A new Stygonitocrella Petkovski (Copepoda: Harpacticoida) from a cave in Northern Mexico with comments on the taxonomy of the genus

The cave-dwelling harpacticoid copepod fauna of Mexico is still yet to be known. There are only a few records related to karstic caves, but most refer to epigean forms. The analysis of samples collected in a cave system in Northern Mexico yielded two female specimens of an unknown harpacticoid copepod species which is described herein. It was assigned to the genus Stygonitocrella Petkovski, 1976 mainly because of the presence of a single endopodal segment on legs 1–4; the new species, S. mexicana n. sp. differs from its congeners by a combination of characters related to the segmentation and armature of the swimming legs 1–4, the fifth leg of the female, and the strcture of the antennae. Based on the current limits of Stygonitocrella, two new subgenera are proposed to recognize different morphological patterns based on the presence or absence of an inner baseoendopodal lobe in the female fifth leg, a character not evaluated before. This lobe is absent in the new species and in other five species now contained in the subgenus Eustygonitocrella. A lobe is present in the new subgenus Fiersiella, also with six species. This is the second record of Stygonitocrella in North America, after S. (Fiersiella) sequoyahi Reid, Hunt & Stanley, 2003; it is the only North American cave-dwelling species of the genus. It is suggested that the influence of marine transgressions in Northern Mexico was related to the origin of the new species as part of a group of troglobitic forms originated from marine interstitial ancestors that colonized the freshwater caves. A key for the identification of all the known species of Stygonitocrellais also provided.     

Gauchergasilus,a new genus for Ergasilus euripedesi Montú, 1980, an abundant parasitic copepod from the Patos Lagoon in southern Brazil

Ergasilus euripedesi is redescribed from newly collected material of both sexes. A new genus, Gauchergasilus, is proposed, with Gauchergasilus euripedesi n. comb., formerly Ergasilus euripedsi Montú, 1980, as its type and only species. The new genus is characterised principally by the five-segmented antennule, the presence of a conspicuous barb on the concave margin of the claw of the antenna, the two-segmented endopod of leg 1 and the reduced fifth leg comprising two setae, one papillate. The male lacks the barb on the antennal claw but its other appendages are similar to those of the female, except for the maxilliped which is absent in females. The affinities of the new genus lie with the Acusicola group of genera.     

A new species of Acontiophorus Brady, 1880 (Copepoda: Siphonostomatoida) from Ushuaia,Argentina

A new species of Acontiophorus belonging to the family Asterocheridae was found in Ushuaia, Patagonia, southern Argentina. The new species is distinctive in having 9-segmented antennule, five setae on terminal endopodal segment of leg 1, seven elements on terminal segment of leg 1 and leg 4 exopods, and characteristic setation on maxillule lobes. This combination of characteristic features does not occur in any other species of the genus. The genus Acontiophorus is recorded for the first time from the South Atlantic.     

A new species ofXantharus Andronov, 1981 (Copepoda: Calanoida) from the mesopelagic zone of the Antarctic Ocean

Xantharus renatehaassae sp. nov. is described from a female taken at mesopelagic depth of the Antarctic Sound. This is the second species within the genus to be described and the first record ofXantharus in the southern hemisphere. A diagnosis of the genus is presented. Primarily, the structure of the maxillar aesthetascs showed thatXantharus belongs to the Scolecitrichidae, and not to the Phaennidae as was originally proposed. Its most outstanding generic feature relates to the structure of the distal segments of the short antennule with some plesiomorphic conditions retained by particular mouthparts.     

Exotic oniscideans (Crustacea: Isopoda) in coastal salt marshes: first record of the families Halophilosciidae and Platyarthridae in Continental Chile

We report two new exotic introduced isopods in Chile: Halophiloscia couchii of the family Halophilosciidae and Niambia capensis of the family Platyarthridae. This report provides first evidence of the presence of these species in the Southeastern Pacific. These species were found in several salt marshes and beaches spanning nearly 2000?km of the Chilean coast. With the data reported here, the percentage of exotic oniscidean isopods in Chile is 28%.     

Discovery of the genus Skidmorella Johnson (Coleoptera: Ptiliidae) in Japan, with descriptions of two new species

The genus Skidmorella Johnson, previously known only from the South Pacific islands, is discovered in Japan. The type species, Skidmorella magnifica Johnson, is confirmed from Japan as the first record of the species other than the type locality. In addition, two new species, Skidmorella amamiana sp. nov. and Skidmorella quadrisulucia sp. nov., are described from the Ryukyus, Japan. Phylogenetic relationships of the genus Skidmorella and its allies are discussed on the basis of their morphological characters.     

How many species of Diacyclops? New taxonomic characters and species richness in a freshwater cyclopid genus (Copepoda,Cyclopoida)

The genus Diacyclops Kiefer, 1927 emend. Morton (1985) includes more than 100 species, widely distributed in all kinds of freshwater environments, and is the richest genus in the family Cyclopidae. Traditionally, Diacyclops species were defined according to differences in a few morphological characters; some characters (number of antennulary segments, segmentation pattern of swimming legs) are useful only in the separation of species groups, others (length of caudal rami and caudal setae) are highly variable even within the same population. During the study of the D. languidoides-group, minute morphological characters were used to differentiate between species (spinulation pattern and setation of antennary basis, setation and aesthetasc shape of male antennule, setation of mandibulary palp and maxilliped, shape of leg 4 basis) which allow to identify several valid species up to now concealed under the name `Diacyclops languidoides' (Lilljeborg, 1901). The coexistence of up to six congeneric species in the same sampling area: (a) supports the validity of the proposed taxonomic characters, (b) demonstrates that species richness may be highly underestimated in freshwater cyclopoid assemblages in absence of good taxonomic practice; and (c) requires an ecological explanation of species coexistence. The role of morphologically based taxonomy in order to solve general problems of distributional ecology and theoretical biology is explored.     

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.     

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.     

Two morpho-types of Botryllophilus (Cyclopoida,Ascidicolidae)

In taxonomic studies (in preparation) of the genus Botryllophilus from the eastern and western coastal waters of the Pacific and from the northern Gulf of California, we have found that the females are morphologically divided into 2 types. The 2 morpho-types in our material, which includes 10 species, are characterized by features of the urosome including anal segment and caudal rami, rostrum, antennule, antenna, mandible, maxillule, maxilla, maxilliped, 1st to 5th legs, and the apparatus at the oviducal aperture. These characters are described and the significance of the recognition of the 2 morpho-types is discussed for the purpose of solving taxonomic problems in Botryllophilus.     

Munnogonium affinissp. n.: A New Species of Isopod (Asellota: Paramunnidae) from the Coast of Korea,Sea of Japan

The new species Munnogonium affinisfrom the coast of Korea (the Sea of Japan) is described. This is the first record of the genus Munnogoniumfrom the western Pacific. The new species differs considerably from the four eastern Pacific American species of this genus and is most similar to M. maltiniifrom the Mediterranean Sea.     

Mospicalanus schielae,a new genus and species of calanoid copepod (Crustacea: Spinocalanidae) from deep Antarctic water

A new genus and species,Mospicalanus schielae, collected at bathypelagic depth in the Antarctic Ocean, is described from female specimens and a stage V male. The new species is placed in the Spinecalanidae on account of the absence of fifth legs and leg 1 characteristics. It appears to be closely related toMimocalanus Farran. 1908, sharing apomorphic characters such as the lack of a rostrum, reductions of setal armament on the mouthparts, and absence of an outer spine on the first exopod segment of leg 1.Mospicalanus schielae can be distinguished from other spinocalanid genera by the setation of the antennary exopod, the maxillule, and the paecoxal endite of maxilla. Diagnostic characters of Spinocalanidae and Bathypontiidae are also discussed in order to clarify affiliation of genera tentatively assigned to the latter family. An updated key is given for the spinocalanid genera.     

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.     

A new species of Procolobomatus Castro Romero, 1994 (Copepoda: Philichthyidae) endoparasitic in a deepwater longtail red snapper (Actinopterygii: Lutjanidae) off Ishigaki Island, Japan, with records of philichthyid copepods reported from Asian waters

A new species of the Philichthyidae Vogt, 1877 (Copepoda: Poecilostomatoida), Procolobomatus hoi n. sp., is described based on adult female specimens recovered from the cephalic sensory canals of Etelis coruscans Valenciennes (Actinopterygii: Lutjanidae) caught off Ishigaki Island, the Ryukyu Islands, southern Japan. The new species differs from its congeners by having the following combination of characters: a long medial cephalic lobe about one-third the length of the body; an armature of five spines on the distal exopodal segment of leg 2; one long apical seta on the papillose leg 4; a caudal ramus armed with one medial and four terminal setae (two middle setae are inflated); and spinulose ornamentation covering the body. Procolobomatus hoi n. sp. is the first member of the genus reported from the western Pacific Ocean and from a host of the family Lutjanidae. Previous records of philichthyid copepods from Asian waters are also reported.     

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 species of pikeblenny (Blenniiformes: Chaenopsidae: Chaenopsis) from the tropical eastern Pacific and a key to all species

The genus Chaenopsis presently includes 10 species, four in the eastern Pacific and six in the western Atlantic. Five individuals of an undescribed species of this genus were obtained at Gorgona Island in the eastern Pacific of Colombia, in depths between 3 and 5 m. This new species differs from all the Eastern Pacific species in an array of traits including meristic, coloration and morphometric characters. Chaenopsis celeste new species differs from its only sympatric species, C. deltarrhis, in having fewer pectoral rays, fewer dorsal spines and more dorsal-fin soft rays and anal-fin elements. This new species is found over shallow sandy, rubble and small rocks bottoms from Costa Rica to Colombia.