High diversity of Caligus species (Copepoda: Siphonostomatoida: Caligidae) in Taiwanese waters.

Caligidae, commonly known as sea lice, is the most speciose family of symbiotic copepods comprising over 490 species classified in 31 genera. Caligus Müller, 1785 is the largest genus of this family comprising 255 species. Fifty-three species of Caligus have been reported from Taiwan so far, representing 20.78 % of Caligus currently known in the world. Nevertheless, we believe many more species of Caligus are yet to be discovered from the waters of Taiwan, because only 17.71 % (553/3,121 species) of the potential fish hosts occurring in Taiwanese waters have been examined for parasitic copepods so far. Among the countries in the Far East, Taiwan exhibits the shortest coastline yet displays the highest diversity of Caligus species. This seemingly contradictory phenomenon may be explained by the fact that the Island of Taiwan is straddling over the border of two ecological realms in the western North Pacific, viz. the Temperate Northern Pacific Realm and the Central Indo-Pacific Realm. Pseudocaligus longipes Moon & Kim, 2012 is formally transferred to the genus Caligus as C. longipes (Moon & Kim, 2012) comb. nov.

Caligus lini n.sp., a new caligid (Copepoda, Siphonostomatoida) parasitic on the brilliant pomfret Eumegistus illustris Jordan & Jordan (Perciformes, Bramidae) of Taiwan.

Caligus lini n.sp., a new species of caligid copepod parasitic on the gill rakers and caudal fin of the brilliant pomfret, Eumegistus illustris Jordan & Jordan (Perciformes, Bramidae), is described from fish caught off Tai-Dong, Taiwan. The new species differs from its congeners by its possession of the following, unique combination of features: (1) middle two elements at the tip of leg 1 simple (without accessory process), (2) innermost element shortest and smallest of the four terminal elements on leg 1, (3) leg 4 exopod with an armature formula of I,III, and (4) complex leg 5 represented by 2 seta-bearing processes, a simple anterior process tipped with 1 plumose seta and quadripartite posterior process carrying 3 setae (1 simple and 2 plumose). The new species differs from its closest congener, Caligus tylosuri (Rangnekar, 1956), in the structure of the middle two elements (simple without carrying accessory process) at the tip of leg 1 and a quadripartite (instead of tripartite) posterior process on leg 5.

New records of sea lice (Copepoda: Caligidae) from marine fishes in Jaramijó, an area with potential for sea-cage aquaculture in Ecuador.

Farming of finfish in sea cages is gaining popularity worldwide. These systems are a suitable environment for the emergence, establishment and transmission of parasites or pathogens, such as sea lice (Copepoda: Caligidae), known to cause serious diseases and economic losses in finfish aquaculture worldwide. In coastal waters of Jaramijó, Ecuador, there are plans to culture spotted rose snapper (Lutjanus guttatus) and longfin yellowtail (Seriola rivoliana); however, the information about the occurrence of sea lice on fish from this country is scarce. To address this problem, a parasitological survey of economically important fish caught by artisanal fishermen was conducted between June 2013 and May 2014. A total of 608 fish belonging to 66 species were examined. Sea lice were found on 23 fish species. The diversity of these parasites consisted of 22 species of Caligus and 5 species of Lepeophtheirus. Most sea lice species (66%) occurred in a single fish species only, with low infection levels. The most frequently encountered species were Caligus asperimanus Pearse, 1951, Caligus mutabilis Wilson, 1905 and Caligus rufimaculatus Wilson, 1905. Taxonomic remarks are presented for some of the species recorded during this survey. All but two sea lice records are new to Ecuador, considerably expanding the geographical range of some species.

A new copepod with transformed body plan and unique phylogenetic position parasitic in the acorn worm Ptychodera flava.

Symbiotic copepods compose one-third of the known copepod species and are associated with a wide range of animal groups. Two parasitic copepods endoparasitic in acorn worms (Hemichordata), Ive balanoglossi and Ubius hilli, collected in the Mediterranean Sea and Australian waters, respectively, were described a century ago. Here we report a new parasitic copepod species, Ive ptychoderae sp. nov., found in Ptychodera flava, a widespread acorn worm in the Indo-Pacific Ocean and an emerging organism for developmental and evolutionary studies. The female of I. ptychoderae is characterized by having a reduced maxilliped and five pairs of annular swellings along the body that are morphologically similar but distinguishable from those in the two previously described parasitic copepods in acorn worms. Phylogenetic analysis based on the 18S rDNA sequence shows that I. ptychoderae may belong to Poecilostomatoida but represent a new family, which we name Iveidae fam. nov. Ive ptychoderae is commonly found in the acorn worm population with an average prevalence of 42% during the collecting period. The infection of the parasite induces the formation of cysts and causes localized lesions of the host tissues, suggesting that it may have negative effects on its host. Interestingly, most cysts contain a single female with one or multiple male copepods, suggesting that their sex determination may be controlled by environmental conditions. The relationships between the parasitic copepods and acorn worms thus provide a platform for understanding physiological and ecological influences and coevolution between parasites and hosts.

Revisiting the octopicolid copepods (Octopicolidae: Octopicola Humes, 1957): comparative morphology and an updated key to species.

A review of the present state of knowledge on the octopicolid copepods (Octopicolidae: Octopicola Humes, 1957) is presented. Characteristic morphological features are illustrated with scanning electron micrographs of Octopicola superba superba Humes, 1957. Comparative morphology analysis led to the conclusion that there is sufficient evidence to justify raising the two subspecies of O. superba to full species rank. A new identification key for the four species of Octopicola Humes, 1957, i.e. O. superba Humes, 1957, O. antillensis Stock, Humes & Gooding, 1963, O. stocki Humes, 1963 and O. regalis Humes, 1974, is proposed after evaluation of the morphological characters which vary more markedly between them. Among other characters, these species differ in the ornamentation of the third antennal segment, maxilla and male maxilliped. They are further distinguished by a combination of several character states concerning the fifth pedigerous somite.

Doridicola indistinctus n. sp. (Copepoda: Poecilostomatoida: Rhynchomolgidae) associated with the soft coral Gersemia fruticosa Sars (Octocorallia: Alcyonacea: Nephtheidae) from the White Sea.

A new species of poecilostomatoid copepod, Doridicola indistinctus n. sp. (Rhynchomolgidae), is described from specimens found in association with the soft coral Gersemia fruticosa Sars (Alcyonacea: Nephtheidae), collected from the White Sea. The new species is distinguished from its congeners by the combination of the following features in the female: (i) antenna tipped, with two subequal large claws which are about as long as the segment bearing them; (ii) two naked, extremely unequal setae on the middle segment of the maxilliped, the short, medial seta less than half-length of the outer seta; and (iii) free segment of leg 5 bears the basal swelling and is ornamented with spinules on the outer surface. This is the first report of a copepod occurring in symbiosis with nephtheid corals from the Arctic Zone. It also constitutes the northernmost record for a species of Doridicola Leydig, 1853, which is the largest genus of the Rhynchomolgidae Burmeister, 1835 comprising 52 species, including the present new species.

Pseudolamproglena boxshalli sp. n. (Lernaeidae: Lamprogleninae) parasitic on gills of Cyprinion macrostomum (Teleostei: Cyprinidae) from the Tigris River, Iraq.

Abstract: A new species of lamproglenine copepods, Pseudolamproglena boxshalli sp. n., is described from gills of the cyprinid fish Cyprinion macrostomum Heckel from the Tigris River in Tikreet, north of Baghdad, Iraq. This is the second species of Pseudolamproglena from Iraq and the fourth in the world. It differs from its three congeners mainly in the armature ofantennule, maxilla, maxilliped, legs 1-4 and caudal ramus.

Four new xarifiid copepods (Poecilostomatoida) associated with the scleractinian coral Pavona explanulata (Lamarck) from off Taiwan.

Four new xarifiid copepods are described. They were found in association with the scleractinian coral Pavona explanulata (Lamarck) occurring in shallow water reefs off Yenliao in northern Taiwan. The four species are: Xarifia capillata n. sp., X. parva n. sp., X. pavonae n. sp. and X. taiwanensis n. sp. They were found together in a single washing of the host coral. Previously, 13 species of copepods have been found in association with nine species of Pavona Lamarck. More than half (7/13) of these symbionts are members of Xarifia Humes, 1960.

Redescription of Dinemoura discrepans Cressey, 1967 (Copepoda: Pandaridae) parasitic on four species of sharks off southeast coast of Taiwan.

Dinemoura discrepans Cressey, 1967 (Copepoda, Siphonostomatoida, Pandaridae) is redescribed based on the specimens taken from four species of sharks caught off the southeast coast of Taiwan. The four species of sharks are: pelagic thresher, Alopias pelagicus Nakamura; bigeye thresher, A. superciliosus Lowe; blacktip shark, Carcharhinus limbatus (Müller et Henle); and oceanic whitetip shark, C. longimanus (Poey). Although our redescription shows certain differences from the original description, after reexamination of the museum specimens studied by R. F. Cressey in making the original description, it was confirmed that the specimens from off Taiwan are identifiable with D. discrepans. Carcharhinus limbatus is currently known to host 19 species of parasitic copepods, of which D. discrepans is the first one of this copepod genus.

Caligus ignotus n. sp. (Copepoda: Caligidae) parasitic on Poey's scabbardfish Evoxymetopon poeyi (Günther) off Taiwan.

A new species of caligid copepod, Caligus ignotus n. sp., is described from Poey's scabbardfish Evoxymetopon poeyi (Günther) (Trichiuridae) caught off the southeast coast of Taiwan. The parasite was found in the gill-cavity of this benthopelagic fish. The new species is distinguished from its congeners mainly in the structure of the female genital complex (shaped like a guitar) and abdomen (with three sections and gradually broadening from anterior to posterior). This is the first report of a copepod parasite from Poey's scabbardfish.

Orstomella yaliuensis n. sp., a xarifiid copepod (Crustacea) parasitic in the polyps of hump coral Porites lutea Milne Edwards & Haime off Taiwan.

A new species of xarifiid copepod, Orstomella yaliuensis n. sp., is described. It was found living in the polyps of a scleractinian coral, Porites lutea Milne Edwards & Haime, collected off Yaliu in the northern part of Taiwan. The new species can be distinguished from its two congeners, O. faviae Humes & Ho, 1968 and O. lobophylliae Humes & Ho, 1968, by the presence of five (rather than six) segments on the antennule, a spine only (rather than a seta and a spine) at the tip of the antenna, a uniramous leg 2, and a relatively long (rather than short) spine at the tip of the caudal ramus.

A revision of the family Dissonidae Kurtz, 1924 (Copepoda: Siphonostomatoida).

Two new species of the parasitic copepod genus Dissonus Wilson, 1906 are described: D. excavatus n. sp. from the gills of a labrid, Bodianus perditio, and a lutjanid, Macolor niger, collected off New Caledonia and Taiwan, and D. inaequalis n. sp. from a hemiscylliid elasmobranch, Chiloscyllium punctatum, collected off Sarawak (Malaysia) and the Philippines. Material of D. heronensis Kabata, 1966 is described from a balistid host, Pseudobalistes fuscus, off New Caledonia, and this constitutes a new host record for this parasite. D. manteri Kabata, 1966 was collected from four serranid host species off New Caledonia and from one of the same hosts off Taiwan. Two of the hosts from New Caledonia, Plectropomus laevis and Epinephelus cyanopodus, represent new host records. D. pastinum Deets & Dojiri, 1990 was recognised as a new synonym of D. nudiventris Kabata, 1966, so the total number of valid species is now twelve. Material from museum collections of D. nudiventris, D. similis Kabata, 1966 and D. spinifer Wilson, 1906 was re-examined and provided new information which is utilised in a key to all valid species of Dissonus.

Three species of Caligus Müller, 1785 (Copepoda: Caligidae) parasitic on Caranx spp. (Teleostei: Carangidae) off Taiwan.

Three species of sea-lice (Siphonostomatoida: Caligidae) parasitic on marine fishes of the genus Caranx off Taiwan are reported. They are: Caligus fortis Kabata, 1965 on Caranx ignobilis (Forsskål); Caligus robustus Bassett-Smith, 1898 on Caranx sexfasciatus Quoy & Gaimard; and Caligus inanis n. sp. on Caranx ignobilis. Caligus robustus is a widely distributed species, but this is the first report of C. fortis outside the Australian and Indian regions. The new species is distinguished from its congeners in lacking postantennal process and carrying a pair of tiny, tooth-like, sharp protuberances on the posterior margin of the cephalothoracic shield.

Two new species of taeniacanthid copepods (Poecilostomatoida) parasitic on marine fishes of Taiwan.

Two new species of copepods (Poecilostomatoida Taeniacanthidae) parasitic on fishes of Taiwan are reported. They are: Irodes parupenei n. sp. from Parupeneus spilurus (Bleeker) and P. multifasciatus (Quoy & Gaimard), and Taeniacanthus spiniferus n. sp. from Acanthocepola limbata Valenciennes. I. parupenei is characteristic in having nine (instead of eight) elements on the terminal segment of leg 2 exopod, a spiniform element (instead of a long, plumose seta) on the medial margin of the proximal segment of leg 4 endopod, and thee spines and one long, naked seta (rather than four short setae) on the slender (rather than spatula-like), terminal segment of leg 5. T. spiniferus is distinguished from its 38 congeners in carrying a pair of sharp tines in the ventral area of the rostrum.

Host specificity of Lepeophtheirus crassus (Wilson and Bere) (Copepoda: Caligidae) parasitic on the marlin sucker Remora osteochir (Cuvier) in the Atlantic Ocean.

Three species of remoras--Remora brachyptera (Lowe), Remora osteochir (Cuvier), and Remora remora (Linnaeus)--were collected from 4 species of billfishes--Istiophorus platypterus (Shaw), Makaira nigricans Lacepéde, Tetrapturus albidus Poey, and Tetrapturus pfluegeri Robins and de Sylva--on board a Japanese long-liner Shoyo Maru during her cruise in 2002 across the Atlantic. However, only the marlin sucker (R. osteochir) was found to carry a parasitic copepod, Lepeophtheirus crassus (Wilson and Bere, 1936). Although 12 species of parasitic copepods have been reported from billfishes around the world ocean, none of them is L. crassus. Thus, L. crassus is considered a parasite specific to the marlin sucker.

A new family of poecilostomatoid copepods (Umazuracolidae) based on specimens parasitic on the black scraper (Thamnaconus modestus) in Japan.

Umazuracola elongatus n. gen., n. sp., is described based on specimens collected from the body surface of the black scraper, Thamnaconus modestus (Günther), taken from the Seto Inland Sea in western Japan. The new species belongs to a new family of the copepod order Poecilostomatoida. It is characterised by the reduction of the maxilliped and leg 1 in females and modification in both sexes of legs 2, 3, and 4 into robust attachment organs, with heavy, denticulate outer spines. Although the antenna, mandible, maxillule, and maxilla of U. elongatus resemble those of species of the "bomolochiform complex", a cladistic analysis revealed that phylogenetically this species is embedded in a different clade containing the polychaete-parasitizing families Entobiidae Ho, 1984 and Nereicolidae Claus, 1875.

Copepod parasites of the fatheads (pisces, psychrolutidae) and their implication on the phylogenetic relationships of psychrolutid genera.

Nine species of psychrolutids kept in the Marine Zoology of Hokkaido University were found to carry eight species of copepod parasites. The parasites and their hosts are: Bobkabata kabatabobbus Hogans and Benz, 1990 on Malacocottus zonurus Bean; Chondracanthus parvus n. sp. on Eurymen gyrinus Gilbert and Burke; Chondracanthus yabei n. sp. on Dasycottus setiger Bean and M. zonurus; Ch. yanezi Atria, 1980 on Psychrolutes phrictus Stein and Bond; Caligus similis n. sp. on Neophrynichthys latus (Hutton); Clavella adunca (Strøm, 1762) on M. zonurus; Neobrachiella amphipacifica Ho, 1982 on Ambophthalmos angustus (Nelson), Cottunculus sp., D. setiger, Ebinania brephocephala (Jordan and Starks), E. vermiculata Sakamoto, and P. phrictus; and Naobranchia occidentalis Wilson, 1915 on D. setiger and M. zonurus. Chondracanthus parvus is closest to Ch. deltoideus Fraser, 1920, but differs from it in having only one pair of small knobs on the head and carrying a pair of lateral processes on the second pediger. Chondracanthus yabei resembles Ch. yanezi Atria, 1980, but can be distinguished from it by the presence of three, low protrusions on the mid-dorsal surface of the trunk; besides, maxillule also shows difference. As the name indicates, C. similis resembles several species of Caligus that bear a short abdomen and a formula of I; IV on the exopod of leg 4. However, it can be separated from them by the combination of the following characters: a genital complex distinctly smaller than the cephalothoracic shield, a pair of relatively short caudal rami, a smooth dentiform process on maxillule, and a pair of truncate tines on sternal furca. Analysis of the occurrence of Chondracanthus on the psychrolutid fishes shows that the phylogeny of Chondracanthus is in congruence with that of the Psychrolutidae. It implies that parasitism of Chondracanthus occurred after the Dasycottus clade diverged off the main stock of the Psychrolutidae and the occurrence of Ch. yabei on D. setiger is resulted from a later colonization.

Lernanthropid copepods (Siphonostomatoida) parasitic on fishes of the Gulf of Thailand.

Five species of copepods (Siphonostomatoida: Lernanthropidae) parasitic on fishes of the Gulf of Thailand are reported. They are: Lernanthropus corniger Yamaguti, 1954 from Megalaspis cordyla (Linnaeus); L. latis Yamaguti, 1954 from Lates calcarifer (Bloch); L. nemipteri Jayasree & Pillai, 1976 from Scolopsis lineata Quoy et Gaimard; L. sillaginis Pillai, 1963 from Priacanthus tayenus Richardson; and Norion tayenus n. sp. from P. tayenus. Except for L. sillaginis, the remaining four species are new to Thailand. Lernanthropus priacanthi Kirtisinghe, 1956 is transferred to Norion as N. priacanthi (Kirtisinghe, 1956) n. comb.

The identity of Limnoncaea diuncata Kokubo, 1914 (Copepoda: Poecilostomatoida) from Hokkaido, Japan, with the relegation of Diergasilus Do, 1981 to a junior synonym of Thersitina Norman, 1905.

Both sexes of an ergasilid copepod, Limnoncaea diuncata Kokubo, 1914, are redescribed based on planktonic specimens collected from the type-locality in Hokkaido, Japan. Comparison of this species with Thersitina gasterostei (Pagenstecher, 1861) revealed that they are conspecific. Another ergasilid genus with two claws on the antenna, Diergasilus Do, 1981, is relegated to synonymy with Thersitina Norman, 1905. The diagnosis of Thersitina is amended.

Two species of parasitic copepods (Caligidae) new to Japan.

Two species of parasitic copepods (Siphonostomatoida: Caligidae), Caligus sclerotinosus Roubal, Armitage & Rohde, 1983, parasitic on red seabream Pagrus major (Temminck & Schlegel), and Lepeophtheirus longiventralis Yü & Wu, 1932, parasitic on spotted halibut Verasper variegatus (Temminck & Schlegel), are redescribed based on material found on their respective hosts cultured in Japan. Both species are new to Japan. Preliminary observation on the occurrence of L. longiventralis indicates that the larval development takes place on the body surface of the host and only the post-mated female migrates into the host's gill-cavities. Whilst the occurrence of L. longiventralis in Japan can be considered as due to natural causes, the occurrence of C. sclerotinosus is likely due to anthropogenic activities.