darmawan A. 2021. Crustacean and mollusk species diversity and abundance in the mangrove communities of Mimika District, Papua, Indonesia. Biodiversitas 22: 4146-4157. A mangrove crustacean and mollusk species diversity study was carried out in four mangrove estuaries in Mimika District, Papua, Indonesia. Two locations were selected on each estuary; for each location, samples of crustaceans and mollusks were collected from 5 m × 5 m plots, and mangrove trees were recorded on 10 m × 10 m plots at a distance of 10 m, 250 m and 500 m perpendicular to the riverbank. This study recorded a total of 41 species of crustaceans and 32 species of mollusks the latter comprising three species of bivalves and 29 gastropod species. The number of crab species found was among the highest compared to similar studies in the world. The average number of species collected from each 25 m2 plot was 7.6 ± 4.2 species for crustaceans, with an average abundance of 87 ± 3.5 individuals; for mollusks, it was 3.3 ± 3 species with an average abundance of 28 ± 48.4. Crustacean abundance and species composition were influenced by inundation frequency. There was a strong correlation between the crab Parasesarma cricotum and the association of Rhizophora apiculata and Bruguiera gymnorrhiza mangroves, and Clistocoeloma amamaparense and the association of B. gymnorrhiza, R. apiculata, and Bruguiera parviflora mangroves. For mollusks, correlations were found between Terebralia palustris and Ellobium aurisjudae and the association of R. apiculata and B. parviflora mangroves. The highest crustacean Shannon-Wiener diversity index was associated with Sonneratia alba and Avicennia marina mangroves, and the highest mollusk Shannon-Wiener diversity index was associated with R. apiculata and B. gymnorrhiza mangroves.

Differential Expression of Long Non-Coding RNA (lncRNA) in Mediterranean Mussel (Mytilus galloprovincialis) Hemocytes under Immune Stimuli

The Mediterranean mussel is one of the most economically relevant bivalve mollusk species in Europe and China. The absence of massive mortalities and their resistance to pathogens affecting other cultured bivalves has been under study in recent years. The transcriptome response of this species to different immune stimuli has been extensively studied, and even the complexity of its genome, which has recently been sequenced, has been suggested as one of the factors contributing to this resistance. However, studies concerning the non-coding RNA profiles remain practically unexplored—especially those corresponding to the lncRNAs. To the best of our knowledge, this is the second characterization and study of lncRNAs in this bivalve species. In this work, we identified the potential repertoire of lncRNAs expressed in mussel hemocytes, and using RNA-Seq we analyzed the lncRNA profile of mussel hemocytes stimulated in vitro with three different immune stimuli: LPS, poly I:C, and β-glucans. Compared to unstimulated hemocytes, LPS induced the highest modulation of lncRNAs, whereas poly I:C and β-glucans induced a similar discrete response. Based on the potential cis-regulatory activity of the lncRNAs, we identified the neighboring protein-coding genes of the regulated lncRNAs to estimate—at least partially—the processes in which they are implicated. After applying correlation analyses, it seems that—especially for LPS—the lncRNAs could participate in the regulation of gene expression, and substantially contribute to the immune response.

Abdominal angiostrongyliasis in the Americas: fifty years since the discovery of a new metastrongylid species, Angiostrongylus costaricensis

Angiostrongylus costaricensis is a zoonotic parasitic nematode described for the first time in 1971 by Pedro Morera and Rodolfo Céspedes in Costa Rica. This parasite causes an infection known as abdominal angiostrongyliasis, affecting mainly school-aged children and young adults. Infection with A. costaricensis has been associated with a myriad of rodent and mollusk species in the Americas and the Caribbean, as its natural hosts and reservoirs. In this commemorative review, we highlight the extensive research collected through a 50-year journey, which includes ecological, pathological, and molecular studies on A. costaricensis and its implicated disease. We also identify major knowledge gaps in its evolutionary history, the ecological role of imported and invasive mollusk species, and immune response. We propose that the advent of -omics analyses will allow us to gather novel information regarding A. costaricensis biology and infection dynamics, as well as to promote the design of much-needed sensitive and specific diagnostic tools.

Analysis of lead (Pb) levels in water, sediment and mollusks in secondary irrigation channels in Gorontalo Province, Indonesia

Tahir IA, Lamondo D, Baderan DWK. 2020. Analysis of lead (Pb) levels in water, sediment and mollusks in secondary irrigation channels in Gorontalo Province, Indonesia. Intl J Bonorowo Wetl 11: 1-6. This study was conducted in July-August 2020 in the secondary irrigation channels of Gorontalo Province, aimed to determine the lead content in the water, sediment and gastropods in the channels. The sampling points were located in four sub-districts, i.e., North Bulango Sub-district, Sipatana Sub-district, Central City Sub-district and Hulonthalangi Sub-district. The samples were analyzed using Atomic Absorption Spectrophotometer (AAS). The data were analyzed qualitatively by comparing them with the contamination thresholds set by the government of Indonesia. The results showed that the levels of lead in water in the four stations were 0.37 mg/L, 1.30 mg/L, 1.69 mg/L and 0.38 mg/L, respectively, in the sediment 1.1268 ppm, 0.9719 ppm, 0.7602 ppm, and 0.5290 ppm, respectively, and in each mollusk species, i.e., Bellamnya sp. 0.2924 mg/kg, Pomacea canaliculata 0.2413 mg/kg and Pomacea canaliculata 0.1873 mg/kg. The lead levels in the water, sediment and gastropods in the study sites exceeded the contamination thresholds set by the Indonesian government.

DNA Barcoding of Marine Mollusks Associated with Corallina officinalis Turfs in Southern Istria (Adriatic Sea)

Presence of mollusk assemblages was studied within red coralligenous algae Corallina officinalis L. along the southern Istrian coast. C. officinalis turfs can be considered a biodiversity reservoir, as they shelter numerous invertebrate species. The aim of this study was to identify mollusk species within these settlements using DNA barcoding as a method for detailed identification of mollusks. Nine locations and 18 localities with algal coverage range above 90% were chosen at four research areas. From 54 collected samples of C. officinalis turfs, a total of 46 mollusk species were identified. Molecular methods helped identify 16 gastropod, 14 bivalve and one polyplacophoran species. COI sequences for two bivalve species (Musculus cf. costulatus (Risso, 1826) and Gregariella semigranata (Reeve, 1858)) and seven gastropod species (Megastomia winfriedi Peñas & Rolán, 1999, Eatonina sp. Thiele, 1912, Eatonina cossurae (Calcara, 1841), Crisilla cf. maculata (Monterosato, 1869), Alvania cf. carinata (da Costa, 1778), Vitreolina antiflexa (Monterosato, 1884) and Odostomia plicata (Montagu, 1803)) represent new BINs in BOLD database. This study contributes to new findings related to the high biodiversity of mollusks associated with widespread C. officinalis settlements along the southern coastal area of Istria.

Fermenting Bread Dough as a Cheap, Effective, Nontoxic, and Generic Attractant for Pest Snails and Slugs

Invasive slugs and snails are among the most damaging pests of agriculture in temperate and tropical regions of the world. Control options, however, are limited and there is a heavy reliance on chemical molluscicides of variable efficacy. There is an ongoing need to improve management methods. Here, we show that a simple fermenting bread dough formulation (flour, water, and yeast) was effective in attracting pest mollusk species in laboratory tests, and in multiple replicated field trials in Hawaii, Oregon, and Montana. The dough attracted substantially more terrestrial pest gastropods, including invasive species of major economic importance such as Cornu aspersum, Deroceras reticulatum, Ambigolimax valentianus, Xerolenta obvia, Lissachatina fulica, and Parmarion martensi, than water controls. The dough remained attractive for at least 8 days and was significantly more attractive than a widely used metaldehyde-based bait, Deadline® M-Ps™. Thus, fermenting bread dough represents a nontoxic, generic, and effective tool to aid in managing pest gastropod infestations, either using baited traps or in attract-and-kill approaches. Given its simplicity, low cost, and the ready availability of its ingredients, the dough also has potential to be used in developing countries where access to commercial molluscicide baits is limited by cost.

Ca2+/Calmodulin-NOS/NO-TNFs Pathway Hallmarks the Inflammation Response of Oyster During Aerial Exposure

Aerial exposure (emersion) due to the periodical ebb and flow of tides is a major stressor for intertidal organisms and a key environmental factor in shaping their local communities. Oysters are among the most emersion-tolerant mollusk species and can survive for several days under aerial exposure. Noticeably, overwhelming inflammation responses could occur during the emersion stress. However, mechanisms beneath the activation and modulation of emersion-induced inflammation response have remained largely unknown. Ca2+ is an important intracellular second messenger that plays indispensable roles in inflammation response by cooperation with calmodulin (CaM) genes. Here, we showed that intracellular Ca2+ accumulates rapidly in oyster hemocytes during emersion stress along with the changes in the protein levels of three CaM genes, which function as intracellular sensors of Ca2+. As downstream effector of Ca2+/CaM complex, nitric oxide synthase (NOS) activity in hemocytes was enhanced during the emersion stress, facilitating a greater production of nitrite oxide (NO). Augmentation of NO concentration was associated with the increased mRNA expression levels of two oyster cytokines (CgTNFs) during aerial exposure. The robust accumulation of cytokines and severe injury of tissues in oysters have been regarded as potential cause and marker of their death in prolonged emersion stress. Here, both the expression levels of CgTNFs and the tissue injuries of oysters were attenuated when Ca2+/CaM complex or NOS activity were repressed in vivo during the emersion stress. These findings indicate that Ca2+/CaM-NOS/NO-CgTNFs pathway is critically involved in the emersion-induced inflammation response in oysters and plays a role in the resistance against long-term aerial exposure.

Microplastic ingestion and feeding ecology in three intertidal mollusk species from Lima, Peru

Microplastics (< 5 mm) are ubiquitous contaminants in the marine environment. The aims of the present study were to report the incidence of microplastic pollution in three mollusk species from the coast of Lima and to investigate the relationship between microplastic ingestion and feeding ecology. Specimens of three mollusk species Semimytilus algosus, Tegula atra and Chiton granosus were sampled from the intertidal rocky zone. For microplastic isolation, soft tissues were digested in 10% KOH, vacuum filtrated and analyzed under a microscope. Rigorous contamination prevention measures were taken into account. C. granosus was the most contaminated mollusk (6.92 ± 2.13 particles g-1). Red fibers were the overall most abundant microplastic. The feeding behavior of T. atra promotes microplastic exposure to C. granosus. More research is needed to fully understand the microplastic effects on mollusk species.