Revision of the genus Diclidophora Krøyer, 1838 (Monogenea: Diclidophoridae), with the proposal of Macrouridophora n. g.

The present study re-examines the detailed morphology of the type-species, Diclidophora merlangi (Kuhn, in Nordmann, 1832) Krøyer, 1838, and other Diclidophora species parasitic on gadid fishes: D. denticulata (Olsson, 1876) Price, 1943, D. esmarkii (Th. Scott, 1901) Sproston, 1946, D. luscae (van Beneden & Hesse, 1863) Price, 1943, D. minor (Olsson, 1868) Sproston, 1946, D. palmata (Leuckart, 1830) Diesing, 1850, D. phycidis (Parona & Perugia, 1889) Sproston, 1946, D. pollachii (van Beneden & Hesse, 1863) Price, 1943 and the recently described D. micromesisti Suriano & Martorelli, 1984. An amended generic diagnosis of Diclidophora Krøyer, 1838 (synonym Diclidophora Diesing, 1850) is provided, which includes the presence of a prostatic vesicle in the terminal male genitalia and the distal fusion of the median and peripheral sclerites, a₁ and c₁ in the clamp anterior jaw. Macrouridophora n. g. is herein proposed for species previously considered in Diclidophora, which are parasitic on macrourid and morid fishes. The clamp morphology in Macrouridophora n. g. has distinct lamellate extension attachments to peripheral sclerites c₁ and the distal portion of d₁, with no distal fusion between a₁ and c₁ in the anterior jaw. Macrouridophora macruri (Brinkmann, 1942) n. comb. is chosen as the type-species. Nine other species are herein transferred to Macrouridophora n. g.: M. coelorhynchi (Robinson, 1961) n. comb., M. lotella (Machida, 1972) n. comb., M. nezumiae (Munroe, Campbell & Zwerner, 1981) n. comb. and M. tubiformis (Rohde & Williams, 1987) n. comb. are redescribed, based on the re-examination of type or voucher specimens. Macrouridophora attenuata (Mamaev & Zubtschenko, 1979) n. comb., M. caudata (Mamaev & Zubtschenko, 1984) n. comb., M. papilio (Mamaev & Avdeev, 1981) n. comb., M. paracoelorhynchi (Mamaev & Paruchin, 1979) n. comb. and M. physiculi (Mamaev & Avdeev, 1981) n. comb. have adequately described haptoral clamps in the literature. The clamp morphology in Macrouridophora sp. from Lepidorhynchus denticulatus in Australia is also considered. Diclidophora whitsonii Suriano & Martorelli, 1984 is herein transferred to the genus Macruricotyle Mamaev & Ljadov, 1975, as M. whitsonii (Suriano & Martorelli, 1984) n. comb. D. embiotocae Hanson, 1979 is herein considered a species incertae sedis. D. caudospina Khan & Karyakarte, 1983 and D. paddiforma Deo & Karyakarte, 1979 are herein considered species inquirendae. D. aglandulosa Deo, 1977, D. glandulosa Das, 1972, D. minuta Das, 1972 and D. spindale Deo, 1977 are formally dismissed as nomina nuda. The systematic position of Diclidophora Krøyer, 1838 and Macrouridophora n. g. in the subfamily Diclidophorinae Cerfontaine, 1895 (sensu Mamaev, 1976) is discussed.     

The association between the caprellid Pariambus typicus Krøyer (Crustacea,Amphipoda) and ophiuroids

The work of Kazutsugu Hirayama over the past 25 yearspromoted the wide use of the marine rotifer Brachionusplicatilis as an experimental model in zooplanktonecology. His reports about the nature of geneticvariation in the B. plicatilis complex stimulated usto investigate how mate recognition maintains speciesboundaries. For the past several years, we haveexamined chemical communication between female andmale B. plicatilis. Here we report on the comparativebinding of polyclonal antibody against the materecognition pheromone (MRP) to three B. plicatilisstrains and three B. rotundiformis strains.Quantification of anti-MRP binding permitsinvestigation of how the female mating signal differsamong closely related Brachionus species and strains.Antibody binding reflects differentiation independentof the male receptor which has been describedelsewhere. Anti-MRP bound to females of all sixstrains and was localized in the corona. Antibodybinding greatly reduced mating in all three B. plicatilis strains. However, antibody bindingsignificantly reduced mating in only one of the B. rotundiformis strains. The MRP of both species has asimilar molecular weight, but the differential bindingsuggests that the mate recognition pheromone onfemales has differentiated in B. plicatilis and B. rotundiformis.     

A new species of eel cods Muraenolepis trunovi sp. nova (Muraenolepididae) from the Lazarev Sea with redescription of lectotypes Muraenolepis marmorata Günther, 1880 and M. microps (Lönnberg, 1905)

A new species of eel cods Muraenolepis trunovi sp. nova (Muraenolepididae) from the Lazarev Sea is described. The type specimen is caught at the depth 730–860 m. The new species differs from all known species in very elongated first dorsal and pectoral fins. With respect to the body proportions and the number of rays in the second dorsal fin and the anal fin, it is related to M. marmorata but clearly differs from the latter in a greater number of vertebrae (73 vs. 67–69), in the reduced upper lateral line (to one sensory tube), and in complete absence of the lower lateral line on the body. The lectotypes of Muraenolepis marmorata Günther, 1880 (British Natural History Museum, BNHM) and M. marmoratus microps (Lönnberg, 1905) (Naturhistoriska Riksmuseum, NRM) are redescribed.     

Effects of sea lice (Lepeophtheirus salmonis Kröyer, 1837) infestation on macrophage functions in Atlantic salmon (Salmo salar L.)

Experiments were conducted to determine the effects of sea lice, Lepeophtheirus salmonis, on non-specific defence mechanisms in Atlantic salmon, Salmo salar, by experimentally infesting hatchery-reared 1 and 2 year old post-smolts, S1 and S2, with laboratory grown infective copepodids at moderate to high infection intensities ranging from 15-285 lice per fish. The effects of sea lice-induced stress were investigated by measuring the blood levels of cortisol and glucose as indicators of primary and secondary stress responses, and by changes in macrophage respiratory burst activity and phagocytosis as indicators of tertiary stress responses as well as non-specific defence mechanisms. Fish were sampled prior to sea lice infestation at day 0 and at days 3, 7, 14 and 21 post-infestation. Sea lice were at copepodid stage at day 3, at chalimus stages at days 7 and 14, and at pre-adult stage at day 21. Blood levels of cortisol and glucose were found to be significantly increased at day 21 in fish-infested with the highest levels. Macrophage respiratory burst and phagocytic activities were found to be significantly decreased only at day 21. These results indicate that sea lice do not suppress host defence mechanisms during the earlier stages of infestation. They do have effects on the development of chronic stress and on the host non-specific defence mechanisms soon after the lice reach the pre-adult stage.     

Two New Species of Pristionchus (Rhabditida: Diplogastridae): P. fissidentatus n. sp. from Nepal and La Réunion Island and P. elegans n. sp. from Japan

Pristionchus fissidentatus n. sp., isolated from soil in Nepal, and P. elegans n. sp., isolated from Phelotrupes auratus (Coleoptera: Scarabaeidae) in Japan, are described. The two new species are recognized as basal within the genus and thus occupy an important position for macroevolutionary studies that center on the model P. pacificus. Pristionchus fissidentatus n. sp. is distinguished by its unique stegostomatal morphology: in the stenostomatous form, the right subventral ridge has three prominent cusps and the left subventral sector has, in addition to a plate with two cusps, a prominent denticle slightly left of ventral; in the eurystomatous form, the right subventral stegostomatal sector shows both a tooth and a ridge with several cusps. Diagnostic of P. elegans n. sp. is the structure of the stenostomatous cheilostom, which bulges medially and is underlain by a large vacuolated ring. No eurystomatous form has been observed in P. elegans n. sp. Reproductive modes of P. fissidentatus n. sp. and P. elegans n. sp. are hermaphroditic and gonochoristic, respectively. The additional isolation of P. fissidentatus n. sp. from soil and two species of scarab beetle on La Réunion Island in the Indian Ocean suggests a broad geographic range for this species.     

The phylogenetic position of Furnestinia echeneis (Monogenea, Diplectanidae) based on molecular data: a case of morphological adaptation?

The genus Furnestinia (Diplectanidae) contains only one species, Furnestinia echeneis. However, its close morphological similarity with the genus Lamellodiscus (Diplectanidae) raises doubt concerning its placement in a separate genus. These two genera differ only by their number of lamellodiscs: one for Furnestinia, two for Lamellodiscus. Here, the taxonomic position of F. echeneis is investigated via a phylogenetic reconstruction based on partial 18S rDNA for F. echeneis and several Lamellodiscus species. Furnestinia echeneis appears to be clearly nested into the Lamellodiscus genus, these two genera should then be synonymised. The hypertrophy of its unique lamellodisc is hypothesised to be a morphological adaptation for attachment to the host.     

Three new species, Lamellodiscus tubulicornis n. sp., L. magnicornis n. sp. and L. parvicornis n. sp. (Monogenea: Diplectanidae) from Gymnocranius spp. (Lethrinidae: Monotaxinae) off New Caledonia, with the proposal of the new morphological group ‘tubulicornis’ within Lamellodiscus Johnston & Tiegs, 1922

Three new species of Lamellodiscus are described from four (including two undescribed) species of Gymnocranius off New Caledonia, South Pacific. All three species have a similar body anatomy and morphology of the haptoral hard parts and are distinguished on the basis of the male copulatory organ (MCO). Lamellodiscus tubulicornis n. sp. (type-host: G. grandoculis; other host: Gymnocranius sp. B) has an MCO with a tube and horn; L. magnicornis n. sp. (type-host: G. grandoculis; other hosts: G. euanus, Gymnocranius sp. A and Gymnocranius sp. B) has an MCO with a long horn and a membrane; L. parvicornis n. sp. (type-host: G. euanus; other hosts: G. grandoculis and Gymnocranius sp. B) has an MCO with a small horn and a membrane. Lamellodiscus epsilon Yamaguti, 1968 is redescribed based on the type-specimens (from Monotaxis grandoculis off Hawaii). Lamellodiscus sp. is recorded from Gnathodentex aureolineatus off New Caledonia. All these five species have lamellodiscs that exhibit a unique characteristic: the second lamella forms an almost closed circle, in contrast to all other described species of Lamellodiscus in which the second lamella has the form of one or two crescents. Lamellodiscus spp. are usually classified in two groups, the ‘ignoratus’ and ‘elegans’ groups, according to the structure of the lamellodisc; we propose a new ‘tubulicornis’ group for these five species. In addition to their lamellodisc structure, species of the tubulicornis group are also characterised by their egg (elongate in contrast to tetrahedral in the two other groups) and their hosts (monotaxine lethrinids as opposed to mainly sparids). The generic diagnosis of Lamellodiscus given by Amine & Euzet (2005) is amended to include species with elongate eggs.     

Tinamutrema canoae n. gen. et n. sp. (Trematoda: Digenea: Strigeiformes: Brachylaimidae) in Crypturellus cinnamomeus (Aves, Passeriformes, Tinamidae) from the Area de Conservación Guanacaste, Costa Rica

We propose Tinamutrema as a new genus for Brachylaima centrodes (Braun, 1901) Dollfus, 1935 and for T. canoae, as a new species inhabiting tinamus in the Area de Conservación Guanacaste, Costa Rica. Specimens from Costa Rica resemble B. centrodes in having an elongate body, pretesticular genital pore and terminal genitalia, intercecal uterine loops occupying all available space between the anterior testis and the intestinal bifurcation, an oral sucker width:pharynx width ratio of approximately 1:0.55, an oral sucker:ventral sucker width ratio of approximately 1:1, and vitelline follicles extending into the forebody closer to the pharynx than to the anterior margin of the ventral sucker and by living in the cloaca. They differ from B. centrodes in having vitelline follicles that do not extend as far anteriorly as those in B. centrodes, which extend anteriorly to the level of the anteriormost extent of the cecal "shoulders," dense tegumental spination as opposed to sparse or no spination, relatively smaller cirrus with fewer spines, longer and more sinous pars prostatica, and forebody averaging 36% of total body length (TBL) as opposed to 42% TBL. Both species differ from other members of the Brachylaimidae in possessing a spinose cirrus and a cirrus sac containing both the cirrus and the pars prostatica. Preliminary phylogenetic assessment suggests that these traits are plesiomorphic, and thus the species are basal to the rest of the Brachylaimidae, whose diagnosis we emend accordingly.     

Wallinia chavarriae n. sp. (Trematoda: Macroderoididae) in Astyanax aeneus (Gunther, 1860) and Bryconamericus scleroparius (Regan, 1908) (Osteichthyes: Characidae) from the Area de Conservación Guanacaste,Costa Rica

Wallinia chavarriae n. sp. is described from the small-bodied characids Astyanax aeneus and Bryconamericus scleroparius in the Area de Conservación Guanacaste, northwestern Costa Rica. The species differs from W. valenciae in possessing an acetabulum that is smaller than the oral sucker and vitelline follicles that are ovoid or rounded rather than elongate and tubular. Detailed comparison between these 2 species is handicapped by the less than satisfactory condition of the type and only museum specimen of W. valenciae. Wallinia chavarriae and W. valenciae belong to a subfamily of trematodes, Walliniinae, that arguably includes Creptotrematina spp., Magnivitellum simplex, and possibly Margotrema. The morphology of walliniines suggests that they are macroderoidids, but a clearer understanding of their classification could be gained from their larval morphology or from molecular systematic studies. The host associations of a monophyletic Walliniinae would indicate diversification within 2 groups of freshwater fishes: the neotropical characids for species of Wallinia, Creptotrematina, and Magnivitellum and the endemic central Mexican goodeids for those of Margotrema. The biogeography and host associations of these parasites provide a system for studies of potential host switching and vicariance, involving the middle-American and neotropical regions.     

Lecane donyanaensis n. sp. (Rotifera: Monogononta,Lecanidae) from the Doñana National Park (Spain)

A hitherto unknown rotifer species was found in ponds of Doñana National Park (Spain) during winter 1990, 1991 and 1992. It belongs to the family Lecanidae (Monogononta), is related to Lecane ungulata and superficially resembles Lecane leontina.Two specimens of this species hatched after two days incubation of pond sediments in the laboratory.     

Henneguya polarislonga n. sp. (Cnidaria: Myxosporea) parasitizing Astyanax lacustris (Lütken, 1875) with an insight on its life cycle

Henneguya polarislonga n. sp. is described from the gills of Astyanax lacustris (Lütken, 1875) (Characiformes, Characidae) from streams of the Middle Paranapanema River, Upper Paraná River basin, in the São Paulo State, Brazil. The proposed new species is supported by a combination of morphological and molecular characterization (partial fragment of the SSU rDNA). Thirty specimens of A. lacustris were analyzed and myxospores were found in the gill lamellae of one specimen (Prevalence = 3.3%). Henneguya polarislonga n. sp. was morphometrically and genetically distinct from other Henneguya spp. previously described in Astyanax spp., mainly differing in the total length and caudal appendages length of the mature myxospores. Comparative analysis of the SSU rDNA sequences revealed that Seisactinomyxon-type actinospores previously reported parasitizing oligochaetes are developmental stages of the life cycle of Henneguya polarislonga n. sp. (similarity of 99.9%). This is the first time that an actinospore and a myxospore are correlated through molecular analysis in Brazil, contributing to the knowledge of the myxozoan ecology and biodiversity.     

Three new species of Polyclithrum Rogers, 1967 (Gyrodactylidae: Monogenea) from mugilid fishes from Australia and Brazil, with a redescription of P. mugilini Rogers, 1967

Polyclithrum mugilini Rogers, 1967, a parasite of Mugil cephalus Linnaeus, is redescribed from type-material from Lake Seminole, Georgia, USA. Three new species of Polyclithrum Rogers, 1967 are also described: P. alberti n. sp. from M. cephalus from the Albert River, Queensland, Australia; P. boegeri n. sp. from M. platanus Günther from Rio da Guarda, State of Rio de Janeiro, Brazil; and P. corallense n. sp. from M. cephalus from Heron Island, Great Barrier Reef, Australia. The four species can be distinguished by the size and shape of haptoral sclerites, but in particular by accessory bar number 3, the dorsal bar, the marginal hooks and the hamulus point to shaft angle. The validity of Micropolyclithrum parvum Skinner, 1975, a parasite of M. cephalus in Biscayne Bay, Florida, is discussed, and a key to the species of Polyclithrum is presented.     

The ‘Pseudorhabdosynochus cupatus group’ (Monogenea: Diplectanidae) on Epinephelus fasciatus, E. howlandi, E. rivulatus and E. merra (Perciformes: Serranidae) off New Caledonia, with descriptions of Pseudorhabdosynochus cyathus n. sp. and P. calathus n. sp.

Pseudorhabdosynochus cupatus (Young, 1969) is characterised by small lamellosquamodiscs made up of central telescopic rings and peripheral rows of rodlets, and a sclerotised vagina in the shape of a thin-walled coiled tube with three accessory chambers. Two new species of Pseudorhabdosynochus are herein described from epinepheline fish off New Caledonia, South Pacific, and are considered part of the 'P. cupatus group'. P. cyathus n. sp. from Epinephelus howlandi has lamellosquamodiscs made up of four telescopic rings and four rows of separate rodlets; there are dorsal tegumental scales. This species was found only in young hosts; older hosts harbour P. venus Hinsinger & Justine, 2006. P. calathus n. sp. from Epinephelus rivulatus has lamellosquamodiscs made up of four telescopic rings and five rows of separate rodlets; the tegument is smooth. The three species, P. cupatus, P. calathus and P. cyathus, are strictly species specific; although morphologically very similar, they can be distinguished by features of the tegumental scales and measurements of the vagina and haptoral hard parts. P. melanesiensis (Laird, 1958) from E. merra is close to the 'P. cupatus group' according to the morphology of its sclerotised vagina but is distinguished by its squamodiscs which lack telescopic rings. Rare specimens found in E. merra are tentatively attributed to P. coioidesis Bu et al., 1999. A paratype of P. coioidesis is figured for comparison. E. merra, E. fasciatus, E. rivulatus and E. howlandi each have a Pseudorhabdosynochus species of the P. cupatus lineage: these are the dominant species in each host. In addition, E. merra, E. fasciatus and E. howlandi harbour a rare species of Pseudorhabdosynochus, respectively P. cf. coioidesis, P. caledonicus Justine, 2005 and P. venus; these rare species are morphologically unrelated to each other and to the 'P. cupatus group'.     

Paracreptotrema profundulusi n. sp. and P. blancoi Choudhury, Pérez-Ponce De León, Brooks, and Daverdin, 2006 (Trematoda: Allocreadiidae) from freshwater fishes of the genus Profundulus (Teleostei: Profundulidae) in southern México

Paracreptotrema profundulusi n. sp. (Trematoda: Allocreadiidae) is described from the intestine of the freshwater fishes Profundulus punctatus and P. balsanus (Teleostei: Profundulidae) from the Tehuantepec and the Atoyac-Verde River basins, in Oaxaca, México, in the western extreme of Central America. The new species is distinguished from Paracreptotrema blancoi Choudhury, Pérez-Ponce de León, Brooks, and Daverdin, 2006 , to which it is most similar, and from P. mendezi (Sogandares-Bernal, 1955) Choudhury, Pérez-Ponce de León, Brooks, and Daverdin, 2006 , by the caeca extending beyond the testes, vitelline follicles that invade the postesticular area, and uterus with transverse loops located mainly between the testes and the genital pore. Paracreptotrema blancoi was collected from the same host species and also from Profundulus oaxacae. Here, we provide data that show its broad distribution in several river basins of Neotropical southern México, including the Papagayo River basin, Guerrero, México, and the Atoyac-Verde and Tehuantepec river basins, and other rivers in Oaxaca, México. Freshwater fishes of the Profundulidae are endemic to Central America and host a helminth fauna that includes at least 4 species found only in these hosts.     

Two nematodes, Dentinema trichomycteri n. g., n. sp. (Cosmocercidae) and Procamallanus chimusensis Freitas & Ibáñez, 1968 (Camallanidae), from catfishes Trichomycterus spp. (Pisces) in Colombia

Light and scanning electron microscopical examinations of nematode samples collected from the stomachs and intestines of catfishes Trichomycterus spp. (Trichomycteridae, Siluriformes) from three streams in Colombia revealed the presence of two species, Dentinema trichomycteri n. g., n. sp. (Cosmocercidae) (type-host Trichomycterus sp.) and Procamallanus (Spirocamallanus) chimusensis Freitas &; Ibáñez, 1968 (Camallanidae). The new, monotypic genus Dentinema is characterised mainly by the presence of a triangular mouth surrounded by three poorly developed lips, four submedian cephalic papillae, three conical teeth in the well-developed buccal cavity, an elongate oesophageal isthmus which is clearly separated from the corpus, precloacal oblique muscle bands, and by the absence of a ventral sucker. P. chimusensis, recorded from Colombia for the first time, is redescribed from specimens collected from Trichomycterus chapmani (Eigenmann) (a new host record) and Trichomycterus sp.; new observations show that this species belongs to a small group of Procamallanus spp. exhibiting a distinct sexual diversity in the structure of the buccal capsule. P. pexatus Pinto, Fábio, Noronha &; Rolas, 1976 is synonymised with P. chimusensis.     

Ecological investigations on the zooplankton community in Balsfjorden,Northern Norway: seasonal changes in the lipid class composition of Meganyctiphanes norvegica (M. Sars), Thysanoessa raschii (M. Sars), and T. inermis (Krøyer)

The lipid class composition of three krill species, Meganyctiphanes norvegica (M. Sars), Thysanoessa raschii (M. Sars), and T. inermis (Krøyer), was determined throughout the year in Balsfjorden, Northern Norway. Meganyctiphanes norvegica had triglycerides as its major neutral lipid, Thysanoessa raschii had mainly triglycerides with small amounts of wax esters, whereas T. inermis had mainly wax esters with lesser amounts of triglycerides. Neutral lipids were generally accumulated by the krill during spring-early summer, maintained at high levels through to mid-winter and then declined to minimal levels during early spring. Differences in rates of deposition and mobilization of neutral lipid between males and females occurred in Meganyctiphanes norvegica and Thysanoessa raschii but not in T. inermis. T. raschii accumulated lipid somewhat later in the year than T. inermis but earlier than Meganyctiphanes norvegica. A major rôle for lipid in the elaboration of gonads is indicated. The accumulation of either wax esters or triglycerides by euphausiids is considered in terms of the feeding habits and ecological niche differentiation of the species.