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 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 new Hesperodiaptomus Light (Copepoda, Calanoida, Diaptomidae) from Mexico with comments on the distribution of the genus

A new species of the freshwater planktonic copepod genus Hesperodiaptomusis described from material collected in several water bodiesin the state of Morelos, central Mexico. Hesperodiaptomus morelensisn. sp. differs from its congeners in having a very reduced endopodon the male fifth right leg, and a hook-shaped cuticular processon the inner margin of the first exopodal segment of the sameleg. Besides other characters of the female fifth legs, thenew species has a distinctive genital somite, with asymmetricallateral wing-like processes. This species seems to be closelyrelated to H. kiseri mainly because of similarities betweenthe male fifth legs and the structure of the female genitalsomite. This predominantly nearctic genus is known to be distributedmainly in north-western and central North America, althougha few species have been recorded in north-eastern Asia (Siberia).Hesperodiaptomus has not been recorded previously south of California.Apparently, this genus radiated in North America and spreadin different directions. The apparent disjunct distributionof at least two species (including the new one) could be explainedas resulting from a previous extensive radiation related toglaciation and consequent post-glacial repopulation that mighthave left these forms as stranded remnants, or by dispersalprocesses: central Mexico is connected with North America bytwo high-altitude potential passages. The new species seemsto be restricted to a high altitude area in Mexico. It seemsunlikely that species of Hesperodiaptomus will be recorded furthersouth on the American continent.     

A new species of Leptodiaptomus (Copepoda, Diaptomidae) from Northwestern Mexico with comments on the distribution of the genus

A new species of the freshwater planktonic copepod genus Leptodiaptomus is described for a small pond in Northwestern Mexico. Leptodiaptomus dodsoni n. sp. can be easily distinguished mainly by the presence of an unusually large sinusoid spine on male antennular segment 13, and by the features of the fifth legs of both sexes. This genus is known to be distributed mainly in North America with 19 recognized species. Of these, six ocur in Mexico, and the new species seems to be closely related to most of them. It is probable that this group of species (including the new one) represents the southwards radiation of the genus from North America. Compared to the Caribbean and South American, the North American influence seems to be the most relevant for diaptomid copepods in Mexico. At least two Mexican species of Leptodiaptomus, including L.dodsoni, are restricted in distributional range to high-altitude temporal ponds, and both could be considered endemics.      

A new pelagic <Emphasis Type="Italic">Alteutha</Emphasis> (Copepoda: Harpacticoida) from Potter Cove,King George Island,Antarctica—description,ecology and information on its year round distribution

A new harpacticoid copepod species was found during a year round plankton survey in a shallow Antarctic bay. Both the dominant Calanoida and Cyclopoida and the often neglected Harpacticoida, their abundances in relation to sea-ice formation and decline in presence of Euphausia superba are regarded, in this study. Alteutha potter sp. n. (Peltidiidae) was collected in Potter Cove, King George Island, Antarctica. While its geographical region occurrence and planktonic life style are comparable to many of its congeners, morphological characters such as shape and setation of the maxilliped and the almost complete fusion of the baseoendopod and the exopod of the fifth leg in the female are described for the first time for this genus. Morphological peculiarities such as the lack, the deformation or fusion of setae on only one body side have been detected in several specimens. This copepod species is obviously sea-ice related. Its abundances in the plankton reached a maximum under the winter sea-ice. The year round population structure did not show very high variability whereas ovigerous females mostly occurred in spring and summer. Assuming different possible ecological strategies and environmental temperatures generation times between 46 and 77 days are calculated for A. potter sp. n. Handling editor: K. Martens     

Morphological characterization of new populations of the copepod Eurytemora velox (Lilljeborg, 1853) (Calanoida,Temoridae) found in Austria and Hungary

The calanoid copepod Eurytemora velox (Lilljeborg, 1853) was found in the backwater system of the Danube River upstream of Vienna (km 1948) in 1994. Since that time, the species has invaded the side arms of the river between kms 1897 and 1988, as confirmed by findings from 10 different localities. In Hungary, the species has been known since 1992. In the present article, we report 15 new sites in the westernmost part of this country.A brief diagnosis of the morphology of male and female of the Austrian specimens is presented, including detailed illustrations of the structures used in this paper for taxonomic analysis. Females show morphological variability mainly on the structure of the fifth leg pair. Right and left legs frequently have a different spinulation pattern. Males show less morphological variability, particularly in the structure of the basis and the distal section of exopod 2 of the fifth left leg. Morphological variation within E. veloxwas determined by comparing specimens from Austria, Hungary and Rumania. The geographic distribution of the species in the Palearctic region, Austria and Hungary is presented.     

Gladioferens Henry (Copepoda: Calanoida) discovered in Antarctica: G. antarcticus sp. nov. described from a lake in the Bunger Hills

A new species of Gladioferens is described from a freshwater lake in the Bunger Hills, Greater Antarctica. A key to the six species of Gladioferens is provided for both sexes. Most species of the subgenus containing G. antarcticus sp. nov. are remarkable in possessing asymmetries in the second legs (male) and fourth legs (female). This suggests that the mating behaviour of these species may be radically different from that in most heterarthrandrian calanoids and calls for further study. However, G. antarcticus is more primitive than its consubgeners in having, in the male, symmetrical second legs and 3-segmented endopods in the fifth legs. The genus shows a highly disjunct distribution (Australia, New Zealand and Bunger Hills) and its biogeography is now of outstanding interest.     

Badijella jalzici - a new genus and species of calanoid copepod (Calanoida, Ridgewayiidae) from an anchialine cave on the Croatian Adriatic coast

A new genus and species of calanoid copepod belonging to the family of Ridgewayiidae is described from an anchialine cave on the small island of Badija, Croatia. In the new species Badijella jalzici, body length varies from 720-870 µm in both sexes. The prosome is 6-segmented, the female urosome is 4-segmented and 5-segmented in the male. The antennules are symmetrical and 26-segmented in the female, and 23-segmented on right side in the male, with two areas of geniculation. The caudal rami are symmetrical and longer than wide. The mouthparts and swimming legs 1-4 are identical in both sexes. The female fifth leg is biramous and symmetrical; the male fifth legs are strongly developed, asymmetrical, biramous on both sides, endopods 2-segmented and exopods 2-segmented and complex in structure.     

Copepoda associated with the coral Gardineroseris planulata (Dana) on the Great Barrier Reef,northeastern Australia

Three new lichomolgid copepods associated with the scleractinian Gardineroseris planulata (Dana) are described: Sociellus torus, n. gen., n. sp., characterized by a 2-segmented endopod in leg 3 and the lack of an inner seta on the first segment of the endopod in legs 1–3; Odontomolgus pumilus, n. sp., of very small size and having a much elongated free segment in leg 5 of the female; and Paramolgus ampullaceus, n. sp., distinguished by the bottle-shaped genital segment of the female. In addition, the harpacticoid Alteuthellopsis corallina Humes, 1981, is reported from this coral. With the inclusion of 3 species of the poecilostomatoid genus Xarifia already described (Humes, 1985) there are now 7 species of copepods known to be associated with Gardineroseris planulata on the Great Barrier Reef.     

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.     

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.     

Three new species of <Emphasis Type="Italic">Hatschekia</Emphasis> Poche, 1902 (Copepoda: Siphonostomatoida: Hatschekiidae) parasitic on <Emphasis Type="Italic">Abalistes filamentosus</Emphasis> (Pisces: Tetraodontiformes: Balistidae) from off Okinawa,Japan

Three new species of the copepod genus Hatschekia Poche, 1902, H. lima n. sp., H. cylindrus n. sp. and H. sunaoi n. sp., are described from the gill filaments of a triggerfish, Abalistes filamentosus Matsuura & Yoshino, caught off the Ryukyu Islands, Okinawa, Japan. These new species share an unusual morphological character, i.e. four stout posterior spines on the intercoxal sclerites of legs 1 and 2. H. lima n. sp. differs from its congeners in having a robust inner lobe on the maxillule and leg 3 with a swollen basal lobe. H. cylindrus n. sp. is distinguishable from its congeners by having a cephalothorax fused to the trunk and a double-semicircular chitinous frame. H. sunaoi n. sp. is characterised by leg 3 with a swollen basal lobe and an oval cephalothorax.     

Boeckella diamantina n.sp. (Calanoida,Centropagidae), from a high Andean lake in Mendoza,Argentina

A new species of Boeckella from limnetic samples of Laguna del Diamante, a high lake in the Andes (34°10 S) is described and illustrated. The species is defined by the characters of the male fifth leg: the right two segmented endopod bears four peculiar, short, claw-like spines, the left endopod is a simple finger-like projection. This species is related to B. gibbosa, also a species from the Andes and B. vallentini from Malvinas (Falkland Islands) and other subantarctic islands. It is distinguished from them by diagnostic features of the fifth legs of the male and abdominal structure and fifth legs of the female. Some current views on the features used in the taxonomy of the genus Boeckella are discussed.     

A new genus and species of hatschekiid copepod (Siphonostomatoida) from groupers (Actinopterygii: Serranidae) collected off the Ryukyu Archipelago, Japan

A new genus and species of copepod, Mihbaicola sakamakii n. g., n. sp., belonging to the siphonostomatoid family Hatschekiidae, is described based on the females collected from inside the tissue of the branchiostegal membrane in three species of the groupers, Epinephelus fasciatus (Forsskål) (type-host), E. merra Bloch and Cephalopholis leopardus (Lacépède), collected off Okinawa-jima Island and Iriomote-jima Island, Ryukyu Archipelago, North Pacific Ocean. The new genus can be distinguished from other hatschekiid genera by a combination of the following characters in the female: the head is composed of the cephalosome and the pedigerous somite; the cephalothorax is expanded into a pair of posteroventral lobes carrying leg 1; legs 1 and 2 are biramous and composed of the protopod and both rami are 2-segmented; leg 3 is absent; and leg 4 is represented by a rounded lobe with a chitinous pointed apical process.     

Belizia brevicauda,a new genus and species of caligid copepod from the western Caribbean Sea

A new genus and species of parasitic copepod collected from the fishes Calamus pennatula and Clepticus parrae from off Belize, Central America is described. The new genus is characterized by a very reduced sternal furca, a pair of sclerotized knobs between the interpodal plates of the first and second legs, and endopod of third leg with 4 setae.     

Ryocalanus spinifrons,a new species of Ryocalanidae (Copepoda: Calanoida), from the southwestern part of Sagami Bay,Japan

A new Ryocalanoid copepod, Ryocalanus spinifrons, collected by the MTD net system at a depth of 1400 m from the southwestern part of Sagami Bay, Japan, is described. The new species is morphologically very close to R. infelix Tanaka, 1956 (female unknown) from the Izu region of Sagami Bay. It is distinguished from other species by the presence of 12 long spinules on the ventral inner side of the fifth pedigerous somite, nine setae on the coxal epipodite of the maxillule and nine large robust spinules on the coxal segment of the fourth leg. The row of five robust spines on the paragnath distinguishes R. spinifrons.     

A new poecilostomatoid copepod (Erebonasteridae) from deep-sea cold seeps at the West Florida Escarpment

A new species of poecilostomatoid copepod, Erebonaster spinulosus (Erebonasteridae), is described on the basis of a single female from a depth of 3 266 m at cold seeps near the base of the West Florida Escarpment in the eastern Gulf of Mexico. Among its distinctive features are: the large body highly ornamented with setules and spinules, the rostrum with small median teeth and lateral setules, the claw of the second maxilla with a prominent knob on the concave margin, the maxilliped ornamented with setules and its claw bearing a digitiform process near the seta, the third segment of the exopod of leg 4 with the formula II,I,4, and the highly ornamented leg 5 having on the free segment a very long seta 9 times the length of the segment.The genus Erebonaster now contains two species, the previously described Erebonaster protentipes found in 2000 m at the Guaymas Basin, Gulf of California, and the new Erebonaster spinulosus.     

A new species of Peltidium Philippi, 1839 (Crustacea,Copepoda, Harpacticoida) from the Pacific coast of Mexico

During the analysis of phytal meiobenthic samples collected from a rocky-sandy beach in the state of Nayarit, in the Mexican Pacific, several specimens of harpacticoid copepods were obtained and taxonomically examined. These specimens were found to represent an undescribed species of the peltidiid genus Peltidium Philippi, 1839. The new species, Peltidium nayarit sp. n. is described herein. It resembles Peltidium nichollsi Geddes and Peltidium lerneri Geddes from Bahamas but also the widespread Peltidium speciosum Thompson & Scott and Peltidium purpureum Philippi. The new species from the Mexican Pacific differs from its known congeners by its possession of a unique combination of characters, including a modified pectinate seta on the antennary exopod, three terminal setae on the second endopodal segment of leg 1, third exopodal segment of leg 1 with three elements, inner terminal claw twice as long as outer claw, female fifth leg with 5 exopodal setae, exopodal setae I-III stout, spinulose and seta IV being as long as seta V. This is the second species of the family known to be distributed in the Eastern Tropical Pacific and in Mexico. Pending additional data, the distribution of this species appears to be restricted to this area of the Mexican Pacific.     

Labidocera boxshalli sp. nov., a new calanoid copepod (Crustacea; Pontellidae) from the Red Sea

A pontellid copepod, Labidocera boxshalli sp. nov., is described from the Egyptian coast of the northern Red Sea. This species is most readily distinguished from its congeners by the presence of a mid-dorsal process on the female genital double somite, the female fifth leg exopod terminating in two superimposed processes (the ventral of which is shorter), and by the elongated first exopodal segment of the male right fifth leg carrying a stout, blunt-tipped process and a small papilla laterally near the base of the thumb that bears one seta. The new species belongs to the L. detruncata species group, which is distributed mainly in the tropical/subtropical waters of the Indo-West Pacific.