Rapana Venosa Research Articles

Study on the influence of freezing on certain chemical compounds in Rapana venosa meat

Study on the influence of freezing on certain chemical compounds in Rapana venosa meat

Expression and activity of critical digestive enzymes during early larval development of the veined rapa whelk, Rapana venosa (Valenciennes, 1846)

Metamorphosis is a vital developmental event in the life cycle of molluscs and involves extensive morphological and physiological changes. Remodeling of the digestive system is suggested to occur anticipatorily to enable the larva to shift its diet (from filter feeding on microalgae to feeding on small bivalves) after metamorphosis. Changes in the profiles and activities of digestive enzymes, the main executors of digestion, can reflect substantial remodeling of the digestive system. Artificial aquaculture of Rapana venosa, an important commercial shellfish in China, has been hampered because the transition of its food habit during metamorphosis makes determining the timing and dose for bait regulation difficult. In the present study, full-length cDNA sequences encoding cellulase and trypsin were characterized, and cellulase and trypsin mRNA expression levels were analyzed. Additionally, patterns in the activities of six digestive enzymes, including trypsin and cellulase, were investigated throughout the early developmental stage of R. venosa. In the present study, the full-length cDNA of the cellulase gene, comprising 2,086 bp, was found to contain a 1,719-bp open reading frame encoding 572 amino acids, and the full-length cDNA of the trypsin gene was found to be 1,587 bp in length and contained an 855-bp open reading frame encoding 284 amino acids. Quantitative real-time PCR showed that the cellulase levels in R. venosa increased beginning at the early intramembrane veliger stage, whereas cellulase activity was significantly increased in the one-spiral whorl stage. The mRNA expression and activity of trypsin were greatly increased in the juvenile stage (postlarva), whereas those of cellulase were decreased during this stage, which indicated functional changes in the digestive system during larval food habit transition. Our results showed that remodeling of the digestive system occurs prior to metamorphosis and suggest that animal bait should be provided as early as possible to R. venosa in the four-spiral whorl stage to meet its nutritional requirements for the development of its digestive system and to ensure successful metamorphosis of competent larvae.

Physicochemical and Biological Properties of Gelatin Extracted from Marine Snail Rapana venosa.

In this study, we aimed to obtain gelatin from the marine snail Rapana venosa using acidic and enzymatic extraction methods and to characterize these natural products for cosmetic and pharmaceutical applications. Marine gelatins presented protein values and hydroxyproline content similar to those of commercial mammalian gelatin, but with higher melting temperatures. Their electrophoretic profile and Fourier transform infrared (FTIR) spectra revealed protein and absorption bands situated in the amide region, specific for gelatin molecule. Scanning electron microscopy (SEM) analysis showed significant differences in the structure of the lyophilized samples, depending on the type of gelatin. In vitro studies performed on human keratinocytes showed no cytotoxic effect of acid-extracted gelatin at all tested concentrations and moderate cytotoxicity of enzymatic extracted gelatin at concentrations higher than 0.5 mg/mL. Also, both marine gelatins favored keratinocyte cell adhesion. No irritant potential was recorded as the level of IL-1α and IL-6 proinflammatory cytokines released by HaCaT cells cultivated in the presence of marine gelatins was significantly reduced. Together, these data suggest that marine snails are an alternative source of gelatins with potential use in pharmaceutical and skincare products.

피뿔고둥(Rapana venosa)에 감염된 흡충류(trematodes)에 관한 보고

The large gastropod purple shell, Rapana venosa, inhabit in the western and southern coasts of Korea at a depth of approximately 10m. Identification of trematodes found in R. venosa from Sihwa lake, Gyeonggi-do, Korea, was conducted in this study. Trematode infection sites were examined using light microscope and genomic DNAs were extracted from the infected tissues of boiled R. venosa. Mitochondrial cytochrome c oxidase subunit 1 region (mt COI), internal transcribed spacers rDNA regions (ITS1-5.8S-ITS2) and 28S rRNA region of the trematode DNA were amplified by polymerase chain reaction (PCR), and compared with those already registered in GeneBank. Cercaria and redia of trematodes were found by light microscopy. Although the DNA sequence of mt COI gene did not match with the Parorchis sp. mt COI sequence, there was a high genetic similarities of ITS1-5.8S-ITS2 and 28S rRNA genes with those of Parorchis sp. (ITS: 97%, 28S: 99%). The phylogenetic analysis also showed our samples were closely clustered with Parorchis sp. All of these data suggest that our samples found in R. venosa are Parorchis sp., but further studies such as electron microscopic observation with fresh samples will be necessary for clear identification at the species level.

РОЗВИТОК ІНВЕСТИЦІЙНОГО ПОТЕНЦІАЛУ АГРОПРОДОВОЛЬЧОЇ СФЕРИ РЕГІОНУ

The article discusses current trends, threats, problems and factors in the investment potential development of the agri-food sector of the Black Sea region of Ukraine, the formation of which will promote the achievement of the strategic goals of Ukraine by 2030. The aim of the study is to summarize the practical experience of attracting investments, implementing investment projects, creating a favorable investment climate in the agri-food sector and developing the investment potential of the agricultural sector of the Black Sea region in the conditions of Ukrainian economy transformation. Strategic directions for the investment potential development under the conditions of decentralization of the Ukrainian economy are substantiated to ensure sustainable development of the agri-food sector and food security of the Black Sea region of Ukraine. The practical experience of attracting investments, implementing investment projects, creating a favorable investment climate in the agri-food sector and developing the investment potential of the agri-food sector of the Black Sea region under the conditions of the Ukrainian economy transformation is summarized. One of the main anti-crises measures by which it is possible to solve the problems of the agri-food sector is the implementation of innovations. An innovative investment project for the production of meat, fodder flour and other products from the Black Sea clam Rapana Venosa, developed by the scientists of the Odessa National Academy of Food Technologies, is presented. The influence of the proposed project on the investment potential development of the Black Sea region of Ukraine is substantiated. Implementation of the innovative-investment project proposed by the authors will allow the region to develop the infrastructure of the agro-food market, reduce the agro-ecological imbalances, promote the efficient use of the region's bioresources, will not damage the ecology, will allow the government to cooperate with large agroholdings, small enterprises and households, attract investment and advanced technologies, allow the region to enter the international agro-food market, will lead to the rural areas development and improve the living standards of rural residents of the Black Sea region of Ukraine. The factors influence on the investment potential development of the region agro-food sector is substantiated. It is determined how the implementation of the innovation project proposed by the authors will contribute to solving problems of the investment potential development of the agro-food sector. Key words: agri-food sector, stable development, investment potential, Black Sea region of Ukraine, innovation and investment project, food and processing industry, fodder flour, Black Sea rapana.

Settlement and metamorphosis of Rapana venosa (Gastropoda: Muricidae) with implications for artificial culture

The rapa whelk Rapana venosa transforms from a phytophagous larva to a carnivorous juvenile after settlement and metamorphosis. The high mortality rate and low metamorphosis rate (<1%) of larvae are among the key factors limiting the recovery of the resources of R. venosa. We studied these two processes and showed that the larva has the ability to settle and metamorphose in the middle and late 4 spiral whorl period, and the use of substrates (scallop shells with oysters) can significantly improve the settlement and metamorphosis rate of larvae. The presence of darkness, juvenile bivalve shellfish, and oyster polysaccharide could effectively increase the rates of larval settlement and metamorphosis. Our findings broaden the understanding of settlement and metamorphosis in gastropods and can be used to improve population control, resource recovery and commercial breeding strategies for R. venosa.

Transcriptomic Analysis of Marine Gastropod Hemifusus tuba Provides Novel Insights into Conotoxin Genes.

The marine gastropod Hemifusus tuba is served as a luxury food in Asian countries and used in traditional Chinese medicine to treat lumbago and deafness. The lack of genomic data on H. tuba is a barrier to aquaculture development and functional characteristics of potential bioactive molecules are poorly understood. In the present study, we used high-throughput sequencing technologies to generate the first transcriptomic database of H. tuba. A total of 41 unique conopeptides were retrieved from 44 unigenes, containing 6-cysteine frameworks belonging to four superfamilies. Duplication of mature regions and alternative splicing were also found in some of the conopeptides, and the de novo assembly identified a total of 76,306 transcripts with an average length of 824.6 nt, of which including 75,620 (99.1%) were annotated. In addition, simple sequence repeats (SSRs) detection identified 14,000 unigenes containing 20,735 SSRs, among which, 23 polymorphic SSRs were screened. Thirteen of these markers could be amplified in Hemifusus ternatanus and seven in Rapana venosa. This study provides reports of conopeptide genes in Buccinidae for the first time as well as genomic resources for further drug development, gene discovery and population resource studies of this species.

Environmental water flow can boost foraging success of the juvenile rapa whelk Rapana venosa (Muricidae) in aquaculture tanks with still or flowing water: Indication of chemosensory foraging

Artificial breeding of Rapana venosa has been attempted in China, but the high mortality rate of rapa whelk juveniles (10–40 mm) seriously restricts the breeding success of this species in artificial cultivation and the overall aquaculture industry, and thus the scale of industrialization is far from being realized. One main factor was found to contribute to this high mortality rate: the low predation efficiency of juveniles. We studied the foraging behavior of various sized R. venosa juveniles in still, flowing, and circulating water, with the juveniles being positioned either upstream or downstream from the prey in the flowing water experiments. Our findings demonstrated that the distance between juveniles and prey in still water significantly restricted the ability of juveniles to locate food, but water flow significantly enhanced this ability. In addition, the small-sized juveniles were found to be more active predators than the larger sized juveniles. Our findings demonstrated that circulating water flow is important to improve the survival and growth rate of juveniles in R. venosa cultures. Our results broaden the understanding of chemical orientation in gastropods and can be used to develop or improve commercial breeding strategies for R. venosa.

3D structures of hydroxyapatite obtained from Rapana venosa shells using hydrothermal synthesis followed by 3D printing

In this study, hydroxyapatite (HAp) obtained by hydrothermal synthesis from natural sources (whelk shells of Rapana thomasiana) was compared to synthetic hydroxyapatite (prepared from chemical reagents) and used for 3D printing of HAp-based structures. Rapana thomasiana can be found in Romanian coast of Black Sea. The visceral part of Rapana is used for culinary purposes, but the whelk shell, mainly consisting of CaCO3, remains as biowaste and can be used as a source of Ca for hydroxyapatite synthesis. Synthetic and natural hydroxyapatite nanopowders were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), dynamic light scattering (DLS) method and in vitro tests. XRD and FT-IR have confirmed the formation of nanostructured hydroxyapatite irrespective of the raw material used. Both types of powders were further used for 3D printing of HAp-based structures, which have also been characterized by SEM and in vitro tests. In vitro tests performed on natural HAp disks (made from whelk shell) lack cytotoxicity and were associated with cell viability similar to that for the synthetic hydroxyapatite disk.

The responses of digestive enzymes in juvenile and adultRapana venosa(Valenciennes, 1846) to different temperatures

The veined rapa whelk, Rapana venosa (Valenciennes, 1846), is an important and valuable fishery species; however, it has not been routinely artificially cultured on a large scale. Here, we studied the effect of temperature (6, 16, 22 and 28°C) on the digestive enzymes in R. venosa of different sizes (Juvenile (small, S: 1.2–1.8 cm) and adult (medium, M: 4.1–5.2 cm; large, L: 7.6–8.9 cm)) by detected the enzyme activity in different digestive glands (the salivary gland, Leiblein's gland (oesophageal gland) and liver) using spectrophotometric method, to determine the optimal temperature for artificial cultivation and to explore the feeding habits of this whelk. The optimal temperature was determined to be approximately 22°C. The food intake was significantly higher at 22°C than at other temperatures, and the activity of the digestive enzyme, trypsin, was at the highest in the main digestive gland of R. venosa, the liver, at 22°C. In addition, the observed presence of cellulase and α-amylase may suggest that carbohydrates are necessary during R. venosa development. The results of this study will help in the formulation of technical procedures for R. venosa aquaculture and in preventing its overexploitation, and explained its invasion mechanism to some extent.

Chamelea gallina in the coastal waters of the Anapa bay bar (the Black Sea) as a carbonate sediment producer

Summary The paper presents preliminary results of monitoring the population of the bivalve Chamelea gallina, which is the main source of biogenic carbonates for the Anapa bay bar beaches (the Black Sea). It is shown that by 2017, the biomass of the clams decreased more than twice compared to 2010, but began to increase in 2018. The average sizes of C. gallina are clearly divided in terms “year” – “section” – “age”. At the same time, interannual variations of the average size are very strong in all age groups. The average shell length of C. gallina significantly increased in 2018 compared to 2016, and especially – to 2017. This may be caused by the population decline of the predator Rapana venosa feeding on clams. Geographic differences in the shell length between sections are not directly related to the distribution of biogenic elements (nitrogen and phosphorus). The differences in longevity and shell size between C. gallina from the Anapa region and distant populations from the other parts of the distribution area are likely related to its significant negative correlation with the growth rate, which in turn negatively correlates with latitude.

The resilience of macrozoobenthos of boreal coastal lagoons to non-indigenous species invasion: A case study of Taman Bay (the Sea of Azov)

The aim of the present study is to reveal the consequences of the blood ark (Anadara kagoshimensis) invasion of Taman Bay (the Sea of Azov), one of the biggest boreal brackish coastal lagoon. Anadara kagoshimensis was found there for the first time in 2003. During our work from 2003 to 2013, the blood arks were found at eleven of 83 stations in the bay. The invader was observed at 0.5–6 m depths in two habitat types: unvegetated muddy bottom and sparse Phragmithes sp. vegetation. The occurrence of both A. kagoshimensis and indigenous dominant species in the same localities varied from year to year. The ES100 index and taxonomic composition did not significantly differ between stations with and without the arks. The variation in the macrozoobenthos species abundance did not depend on whether the alien or indigenous species were dominant. The arks have integrated into the local communities with dominating native macrozoobenthos organisms. This scenario contrasts with the blood arks’ invasion into the Adriatic, Black and Azov Seas, and the adjacent Kerch Strait. There, distinct ark communities have replaced disturbed communities with native dominant species. The main factors that determine the resilience of macrozoobenthos in Taman Bay are: no pressure from the Rapa whelk (Rapana venosa); no persistent disturbances and the eurybiontic type fauna of the bay.

Ecosystem attributes of trophic models before and after construction of artificial oyster reefs using Ecopath

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 11:111-127 (2019) - DOI: https://doi.org/10.3354/aei00284 Ecosystem attributes of trophic models before and after construction of artificial oyster reefs using Ecopath Min Xu1,2,3,6,7, Lu Qi4, Li-bing Zhang1,2,3, Tao Zhang1,2,3,*, Hong-sheng Yang1,2,3, Yun-ling Zhang5 1CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China 2Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China 3Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, PR China 4Ocean University of China, Qingdao 266100, PR China 5Hebei Provincial Research Institute for Engineering Technology of Coastal Ecology Rehabilitation, Tangshan 063610, PR China 6Present address: Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture, Shanghai 200090, PR China 7Present address: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, PR China *Corresponding author: tzhang@qdio.ac.cn ABSTRACT: The deployment of artificial reefs (ARs) is currently an essential component of sea ranching practices in China due to extensive financial support from the government and private organizations. Blue Ocean Ltd. created a 30.65 km2 AR area covered by oysters in the eastern part of Laizhou Bay, Bohai Sea. It is important for the government and investors to understand and assess the current status of the AR ecosystem compared to the system status before AR deployment. We provide that assessment, including trophic interactions, energy flows, keystone species, ecosystem properties and fishing impacts, through a steady-state trophic flow model (Ecopath with Ecosim). The model estimated values of 4721.2 and 4697.276 t km-2 yr-1 for total system throughput and 534.74 and -519.9 t km-2 yr-1 for net system production before and after AR deployment, respectively. After AR deployment, sea cucumber and oyster showed the same trophic level (TL = 2.0) while veined whelk Rapana venosa had TL = 3.0. The mean TL of catches was 2.484 after AR deployment and the primary production required to support fisheries (PPR) was 1104 t km-2. Detritus production dominated over primary production and represented 73.82% (2530.82 t km-2) of total primary production required. The sea cucumber showed the lowest PPR/catch value (5.6) among functional groups, indicating that fishing catch biomasses were close to primary production values. The total primary production to total respiration and total primary production to total biomass ratios showed higher system maturity after AR deployment. The trophic flow diagram showed 1 grazing and 2 detritus food chains. Pelagic and bottom fish and different benthic organisms, including large crustaceans and zoobenthos, were the dominant community before AR deployment. Zoobenthos was the key functional group, followed by large crustaceans and Gobiidae, which were the most important prey for top predators after AR deployment. We draw the following conclusions for the management of this area: (1) AR deployment contributes to the maturity of the improved ecosystem; (2) the artificial oyster system is similar to a natural reef system; (3) the enhancement and release of benthic animals in the AR area benefit the ecosystem; and (4) low TL catches do not cause the system to collapse. KEY WORDS: Ecopath model · Artificial oyster reef · Apostichopus japonicus · Rapana venosa · Ecosystem properties · Sea ranching Full text in pdf format Supplementary material PreviousNextCite this article as: Xu M, Qi L, Zhang Lb, Zhang T, Yang Hs, Zhang Yl (2019) Ecosystem attributes of trophic models before and after construction of artificial oyster reefs using Ecopath. Aquacult Environ Interact 11:111-127. https://doi.org/10.3354/aei00284 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 11. Online publication date: March 14, 2019 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2019 Inter-Research.

First Report of Predation on Egg Capsules of Invasive Rapa Whelk by Sharpsnout Seabream (Diplodus puntazzo) in the Black Sea

The presence of the egg capsules of Rapa whelk, Rapana venosa, in the stomachs of sharpsnout seabream was observed for the first time. Samples were collected on August, 2017 in the Artvin, Hopa region (Black sea of Turkey). Rapa whelk is one of the successful invasive species in the world. Due to high predation pressure on native mussels by invasive whelk in the Black Sea, their populations decreased. Female rapa whelks lay high amount of egg capsules on hard substratum (stones, mussels, whelks etc) during summer. The sharpsnout seabream seems to be an important predator on egg capsules of Rapa whelk due to both species shared same habitat in summer months.

Starvation intensifies the impacts of interspecific interactions on foraging behavior of swimming crab (Portunus trituberculatus)

Although local species usually suffer from starvation during the early stage of marine ranching construction, few studies focus on the effects of starvation on predation and competition among benthic economic species. A multi-trophic species foraging system was established in the laboratory to investigate how starvation and a rapa whelk (Rapana venosa) affect the behavior of swimming crab (Portunus trituberculatus) preying on Manila clams (Ruditapes philippinarum). We calculated the predation rate and quantified the foraging behavior and encounter behavior between predators. Under no starvation (0 d) and short-term starvation (3 d), the interactions between crab and whelk, including intraguild predation and kleptoparasitism, were relatively weak, which did not have the significant impacts on crab. However, the interspecific interactions were intensified by the long-term starvation (6–12 d). Specifically, the probability of intraguild predation was increased, but crab did not obtain revenue from preying on whelk. These made crab reduces the investments for foraging on clams, such as the decreasing of handling time and probability of capture upon encounter. Additionally, the active foraging of whelk stimulated the occurrence of kleptoparasitism under long-term starvation, promoting the foraging of crab partly, included the increasing of encounter rate with clam and probability of consumption upon capture. In long-term starvation treatments, the positive effects provided by whelk perhaps were swamped by the negative effects of intraguild predation, which impeded the foraging behaviors of crab, resulting in the decline of predation rate of crab eventually.

Influence of Anthropogenic Contamination on the Content of Immune Complexes and Lipids and on the Oxidative Processes in Rapana venosa (Valenciennes, 1846)

Results of comparative analysis of the content of immune complexes and lipids and of the oxidative processes in the muscle tissues of Rapana venosa occurring in various sections of the coastal zone of the Caucasus coast of the Black Sea differing in the degree of anthropogenic load are given in the paper. It has been found that the specimens caught in the sections subjected to intensive anthropogenic load were characterized by a rather high content of the products of lipid peroxidation and immune complexes and by a low antioxidant activity.

Genetic Structure in Different Subsequent Generations of Sexually Mature Rapana venosa Mollusks from the Same Biotope

Two Rapana venosa (R. venosa) samples representing different age groups from the same biotope (Odes’ka zatoka) were compared, using allozyme analysis, by their genetic structure. The genotypes were tested at 19 loci of nine enzymes. The genepool of the collected R. venosa samples was generally characterized by genetic disequilibrium and the elevated level of actual heterozygosity at the studied polymorphic loci (on average, at 16–18%). Sexually mature mollusk generations belonging to different age groups from the same biotope had a comparably lower relatedness between each other than the mollusk samples from different aquatic areas of the Black Sea. However, the genetic distance between the studied R. venosa groups was at the level of local populations in all cases. The analysis of the contribution made by evolutionary factors has shown the leading role of migrations in the formation of the R. venosa genepool in the northern part of the Black Sea.

Antitumour activity of Helix hemocyanin against bladder carcinoma permanent cell lines

Hemocyanins are oxygen-transporting glycoproteins in molluscs and arthropods. In this study, we assayed the biomacromolecules from the molluscs Helix lucorum (HlH), Rapana venosa (RvH) and Megatura crenulata (KLH) including their functional units (FUs), for therapy of bladder cancer permanent cells. In vitro studies antitumour activities of these proteins were performed with bladder cancer permanent cell line CAL-29 and the normal urothelial cell line HL 10/29 in comparison to doxorubicin. The obtained results showed that the human tumour CAL-29 cell line is sensitive to the action of the tested hemocyanins and their isoforms. We observed a dose- and time-dependent inhibition of tumour cell growth after incubation with native HlH and two FUs (βc-HlH-a and FU βc-HlH-h); and of particular significance, FU βc-HlH-h showed a surprisingly stronger effect than that the doxorubicin-treated cells. Cells treated with βc-HlH-h, showed both, apoptotic and necrotic cells. In addition, two-dimensional polyacrylamide gel electrophoresis (PAGE) found for differential up-regulation of several proteins after hemocyanin treatment. Eight different down-regulated and two up-regulated proteins were identified, which may be associated with the apoptosis pathway. No inhibition of the normal urothelial cell line HL 10/29 was observed after treatment with HlH and its isoforms. The most effective inhibition of CAL-29 tumour cells was observed after treatment with βc-HlH-h, probably caused by a specific oligosaccharide structure of HlH with methylated hexoses. These results suggest that hemocyanin glycosylation plays an important role in its anticancer activity.

Консорты брюхоногого моллюска Rapana venosa (Valenciennes, 1846) в северной части Чёрного моря. Часть IV: Arthropoda

Статья посвящена изучению таксоцена Arthropoda и является продолжением цикла по описанию состава консорции брюхоногого моллюска — вселенца Rapana venosa (Valenciennes, 1846). Консорция R. venosa остаётся неучтённой компонентой в структуре биоценозов шельфа Чёрного моря. Использованный материал и методы исследования детально рассмотрены в предыдущих работах цикла. Цель данной статьи ― описание комплекса эпибионтных организмов и составление аннотированного списка таксонов Arthropoda консорции R. venosa. Найденные в консорции рапаны 27 видов типа Arthropoda относятся к двум подтипам ― Chelicerata (класс Arachnida) и Crustacea (классы Malacostraca и Hexanauplia). Единственный представитель класса паукообразных (Arachnida; Acari) ― клещ Rhombognathus notops (Gosse, 1855) ― обнаружен лишь дважды (по одному экземпляру в сборах 2016 и 2017 гг.). Rapana venosa служит субстратом для развития разнообразных водорослей ― благоприятного местообитания для эпифитона, что обуславливает высокую численность и разнообразие ракообразных в этом биотопе. Наибольшее таксономическое разнообразие отмечено для класса Malacostraca ― 25 видов, относящихся к 22 родам 19 семейств. Членистоногие представлены двумя основными экологическими группами (седентарные и подвижные эпибионты). Наибольшее видовое разнообразие Arthropoda присуще свободноживущим подвижным формам (23 вида). Седентарные формы, явно уступая по количеству видов (4), доминируют по численности (86 %) и биомассе (94 %). Единственный представитель Cirripedia ― Amphibalanus improvisus (Darwin, 1854) ― является самым распространённым (53 % общей численности) и массовым ракообразным и вносит наиболее существенный вклад в биомассу (91,8 %) в консорции Arthropoda. Более 50 % видов Arthropoda в консорции рапаны — полифаги; фитофаги составляют 21 %, а детритофаги ― 29 % общего числа видов членистоногих. Единственный взрослый экземпляр эктопаразита рыб ― изоподы Elaphognathia bacescoi (Kussakin, 1969) ― найден в консорции песчаной рапаны на глубине 8 м в бухте Голубая (г. Севастополь). Все обнаруженные 27 видов Arthropoda присутствуют в консорции песчаной экоморфы R. venosa, и только 3 вида отмечены на скальной рапане. Различия в составе консорции двух экоморф R. venosa можно объяснить преимущественно большим развитием эпифитов и пониженной динамикой водных масс в зонах обитания песчаной рапаны в районе Севастополя. Благодаря своему таксономическому разнообразию, численности и биомассе Arthropoda являются важным элементом донного биоценоза, ассоциированного пространственно и трофически с особями самой крупной гастроподы Чёрного моря ― R. venosa.

Embryonic and Larval Intracapsular Development of the Rapa Whelk Rapana venosa (Valenciennes, 1846) (Gastropoda, Muricidae)

The duration of embryonic and larval intracapsular development of Rapana venosa, an invasive species of the Black Sea, was studied under experimental conditions (water temperature of 23°C and salinity of 18‰). The development of embryos and larvae in the egg capsules was described day by day. Larvae hatched from the egg capsules on the 19th–20th day after the eggs were laid. The morphology of egg capsule walls and micropores is described, and photomicrographs of them are presented. The studied features of R. venosa reproductive strategy explain the high adaptive capacity and wide distribution of this species.