Kotov А.А., Zharov А.А., Chernova О.F., Neretina А.N., Gololobova М.А., Trofimova S.S., Zinovyev E.V., Izymova E.I., Zanina O.G., Kirillova I.V., Shidlovskiy F.K.
The aim of this study is to analyze the complex of animal and plant remains from the fossil hair found in the Allaikha River basin, Sakha Republic, Russian Federation. We studied the hair structure and we conducted an AMS radiocarbon dating of both hair itself and the remains revealed therein. We found different animal and plant remains in the hair taphocoenosis. The most diverse and numerous remains belong to branchiopod crustaceans: resting eggs and distal portions of the mandibles of Anostraca, distal portions of the mandibles of Notostraca, filtering limbs of some Anostraca or Daphniidae, ephippia of Daphnia (Daphnia) curvirostris, Daphnia (Ctenodaphnia) atkinsoni and D. (Ctenodaphnia) magna. No representatives of D. (Ctenodaphnia) presently occur in the Northeast of Eurasia. But due to our findings of numerous ephippia in the fossil hair of two mammoths, one from the Allaikha River and the other, earlier studied from the Bol’shaya Chukochya (see Kirillova et al., 2016), we can conclude that ctenodaphnias at least did occur in the region and probably were usual and widely distributed there. Extinction of Daphnia (Ctenodaphnia) in northeastern Eurasia needs further special studies. We emphasize the need in further studies of the morphology of ephippia, resting eggs and mandibles of recent Branchiopoda. Without such studies, it is impossible to adequately identify their Plestocene remains.
Sheveleva N.G., Podshivalina V.N., Mirabdullayev I.M.
Females of Mesocyclops leuckarti (Сlaus 1857) inhabiting Lake Baikal (Maloe More Strait) and Lake Gusinoe, Zabaikalye (=Transbaikalia) are redescribed. Peculiar features of the species’ life cycle are due to the anthropogenic impact on the hydrological conditions and the stage of the development (ageing) of the water body.
Degtyareva E.K., Sinev A.Y.
The postembryonic development of males in marine Cladocera (Crustacea) of the family Podonidae was studied for the first time, based on two common species from the White Sea: Evadne nordmanni Loven 1836 and Pleopis polyphemoides (Leuckart 1859). The development of podonid males includes two juvenile instars which differ in size of the testes, the shape and size of the penis, and the morphology of the copulatory hook on the distal segment of the endopodite of thoracic limb I. Females of Podonidae are pedogenetic and lack juvenile instars. Males of Podonidae retain the plesiomorphic postembryonal development, suggesting different speeds of evolution in both sexes in this family.
Kotov А.А., Marin I.N.
In this short communication we present an introductory information concerning the International Conference “Crustacea: diversity, ecology and evolution”, which took place at the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (Moscow) from October 30th to November 2nd, 2017.
Afonina E. Yu.
A Chinese species of Calanoida, Sinodiaptmus sarsi (Rylov 1923), has been found in the plankton of a reservoir-cooler of the Kharanorskaya hydroelectric power station located in the southeast of Zabaikalsky krai (=Transbaikalia). This is the first record of the species from Siberia. Micrographs showing its morphology are presented. The greatest numbers have been registered during cyanobacterial blooms.
Zimina O.L., Strelkova N.A., Lyubina O.S.
The species composition of Peracarida in the Barents Sea is determined, based on material of benthic investigations in 2003–2008. A total of 323 species are identified. 64 peracarid species are new to the Barents Sea fauna, mainly Isopoda, Cumacea and Tanaidacea. The main features of the quantitative distribution of Peracarida are revealed. The most abundant populations are shown to be formed on mixed sandy-silt grounds of the shallows and on the slopes of troughs. In the investigated area, 8 faunistic complexes associated with certain environmental conditions are detected. The biogeographical structure is dominated by Boreal-Arctic species. Boreal species account for 28% of the fauna, while Arctic species for another 21%. The overlap area of Boreal and Arctic species distributions has moved to the east and north compared to the period of 1968–1970, this being the result of an ongoing warming of the Barents Sea.
Mukhortova O.V., Sabitova R.Z., Poddubnaya N. Ya.
The species composition of the summer zooplankton in the middle and lower reaches of the Samara River was studied. Peculiarities of the quantitative characteristics and structure of the plankton invertebrate ripal and medial are shown to depend on the location along the longitudinal profile of the river, the flow velocity and the degree of overgrowth. The maximum quantitative indicators of hydrobionts are registered in the middle section of the flow, the minimum in the lower one. The number of species, the numbers and biomass of communities are determined by the degree of overgrowth with macrophytes and by the flow rate.
Dubovskaya O.P., Glushchenko L.A.
The large, deep, freshwater Norilsk lakes (Lake Lama, Lake Sobachye, Lake Glubokoe and Lake Keta) are located beyond the Arctic Circle, at the northwestern edge of the Putorana Plateau. They underwent a Pleistocene boreal marine transgression. A relict of that transgression, Limnocalanus macrurus Sars 1863 (Copepoda, Calanoida), presently dominates the crustacean zooplankton of these lakes. Sympatric with the native relict species L. macrurus, Senecella siberica Vyshkvartzeva 1994, was found in our zooplankton samples taken from the deep parts of lakes Lama and Sobachye in the summer-autumn of 2014–2016. Sampling was performed using a Juday net hauled vertically from a depth of 15, 20(25/30) and/or 50 m to the surface. All Senecella specimens were older copepodites, mainly CIV stage in Lama and Sobachye lakes in August and CV in Sobachye Lake in September; their abundance was low (25–2000 ind. m –2 ). They inhabited the central deeper regions of the lakes, contributing up to 7–14% to the total wet biomass of net zooplankton in 0–20 and 0–50 m strata. Previous sporadic and rather superficial samplings in these lakes missed Senecella due to its deep locations, low abundance levels and the absence of both the oldest copepodites and adults in summer.
Borisov R.R., Pechenkin D.S.
The coloration of red king crab (Paralithodes camtschaticus (Tilesius)) and blue king crab (Paralithodes platypus (Brandt)) larval stages (zoea I–IV) was compared. Red and yellow star-shaped chromatophores located on the carapace and limbs of red king crab larvae were noted. Blue king crab larvae had the digestive system colored in rich red, as well as red star-shaped chromatophores located on the carapace and limbs. Star-shaped chromatophores reacted to changes in light intensity in both species. When light intensity was low, the pigment was concentrated to the central part of the chromatophore, whereas at high rates of light intensity it was distributed along its outgrowths. The coloration of the internal organs of blue crab larvae did not depend on light intensity. Significant differences in the coloration of red king crab and blue king crab larvae may indicate that they occupy different ecological niches. The absence of yellow chromatophores and the presence of colored internal organs in the blue crab zoea may occur because most of the larvae of this species stay in the water horizons with low light intensity.
Новый вид стигобионтных креветок рода Xiphocaridinella Sadowsky 1930 (Decapoda, Atyidae) описан из пещер Шурубуму и Мухури, Чхороцку, Западная Грузия, Кавказ на основе генетического и морфологического анализа. Новый вид хорошо отличается от других видов рода сильно развитым треугольным невооруженным рострумом, достигающим дистального края базального членика антенны, а также генетически. Ключевые слова: Crustacea, Decapoda, Atyidae, Troglocaris, Xiphocaridinella, стигобионтный, стигобионт, креветки, новый вид, Кавказ