Changes of Heart Rate and Lipid Composition in Mytilus Edulis and Modiolus Modiolus Caused by Crude Oil Pollution and Low Salinity Effects

Blue mussels, Mytilus edulis, inhabiting tidal zones, are naturally exposed to fluctuating environmental conditions (e.g., fluctuations in temperature and salinities), while horse mussels, Modiolus modiolus, live under relatively invariable shelf water conditions. The present investigation tested the hypothesis: blue mussels, in comparison to horse mussels, have an increased ability to tolerate the stress of pollution combined with low salinity. To assess the response of blue mussels and horse mussels to oil pollution at seawater salinities of 25 psu (normal) and 15 psu (low), we used a combination of heart rate and lipid composition as physiological and biochemical indicators, respectively. A sharp decrease in heart rate as well as important fluctuations in cardiac activity was observed under all oil concentrations. Modifications in the concentrations of the main membrane lipid classes (phosphatidylcholine, phosphatidylethanolamine, and cholesterol) and storage lipids (primarily triacylglycerols) in response to different crude oil concentrations were time- and dose-dependent. Both chosen indicators showed a high sensitivity to crude oil contamination. Furthermore, both bivalve species showed similar responses to oil pollution, suggesting a universal mechanism for biochemical adaptation to crude oil pollution.

Toxicity of Carbon, Silicon, and Metal-Based Nanoparticles to the Hemocytes of Three Marine Bivalves

Nanoparticles (NPs) have broad applications in medicine, cosmetics, optics, catalysis, environmental purification, and other areas nowadays. With increasing annual production of NPs, the risks of their harmful influence on the environment and human health are also increasing. Currently, our knowledge about the mechanisms of the interaction between NPs and living organisms is limited. The marine species and their habitat environment are under continuous stress owing to the anthropogenic activities, which result in the release of NPs in the aquatic environment. We used a bioassay model with hemocytes of three bivalve mollusc species, namely, Crenomytilus grayanus, Modiolus modiolus, and Arca boucardi, to evaluate the toxicity of 10 different types of NPs. Specifically, we compared the cytotoxic effects and cell-membrane polarization changes in the hemocytes exposed to carbon nanotubes, carbon nanofibers, silicon nanotubes, cadmium and zinc sulfides, Au-NPs, and TiO2 NPs. Viability and the changes in hemocyte membrane polarization were measured by the flow cytometry method. The highest aquatic toxicity was registered for metal-based NPs, which caused cytotoxicity to the hemocytes of all the studied bivalve species. Our results also highlighted different sensitivities of the used tested mollusc species to specific NPs.

KEANEKARAGAMAN DAN KELIMPAHAN BIVALVIA DI PERAIRAN PANTAI WAEMULANG KABUPATEN BURU SELATAN

Abstrak: Bivalvia merupakan anggota kelas moluska yang memiliki nilai ekonomis dan menjadikannya sering dieksploitasi berlebih oleh masyarakat. Penelitian ini bertujuan untuk mengetahui indeks keanekaragaman dan kelimpahan bivalvia di Perairan Pantai Waemulang Kabupaten Buru Selatan. Pengambilan sampel dilakukan pada kondisi air surut dengan menggunakan metode transek linear kuadrat yang disesuaikan dengan luas area Perairan Pantai Waemulang, panjang garis pantai dan relif pantai. Disamping itu, dilakukan pula pengukuran parameter fisik kimia lingkungan sebagai data pendukung. Hasil penelitian menunjukkan bahwa bivalvia yang ditemukan terdiri dari 5 Ordo, 5 Family, 6 Genus, dan 7 Spesies, yakni Anadara antiquata, Gafrarium dispar, Modiolus modiolus, Fragum unedo, Pinna bicolor, Anadara granosa, dan Tapes literatus. Nilai kelimpahan tertinggi terdapat pada spesies Anadara antiquata, yakni 5.495 dan kelimpahan relatifnya 16.22%. Sedangkan nilai kelimpahan terrendah terdapat pada spesies Tapes literatus, yakni 4.272, dan kelimpahan relatifnya 12.61%. Nilai indeks keanekaragaman, yakni 1.93 atau termasuk kategori sedang dan indeks dominansi sebesar 0.14 yang menunjukkan tidak ada dominansi spesies. Hasil pengukuran parameter fisik kimia pun masih berada dalam kisaran optimal sesuai dengan standar baku mutu air laut untuk biota laut. Guna pemanfaatan dan pengelolaan bivalvia secara berkelanjutan di Perairan Pantai Waemulang Kabupaten Buru Selatan maka diperlukan penelitian sejenis secara berkala.Kata Kunci: Bivalvia, Keanekaragaman, Kelimpahan, Waemulang.Abstract: Bivalves is a member of the mollusk class with economic value and makes it often over exploited by the community. This study aims to determine the diversity index and abundance of bivalves in the Waemulang Coastal Waters of South Buru Regency. Sampling is done at low tide conditions using the linear quadratic transect method that is adjusted to the area of Waemulang Coastal Waters, coastline length and coastline. Besides that, physical chemical parameters were also measured as supporting data. The results showed that bivalves were found to consist of 5 Orders, 5 Families, 6 Genera, and 7 Species, namely Anadara antiquata, Gafrarium dispar, Modiolus modiolus, Fragum unedo, Pinna bicolor, Anadara granosa, and Tapes literatus. The highest abundance was found in Anadara antiquata, which was 5,495 and its relative abundance was 16.22%. While the lowest abundance was found in Tapes literatus, which was 4.272, and the relative abundance was 12.61%. Diversity index value is 1.93 or including a medium category and dominance index of 0.14 which shows no species dominance. The results of the measurement of physical chemical parameters are still in the optimal range in accordance with sea water quality standards for marine biota. For the sustainable use and management of bivalves in the Waemulang Coastal Waters, South Buru Regency, regular research is needed.Keywords: Bivalves, Diversity, Abundance, Waemulang.