Four new species of Halicyclops Norman, 1903 (Copepoda,Cyclopoida) from Brazil

Four new species of Halicyclops are described and figured from plankton samples of the brackish waters of Pomonga River, Sergipe State (NE Brazil). The ornamentation of the median apical setae of the furcal rami is proposed as useful diagnostic character for species distinction.     

A new Diacyclops (Copepoda,Cyclopoida, Cyclopidae) from northwestern Argentina

No species of the genus Diacyclops has been so far cited from continental Argentina. Specimens collected from a roadside pool in the province of Catamarca on a plateau at 3700 m a.s.l. turned out to belong to a new species, Diacyclops andinus, which is described and illustrated in detail for both sexes. Main diagnostic features are: spine formula of swimming legs 3, 4, 4, 4; terminal spines of the distal endopod segment of leg 4 subequal; smooth furcal rami. The new species is a member of the D. bicuspidatus group, and is probably near the base of this line.     

Pseudomoraria triglavensis gen. n., sp. n. (Copepoda,Harpacticoida) from a high-alpine reservoir in Slovenia

Numerous specimens of Pseudomoraria triglavensis gen.n., sp.n. were collected from small, high-alpine, reservoir Moilec. The reservoir is situated in the centre of Triglav national park (NW Slovenia) at an altitude of 1690 m. The new genus differs from related genera Moraria, Morariopsis and Paramorariopsis by the reduced articulation of exopodites and endopodites in both sexes. It also differs from Moraria by possessing sexually dimorphic furcal rami. Detail taxonomic differences between these related genera and their ecology are discussed.     

Parastenocaris andreji n. sp. (Crustacea; Copepoda) – the first record of the genus in Slovenia (SE Europe)

Parastenocaris andreji n. sp. was found in ground water in a northwestern part of Slovenia (southern part of Central Europe). Two adult females of the new species were filtered out of 20 000 l of water during examination of an aquifer for water supply. The bore well was 10 m deep. The aquifer is fed by rainwater and probably only occasionally from a nearby alpine river Sava. The new species differs markedly from other known species of the genus by shape and armature of furcal rami, very long and slim maxillae and some characters on endopodites P2–P5. The closest related species are probably Parastenocaris nolliKiefer, 1938 with subspecies P. nolli alpinaKiefer, 1960, P. gertrudae Kiefer, 1968 and P. austriacaKiefer, 1976.     

Locomotion in Nebalia bipes: a possible model for Palaeozoic phyllocarid crustaceans

The morphofunctional aspects of locomotion in Recent phyllocarid crustaceans are presented, based on combined video observations of living specimens of the cosmopolitan nektobenthic Nebalia (Leptostraca, Nebaliidae) and scanning electron microscopy of fixed material. N. bipes is infaunal by day, showing a preference for organic-rich black muds and dim light conditions. Under natural conditions, emergence from sediment and nocturnal swimming activities are controlled by a circadian rhythm. The 1st and 2nd antennae perform the major role in digging. The carapace rostral plate acts as a ram diverting particles and preventing inputs of sediment into the carapace. Superficial burrowing may provide camouflaged shelter against predation. Swimming is accomplished by the combined action of the first four pairs of pleopods (backward metachronal flexion during the power stroke) and the well-articulated abdominal shaft (downward flap). Plumose setae present on both the pleopods and furcal rami (governed by low Reynolds numbers) behave like paddles maximizing the resistance to the water. Clusters of cuticular microscales (3-5 μm) and microdenticles are present on the external surface of the carapace and the trunk segments, respectively. Both show a uniform directional arrangement suggesting functional interpretations in relation to locomotion (e.g., to prevent back slippage during digging, to reduce turbulence in the flow layer close to the body, and/or to serve as mechanoreceptors for the detection of variation in water flow). Key features of functional importance in the locomotion of living leptostracans (natatory pleopods, a highly flexible abdomen, setulate or paddle-like furcal rami) are also recognized in Palaeozoic archaeostracan phyllocarids, suggesting that swimming was accomplished by the same pleopodal movements as described for N. bipes. Comparisons with Recent analogues (Nebaliopsis) suggest that phyllocarids with a free swimming life-style existed among the lower Palaeozoic archaeostracans (e.g., Caryocaris; Ordovician). Asymmetrical cuticular ornament in some archaeostracans indicates burrowing habits. Some Palaeozoic phyllocarids may have been occasional (possibly diurnal) mud dwellers comparable to modern nebaliids.     

Taxonomic analysis of species characters for copepodid instars 4 and 5 of the subfamily Eucyclopinae of European Russia

Morphological characters useful for taxonomic identification of older copepodid instars of the subfamily Eucyclopinae were studied among 14 species of Eucyclops, Macrocyclops, Ectocyclops, Paracyclops and Tropocyclops known from European Russia. For taxonomic analysis, the following elements of copepodid morphology were chosen: armament and proportion of furcal rami; morphology of swimming legs and reduced 5th and 6th legs; antennule segmentation; and relative body length of copepodid instars in comparison with the female length. Changes in morphology of major copepodid instars of the subfamily Eucyclopinae during ontogenetic development are traced and noticeable differences among five genera and 14 species are described. These differences among major copepodid stages may be important for both taxonomic and ecological analysis. For taxonomy, they provide information on development of sexes and species during maturation. For ecology they allow identification of the specimens at 4–5 copepodid instars in diapause. A key to major copepodid instars of the species from the subfamily Eucyclopinae which are known from limnetic habitats of the European part of Russia is presented.     

The integumental pore signature of Thermocyclops schmeili (Poppe & Mrázek, 1895); Thermocyclops dybowskii(Landé, 1890); Thermocyclops hooki Löffler, 1968; Thermocyclops incisus Kiefer, 1932 and Thermocyclops inopinus (Kiefer, 1926)

Integumental pore signatures supplemented by routine morphological characters were studied in the females of five species of Thermocyclops Kiefer, 1927. Both techniques reveal structures with potential significance to taxonomy. Examples of these include a protruding spine of the sixth antennular segment, and a big opening near the genital pore. Bilaterally symmetrical, species-specific pore groups are found on the cephalosome, metasome and urosome, while conserved pores exist on the rostrum, on well-defined zones of the cephalosome, metasome, urosome and on the furcal rami. Exceptionally, asymmetry in these pore patterns may occur.     

A new species of <Emphasis Type="Italic">Eurycletodes</Emphasis> Sars, 1909 (Copepoda: Harpacticoida: Argestidae) from the southern hemisphere including remarks on the phylogeny of the genus and its subgenera

This paper deals with taxonomy and phylogenetics of the genus Eurycletodes Sars, 1909 (Copepoda: Harpacticoida: Argestidae). Samples, collected from the southeast Atlantic on board RV “Meteor” during the cruises DIVA-1 (M48/1) and DIVA-2 (M63/2), contain specimens of Eurycletodes. Eurycletodes is characterized as a monophylum by A1 segments III + IV fused, basal seta of md palp lost, exp of md palp reduced to 1 seta or completely lost. Similarly, the subgenera Eurycletodes (Eurycletodes) and Eurycletodes (Oligocletodes) are characterized as monophyletic by the loss of the inner seta on P1 exp2 (apomorphic to E. (E.)) and the absence of the inner seta on P5 endopodal lobe (apomorphic to E. (O.)). Eurycletodes profundus is renamed as E. (O.) profundus. Eurycletodes ephippiger is the only species of the genus without subgeneric designation. Eurycletodes (O.) diva sp. nov. is described. The new species differs from described species of the genus by a larger body size, P5 endopodal lobe only slightly protruding, last segment of A1 with 2 outer setae, furcal rami elongated between setae VII and IV. The occurrence of 2 specimens of Eurycletodes (O.) diva sp. nov. at 2 sites separated by the Walvis Ridge supports the hypothesis that geographic obstacles do not prevent harpacticoid copepods from spreading in the deep sea.     

A new notodelphyid copepod,Paranotodelphys illgi n. sp. (Copepoda: Cyclopoida), parasitic in the ascidian Corynascidia herdmani Ritter in the North Pacific

A new species of the Notodelphyidae belonging to Paranotodelphys Schellenberg, 1922 is described from both sexes. The new species, Paranotodelphys illgi, can be distinguished from its congeners by the combination of its 10-segmented female antennule, the bisetose fifth legs and the extreme elongation of the caudal rami of the female, which are more than 10 times longer than wide and 4.4 times longer than the anal somite. The male has non-geniculate antennules. The new species was collected at a depth of 508m in the North Pacific Ocean, from the ascidian Corynascidia herdmani Ritter.     

Revision of the African species of the genus Mesocyclops Sars, 1914 (Copepoda: Cyclopidae)

A revision is made of the African Mesocyclops species, based on type material (when extant) and on collections from various parts in Africa.Diagnostic characteristics are: presence or absence of spinule patterns on antennular segments, structure of the hyaline membrane of the 17th antennular segment, spine pattern on the basipodite of the antenna, armature of the maxillulary palp, presence or absence of a spine on the basipodite of P₁, armature of the connecting lamella, coxopodite and basipodite of P₄, armature of the apical spines of Enp₃P₄, armature of the last thoracic segment, genital segment and the other abdominal segments, armature of the furcal rami and structure of the receptaculum seminis.First, the taxonomical status of M. leuckarti (Claus) is redefined; this species does not occur in Africa and its geographical range is restricted to Europe and the western part of Northern Asia. On the African continent, twelve other taxa are found. Four are described as new to science: M. kieferi sp.n., M. dussarti sp.n., M. spinosus sp.n. and M. aequatorialis similis subsp.n. The remainder are: M. major Sars, M. tenuisaccus (Sars), M. paludosus Lindberg, M. salinus Onabamiro, M. ogunnus Onabamiro, M. aspericornis (Daday), M. rarus Kiefer and M. aequatorialis aequatorialis (Kiefer).Their geographical distribution is discussed. Eleven taxa are restricted to the African continent (including the Arabian Peninsula and the Canary Islands). One taxon is also found in the Oriental Region. Madagascan representatives are briefly mentioned.The importance of breeding and cross-breeding experiments should be stressed in copepod taxonomy. Experiments were performed on African species and M. leuckarti to evaluate the morphological characters used in the present study, and intraspecific morphological variability was examined up to and including the third generation (Van de Velde, in press).In future one should critically reconsider the so-called cosmopolitan species; they may indeed represent a complex of related taxa, each with a geographical range more restricted than that of the species-complex itself.Abstracted from the author's Ph.D. thesis, State University of Ghent, 1982.Abstracted from the author's Ph.D. thesis, State University of Ghent, 1982.     

Larval development of the rhizocephalanSacculina polygenea (Crustacea: Cirripedia)

Larval development of the rhizocephalanSacculina polygenea (Crustacea: Cirripedia: Rhizocephala) parasitizing the coastal crabHemigrapsus sanguineus was studied in Vostok Bay, the Sea of Japan. At 22–23°C, the entire cycle of larval development takes 2.5 days and includes five naupliar stages and one cypris stage. Like other rhizocephalans, the larvae ofS. polygenea are lecithotrophic and only grow slightly in size in the course of development, and like all sacculinids, they have no flotation collar. The naupliar stages IV and V have a tubercle between the furcal rami; this tubercle is absent in the larvae of the genusPeltogasterella, but it has been described inS. carcini. The first seta of the antennule only disappears completely at the fourth stage, although it is markedly reduced at the third stage. No morphological differences, except differences in size, are found between male and female nauplii.     

Two new species of Mesocyclops from southern China and notes on the genus Mesocyclops in China

Two new Mesocyclops species, M. mariae n. sp. and M. shenzhenensisn. sp., are described from southern China, the former species from Guangxi province, the latter from Guangdong province. Both species have setules on the medial margin of the caudal rami. Compared with each other, there are some conspicuous differences, such as the spinule pattern of the antenna basipodite, the structure of receptaculum seminis, the armature of coxopodite and basipodite of P4 and the armature of the caudal rami. The paper also compares the two new species with their supposedly closest relatives, M. pseudospinosus Dussart & Fernando, 1988, M. leuckarti(Claus, 1857) and M. pehpeiensisHu, 1943. In addition, other species of Mesocyclops in China are discussed and a key to 10 Chinese species of Mesocyclops is provided.     

Thermocyclops dumonti sp. n. (Crustacea,Copepoda), from a Temporary Waterbody in China

Six species of the genus Thermocyclops have hitherto been known from Chinese freshwaters. A new species is here recorded from a sample collected from an eutrophic pool in central China. It is described and compared using classical morphology and mapping of its pore signature. Thermocyclops dumonti differs from T. kawamurai by absence of ornamentation on prominences of intercoxal plates of P₁‐P₃, by relative length of apical spines of Enp₃P₄ and caudal ramus. It differs from T. dybowskii by ornamentation of P₄ intercoxal plate, relative length of Enp₃P₄ and caudal ramus, by shape of Tmi. As in other species of Thermocyclops, the perforations are bilaterally symmetrical and, species‐specific patterns occur on the cephalosome, metasome, and urosome. Conserved patterns are found elsewhere on the rostrum, cephalosome, metasome, and furcal branches. Based on pore pattern, Thermocyclops dumonti is separated from two close relatives, T. schmeili and T. dybowskii.     

A new species of Ochridacyclops (Kiefer, 1937) (Copepoda, Cyclopoida) from Japan

A new species of cyclopoid copepod, Ochridacyclops nipponensis is described from Japan. This is the third species of the genus. The type material was collected from small streams in the mountainous regions in Shikoku. The new species can easily be distinguished from other members of genus by its 12-segmented antennule, by the proportional length of genital double-somite relative to the length of 3 free abdominal somites, and by the shape of caudal rami. The male is unknown.     

A new species of Clausia (Copepoda, Poecilostomatoida, Clausiidae) associated with the polychaete Arenicola brasilliensis Nonata in Korea

A new species of the genus Clausia associated with the polychaete Arenicola brasilliensis Nonata is described from intertidal sands in Korea. The new species, as a primitive member of the genus, has a large, non-transformed body and fully segmented rami on legs 1–4. This is the second record of Clausiidae in the Far Eastern seas. The genus Doviella Rocha, originally placed in the Clausidiidae, is synonymized with the genus Clausia in the Clausiidae.     

A new species of Wellsopsyllus (Copepoda, Harpacticoida, Paramesochridae) from the deep Southern Ocean and remarks on its biogeography

The new deep-sea copepod species of the family Paramesochridae (Copepoda, Harpacticoida) presented here was collected during the scientific ANtarctic benthic DEEP-sea biodiversity cruise II (ANDEEP II) to the Weddell Abyssal Plain and western Weddell Sea and the CROZet natural iron bloom and EXport experiment (CROZEX cruise) to the Crozet Isles in the Indian Ocean. The new species has been allocated to the subgenus Wellsopsyllus within the genus Wellsopsyllus Kunz, 1981, based on the 1-segmented endopods and 3-segmented exopods of swimming legs 2–4. Furthermore, the new species shows a 1-segmented exopod of the antenna. Wellsopsyllus (W.) antarcticus sp. n. can be distinguished from its congeners by its small body size, the presence of two setae on the distal segment of the endopod of the first swimming leg, by the very small furcal rami, the extremely reduced endopods of second and third swimming legs, the reduced mandibular palp and maxillula, as well as by the size and armature of the fifth and sixth swimming legs in both sexes. Difficulties of the placement of the new species into a suitable genus show an insufficiency in the present family classification. In the future, a revision of the genus Wellsopsyllus is essential. With its presence in the western Weddell Sea and the Indian Ocean, the new species may have a wide distribution range. Furthermore, it is the first abyssal species of the genus Wellsopsyllus sampled outside of the Scotia Sea.     

Broadening the definition of the genus Thalassaphorura Bagnall, 1949 (Collembola,Onychiuridae) with a new aberrant species from China

A new species belonging to the tribe Thalassaphorurini, Thalassaphorura problematica sp. n., is described from Northeast China. The new species is closest to the large genus Thalassaphorura by its simple vesicles in PAO and its furcal rudiment, but it does not fit the definition of the genus by the absence of chaeta d0 on head, the number of chaetae in the distal whorl of tibiotarsi and the labium type. We discuss the relative weakness of these last characters at generic level, which lead us to assign the new species to Thalassaphorura instead of erecting a new genus. The diagnosis of Thalassaphorura is broadened accordingly.     

Eodiaptomus phuphanensis n. sp., a New Freshwater Copepod (Calanoida: Diaptomidae) from the Phu Phan National Park,Thailand

Eodiaptomus phuphanensis n. sp. is described from two localities in the Phu Phan National Park, northeast Thailand. The new species is the eighth member of the genus Eodiaptomus and the third species recorded from Thailand. It belongs to the lumholtzi‐group, and is most closely related to E. sanoamuangae Reddy and Dumont , 1998. The third endopodite‐segment of P2‐P4 in both sexes of E. phuphanensis n. sp. bears seven setae as in E. sanoamuangae, instead of six as in the remaining species of the genus. Nevertheless, the new species can be distinguished from the other congeners by the distinct shape of the endopodite of the male right P5 and the absence of hairs on lateral margins of the female caudal rami.