Echiuropus bekmanae n.sp. (Crustacea, Amphipoda, Carinogammaridae) from Lake Baikal, retrieved by a new deep-water sampling device

Lake Baikal is well known for its exceptional diversity of gammarid amphipods, with 95% of endemics from its 270 described species representing about 20% of the world freshwater fauna. Echiuropus (Asprogammarus) bekmanae n.sp. was collected by an `autonomous trap system', a sampling device thoroughly described here. Although not necrophagous itself, this new species was found in two baited trap samples (at 750 and more than 1600 m) from 1995 and 1996. This rather small (13 mm) deep water species is the eighth species of the subgenus Asprogammarus, of the Baikal endemic genus Echiuropus. Diagnoses of the subgenus and the closer species are given.     

Interspecific variability of telomeric DNA length in some siberian and endemic baikal planarians (Plathelminthes,Tricladida)

The length of the telomeric DNA in nine species of planarians inhabiting Lake Baikal and one Siberian species from Baikal rivers was determined using Southern hybridization. According to preliminary estimations, it varied in the range of 25–30 kb (Rimacephalus arecepta, Rimacephalus pulvinar, Sorocelis hepatizon, Sorocelis nigrofasciata, Protocotylus sp., Baikalobia guttata, Bdellocephala baikalensis, Phagocata sibrica) and 50 kb (Baikaloplana valida, Baikalobia copulatrix). It is the first estimation of the values of telomeric region lengths for Baikal free-living flat worms.     

Colorless sulfur bacteria <Emphasis Type="Italic">Thioploca</Emphasis> from different sites in Lake Baikal

The colorless sulfur bacteria Thioploca spp. found in Lake Baikal are probably a marker for the influx of subterranean mineralized fluids. Bacteria act as a biological filter; by consuming sulfide in their metabolism, they detoxicate it and maintain the purity of Lake Baikal’s water. The bacteria were investigated by various techniques. According to analysis of the 16S rRNA gene fragment, Thioploca sp. from Frolikha Bay, Baikal belongs to the clade of freshwater species found in Lake Biwa and Lake Constance; it is most closely related to Thioploca ingrica.     

The Baikalian genus Rhyacodriloides in Europe: phylogenetic assessment of Rhyacodriloidinae subfam. n. within the Naididae (Annelida)

Martin, P., Martínez‐Ansemil, E. & Sambugar, B. (2010). The Baikalian genus Rhyacodriloides in Europe: phylogenetic assessment of Rhyacodriloidinae subfam. n. within the Naididae (Annelida). —Zoologica Scripta, 39, 462–482. Two new species of the oligochaete genus Rhyacodriloides Chekanovskaya, Rhyacodriloides aeternorum sp. n. and Rhyacodriloides latinus sp. n., are described from subterranean water bodies of Italy and Slovenia. A comparison with the known species of this genus, Rhyacodriloides abyssalis Chekanovskaya, 1975 and Rhyacodriloides gladiiseta Martin & Brinkhurst, 1998, both from Lake Baikal, shows that the enigmatic ‘cellular masses’ of the latter two species must be interpreted as different, not homologous structures. As a result, R. gladiiseta is to be ascribed to the Phallodrilinae, a primarily marine naidid subfamily, mentioned for the first time in Lake Baikal, and placed in its own genus, Phallobaikalus gen. n. The two new species are morphologically very similar, but their penial setae differ slightly. The phylogenetic relationships of R. latinus sp. n. and R. abyssalis within the Naididae (formerly the Tubificidae) were investigated using a combination of three genes, one nuclear (18S rDNA) and two mitochondrial (12S rDNA and 16S rDNA). A fragment of the mitochondrial COI gene, used as a barcode, also genetically characterized all Rhyacodriloides species. Sequences of 34 Naididae were obtained from EMBL, representative of five naidid subfamilies, and including five oligochaete outgroups. The data were analysed by parsimony, maximum likelihood and Bayesian inference. Taken in combination, the three genes investigated confirm that the two Rhyacodriloides species analysed are closer to each other than to any other naidid species. However, they are separated by 16S and COI distances that amount to 18.5% and 27.2%, respectively, suggesting an ancient separation between species, in good accordance with their present biogeographic distribution. Rhyacodriloides cannot be considered as a rhyacodriline, as assumed so far, as they never appeared related to this subfamily in any analysis considered. In contrast, they appear at the base of a naidid group, including the Tubificinae, the Phallodrilinae, the Limnodrilinae, as well as Branchiura sowerbyi, a species whose phylogenetic association with the rhyacodrilines has been questioned for a long time. Despite a lack of phylogenetic support, this position is congruent with a morphological reassessment of the Rhyacodrilinae, and strongly supports the erection of a new naidid subfamily to accommodate Rhyacodriloides.     

Two new species of Hyalella from Lake Titicaca,and redescriptions of four others in the genus (Crustacea: Amphipoda)

The amphipod genus Hyalella has its highest diversity in the Andean Lake Titicaca. This genus is the only epigean amphipod present in South America. Eleven endemic and one non-endemic species are known from Lake Titicaca. An additional endemic species, Hyalella nefrens n. sp. and one non-endemic species Hyalella tiwanaku n. sp. are described here. Hyalella cuprea(Faxon, 1876), Hyalella latimanus (Faxon, 1876), Hyalella montforti Chevreux, 1907, and Hyalella neveulemairei Chevreux, 1904 are redescribed. The high diversity of Hyalella in the lake is not well understood, and it has been compared with the spectacular diversity of Lake Baikal.     

Four new species of Gomphocythere (Crustacea, Ostracoda) from Lake Tanganyika, East Africa

Four new species of the ostracod genus Gomphocythere are described from Lake Tanganyika (East Africa): Gomphocythere downingi n. sp. G. coheni n. sp., G. wilsoni n. sp., and G. woutersi n. sp. All species are endemic to the lake and are found within a variety of substrates and depths. The addition of these four new species brings the total number of endemic Gomphocythere species in Lake Tanganyika to nine. Other Gomphocythere species are known from water bodies throughout East and South Africa and in the Levant. Brooding is an important, but not a unique, preadaptation for the persistence and taxic prolific speciation of this lineage in Lake Tanganyika.     

Seven new species and two new subspecies of Sclerocypris SARS, 1924 from Africa,with new records of some other Megalocypridinids (Crustacea,Ostracoda)

Sclerocypris dayae n.sp., S. dedeckkeri n.sp., S. dumonti n.sp., S. zelaznyi n.sp. and S. zelaznyi etoshensis n.ssp. are described from South — West Africa (Namibia). S. exserta makarikarensis n.ssp. originates from the endorheic pan system Makarikari in Botswana. S. woutersi n.sp. was described from Lake Albert where it is quite common. S. virungensis n.sp. is known from the Virunga National Park, south of Lake Edward (Zaire). The latter two species are closely related and from part of the flabella-species group. S. longisetosa n.sp., described from a marsh near Kisumu (Kenya), is an enigmatic species, holding an isolated position in the genus due to an aberrant T1.Present address: Rijksuniversiteit Gent, Laboratorium voor ecologie der dieren, zoögeografte en natuurbehoud (Institute for Ecology), K. L. Ledeganckstraat 35, B9000 Gent, Belgium.     

A new interstitial cyclopoid copepod from a sandy beach on the western shore of Lake Baikal,Siberia

A new species of cyclopoid copepod, Diacyclops biceri sp. nov., is described from Lake Baikal. It was found in the interstitial water of a sandy beach at Buchta Peschanaya on the western shore of the central basin of Baikal. The new species is unique in possessing 2-segmented endopods in swimming legs 3 and 4. Swimming legs 2 to 4 have 3-segmented exopods. The slender body form, the lack of the antennal exopodal seta, and the presence of a secondary pseudosomite anterior to the genital double somite of the adult female are interpreted as adaptations to the interstitial habitat. The harpacticoid Epactophanes richardi Mrazek was found in the same interstitial habitat as D. biceri.     

Description of a new species of Proteocephalus pronini sp.n. (Cestoda: proteocephalidae)--a parasite of grayling from lake Hovsgol

A new cestode species, Proteocephalus pronini sp. n., is described from the Lake Hovsgol Grayling Thymallus arcticus nigrescens (Mongolia, Hovsgol Lake). The new species differs from P. thymalli from the Baikal Lake by the length of strobile, number of proglottids, form of mature proglottids, and number of diverticles of uterus.     

Three New Species of Etamphidelus Andrássy, 1977 (Nemata: Alaimidae) in Southern Chile

Three new species of Etamphidelus are described from Orange Bay, Hoste Island, Chile. All three are distinguished from previously described species by their numerous longitudinal cuticular ridges. E. acucephalus n. sp. is further distinguished by its extremely narrowed anterior body region and posteriorly situated amphids. E. fueguensis n. sp. is distinguished from E. acucephalus by its anteriorly located amphideal fovea, fewer cuticular ridges, smaller V-an/tail ratio and presence of males. E. yamani n. sp. is more similar to E. fueguensis n. sp. differing from it by a wider head end, more posteriorly located excretory pore, longer V-an/tail ratio, more numerous cuticular ridges and smaller spermatozoa. E. puccinelliae (Lorenzen, 1966) Andrássy, 1977 is transferred to Paramphidelus puccinelliae (Lorenzen, 1966) n. comb. The generic diagnosis of Etamphidelus is amended, and a key to species is presented.     

Two Radix spp. (Gastropoda: Lymnaeidae) endemic to thermal springs around Lake Baikal represent ecotypes of the widespread Radix auricularia

In this study, we re‐examine two species of freshwater gastropods of the genus Radix Montfort, 1810 (family Lymnaeidae), endemic to the geothermal springs in the Lake Baikal region in the southern part of eastern Siberia — Lymnaea (Radix) hakusyensis Kruglov et Starobogatov, 1989, and Lymnaea (Radix) thermobaicalica Kruglov et Starobogatov, 1989. The alleged species status of these endemics has been re‐assessed by means of an integrative approach combining molecular genetic taxonomy techniques with the traditional methods based on shell and soft body morphology. Phylogenetic reconstructions were made using both mitochondrial (COI) and nuclear (ITS2) DNA markers. We used topotypic samples of both species and specimens sampled from other sites around Lake Baikal. The results demonstrate that the two endemic species are only synonyms of a widespread Holarctic species, Radix auricularia (Linnaeus, 1758), and represent its intraspecific morph (ecotype) adapted to living in thermal springs. A new synonymy is proposed: Thermoradix Kruglov et Starobogatov, 1989 = Radix Montfort, 1810 (syn. n.).     

The species composition and distribution of free-living nematodes (Nematoda) in an area of natural oil and gas seeps in Lake Baikal

The species composition and quantitative parameters of free-living nematode fauna have been studied in an area of natural oil seeps off Cape Gorevoi Utes (Middle Baikal). A total of 34 species of 17 genera, 10 families, and 8 orders have been found, 18 of them endemic to Lake Baikal. The nematode fauna of bitumen volcanoes was found to be represented by three specialized species (Monhystera naphthera Gagarin et Naumova, 2010; Eumonhystera abyssalis Gagarin et Naumova, 2010; and Eutobrilus mirandus Gagarin et Naumova, 2011). Areas of the bottom with scattered oil seeps are dominated by eurybathic species endemic to Lake Baikal. The maximal values of nematode population density and maximum proportion of nematodes in the meiozoobenthos were recorded in areas directly adjacent to oil seeps.     

Trichodinid (Ciliophora; Peritricha) gill parasites of freshwater fish in South Africa

Summary Trichodinella epizootica (Raabe, 1950) and seven new species of trichodinid ectoparasites (Ciliophora: Peritricha) were identified from both wild and pond fishes collected during an extensive survey of fish ponds, rivers and lakes in the Transvaal, South Africa. The new species are Tripartiella clavodonta n. sp., T. lechridens n. sp., T. leptospina, n. sp., T. macrosoma n. sp., T. nana n. sp., T. orthodens n. sp. and Trichodinella crennulata n. sp.     

AN UNUSUAL NEW SPECIES OF DRAPARNALDIA FROM LAKE CHAMPLAIN1,2,3

Draparnaldia champlainensis sp. nov. is described and compared with other species of the genus and with Draparnaldiopsis. It closely resembles certain species described by Meyer from Lake Baikal and also Draparnaldiopsis simplex Jao. Its distinguishing features are (1) determinate branches borne in whorls on nearly every cell of the main axis; (2) one or a few broad hairs originating near the base of the determinate branch system; (3) a well-defined group of meristematic cells at the base of the hair; and (4) extensive rhizoidal cortication in the lower portions of the plants and at the base of the main branches. Draparnaldiopsis simplex Jao is transferred to the genus Draparnaldia and renamed Draparnaldia jaoi nom. nov.     

The endemic Cladophorales (Ulvophyceae) of ancient Lake Baikal represent a monophyletic group of very closely related but morphologically diverse species

Lake Baikal, the oldest lake in the world, is home to spectacular biodiversity and extraordinary levels of endemism. While many of the animal species flocks from Lake Baikal are famous examples of evolutionary radiations, the lake also includes a wide diversity of endemic algae that are not well investigated with regards to molecular‐biological taxonomy and phylogeny. The endemic taxa of the green algal order Cladophorales show a range of divergent morphologies that led to their classification in four genera in two families. We sequenced partial large‐ and small‐subunit rDNA as well as the internal transcribed spacer region of 14 of the 16 described endemic taxa to clarify their phylogenetic relationships. One endemic morphospecies, Cladophora kusnetzowii, was shown to be conspecific with the widespread Aegagropila linnaei. All other endemic morphospecies formed a monophyletic group nested within the genus Rhizoclonium (Cladophoraceae), a very surprising result, in stark contrast to their morphological affinities. The Baikal clade represents a species flock of closely related taxa with very low genetic differentiation. Some of the morphospecies were congruent with lineages recovered in the phylogenies, but due to the low phylogenetic signal in the rDNA sequences the relationships within the Baikal clade were not all well resolved. The Baikal clade appears to represent a recent radiation, based on the low molecular divergence within the group, and it is hypothesized that the large morphological variation results from diversification in sympatry from a common ancestor in Lake Baikal.     

Pharyngodonidae (Oxyuroidea; Nematoda) of Agama yemenensis in Saudi Arabia: hypothesis on the origin of pharyngodonids of herbivorous reptiles

Summary Five new species of pharyngodonid (Oxyuroidea) nematodes are described from the posterior gut of Agama yemenensis (Agamidae) in Saudi Arabia: Tachygonetria paradentata n.sp., a member of the T. dentata complex, most closely resembles T. quentini Petter, 1966 from Testudo tentoria verreauxi from South Africa in the form and disposition of cephalic sense organs; it is distinguished by having caudal alae, an anterior anal lip in the male formed by two sharply-elbowed lobes and by the fact that the terminal spine on the caudal appendage of the male is much shorter than that in T. quentini. Alaeuris asirensis n.sp. is most similar to a species described as Thelandros sexlabiata Ortlepp, 1933 from Testudo tentoria verreauxi from South Africa: the last pair of caudal papillae in the male is subterminal, and there are six lips and a slight prevulvar swelling in the female. Males of the two species are easily distinguished by the presence of caudal alae and a longer caudal appendage in A. asirensis females are distinguished by the fact that lips are less developed in the new species. The fact that two such similar species cannot be included in the same genus reflects the need for a redefinition of Alaeuris. Thelandros agama n.sp. resembles T. alatus Wedl, 1862 from Uromastix sp. in North Africa in the cephalic structure of the female and in the shape of the peduncles supporting adanal papillae in males; the new species is distinguished by its longer spicule and by the presence of caudal alae and the absence of lips in males. T. masaae n.sp. resembles T. taylori Chatterji, 1935 and T. baylisi Chatterji, 1935 from Agama sp. and Uromastix sp. in India in that the peduncles supporting the caudal papillae in the male are elongate; it differs from both and from all other members of the genus in that the vulva is located at the end of a long tube-like exvagination of the body wall and the anterior anal lip of the male is simple rather than fringed. T. petterae n.sp. resembles T. taylori and T. baylisi in having well-developed caudal alae in males and six prominent lips in females; it is distinguished from both by its flask-shaped adanal peduncles in the male. Thelandros is redefined to include only those species in which the pre- and adanal papillae are pedunculate and the opening to the spicular pouch is markedly postanal. The nine genera of the Pharyngodonidae in herbivorous and omnivorous reptiles form an evolutionary line distinct from that in insectivorous reptiles. It is suggested that this line arose in tortoises in Laurasia in the Eocene, spread with these hosts to Africa, Madagascar and South America, and subsequently underwent evolutionary radiations in each of these regions. Pharyngodonids of A. yemenensis have a double origin: the Thelandros spp. probably evolved with agamids whereas species of Tachygonetria and Alaeuris are likely captures from tortoises. ac]19831111