Sandy Ground Zoobenthos Of Opuk Nature Preserve
SANDY GROUND ZOOBENTHOS OF OPUK NATURE PRESERVE
А.S. Теrentijev1, А.M. Semik2
1Southern Scientific Research Institute of Marine Fisheries
and Oceanography (YugNIRO), Kerch, Ukraine
2Opuk Nature Preserve, Kerch, Ukraine
Complex of hydrobiological works was carried out aiming to make the fauna inventory in the area of Opuk Nature Preserve.
Data were collected in autumn 1999 and in summer 2000 using dredger ДЧ-0,025. A total of 34 samples were collected. Species composition was determined according to fauna determinant of the Black and Azov Seas [1]. While calculating average indices of zoobenthos abundance and biomass were used. Species constancy (С) was calculated according to formula С=100р/Р, where р – is number of samples containing the species in question, Р – is total number of samples. Depending on the value (С) the following species category were distinguished: more than 50% - constant, 25 – 50% additional, less than 25% - rare species [2,3]. Species that occurred once formed the category of very rare species. Sharlier’s coefficient [4] was used as a measure of species conjugation.
32 animal species belonging to five taxonomic groups were found in zoobenthos species composition of Opuk Nature Preserve (Table 1).
Table 1. Zoobenthos species composition of Opuk Nature Preserve
Species
Bivalve
mollusks
Cerastoderma glaucum, Chamelea gallina, Donax trunculus, Galactella lactea, Gastrana fragilis, Loripes lucinalis, Moerella tenuis, Mytilaster lineatus, Mytilus galloprovincialis, Parvicardium exidium, Pitar rudis, Plagiocardium simile, Spisula subtruncata
Gastropods
Bela nebula, Bittium reticulatum, Calyptraea chinensis, Cerithidium pusillum, Retusa truncatella, Tritia reticulata
Ascidians
Ctenicella appendiculata
Crustaceans
Ampelisca diadema, Apseudopsis ostroumovi, Balanus improvisus, Diogenes pugilator, Eurydice spinigera
Polychaetes
Glycera alba, G. Tridactyla, Melinna palmata, Nephthys cirrosa, N. hombergii, Platynereis dumerilii, Staurocephalus kefersteini
Average zoobenthos abundance was 650±140 specimens/m2, biomass was 125±38 g/m2.
According to our observations bivalve mollusks had the highest level of the development (Figure 1). 40% of species variety, 69% of abundance and 95% zoobenthos biomass fell to the share of this class. 16% of species variety and 26% of zoobenthos abundance fell to the share of crustaceans. High species variety of polychaetes (22% of all species) was observed. However this group abundance and biomass was very low.
Gastopod C. gallina was dominant species. 58% of abundance and 91% of zoobenthos biomass fell to its share (Table 2).
Table 2. Development level of zoobenthos of Opuk Nature Preserve
Species
Abundance, sp./м2
Biomass, g/м2
1.
2.
3.
Constant:
C. gallina
374,00±88,00
113,000±37,000
1.
2.
3.
Additional:
B. improvisus
158,00±73,00
1,810±0,770
Rare:
D. pugilator
C. appendiculata
G. fragilis
S. subtruncata
M. palmata
M. lineatus
N. hombergii
P. exidium
P. simile
T. reticulata
4,70±0,48
8,24± 0,90
38,80± 3,70
4,71± 0,48
2,35± 0,28
5,88± 0,83
3,53± 0,34
4,71± 0,48
5,88± 0,72
2,35± 0,28
0,950±0,110
0,064± 0,011
0,285± 0,030
0,528± 0,078
0,006± 0,001
0,561± 0,086
0,018± 0,002
0,729± 0,072
0,229± 0,033
4,282± 0,511
Very rare:
A. diadema, A. ostroumovi, B. nebula, B. reticulatum, C. chinensis, C. glaucum, C. pusillum, D. trunculus, E. spinigera, G. alba, G. tridactyla, L. lucinalis, M. tenuis, M. galloprovincialis, N. cirrosa, P. rudis, R. truncatella, S. kefersteini
Total:
650,00±140,00
125,000±38,000
This species occurrence was 71%. Mollusks of young age groups were predominant in the population (Figure 2).
B. improvisus was also a very wide-spread species. It occurred at about a half of all the stations. 24% of abundance fell on its share, but it is only 1.5% of zoobenthos biomass. This species has a strong tendency to aggregated distribution (its dispersion index is 2.7). This phenomenon can be explained by the fact that at sandy grounds balanus suffers deficit of substratum for settling. That’s why in most cases it is fastened to the shells of bivalve mollusks, to the shell of C. gallina in particular and often several specimens to one animal. Under these conditions balanus is a commensal of bivalve mollusks. It explains the fact that its distribution is closely connected with C. gallina distribution (Sharlier’s conjugation coefficient was 0.48±0.13).
Sestonophagens prevailed in trophic structure (Figure 3). Maximum both of species variety and zoobenthos abundance and biomass fell on the share of its trophic group.
Species variety of animals collecting detritus from the ground surface and carnivora was rather high. 24% and 21% of all zoobenthos species variety fell to their share. But their share in total zoobenthos abundance and biomass was not high. Low development level of polyphagens was observed. Phytophagens were presented by the only species – gastropod B. reticulatum.
References
1. Fauna determinant of the Black and Azov Seas. Vol. 1, 2, 3. – Kiev: Naukova dumka, 1968, 1969, 1972. - 437 p., - 536 p., - 340 p.
2. Balogh J. Lebensgemeinschaften der Landtiere. - Berlin, 1958. – 560 S.
3. Bodenheimer F.S. Precis d,ecologie animal. - Paris, 1955. - 315 P.
4. Terentiyev P.V., Rostova N.S. Practical works on biometry. - L.: Publ. LSU, 1977. - 152 p.
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