Taxonomic studies on Danielssenia (Crustacea, Copepoda, Harpacticoida) with descriptions of two new species from Norway and Alaska

As a result of an examination of the original material of G. O. Sars and of new material from Björnehodebukta, Oslofjord, Danielssenia fusiformis (Brady) is synonymized with Danielssenia typica Boeck and the latter species redescribed. Two new species are described; D. quadriseta , from Oslofjord, is distinguished from all other known species by the presence of only 1 inner seta on the distal endopodite segment of swimming leg 3; Danielssenia reducta , from Alaska, is the only species in the genus with just 3 setae on the terminal endopodite segment of swimming leg 4. A new key to species of Danielssenia is also provided.     

A revision of Thompsonulidae Lang, 1944 (Gopepoda: Harpacticoida)

The harpacticoid copepod subfamily Thompsonulinae Lang, 1944, formerly recognized as belonging to the family Tachidiidae (Lang, 1948) is raised to family rank and redefined to include only the genera Thompsonula T. Scott and Caribbula gen. nov. Thompsonula hyaenae (I. C. Thompson) and T. curticauda (Wilson) are redescribed and refigured. Re-examination of the original material showed that Wilson's Rathbunula agilis is synonymous with T. curticauda and not with T. hyaenae , as suggested by Lang (1948). It is now clear that the two species of Thompsonula have distinct distributions, T. curticauda being confined to the North American continent and T. hyaenae to western Europe and the Mediterranean. The genus Caribbula is established to accommodate the type species, T. hyaenae elongata (Gee) and C. fleegeri sp. nov. which are described and figured. The genus Caribbula is distinguished from Thompsonua , primarily by the unique sexual dimorphism on the exopod of P4 and, at present, is known only from the eastern seaboard of the United States and Gulf of Mexico. The genera Danielssenia, Psammis, Paradanielssenia, Micropsammis and Leptotachidia are tentatively assigned to the family Paranannopidae Por.     

Two new species of harpacticoid copepod from the South Orkney Islands, Antarctica, and a redescription of Idyellopsis typica Lang (Tisbidae)

Two new species of harpacticoid copepod belonging to the families Ameiridae and Ancorabolidae are fully described and illustrated. Pseudameria signyensis sp. nov. is very similar to P. crassicomis Sars but is distinguished from it by the presence of an extra seta on the inner border of the terminal segment of the endopodite of the fourth swimming leg. Laophontodes macropodia sp. nov. is distinguishable from all other species in the genus by the setal formula of the first four swimming legs but more particularly by the unique shape of the fifth leg. Idyellopsis typica Lang is by far the most abundant harpacticoid inhabiting sublittoral fine sand in Borg Bay, Signy Island, Antarctica. The female of this species is redescribed and the male described and illustrated for the first time.     

A new species of Harpacticella Sars, 1908 (Copepoda,Harpacticoida), from a tidal pool on Jeju Island,Korea

A new species of the genus Harpacticella Sars, 1908 is described from a tidal pool on Jeju Island, Korea. Harpacticella jejuensis sp. n. is closely related to Harpacticella itoi Chang & Kim, 1991, with regard to the structure of P1 exp-1 and enp-1, the length of P1 exp-1 and exp-2, and the setal number of the P5 exopod in males. However, the new species is clearly distinguishable from Harpacticella itoi by the combined following characters: six setae on the P5 exopod in females, one naked seta on the inner margin of P1 exp-2, the short endopod of P1 compared to the exopod, and a naked long seta on the proximal inner margin of the P5 exopod of males. The mtCOI partial sequence is provided as a DNA barcode for the new species.     

First descriptions of copepodid stages, sexual dimorphism and intraspecific variability of Mesocletodes Sars, 1909 (Copepoda, Harpacticoida, Argestidae), including the description of a new species with broad abyssal distribution

Mesocletodes Sars, 1909a encompasses 37 species to date. Initial evidence on intraspecific variability and sexual dimorphism has been verified for 77 specimens of Mesocletodes elmari sp. n. from various deep-sea regions, and ontogenetic development has been traced for the first time. Apomorphies are a strong spinule-like pinna on the mx seta that is fused to the basis, P2-P4 exp3 proximal outer seta lost, P1-P4 enp2 extremely elongated, furcal rami elongated, female body of prickly appearance, female P2-P4 enp2 proximal inner seta lost. Intraspecific variability involves spinulation, ornamentation and size of the body and setation and spinulation of pereiopods. Sexually dimorphic modifications of adult females include prickly appearance of the body, P1 enp exceeds exp in length, P1 coxa externally broadened, seta of basis arising from prominent protrusion, hyaline frills of body somites ornate. Sexual dimorphism in adult males is expressed in smaller body size, haplocer A1, 2 inner setae on P2-P4 enp2 and on P5 exp, P5 basendopodal lobe with 2 setae. Some modifications allow sexing of copepodid stages. The female A1 is fully developed in CV, the male A1 undergoes extensive modifications at the last molt. P1-P4 are fully developed in CV. Mesocletodes faroerensis and Mesocletodes thielei lack apomorphies of Mesocletodes and are excluded.     

New species of the genus Scaphocalanus (Calanoida: Scolecithricidae) from the Iskenderun Bay – northeastern Levantine Basin

A new calanoid copepod species Scaphocalanus emine n. sp. is described for the first time from the Iskenderun Bay, northeastern Levantine Basin. S. emine is similar to S. affinis (Sars, 1905) having both identical orientation of the posterolateral corners of the cephalothorax and a median crest on the forehead. The new species is also similar in some features to S. affinis in the structure of Re1P1- lacking the outer marginal spine and by the presence of the rounded apex on the distal internal margin. It differs from S. affinis as the median crest on the forehead is smaller and due to the presence of a rudimentary endopod furnished with an apical spine on the P5. Originality in construction of the P1 and P5 distinguish the new species from other Scaphocalanus species.     

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.     

Contribution to the knowledge of the genus Phyllopodopsyllus T. Scott (Copepoda,Harpacticoida) from Africa with description of two new species

Two new species of marine, sand-dwelling harpacticoids are described: Phyllopodopsyllus pallaresae n. sp. from Namibia, and P. hartmannorum n. sp. from Tanzania. The hitherto unknown male of P. xenus (Kunz) is described from Namibia. Further remarks are made on P. furciger Sars from Tanzania.Zwei neue sandbewohnende Harpacticoiden-Arten werden beschrieben: Phyllopodosyllus pallaresae n. sp. von Namibia und Phyllopodopsyllus hartmannorum n. sp. von Tansania. Außerdem wird das bisher unbekannte Männchen von Phyllopodopsyllus xenus (Kunz) von Namibia beschrieben. Morphologische Merkmale von Phyllopodopsyllus furciger Sars werden anhand eines Fundes von Tansania ergänzt.     

A revision of the genus Halectinosoma (Harpacticoida: Ectinosomatidae): a reappraisal of H. sarsi (Boeck) and related species

Ectinosomatid material was examined from extensive collections around the British Isles and from several additional world localities and museum collections, permitting a revision of the genus Halectinosoma. This paper describes 12 morphologically similar species and erects five new species. H. sarsi (Boeck) is regarded as species incertae sedis, while H. sarsi sensu Sars (1904) is redescribed as H. pseudosarsi sp. nov.; H. sarsi sensu T. & A. Scott (1894) is synonymized with H. canaliculatum (Por). H. propinquum is regarded as a junior subjective synonym of H. chrystalli (T. Scott). H. clavatum (Sars) is resurrected, having previously been regarded as a synonym of H. brunneum (Brady). A key for the identification of females belonging to this group of species is provided.     

Redescription of Scapholeberis echinulata Sars 1903 (Crustacea,Cladocera)

Scapholeberis echinulata Sars is rediscribed, based on type material of Sars (S. echinulata), Daday (s. erinaceus) and the author's own samples. A differential diagnosis with Scapholeberis spinifera Nicolet and S. mucronata O. F. Müller, S. microcephala Sars, S. kingi Sars and S. aurita Fischer is given.     

Four new species of Desmosomatidae Sars, 1897 (Crustacea: Isopoda) from the deep sea of the Angola Basin

From a total of 104 species and 1741 individuals of Isopoda, the material from DIVA-1 (DIVersity of the Atlantic benthos) contained 364 specimens belonging to Desmosomatidae Sars, 1897. They are represented by 10 genera and 27 species. Most species (93%) are new to science. Four species are described in this study (Eugerdella theodori sp. nov., Desmosoma renatae sp. nov., Torwolia tinbiene sp. nov. and Momedossa longipedis sp. nov.). A discussion of the genera Desmosoma Sars, 1864, Momedossa Hessler, 1970 and Torwolia Hessler, 1970 is presented.     

A revision of the genus Monstrillopsis Sars (Crustacea: Copepoda: Monstrilloida) with description of a new species from Chile

In the course of a comparative analysis of the species included in the copepod genus Monstrillopsis Sars, a new species of the genus was discovered. The new species, Monstrillopsis chilensis n. sp., was found in a plankton sample collected in coastal waters off central Chile in the Southeastern Pacific. The adult female is similar to females of the type species M. dubia Scott and related forms but differs from its congeners by a combination of characters including: (1) a pair of small cephalic processes present between bases of antennules; (2) deep corrugations present on proximo-lateral surface of fifth pedigerous somite; (3) exopodal lobe of fifth leg not distally elongated; and (4) endopodal lobe of fifth legs short. This is the first record of the genus in the Southeastern Pacific and the second record of any monstrilloid in Chile. A comparative analysis of the species assigned to Monstrillopsis allowed a clarification of the generic characters and limits. The most important apomorphic characters in the genus are the presence of four caudal setae and modifications of the male antennule; other potentially useful characters are the pattern of antennule segmentation and the uniform presence of a reduced inner lobe of the fifth leg. The female of Monstrilla reticulata Davis should be retained in Monstrilla, but the purportedly conspecific male is probably a Monstrillopsis. Monstrillopsis ciqroi Suárez-Morales and M. angustipes Isaac should be transferred to Monstrilla. Haemocera filogranarum Malaquin is probably a species of Monstrillopsis. Monstrillopsis zernowi is tentatively retained in this genus as an aberrant form. A key for the identification of the species of this genus is included.     

A checklist of the littoral cladocerans from Mexico,with descriptions of five taxa recently recorded from the Neovolcanic Province

By 1996 an inventory of Mexican cladocerans hadrecorded 48 species of which 22 belonged toChydoridae, Macrothricidae and Ilyocryptidae.Unfortunately, most of the surveys were made beforeresearchers knew that these crustaceans are notentirely cosmopolitan. For this reason and the lack ofdeposited type material, many of these records aredoubtful and need detailed analyses. In this study,material from 18 water bodies located in theNeovolcanic Province of Mexico is analyzed andcompared with the literature. Also, males of Camptocercus dadayi Stingelin and Leydigialeydigi (Schoedler) and new records Eurycercus longirostris Hann and Biaperturaintermedia (Sars) are described. Half of thetotal number of species recorded are American endemicsand represents a mixture of the North and SouthAmerican fauna, suggesting that Mexico constitutes atransition between Nearctic and Neotropicalzones.     

A preliminary revision of sordidus-like species of Ilyocryptus Sars, 1862 (Anomopoda, Branchiopoda) in North America, with description of I. bernerae n. sp.

Presently the inter-generic structure of the Ilyocryptus Sars, 1862 is not clear, and we regard as `sordidus-like' all the species with (1) incomplete moulting, (2) valves without lateral horns or other remarkable structures, (3) non-distal position of anus on postabdomen, (4) long lateral setae on the postabdomen, which reaches the anus; (5) single or doubled teeth on preanal margin of postabdomen. Available material on sordidus-like forms of Ilyocryptus Sars, 1862 (Anomopoda, Branchiopoda) from North America was investigated. We also analyzed a limited amount of material similar to I. sordidus s. str., but not enough to be presented now. Three other conventional species were found and redescribed: the exclusively North American I. gouldeni Williams, 1978, as well as I. cuneatus?tifter, 1988 and I. spinosus?tifter, 1988, both described earlier from Europe. An original analysis of the differences between all species was performed. A new sordidus-like species, I. bernerae n. sp., from a single locality in South Carolina, U.S.A., is described. The main diagnostic features of this new species within sordidus-like members of the Ilyocryptusare: thin and sharp dorsal keel; exclusively single preanal teeth, greatly increasing in size in basal direction; lateral setae on postabdomen, not decreasing in size basad; absence of denticles on base of postabdomen; complete absence of any denticles on distal and middle portion of ventral margin of postabdominal claws; distalmost spine on claw base longer than basalmost; bases of antennules compressed against each other (although not touching); slightly different armature of two sides of lateral swimming setae; presence of small hooks on tips of lateral swimming setae; distal segments of setae on trunk of limb I setulated only in basal portion; sensillum on gnathobase II curved.     

Paradiaptomus peninsularis, P. hameri and P. warreni, three new species of Paradiaptomus (Calanoida: Diaptomidae) from South Africa

Three new species of Paradiaptomus from southern Africa are described, Paradiaptomus peninsularis, P. hameri and P. warreni. Paradiaptomus peninsularis occurs in temporary blackwater pools on the peninsula of the Western Cape province, P. hameri in saline pools in the Western Cape province and P. warreni in mountain tarns in the Drakensberg Range in Kwazulu Natal and Lesotho. The genus Paradiaptomus was first established by Sars (1895) for Paradiaptomus lamellatus. There are five described species of Paradiaptomus endemic to Africa ( lamellatus, schultzei, similis, natalensis and rex) and P. greeni from India and Sri Lanka. The three new species have highly-weighted morphological characters which set them apart from each other and from any of the described species of Paradiaptomus.