Cyclopoida Burmeister, 1834

Novichkova, Anna A. & Chertoprud, Elena S., 2015, The freshwater crustaceans (Cladocera: Copepoda) of Bering Island (Commander Islands, Russian Far East): species richness and taxocene structure, Journal of Natural History 50, pp. 1357-1368 : 1361-1363

Order Cyclopoida Burmeister

Family Cyclopidae Dana

Acanthocyclops vernalis (Fischer) * ( Vekhov 1973)

Cyclops cf. abyssorum Sars *

C. furcifer Claus *

C. scutifer Sars * ( Kurenkov 1970; Vekhov 1973)

C. strenuus Fischer *

Diacyclops bisetosus (Rehberg) *

Ectocyclops phaleratus (Koch) *

Eucyclops macruroides (Lilljeborg) *

E. macrurus (Sars) *

E. serrulatus (Fischer) *

E. speratus (Lilljeborg) *

Megacyclops viridis (Jurine) *

Mesocyclops leuckarti (Claus) *

Microcyclops rubellus (Lilljeborg) *

Order Calanoida Sars Family Diaptomidae Baird

Acanthodiaptomus denticornis (Wierzejski) *

A. paci fi cus (Burckhardt) (syn. A. yamanacensis Brehm )* ( Vekhov 1973) Diaptomus ambiguus (Lilljeborg) ( Lilljeborg 1887)

D. glacialis Lilljeborg *

Eudiaptomus gracilis Sars *

E. graciloides (Lilljeborg) *

Sinodiaptomus sarsi (Rylov) *

Family Temoridae Sars

Eurytemora gracilicauda Akatova (syn. E. kurenkovi Borutzky )* ( Vekhov 1973)

Family Calanidae Dana

Neocalanus cristatus (Kroyer) ( Lilljeborg 1887)

Order Harpacticoida Sars Family Canthocamptidae Brady

Bryocamptus cf. subarcticus (Willey) *

Mesochra pygmaea (Claus) *

M. rapiens (Schmeil) *

Family Harpacticidae Dana

Zaus cf. goodsiri (Brady) *

Family Laophontidae Scott

Onychocamptus mohammed (Blanchard and Richard) *

Pseudonychocamptus paraproximus Lang *

Family Nannopodidae Brady

Huntemannia jadensis (Poppe) *

Characteristics of fauna and taxocenes of the observed water bodies

The species composition of crustaceans in most of the investigated water bodies is composed equally of Cladocera and Copepoda, both in abundance and species number. However, the number of monodominant species among Copepoda is higher, whereas cladocerans usually form dominant complexes of species in the taxocenes. These specific groups of crustaceans were allocated using the modified Braun–Blanquet method. However, as the general species richness in water bodies tends to be rather low, it is possible to learn about the existence of certain complexes of organisms in general. Fauna of the majority of reservoirs has a ‘mixed’ character and appears to be a uniform faunistic set presented in different lakes to a greater or lesser extent. In terms of the zooplanktonic taxocenes, all studied water bodies can be divided into four groups:

(1) Bodies of water dominated by Daphnia cf. longispina , often along with Chydorus sp. , species of the genus Bosmina and Eucyclops serrulatus . Water bodies with this type of species assemblages are usually small and located near the large lakes in wetlands;

(2) Bodies of water with only prepotent species tend to contain Chydorus sp. (at more than 90% of the total abundance). This type of community has already been described in the literature in reservoirs with extremely adverse conditions. The same reservoirs, for example, are abundant in the corrie lakes and dams of Altai ( Belyaeva 2003);

(3) Bodies of water where the dominant complex comprises Eurytemora gracilicauda and different species of Harpacticoida ( H. jadensis , O. mohammed and others) were also found. Apparently, this type of system is mostly present in large lakes affected by salinisation, such as Lodyginskoe;

(4) All other bodies of water, in which the dominant role is played by one or two species which occur in only a small number of lakes, but assume a leading position in terms of abundance. These species include E. glacialis , A. werestschagini , Drepanothrix dentata , Diaptomus glacialis and Sinodiaptomus sarsi , as well as several others.

Based on the total species list of freshwater crustaceans, an analysis of the biogeographical structure of the fauna was carried out. The investigated fauna consisted not only of Holarctic (64.3%) and Palaearctic (20.1%) species but also of Nearctic (6.7%) elements and representatives of the Beringian province (8.9%).