Third Exopodal Segment Of Leg Research Articles

Two new genera and four new species of Asterocheridae (Copepoda: Siphonostomatoida) associated with sponges (Porifera) from the Korean East Sea.

Two new genera and four new species of siphonostomatoid copepods of the family Asterocheridae associated with sponges are described from the Korean East Sea (Sea of Japan). These new copepods are distinguishable from related genera and species by their diagnostic morphological characters as follows: Amalomyzon elongatum n. gen. n. sp. bears an elongated body, two-segmented rami of legs 2, a uniramous leg 3 with two-segmented exopod, and a rudimentary leg 4 represented by a lobe. Dokdocheres rotundus n. gen. n. sp. has an 18-segmented female antennule, a two-segmented endopod of antenna, and unusual setations of swimming legs, including three spines plus four setae on the third exopodal segment of legs 2-4. Asterocheres banderaae n. sp. has no inner coxal seta on leg 1 or 4, but has two strong, sexually dimorphic inner spines on the second endopodal segment of male leg 3. Scottocheres nesobius n. sp. bears elongate female caudal rami about six times longer than wide, a 17-segmented female antennule, and two spines plus four setae on the third exopodal segment of leg 1.

A Redescription of Lepeophtheirus longipes Wilson, 1905 (Copepoda; Caligidae) Parasitic on Giant Sea Bass, Stereolepis gigas Ayres, 1859 (Polyprionidae), off California

The giant sea bass (GSB), Stereolepis gigas Ayres, 1859, is the largest teleost (exceeding 2 m in length and 200 kg in weight) and megacarnivore found in California kelp forest communities. Overfishing of GSB in the late 1920s crashed the population off California and in 1996 it was classified as an International Union for Conservation of Nature (IUCN) critically endangered species. Recently, three GSB were collected off San Onofre, California and held at the Southern California Marine Institute in San Pedro. Two of the three GSB were infected with Lepeophtheirus longipes Wilson, 1905 (Siphonostomatoida; Caligidae), a poorly described species of parasitic copepod previously recorded from the GSB and purportedly on other fish hosts. In this study, a detailed redescription of the female and the first description of the male of L. longipes are provided and all records of Lepeophtheirus longipes are reviewed. The latter revealed that L. longipes is host specific to GSB. Lepeophtheirus longipes is distinguished from its congeners by a combination of female characters that includes: (1) genital complex with prominent posterolateral lobes and is about half the length of the cephalothorax and just over two times longer than the cylindrical, indistinctly 2-segmented abdomen; (2) an antennule with a small conical process on the proximal segment; (3) maxillule with an outer conical process at the base of the dentiform process; (4) sternal furca with pointed and slightly splayed tines; (5) first exopodal segment of leg 3 with a terminal spine; and (6) third exopodal segment of leg 4 with three unequal apical spines.

A new species of Stygiopontius (Copepoda, Siphonostomatoida, Dirivultidae) from a deep-sea cold seep in the South China Sea

Abstract A new species of the copepod genus Stygiopontius is described based on samples from a cold seep in northeastern South China Sea southwest to Taiwan, which were collected by the ROV Faxian with its mother vessel R/V Kexue in September 2017. The copepods were obtained by washing Shinkaia crosnieri Baba & Williams, 1998 (Decapoda: Munidopsidae) caught at a depth of 1124 m. The new species can be distinguished from its congeners by the combination of the following characteristics: caudal rami about 3.5 times as long as wide; basis of maxilliped with plumose seta, endopodal claw of maxilliped stout, with a row of fine spinules on inner margin; coxa of leg 1 with one inner seta; basis of leg 1 with stout spine exceeding to end of first endopodal segment; second endopodal segment of female leg 4 with pointed process; third exopodal segment of leg 4 with three outer spines. This is the first record of a Stygiopontius species from a cold seep.

Pseudanuretes anfoozi n. sp. (Copepoda: Siphonostomatoida: Caligidae) from the yellowbar angelfish Pomacanthus maculosus (Forsskål) in coral reefs off Iraq.

A new species of Pseudanuretes Yamaguti, 1936 (Copepoda: Caligidae) parasitic on the gills of the yellowbar angelfish Pomacanthus maculosus (Forsskål) from a coral reef off Iraq, north-western Arabian Gulf, is described. Pseudanuretes anfoozi n. sp. belongs within a group of species characterised by the spear-like structure of leg 4. Morphologically P. anfoozi n. sp. is similar to P. papernai Kabata & Deets, 1988 in possessing an armature of I,6 on the third exopodal segment of leg 2 rather than I,7 in the other species of this group. However, P. anfoozi n. sp. can be distinguished from P. papernai by the possession of only 5 caudal setae instead of 6, and in the shape of the caudal rami, which are shorter and wider in new species. In addition, these two species differ in the shape of the genital complex of the adult female.

Two new species of Cryptopontius Giesbrecht, 1899 (Copepoda, Siphonostomatoida, Artotrogidae) associated with invertebrates from Northeastern Brazil.

Cryptopontius is the most species-rich genus in the family Artotrogidae with 25 species, being recorded in almost all oceans, except in the Arctic. However only three species of this genus have been recorded from the Brazilian coast, all of them along the coast of Pernambuco state. This study describes two new species of the genus. Cryptopontius phyllogorgius sp. nov. differs from other species by having 9-segmented antennule, and nine elements on the third exopodal segment of leg 4. Cryptopontius pentadikos sp. nov. differs from its congeners by having five expressed antennulary segments proximal to fused ancestral IX-XII, two setae on second endopodal segment of leg 1, eight elements on third exopodal segment of leg 1 and the free segment of leg 5 with two setae. A key to species of the genus Cryptopontius is provided.

A New Species of Rhinergasilus Boeger et Thatcher, 1988 (Copepoda: Ergasilidae) from Gills of Astyanax fasciatus (Cuvier, 1819) (Actinopterygii: Characidae)

To describe a new species of a parasitic copepod, Rhinergasilus digitus n. sp. (Cyclopoida, Ergasilidae), collected from the gills of the red-tailed lambari Astyanax fasciatus (Characiformes, Characidae) in two tributaries of the Jurumirim Reservoir (Upper Paranapanema River), São Paulo State, Brazil: Ribeirão dos Veados and Paranapanema River. Fish were collected using multi-panel gills nets. The gill of each fish was washed and examined in a stereo microscope for copepods. The copepods found were stored in 70% ethanol, cleared in lactic acid, and mounted in Hoyer's medium. Drawings were made with the aid of a Leica microscope DMLS equipped with a drawing tube. The new species differs from its congeneric species, Rhinergasilus piranhus (type-species), in having comparatively biggest body size (body length: 535-598µm in the new species vs. 237-282µm in R. piranhus); second antennary segment armed with a minute sensillum near middle of inner margin and a row of spinules on outer margin; third exopodal segment of leg 1 with digitiform process; interpodal plates two and three both ornamented with spinules along posterior margin; leg 5 reduced and represented by two unequal setae. Based on the morphological differences described above, we erected a new species of Rhinergasilus. Rhinergasilus digitus n. sp. is the second ergasilid described from A. fasciatus, as well as it represents the first report of this genus in a characid fish.

Two new species of Siphonostomatoida (Copepoda) found on cnidarians in Tokara Islands, Southern Japan

ABSTRACTTwo new species of siphonostomatoid copepods are described based on specimens collected off Tokara Islands located in the northern part of the Ryukyu Islands, Southern Japan. Cholomyzon multisetum sp. nov. (Coralliomyzontidae) found from the orange cup coral Tubastraea coccinea Lesson, 1829 (Hexacorallia: Scleractinia: Dendrophylliidae) has the following characters: armature formula of the antennule of the female; the outer lobe of the maxillule; and numbers of elements on the legs 1 to 3. Another species, Entomopsyllus takara sp. nov. (Entomolepididae), was found from both the Indo-Pacific blue coral Heliopora coerulea (Pallas, 1766) (Octocorallia: Helioporacea: Helioporidae) and the race coral Distichopora violacea (Pallas, 1766) (Hydrozoa: Anthoathecata: Stylasteridae). This new species of the male specimen is characterized by the antennule with shortest sixth segment, the endopod of leg 2 bearing two inner setae on the second segment and five setae on the third segment, the third exopodal and endopodal segments of leg 3 bearing three spines and three setae, respectively, and the third exopodal segment of leg 4 bearing four setae. These two species represented the first records of the families Coralliomyzontidae and Entomolepididae from Japanese waters.http://www.zoobank.org/urn:lsid:zoobank.org:pub:7C8DED0A-9CEB-405D-9BBF-FAF2043B0858

A new Setacheres (Copepoda, Siphonostomatoida, Asterocheridae) associated with Ircinia felix (Duchassaing & Michelotti) (Porifera) from Brazil.

Recent surveys of the copepod fauna associated with the sponge Ircinia felix (Porifera, Dictyoceratida) in Brazil resulted in the discovery of a new siphonostomatoid species belonging to a recently erected genus of Asterocheridae. Setacheres portobarrensis sp. nov. possesses a 21-segmented antennule, with 3 free distal segments, after the aesthetasc. The third exopodal segment of leg 3 shows a distal seta instead of a spine as in some other congeners. The new species shows several unique features on the third endopodal segment of the antenna, the mandibular stylet, the inner lobe of the maxillule, and setules and spinules located in specific regions of legs 1 to 4. Setacheres portobarrensis sp. nov. follows the same distributional pattern as its congeners, and this is the first record of a siphonostomatoid copepod associated with Ircinia felix.

A New Species of Hyperbenthic Cyclopoid Copepod from Japan: First Record of the Genus Cyclopicina in the Indo-Pacific Region.

A new species of the cyclopinid genus Cyclopicina, C. toyoshioae sp. nov., was collected from the hyperbenthic layer off northern Kyushu Island, Japan; its description is based on two adult female specimens. This is the first record of the genus from the Indo-Pacific region. The new species can be distinguished from its two known congeners in: (1) the relatively short antennules which do not reach the posterior margin of the dorsal cephalothoracic shield; (2) the shape of seminal receptacles; (3) the segmentation and armature of the cephalothoracic appendages; (4) the shape of the basal protrusion between the rami of legs 1-4; (5) the presence of three outer spines on the third exopodal segment of leg 4; and (6) the presence or absence of outer setae on the free exopodal segment of leg 5. The genus Cyclopicina shows a wide but scattered distribution in hyperbenthic layers, from the continental shelves to deep-sea basins, in the northern hemisphere.

A new species of Caligus Müller, 1785 (Copepoda: Siphonostomatoida: Caligidae) from coral reef plankton in the Mexican Caribbean.

During a survey of the zooplankton community of a protected reef system on the southern coast of the Mexican Caribbean, many female and male specimens of an undescribed species of Caligus Müller, 1785 were collected. The new species closely resembles C. wilsoni Delamare Deboutteville & Nunez-Ruivo, 1958 and C. belones (Krøyer, 1863) and has affinities with C. balistae Steenstrup & Lütken, 1861 and C. longipedis Bassett-Smith, 1898, all known from the Caribbean Sea and adjacent waters of the north-western Atlantic Ocean. Caligus ilhoikimi sp. nov., is described in full and illustrations of both sexes are also provided. The new species differs from C. wilsoni and C. belones in several features, including the shape of the sternal furca, the shape and proportions of the genital complex and abdomen, the lack of accessory processes on the distal elements of leg 1 exopod, and the presence of a lateral spine on the third exopodal segment of leg 2. This is the seventh species of Caligus known from waters of the Atlantic seaboard of Mexico and the 32nd species of the genus recorded in Mexican waters. The specimens were caught with a plankton light trap. The unusually high number of individuals captured and the fact that the sample was monospecific (i.e. only adults of this caligid species were collected) suggests that it is a chiefly planktonic form. This is a mode of life recently revealed as being more common among caligids than previously thought.

A new species of Monocheres Stock (Copepoda, Siphonostomatoida, Asterocheridae) from shallow waters off Florida, USA: an unexpected discovery.

The rare asterocherid copepod genus Monocheres, ectosymbionts of corals and sponges, contains only two species, one from Mauritius (Indian Ocean) and the other one from Brazil (western Atlantic). From the analysis of the digestive caecum contents of the benthic hesionid polychaete Hesione picta Müller, 1858, an adult female of an undescribed species of Monocheres was unexpectedly recovered; it is the third species of this rare asterocherid genus. The new species, Monocheres sergioi sp. n., has the distinctive reduction of the fifth leg as a process with a single seta. It differs from its two other congeners by several characters including the presence of an inner basipodal spine, the armature details of the third exopodal segment of leg 1, the shape of the cephalosome and pedigerous somites 3 and 4, and the ornamentation of the postero-lateral corners of the genital double-somite. The main synapomorphies include the presence of spinules along the posterior margin of the first leg coxal sclerite and the reduced, spiniform coxal seta on leg 4. The biology and feeding habits of the polychaete containing this specimen suggests that the copepod was ingested as an ectosymbiont from sponges or coral but it is also possible that it was consumed from an ophiurid echinoderm. This finding allows an expansion of the genus geographical distribution in the northwestern Atlantic. A key to the species of Monocheres is also provided.

Two New Species of Clausidiidae (Copepoda, Poecilostomatoida) from Korea

Two new species of Clausidiidae, each belonging to the genera Clausidium Kossmann, 1875 and Hippomolgus G. O. Sars, 1917, are described from Korea. Clausidium maximus n. sp. is an associate of a burrowing decapod of the genus Callianassa living on the Korean coast of the Yellow Sea and has, as diagnostic characters, two inner setae on the second endopodal segment of legs 2-4, nine elements on the third exopodal segment of leg 4, an inner seta on the second exopodal segment of male leg 1, and a relatively large body size, exceeding 2.0 mm in the female. Hippomolgus limiticus n. sp. was found in the bottom sediments in the East China Sea. It is similar to H. furcifer G. O. Sars, but distinghuishable from the latter species by having shorter caudal rami, 4-segmented female maxilliped, and inner coxal spine (instead of seta) on legs 2 and 3. This is the first record on the genera Clausidium and Hippomolgus in the West Pacific.

Anthessius antarcticus n. sp. (Copepoda: Poecilostomatoida: Anthessiidae) from Antarctic waters living in association with Charcotia granulosa (Mollusca: Nudibranchia: Charcotiidae)

A new species of the genus Anthessius Della Valle, 1880 is described under the name A. antarcticus. It is ectosymbiont of the nudibranch Charcotia granulosa Vayssiere, 1906 from the South Shetland Islands in the Southern Ocean. The female of the new species is distinguished from its congeners by the following combination of diagnostic morphological characters: 1) antenna with two terminal claws; 2) mandible with a seta between distal and outer lashes; 3) third exopodal segment of leg 4 with four spines and five setae (formula: III, I, 5); and 4) caudal ramus 2.40 times as long as wide. Its relationship with its congeners and other anthessiid genera are discussed. This is the first species of the genus found to be related to a nudibranch, and remarkably, it is also the only record of Anthessiidae from Antarctica.

Three artotrogids (Crustacea: Copepoda: Siphonostomatoida) from the Ross Sea, Antarctica

The Artotrogidae, one of the most primitive of siphonostomatoid families, consists currently of 117 species in 21 genera. Most of these species (65%) are poorly or incompletely described since they have been rarely recorded in recent decades and, when encountered, have been found in very low numbers. During the 19th Italian Antarctic Expedition, with the RV Italica, to the Ross Sea in austral summer 2004, some artotrogid copepods were collected. This paper redescribes two species of artotrogid copepods, which are known only from the Southern Ocean, Neobradypontius neglectus and Cryptopontiuslatus, and describes for the first time a male of the genus Neobradypontius. Furthermore, a new species is described and added to Sestropontius, increasing the number of known species of this genus to three. The main discrepancies between the original descriptions and the specimens of the two species collected from the Ross Sea redescribed here were on the armature of the antennary exopod and leg 5. The new species, Sestropontius italicae, shares with its most similar congener, S. mckinnoni, the armature of the third endopodal segment of leg 1 and leg 2 and that of the third exopodal segment of leg 4. However, the segmentation of the antennae and the armature on the antennary exopod are different.Keywords: Antarctica; Artotrogidae; redescription; Neobradypontius; Sestropontius; CryptopontiusTo access larger versions of Figs. 2–12 please see the supplementary file in the column to the right (under Article Tools)(Published: 8 December 2014)Citation: Polar Research 2014, 33, 24135, http://dx.doi.org/10.3402/polar.v33.24135

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.

New species ofStygiopontius(Copepoda: Siphonostomatoida: Dirivultidae) from a deep-sea hydrothermal volcano in the New Ireland Fore-Arc system (Papua New Guinea)

A male of the new speciesStygiopontius senckenbergibelonging to the family Dirivultidae Humes & Dojiri, 1980 (Copepoda: Siphonostomatoida) and endemic to deep-sea hydrothermal vents, is described from a raised fault block structure south of Edison seamount of the New Ireland Fore-Arc system (Papua New Guinea). The copepods were collected in by box-corer during cruise SO-133 of the RV ‘Sonne’ at a depth of 1610–1625 m, 3°19′S 152°35′E. The new species belongs to a group of eight species that are separate from 21 congeners on the basis of setation of legs 1 and 4: the coxa of leg 1 has an inner seta (absent on the others) and the third exopodal segment of leg 4 has three outer spines (instead of two spines). The new species shares withS. pectinatusHumes, 1987 a pectinate maxilliped but differs from it in lacking two pectinate, terminal claw-like setae on the endopod of the antenna.

A new species of Taeniacanthus (Copepoda: Taeniacanthidae) parasitic on two pufferfish species, Marilyna meraukensis and M. darwinii (Teleostei: Tetraodontidae), from Australia

A new species of Taeniacanthidae (Copepoda, Cyclopoida), Taeniacanthus kiemae sp. n., is described based on adult female and male specimens collected from the branchial cavity wall of Marilyna meraukensis (de Beaufort) and M. darwinii (Castelnau) (Teleostei, Tetraodontidae) caught in Australian waters. The new species differs from its congeners by having the following combination of characters in the adult female: (1) maxilla armed with a stout terminal process and two small elements; (2) multiple rows of spinules on the large pectinate process of the antenna; (3) an extremely long and thin maxilliped claw; (4) second exopodal segment of leg 1 with eight setae; (5) third exopodal segment of leg 3 with three spines and four setae; (6) third exopodal segment of leg 4 with three spines and two setae; and (7) each spine on the free exopodal segment of leg 5 with a subterminal flagellum. Taeniacanthus kiemae is the second copepod species reported from M. meraukensis and M. darwinii and the first taeniacanthid species reported from pufferfishes in Australia.

Five new species of lichomolgid copepods associated with ascidians from Korea, with proposal of two new genera (Crustacea, Copepoda, Lichomolgidae)

Five new species of the family Lichomolgidae associated with solitary ascidians are described from the east coast of Korea. Two new genera are proposed: Protomolgus n. gen. to incorpotate Protomolgus duplex n. sp. and P. singularis n. sp., and Dontimolgus n. gen. to incorporate Dontimolgus brevicaudatus n. sp. Protomolgus n. gen. characteristically has a four-segmented female maxilliped and a bipartite mandible. Dontimolgus n. gen. possesses a large, tooth-like process on the first maxillary segment and three spines on the third exopodal segment of leg 3. Other two new species described are Lichomolgus infirmus n. sp. and L. pectinatus n. sp.

A new species of Tigriopus (Copepoda, Harpacticoida, Harpacticidae) from Thailand with the description of its naupliar development

Both genders of Tigriopus thailandensis sp. nov. are described from a laboratory stock raised from individuals collected from the seaweed Enteromorpha clathrata in Thailand (Bangsaen Beach, Chonburi Province). Tigriopus thailandensis sp. nov. shares with its closest relative T. japonicus Mori, 1932 two setae on the third exopodal segment of leg 4 while other congeners bear 3 inner setae. However, allobasis and exopod of antenna in both genders are much more slender and elongate than in T. japonicus. All six naupliar stages of T. thailandensis are described from the offspring of isolated females. In comparison with nauplii of T. japonicus, T. thailandensis nauplii are characterized by the following: a smaller body size throughout the naupliar phase; first antennular segment without seta, second antennular segment with only one small seta plus two longer setae; third antennular segment with additional spinules from naupliar stage II onwards; antenna bears three small spinules on the terminal exopodal segment; one additional seta on the anterior surface of the antennary basis, tubular endopod of antenna with one tiny seta midlength at naupliar stage III that increases in size; mandibular basis with several spinules on anterior surface; mandibular coxa with one spinulose seta that is smooth in T. japonicus.

A new genus and species of Brychiopontiidae Humes, 1974 (Crustacea: Copepoda:Siphonostomatoida) associated with an abyssal holothurian in the NortheastPacific nodule province

A new genus and species Neobrychiopontius galeronae gen. nov. sp. nov. is described based on female specimens from the Pacific nodule province associated with the abyssal holothurian Oneirophanta cfr. setigera (Ludwig, 1894) (Elasipodida, Deimatidae). The holothurian and copepods were collected at a depth of 4978 m during the cruise “Nodinaut” (Ifremer, 17 May – 28 June 2004) on RV Atalante using a spade corer operated from the submersible Nautile. The new genus has retained a greater number of plesiomorphic characters, when compared to its closest relative the monotypic genus Brychiopontius Humes, 1974 from the abyssal zone of the North Atlantic: proximal 3 segments of antennule articulates (fused in Brychiopontius), well developed mandibular palp and inner lobe of maxilla (both absent in Brychiopontius). On the other hand the new genus has only 2 outer spines on the third exopodal segment of leg 1 (instead of 3 in Brychiopontius). Two plesiomorphic characters hitherto unknown for the order Siphonostomatoida are present in the new genus viz. the inner lobe of the first segment of the maxilla is armed with 2 setae and the first segment of the mandibular palp is armed with 1 seta. Neobrychiopontius galeronae gen. et sp. nov. is the second species of Siphonostomatoida found in association with abyssal holothurians (both belonging to the genus Oneirophanta) and represents the first record of the family Brychiopontiidae in the Pacific Ocean.