scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the northern Black Sea. Part V: Annelida (Polychaeta)

2021 ◽  
Vol 6 (2) ◽  
pp. 18-32
Author(s):  
I. P. Bondarev ◽  
N. A. Boltachova
Keyword(s):  
Black Sea ◽  
Native Species ◽  
Taxonomic Diversity ◽  
Research Area ◽  
Water Area ◽  
The Black Sea ◽  
Rapana Venosa ◽  
Number Of Species ◽  
Plastic Bag ◽  
Rapa Whelk

The study of Annelida (Polychaeta) taxocene – epibionts of the invasive gastropod Rapana venosa – continues the cycle of publications describing the composition of the consortium of the largest gastropod of the Black Sea benthos. R. venosa consortium is still a poorly investigated and unaccounted component in the structure of the Black Sea shelf biocenoses. The aim of this work is to study the complex of polychaetes of R. venosa consortium. The objectives of this stage are as follows: compiling a list of Annelida (Polychaeta) taxa – rapa whelk epibionts; studying taxocene biogeographic and trophic structure; and analyzing ecological relationships of polychaetes with the consortium core. To study the consort community of rapa whelk, sampling was conducted in seven areas of the northern Black Sea: 1 – Mamaia, Romania; 2 – northwestern Black Sea, Crimea offshore; 3 – Sevastopol; 4 – Alupka; 5 – Yalta – Alushta; 6 – Karadag; 7 – Kerch Strait. In the coastal area down to a depth of 15 m, R. venosa was sampled totally using surface-supplied diving equipment; in the deeper-water area (up to 40 m), samples were taken with an “Ocean-50” bottom grab from the board of the RV “Professor Vodyanitsky”. Each rapa whelk specimen (sample) was placed in a separate plastic bag, with the indication of the area, depth, and biotope. In total, 2,411 samples were taken and analyzed: 977 – rock rapa whelks and 1434 – sand rapa whelks. R. venosa shell coverage with epibionts (fouling intensity) was determined as a percentage of the total area of the outer shell surface. Polychaeta taxocene of R. venosa consortium includes 31 species representing 31 genera of 15 families of 2 subclasses. Most species (18) belong to Errantia, and half of them are representatives of the families Nereididae and Syllidae. Sedentaria includes 13 species; by the largest number of species (4), the family Serpulidae is represented. Polychaeta taxocene of R. venosa consortium is represented by three biogeographic groups: native species of the Mediterranean-Atlantic genesis (84 %), the Black Sea endemics (10 %), and recent invaders of various geographical genesis (6 %). On sand rapa whelk, 31 Polychaeta species were found; on rock rapa whelk, only 5 species were recorded. The indicators of Polychaeta fauna development differ significantly by the depth and research area. The most diverse polychaetes are those in bays of Sevastopol (the area No. 3) at depths of 2–10 m; the maximum depth of Polychaeta finding (40 m) corresponds to the greatest depth of rapa whelk sampling. The area of shell coverage with polychaetes reaches 70 %; occurrence in several areas is up to 95 %. The maximum number of species found at a single rapa whelk specimen is 8; on average, 2–4 Polychaeta species are recorded at R. venosa individuals. Taxonomic diversity and abundance of polychaetes determine their significance in R. venosa consortium. Due to the invasive predatory mollusc R. venosa, polychaetes get additional opportunities for spread on the Black Sea shelf.

scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the Northern Black Sea. Part IV: Arthropoda

2019 ◽  
Vol 4 (2) ◽  
pp. 11-22 ◽  
Author(s):  
I. P. Bondarev ◽  
L. V. Bondarenko
Keyword(s):  
Black Sea ◽  
Taxonomic Diversity ◽  
The Black Sea ◽  
Ecological Groups ◽  
Free Living ◽  
Rapana Venosa ◽  
Arthropod Species ◽  
Annotated List ◽  
Mobile Forms ◽  
Rapa Whelk

This article containing information about study of the taxocene Arthropoda is a continuation of the cycle describing the composition of the consortium of the invasive gastropod mollusk Rapana venosa (Valenciennes, 1846). The consortium of R. venosa is still an unaccounted component in the biocenosis structure of the Black Sea shelf. The material used and the research methods are discussed in detail in previous articles of the cycle. The purpose of this work is to describe the complex of epibiontic organisms and to compile an annotated list of Arthropoda taxa of the consortium of R. venosa. The 27 species of phylum Arthropoda found in the consortium belong to two subphyla: Chelicerata (class Arachnida) and Crustacea (classes Malacostraca and Hexanauplia). The only representative of the arachnids class (Arachnida; Acari) – Rhombognathus notops (Gosse, 1855) – was found just twice (in a single specimen in samplings of 2016 and 2017). The shell of R. venosa serves as a substrate for the development of a variety of algae – favorable habitat for the epiphyton, which causes a high number and diversity of crustaceans in this biotope. The greatest taxonomic diversity was noted for the Malacostraca class – 25 species belonging to 22 genera of 19 families. Arthropods are represented in consortium of R. venosa by two main ecological groups – sedentary and mobile epibionts. The largest species diversity of Arthropoda is inherent in free-living mobile forms (23 species). Sedentary forms, which inferior in number of species (4), dominate by quantity (86 %) and biomass (94 %). The only representative of Cirripedia – Amphibalanus improvisus (Darwin, 1854) – is the most common (53 % of the total quantity) and massive crustacean, which contributes the most significant amount to the biomass (91.8 %) of Arthropoda in the consortium. More than 50 % of the Arthropoda species in the consortium are polyphages; phytophages are 20 %; detritophages are 28 % of the total number of arthropod species. The only adult specimen of fish ectoparasites is the isopod Elaphognathia bacescoi (Kussakin, 1969) found in a consortium of sandy rapa-whelk at a depth of 8 m in the Golubaya Bay of Sevastopol. All of the 27 species of Arthropoda found are present in the consortium of the sandy R. venosa, and only 3 species are noted on the rocky rapa-whelks. The differences in the composition of the consortium of the two ecomorphs of R. venosa are mainly due to the great development of the epiphytes and the reduced dynamics of the water masses in the sandy rapa-whelk habitats in Sevastopol region. Due to their taxonomic diversity, quantity and biomass, Arthropoda are an important element of the bottom biocenosis spatially and trophically associated with individuals of the largest gastropod of the Black Sea – R. venosa.

scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the Northern Black Sea. Part I: Porifera, Cnidaria, Bryozoa, Chordata

2017 ◽  
Vol 2 (2) ◽  
pp. 20-33 ◽  
Author(s):  
I. P. Bondarev ◽  
N. K. Revkov
Keyword(s):  
Surface Area ◽  
Coastal Zone ◽  
Black Sea ◽  
The Black Sea ◽  
Bottom Fauna ◽  
Depth Range ◽  
Shell Surface ◽  
Rapana Venosa ◽  
The Core ◽  
Rapa Whelk

Gastropod mollusk-invader Rapana venosa (Valenciennes, 1846) in the 1940s took a free ecological niche terminal predator in benthic communities of the Black Sea shelf and has become an important element of the ecosystem. The ability of rapa whelk to have a devastating impact on the biocenosis filter feeders determines the necessity of constant monitoring of this species populations’ state. The study of rapa whelk showed that the ecological role of this species is not limited to predation. Fairly large shell R. venosa is a solid substrate for alga, attached and restrictedly movable (sedentary) benthic animal organisms, among which mobile free-living forms sometimes find shelter. The aim of the work is to describe specific complex of epibiotic organisms formed on rapa-whelk shells, which is regarded as a consortium, where of R. venosa is the core. To study the consort community of R. venosa a sampling was made in 7 regions of the northern part of the Black Sea: 1 – Mamaia beach, Romania, 2 – the north-western part of the Black Sea (NWBS), Crimean sector, 3 – Sevastopol, 4 – Alupka, 5 – Yalta – Alushta, 6 – Karadag, 7 – the Kerch Strait. The sampling in the coastal zone (less then 15 m depth) was carried out by SCUBA and snorkel diving, deeper (up to 40 m) was used “Ocean-50”grab corer was used. Totally of 856 specimens of R. venosa were collected and analyzed. The main bulk of the material in the amount of 750 specimens of R. venosa was sampled in the coastal zone in Sevastopol vicinity (south-western Crimea) at the depth range of 1.5–10.0 m. The collection of the rapa whelk specimens was carried out totally and each specimen was placed in a separate plastic bag indicating the collection area, depth and biotope. Along with the mollusks sampling, visual observations and photographic fixation of hydrobionts in situ were carried out. Based on the research results the taxonomic list of rapa whelk epibiotic organisms was extended and for the first time the taxonomic composition of the mobile forms permanently or temporarily present in the R. venosa consortium was given. The first part of the investigation provides a list of rapa whelk epibionts taxa relating to four (Porifera, Cnidaria, Bryozoa, Chordata) of the seven detected Phyla with indication of sampling depths and bottom type and comments on the frequency of occurrence, the quantity and of their interaction with the consortium core. Phylum Porifera is represented by 1, Bryozoa – 3 Cnidaria – 2 and Chordata – 4 species. The drilling sponge Pione vastifica was found in all the investigated areas, except region 2 (NWBS), with a frequency of 20 to 90 % and the shell surface area damage was up to 100 % (average 30–35 %). Not numerous representatives of Cnidaria were found singly in the region 3 (Actinia equina) and in the region 5 (Diadumene lineata). Bryozoans are the most common group of animal-consorts of rapa whelk present in all the areas of our research. The frequency of their occurrence ranged from 10 to 100 %, the covering area of the shell surface was from 0 to 85 %. More than 90 % of the total surface area of rapana shell cover with bryozoans and their occurrence is in Cryptosula pallasiana. The second bryozoans’ species on development indices is Conopeum seurati, which was found in areas 3, 6 and 7, where the occurrence was up to 30 % and the coverage was up to 25 %. The other 3 species of bryozoans (Schizomavella auriculata, Bowerbankia imbricata, Hippothoa sp.) were found rarely. Representatives of Chordata – 2 species of ascidians (Botryllus schlosseri, Ciona intestinalis) and 3 species of fish (Diplecogaster bimaculata, Parablennius tentacularis, Scorpaena porcus) were recorded singly in regions 2, 3, 5. For the four Phyla of animal organisms considered the consorts list of R. venosa of the sandy bottom biotopes (10 species) is twice more numerous than that of the rocky eco-form (5 species). The organisms studied are of a different degree and nature of relations with the core consortium from commensalism to parasitism. Generalized information on periphyton and total coverage of rapa whelk shells with epibiotic complex is given. The results of the work show that in the Black Sea R. venosa has become an important element of the ecosystem, increasing biological diversity of the bottom fauna due to the formation of its own consortium complexes of epibiontic organisms.

scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the Northern Black Sea. Part III: Mollusca (Gastropoda)

2018 ◽  
Vol 3 (1) ◽  
pp. 23-34
Author(s):  
I. P. Bondarev ◽  
N. K. Revkov
Keyword(s):  
Black Sea ◽  
Biological Diversity ◽  
Solid Substrate ◽  
Taxonomic Composition ◽  
Egg Laying ◽  
The Black Sea ◽  
Southern Coast ◽  
Gastropod Species ◽  
Rapana Venosa ◽  
Rapa Whelk

This work is a continuation of a series of descriptions of the taxonomic composition of the consort community of Rapana venosa. The shell of the large invasive gastropod R. venosa, which occupies the ecological niche of the terminal predator in benthic community, is simultaneously an attractive substrate for various hydrobionts – fouling and associated mobile forms, one of which is small gastropod mollusks. The latter are poorly explored and accounted for in the R. venosa consortium. The study of this group of hydrobionts in the composition of epibionts of rapana was carried out on the material obtained in 7 regions of the northern part of the Black Sea: 1 – Mamaya, coast of Romania; 2 – NW Crimean coast, Tarkhankut area; 3 – SW coast of Crimea, Sevastopol; 4 – Southern coast of Crimea, Alupka; 5 – Southern coast of Crimea, Yalta – Alushta; 6 – SE coast of Crimea, Karadag; 7 – Kerch Strait. Sampling of rapa-whelk in the coastal zone up to a depth of 15 m was carried out using light water diving equipment, in the deeper zone (up to 40 m), the “Ocean-50” bottom grabber was used from the board of the RV “Professor Vodyanitsky”. Gastropods as consorts of rapa-whelk were found predominantly in reg. 3, where in the summer – autumn season 2015–2017 the most detailed works were carried out and about 90 % of the material was sampled (1100 of 1216 R. venosa specimens). It was found that gastropods in the consortia of rapana were represented by 14 species of 9 genera of 6 families, 7 species of them with egg laying. The gastropods were observed in the consortium of R. venosa mainly in the epiphyton community of algal fouling of the shell, where the mollusc-consorts can form significant clusters – more than 60 individuals. Directly on the shell of the rapa-whelk, the gastropods were found singly or in small groups – from 2–5 to 10 individuals. The most numerous and often occurring (up to 25 %) gastropod species in the consortium of R. venosa was Bittium reticulatum (Cerithiidae). Less numerous were Tricolia pullus (Phasianellidae) (5–10 %, in Kazachya Bay – up to 25 %) and Rissoa splendida (Rissoidae) (the occurrence on the average was about 10 %). The remaining species were observed singly. The highest species diversity and abundance of gastropods were recorded at the depth of 4–10 m in the consortium of loose soils R. venosa ecomorph – 14 species; on the rocky ecomorph of rapa-whelk inhabiting the zone of more intensive hydrodynamics – only 2 species. Our research demonstrates that the ecological role of the invasive species of the Black Sea fauna, R. venosa, is not limited to be a predation. In particular, it contributes to reproduction, development and resettlement of other gastropod species. In the biotope of loose soils, where the there is a deficit of the solid substrate necessary for reproduction of many species of hydrobionts, including gastropods, R. venosa is “oasis” increasing the biological diversity of the benthos as a whole.

scholarly journals Adaptive strategy of Rapana venosa (Gastropoda, Muricidae) in the invasive population of the Black Sea

2020 ◽  
Vol 28 (1) ◽  
pp. 48-52
Author(s):  
Е. Е. Slynko ◽  
Y. V. Slynko ◽  
V. I. Rabushko
Keyword(s):  
Genetic Diversity ◽  
Black Sea ◽  
Molecular Genetic ◽  
Coi Gene ◽  
The Black Sea ◽  
The Sea Of Japan ◽  
High Fertility ◽  
Rapana Venosa ◽  
Morphological Studies ◽  
Rapa Whelk

We conducted molecular-genetic and morphological studies on the veined rapa whelk Rapana venosa (Valenciennes, 1846) in the Crimean waters of the Black Sea in order to determine possible reasons of the invasive success of this mollusk. Molecular-genetic tests were performed using COI gene; the surveyed samples reliably identified to R. venosa species. We compared the data on initial (from the Far-Eastern seas) and some invasive populations. In the natural conditions of the Yellow, East China Seas, and the Sea of Japan, the genetic diversity of rapa whelk is high (Hd = 0.933, π = 0.002). In all the invasive populations of rapa whelk (Black Sea, European and North American), an extremely low level of haplotypic and nucleotide diversity was determined (Hd = 0.0, π = 0.0). Despite low values of genetic diversity, the invasive populations of rapa whelk are characterized by ecological success. We noted stable growth of populations, tolerance to diseases and parasites, effective reproduction, high fertility. This contradicts the main provisions of the population genetics theory of formation of edge of range populations, because usually only a small number of specimens of rapa whelk were introduced. The explanations of the unique condition of the invasive populations of rapa whelk, both from an ecological perspective (high resistance to fluctuations of hydrological factors and chemical pollution, absence of enemies, high fertility) and genetic perspective (high selective value of separate haplotypes settled in the new water areas) have not been confirmed. We determined that a very important factor for the naturalization of the rapa whelk at low genetic diversity is the intra-species morpho-ecological divergence. In the Crimean water area of the Black Sea, R. venosa was found to have two morpho-ecological forms associated with the peculiarities of the development of the proportions of the shell. Study of successful invasive species would allow timely and adequate reaction to new cases of introduction.

scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the Northern Black Sea. Part II: Mollusca (Polyplacophora, Bivalvia)

2017 ◽  
Vol 2 (3) ◽  
pp. 12-22 ◽  
Author(s):  
I. P. Bondarev ◽  
N. K. Revkov
Keyword(s):  
Black Sea ◽  
Benthic Communities ◽  
Common Species ◽  
Taxonomic Composition ◽  
The Black Sea ◽  
Rapana Venosa ◽  
The Core ◽  
The North ◽  
Close Relationship ◽  
Plastic Bag

The study of mollusks-symbionts of the predatory gastropod Rapana venosa is a continuation of the work on the description of the taxonomic composition of the epibiont complex formed on the shell of the rapana. Modern studies of invasive gastropods R. venosa show that the ecological role of this species is not reduced only to predation. On a fairly large rapana shell a specific complex of organisms-epibionts considered as a consortium can be formed, the core of which is R. venosa. The consort of the gastropod mollusk-invader R. venosa is poorly understood and unaccounted for link in benthic communities and the ecosystem of the Black Sea shelf. In order to study the rapana consortian community, sampling were conducted in 7 regions of the Northern part of the Black Sea: 1 – Mamaya, Romania; 2 – the north-western part of the Black Sea, Crimean sector; 3 – Sevastopol, 4 – Alupka, 5 – Yalta – Alushta, 6 – Karadag, 7 – Kerch Strait. The sampling of R. venosa in the coastal zone to a depth of 15 m was carried out with the use of light-diving equipment, while in the deeper zone (up to 40 m), the “Ocean-50” bottom grab was used on board of the RV “Professor Vodyanitsky”. The collection of specimens was carried out totally, each sample was placed in a separate plastic bag indicating the collection region, depth and biotope. Along with the collection of mollusks, visual observations and photographic fixation of hydrobionts in situ were carried out. A total 890 specimens of R. venosa were sampled and analyzed. Compared with previous studies, the taxonomic list of consonant mollusks of R. venosa has been significantly expanded. The mollusc-consorts found on rapana have been classified into three classes: Polyplacophora, Bivalvia, Gastropoda. In this part of the investigation Polyplacophora, presented in a consortium of 3 species of 2 genera of 2 families, and Bivalvia, 7 species of 7 genera of 5 families, were considered. It was found that mollusks are an important component of the consortium of rapana. On rocky rapana ecomorph chitons were observed at a frequency of up to 25 %, on sandy rapana — up to 10 %, in the consortium of rapans as a whole chitons were found in around 12 % frequency. More than 80 % of the all chitons total number on rapana is in Lepidochitona cinerea. The occurrence of Bivalvia in most of the investigated regions is 50–75 %. The area of covering the shell of rapana with bivalves is usually 2–20 %, sometimes reaching 85 %. The most common species of bivalves and mollusks as a whole in the consortium of the Black Sea rapana is the Mytilaster lineatus. Most Bivalvia have a close relationship with the core of the consortium attaching to the surface of the shell of the rapana, and at the earliest stages and to the surface of the epiphytes. Representatives of Polyplacophora are confined mainly to the rocky form of rapana, while Bivalvia show a greater species diversity in the consociation of the ecomorph R. venosa of loose grounds (6 species) than the rocky form (3 species). Differences in the taxonomic composition of epibionts and the percent coverage of the shell of the two ecoforms of R. venosa are predominantly determined by specific dynamic impact of the water mass in the zones of development of rocky and loose grounds.

Oithona davisae: naturalization in the Black sea, inter-annual and seasonal dynamics, effect on the structure of the planktonic copepod community

2019 ◽  
Vol 59 (6) ◽  
pp. 1008-1015
Author(s):  
A. D. Gubanova ◽  
O. A. Garbazey ◽  
D. A. Altukhov ◽  
V. S. Mukhanov ◽  
E. V. Popova
Keyword(s):  
Black Sea ◽  
Coastal Waters ◽  
Native Species ◽  
Significant Decline ◽  
Acartia Tonsa ◽  
The Black Sea ◽  
Copepod Community ◽  
Oithona Davisae ◽  
Sevastopol Bay

Long-term (20032014) routine observations of zooplankton in Sevastopol Bay (the Black Sea) have allowed the naturalization of the invasive copepod Oithona davisae to be studied in the Black Sea coastal waters. Inter-annual and seasonal variability of the species and their impact on the native copepod community have been analyzed. The invasion of O. davisae and their undoubted dominance in terms of abundance were shown to alter the community structure but, at the same time, the abundances of the native species did not decrease, excepting the Black Sea earlier invader Acartia tonsa. A significant decline in A. tonsa numbers over the stages of O. davisae establishment and naturalization provided evidence of competition between the species. O. davisae have been demonstrated to gain competitive advantage over A. tonsa, that ensured their fast dispersal in the Black Sea, acclimatization in the new habitat and the successful competition over native species.

scholarly journals Engineering geophysical studies in the Black Sea from onboard the R/V Ashamba during 2017

2019 ◽  
Vol 59 (2) ◽  
pp. 319-320
Author(s):  
N. N. Dmitrevskiy ◽  
R. A. Ananyev
Keyword(s):  
Transition Zone ◽  
Continental Slope ◽  
Black Sea ◽  
Water Area ◽  
The Black Sea ◽  
Echo Sounder

In May and October 2017, expeditionary research was carried out in the area of Gelendzhik in the Black Sea at the R/V «Ashamba». The main tasks were the mapping of the seabed and the search for small-sized objects at the bottom of the water area using a WASSP WMB-3250 multibeam echo sounder. Surveys included areal surveying and drawing up bathymetric maps of test sites in Gelendzhik Bay and in the transition zone from the shelf to the continental slope. In addition, the echo sounder was used to search and determine the exact coordinates of the bottom seismograph installed at the seabed near the Divnomorskoye village in May 2016. The article presents the results of the work carried out.

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