Многолетняя динамика обилия моллюсков-фильтраторов Mytilaster linneatus на гидротехническом сооружении

Проведено исследование пространственной и временной изменчивости обилия и массразмерных характеристик поселений моллюска Mytilaster lineatus (Gmel., 1790) за период с 2005 по 2018 гг. на примере крупного гидротехнического сооружения прибрежной зоны г. Севастополя. Плотность поселения митилястеров на подводной части набережной Севастопольской бухты в период с 2005 по 2018 гг. варьировала в диапазоне от 293±115 до 51562±7120 экз.∙м-2. Биомасса имела широкий диапазон колебаний и составляла от 9±3 до 3400±3222 г∙м-2. В 2009 г. были отмечены пониженные показатели обилия митилястеров. Исследование достоверности пространственного изменения плотности поселения, и их биомассы не показало значимых изменений исследуемых величин. Обнаруженные в период исследования митилястеры можно отнести к размерным группам от 1 до 30 мм, что может свидетельствовать об относительно благоприятных условиях для обитания данного вида.

BOTTOM FAUNA OF LAKE DONUZLAV UNDER CONDITIONS OF INDUSTRIAL SAND MINING

In 2019, the composition and quantitative representation of the zoobenthos in Donuzlav Lake, in the area of fine sediment discharge after the sand mining, and in the adjacent water area were studied. The accounting of the macrozoobenthos at the species level and of the meiobenthos at the major taxa level indicates the presence of a typical Pontic bottom fauna in the Lake, which has developed over 58 years of it existence. The benthic macrofauna was represented by a biocoenosis of Chara algae with Mytilaster lineatus, existing in a two-tier biotope – of a soft-bottom and of a Chara algaes developing on it. The epiphyton macrofauna quantitatively dominated the benthic macroinfauna. A total of 102 species and 7 superspecies taxa of the macrozoobenthos were registered in the identified biocoenosis. That increases the overall level of the macrozoobenthos representation up to 171 species and 9 superspecies taxa in Donuzlav for the period since 1981. In meiobenthos 11 taxa in the rank of type were recorded. The abundance and biomass of the macrozoobenthos averaged 34.658±1.655 ind./m2 and 316±93 g/m2 respectively, that is comparable with the previous studies. The average abundance of meiobenthos in the bottom biotope reached 247.2×103 ind./m2. Nematodes were the dominant group in meiobenthos, followed by harpacticids, with a combined share of 81 % in total meiobenthos abundance. The local impact of the discharging finely dispersed soil fractions to the benthic fauna of the southern part of the Donuzlav Lake was revealed. There was a 12, 3.5 and 2-fold decrease in abundance, biomass and number of macrozoobenthos species respectively and a 3.2-fold decrease in meiobenthos abundance, in the discharging area compared to the neighboring water areas of the Lake.

ASSESSMENT OF INFLUENCE OF THE AUTOACCLIMATIZERS ON AUTOCHTHONOUS BIVALVE MOLLUSKS

Anthropogenic transformation of the Caspian Sea biocenoses results in the loss of their uniqueness and decrease of their biodiversity. In recent years the main role in the formation of biomass has played the autoacclimatizant mollusks Abra ovata , Mytilaster lineatus and Cerastoderma glaucum which dominate the biocenoses of the Caspian sea and are the main food components of valuable commercial benthivorous fishes. In 2018 live specimens of Corbicula fluminalis (O. F. Muller, 1774), a new species of bivalve mollusks for the Russian sector of the Caspian sea and the entire European part of Russia, were first discovered on the Daghestan coast.

Хорологічна структура прибережного угруповання обростання, що формується чорноморською мiдiєю Mytilus galloprovincialis

Виявлені особливості хорологічної структури прибережного угруповання обростання, що формується двостулковим молюском Mytilus galloprovincialis Lamarck, 1819 на підводній поверхні берегозахисних споруд, розташованих в межах Одеської затоки Чорного моря. Визначено просторовий розподіл седентарних безхребетних Mytilus galloprovincialis, Mytilaster lineatus (Gmelin, 1791) (Bivalvia) і Amphibalanus improvisus (Darwin, 1854) (Cirripedia), які утворюють основу угруповання обростання. З’ясовано, що ці безхребетні розподілені на вертикальній поверхні субстрату досить нерівномірно. Визначено частоту зустрічальності розмірних груп, та особливості кількісного розвитку цих видів в межах різних горизонтів угруповання на глибини 0,5 і 2,0 м. В Одеський затоці Чорного моря заселення поверхонь берегозахисних споруд відбувається в результаті осідання личинок згаданих безхребетних. Подальший розвиток хорологічної структури угрупування обростання здійснюється в ході сукцесії, в результаті якої на субстраті формується складне багатоярусне утворення, що складається в основному з мідій, мiтiлястерiв і балянусів. Ці безхребетні відносяться до функціональної групи видів «довгострокових архітекторів», які формують просторову конфігурацію угруповання обростання. Дрібни двостулкові (Abra segmentum (Recluz, 1843) і Lentidium mediterraneum (Costa, 1830)) та черевоногі молюски (Pusillina lineolata (Michaud, 1830) і Setia valvatoides (Milaschewitsch, 1909)), а також малорухливі ракоподібні (Ampithoera mondi Audouin, 1826 і Ericthonius difformis M.-Edwards, 1830) і багатощетинкові черви (Polydora cornuta Bosc, 1802 і Fabricia stellaris (Muller, 1774)), які мешкають в самостійно побудованих трубках і живуть менше одного року відносяться до категорії «короткострокових архітекторів». Ці функціональні групи видів вносять відповідний архітектурний елемент в угруповання обростання, створюючи сприятливі умови для мешкання інших організмів.

Mollusk fauna associated with Cystoseira barbata (Stockhouse) C. Agardh, 1820 in the Sea of Marmara (Turkey)

Mollusk species associated with Cystoseira barbata were examined in the Sea of Marmara in 2012 at 14 sampling sites with a depth ranging from 0.2 to 0.5 m. A total of 18 468 specimens belonging to three classes (Polyplacophora, Gastropoda and Bivalvia) and 30 species were identified. Alvania mamillata Risso, 1826 is a new record for the marine mollusk fauna of the Sea of Marmara. The number of species at the sampling sites varied from 2 to 11 (400 cm–2), the density ranged between 758 and 63 083 ind. m–2, and wet weight between 0.4 and 34.3 g m–2. Gastropoda were the richest class, represented by 22 species and 7611 individuals. The families Rissoidae, Mytilidae and Pyramidellidae were represented by the largest number of species. The most dominant mollusk species in C. barbata facies were Mytilaster minimus (Poli, 1795) (37.77%), Rissoa splendida Eichwald, 1830 (27.20%), Mytilaster lineatus (Gmelin, 1791) (18.69%) and Bittium reticulatum (da Costa, 1778) (6.89%). However, the mollusks R. splendida (86%), M. lineatus (71%), M. minimus (69%) and Steromphala adansonii (Payraudeau, 1826) (67%) were characterized by the highest values of the frequency index. Canonical correspondence analysis showed that the main factors affecting the assemblages of mollusks were the content of total nitrogen, the maximum thallus height, algal wet weight and temperature

Investigation of sub-acute levels of zinc oxide nanoparticles on the filtration rate of Mytilaster lineatus and Dressina polymorpha in the short term

Qadermarzi A, Pouladi M, Rezamand A, Hoseinifar SH, Hedayati AA. 2018. Investigation of sub-acute levels of zinc oxide nanoparticles on the filtration rate of Mytilaster lineatus and Dressina polymorpha in the short term. Nusantara Bioscience 10: 53-57. The filtration rate is one of the physiological indices in the bivalves which indicate the degree of efficacy of the filtration function in the exposure to contaminants. In this study, changes in the filtration rate of freshwater bivalves (D. polymorpha and M. lineatus) were investigated after exposure periods of 5 and 10 days with nanoparticles. Bivalves were transferred from the natural environment to the laboratory. The distribution of nanoparticles was measured by differential light scattering (DLS). Bivalves were exposed to 2.5, 25 and 50 ppm nanoparticles for ten days in water reservoirs. The filtration rates were significantly different in the treatments compared to the control samples, with the highest filtration rate was observed in the control group. On the fifth day, the highest filtration rate was obtained in the first treatment of M. lineatus and the lowest filtration rate was obtained in the third treatment of D. polymorphia. The highest filtration rates were observed in the first and second treatments and the lowest filtration rate was observed in the third treatment. Also, there was no significant difference in the filtration rate of M. lineatus in the 1st treatment with control (P> 0.05) on the 5th day, but filtration rate was significantly (P <0.05) less than other concentrations and control group in the third treatment. On the other hand, the filtration rates on the 10th day showed similar differences compared to the 5th day. It could be concluded that the changes infiltration rate are an appropriate indicator for the measurement of contamination in nanoparticles.

Species Composition of the Benthic Macroinvertebrates on the Coastline Vegetated Rocky Substrates of the Southern Caspian Sea

For studying benthic macrofaunal composition associated with seagrass rocky beds of the southern Caspian Sea, two time samplings were carried out along the coast line in the winter and summer of 2013. In total, 1,286 specimens of the five species were identified: Pontogammarus maeoticus, Balanus improvisus, Mytilaster lineatus, Palaemon elegans and Alitta succinea. The total recorded abundance was 5,675 and 755 ind./m2, with a biomass of 147,271 and 31,238 mg/m2 in the winter and summer respectively. The collected species in this study are generally non-indigenous (except P. maeoticus) and could potentially have an effect on native benthic fauna, as an additional food source could facilitate the commercially exploited fish stocks. Thus further studies are required to monitor their potential interactions on the Caspian Sea fauna