Distribution and characterization of species of Gyrodactylus Nordmann, 1832 (Monogenea) parasitizing salmonids in the UK,and their discrimination from G. salaris Malmberg, 1957

The reported pathogenicity of the monogenean Gyrodactylus salaris Malmberg, 1957 on Atlantic Salmo salar in Norway has necessitated a national survey of salmonid sites throughout the British Isles to determine which species of the genus Gyrodactylus are resident on these hosts in British waters. Eight morphotypes were identified following examination of the opisthaptoral sclerites at both the light and scanning electron microscope level. Gyrodactylus truttae Gläser, 1974 was found on wild brown trout Salmo trutta in Scotland, England and Wales with an uncharacteristic morphotype, having long, thin marginal hooks. Two morphotypes of Gyrodactylus derjavini Mikailov, 1975 were recorded for the first time from Britain. G. caledoniensis n. sp. from Scottish S. salar is erected, based on differences in the shape and size of the marginal hooks. Two possible new species from English Salvelinus alpinus and a possible new species from Welsh S. salar and Scottish O. mykiss are described.     

Species of Gyrodactylus von Nordmann, 1832 (Monogenea: Gyrodactylidae) from freshwater fishes in southern England,with a description of Gyrodactylus rogatensis sp. nov. from the bullhead Cottus gobio L.

Eleven species of Gyrodactylus were found infecting five species of freshwater fishes collected from Rogate (West Sussex, England). These were G. arcuatus and G. gasterostei from Gasterosteus aculeatus, G. pungitii from Pungitius pungitius, G. aphyae, G. laevis, G. limneus, G. macronychus and G. minimus from Phoxinus phoxinus, G. pavlovskyi and G. sedelnikowi from Noemacheilus barbatulus and G. rogatensis n.sp. from Cottus gobio. G. (Limnonephrotus) rogatensis is a member of the G. wageneri species group, and can be distinguished from closely related species (G. aphyae, G. pungitii and G. gasterostei) by its relatively long marginal hooks and by the abruptly tapering toes of its marginal hook sickles. Each parasite was collected from a single host species, and each was narrowly site-specific. With the exception of G. rogatensis, all of the gyrodactylids collected at Rogate also occur in Continental Eurasia, suggesting that they colonized Britain with their hosts via the Doggerland land bridge after the Devensian glaciation. This study demonstrates both the potential of Gyrodactylus for studies of parasite-host coevolution, and the need for critical taxonomic analysis of members of the genus.     

Halvorsenius exilis gen. et sp. nov., a new didymozoid trematode from the mackerel Scomber scombrus L.

Summary

A new genus and species of nematobothriine didymozoid, Halvorsenius exilis, is described. These worms occur unpaired and unencysted in the connective tissue of the mackerel Scomber scombrus, especially in the pericardium, the ‘throat’ region, the orbits and the region of the kidneys. Halvorsenius belongs to a group of genera which possess three uterine loops and two testes, but can be distinguished by the atrophy of the gut and other features. Live worms occur only in young mackerel, although aggregations of eggs are found in older fish. It appears that the eggs are retained in utero until the death of the worm and that there is no obvious mechanism for voiding the eggs from the fish other than through the death of this host.     

Species status of two colour morphs of Eupelmus vesicularis (Hymenoptera: Eupelmidae) as revealed by allozyme electrophoresis,morphometric and host preference data

Eupelmus vesicularis (Retzius) is considered to be a widespread and polyphagous parasitoid recorded from more than 200 hosts. The aim of this study was to determine whether two colour forms of the putative species represent two different morphs of a single species or a pair of cryptic species. Three different methods – morphometric analysis, allozyme electrophoresis and evaluation of host preferences – were used to investigate the existence of two cryptic species. Bivariate and multivariate analyses clearly indicate two species that are also distinguishable electrophoretically at the Idh-2, G6pdh, Me, Pgm and Xdh loci. The evaluation of host preferences indicates some overlap in host range between the two species.     

Metazoan parasite fauna of the round goby Neogobius melanostomus Pallas, 1811 (Perciformes: Gobiidae) collected from the Black Sea coast at Sinop,Turkey

Round gobies (Neogobius melanostomus) were collected from a small stream connected to the Black Sea coast of Sinop, Turkey and examined for metazoan parasites. A total of 122 gobies was investigated throughout a 1‐year period. Long‐term investigations can be useful for finding rare parasites and for determining the diversity and seasonality of parasites. Parasite species recovered were a Digenea gen. sp., Pygidiopsis genata, Ascocotyle sp., Gyrodactylus proterorhini, Dichelyne minutus, Hysterothylacium aduncum, Spiroxys sp., Neoechinohynchus rutilii, and Ergasilus sieboldi. Overall infection prevalence (%) and mean intensity values were 97.5% and 78.2±23.1 parasites per infected fish, respectively. Infection prevalence and mean intensity values for each parasite species in relation to season, fish size, and sex were also determined and discussed.     

Gobiid fishes from the Cape Verde Islands,including two new species of Gobius (Teleostei: Gobioidei)

Ten species of gobiid fishes (Teleostei: Gobioidei) now listed from the Cape Verde islands fall into several zoogeographical categories, including tropical West African Bathygobius casamancus, Mauligobius nigri, Porogobius schlegelii (unconfirmed) and Vanneaugobius canariensis, tropical amphiatlantic B. soporator and Gnatholepis thompsoni, and Canarian Didogobius kochi. Two new species of the eastern Atlantic, predominantly temperate genus Gobius are described: G. ateriformis sp. nov. and G. tetrophthalmus sp. nov., known so far only from the Cape Verdes, but reported occurrence of the congeneric Atlantic-Mediterranean G. paganellus has not been confirmed. The pattern of free neuromast organs (sensory papillae) of the head lateral-line system in Mauligobius nigri and the habitat of this species are described for the first time and its distribution further discussed. Diversity of gobies and other inshore fishes at the Cape Verdes is briefly indicated.     

Description of Ghatiana,a new genus of freshwater crab,with two new species and a new species of Gubernatoriana (Crustacea: Decapoda: Brachyura: Gecarcinucidae) from the Western Ghat Mountains,India

A new genus of freshwater crab, Ghatiana, with two new species, Ghatiana aurantiaca and Ghatiana hyacintha, and a new species of Gubernatoriana Bott, 1970, are described from the Western Ghat Mountains in Maharashtra State, India. Ghatiana is most similar to Gubernatoriana by its wide, highly arched carapace and by the shape of the male abdomen. Nevertheless, the new genus can be distinguished from Gubernatoriana by the broadness of carapace, length of male abdomen, shape of sixth abdominal somite, length of telson and length of G1 terminal article. Ghatiana aurantiaca sp. nov. and G. hyacintha sp. nov. are distinguished by differences in body colour, carapace width, and G1 morphology, whereas Gubernatoriana triangulus sp. nov. is distinguished from two other known species [Gubernatoriana gubernatoris (Alcock, 1909) and Gubernatoriana pilosipes (Alcock, 1909)] by its triangular G1 subterminal segment and by its carapace morphology. Keys to the species of both the genera are provided.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:36BAA1EA-DC15-4B06-BA09-7BD26C63FF54     

A new genus of viviparous gyrodactylid (Monogenea) from the Great Barrier Reef,Australia with descriptions of seven new species

Acanthoplacatus gen. nov., a new genus of viviparous gyrodactylid, is described from the fins and skin of siganid fishes from the Great Barrier Reef, Australia. The genus is characterized by a muscular, tube-like haptor with 16 marginal hooks on the posterior margin. The ventral lobe of the haptor is located anteriorly relative to the dorsal lobe and contains a pair of hamuli and a ventral bar with posteriorly-projecting ventral bar membrane. A dorsal bar is absent. Five pairs of posterior gland cells surround the posterior terminations of the gut. The male copulatory organ is a muscular, non-eversible bulb with several spines around the distal opening. Species of Acanthoplacatus have a bilateral excretory system consisting of six pairs of flame cells and a pair of excretory bladders. Seven new species are described: Acanthoplacatus adlardi sp. nov. and A. amplihamus sp. nov. from Siganus punctatus (Forster, 1801), A. brauni sp. nov. from S. corallinus (Valenciennes, 1835), A. parvihamus sp. nov. from S. vulpinus (Schlegel and Mueller, 1845), A. puelli sp. nov. from S. puellus Schlegel, 1852, A. shieldsi sp. nov. from S. lineatus (Valenciennes, 1835) and A. sigani sp. nov. from S. fuscescens (Houttuyn, 1782). Species can be discriminated by shape and size of the hamuli, marginal hooks and ventral bar and by male copulatory organ sclerite morphology. Three species (A. brauni sp. nov., A. shieldsi sp. nov. and A. sigani sp. nov.) were assessed for seasonal variation of sclerite size. Ten of thirteen morphological characters showed seasonal variation in size for at least one of the species. The characters were longer in winter except dorsal root tissue cap width. Only one character, marginal hook length, showed significant seasonal variation for all three species. Species of Acanthoplacatus were observed to attach using only the marginal hooks and the role of hamuli in attachment is unclear. The dorsal fin of the host is the preferred site for most species but the anal fin, caudal fin and body surfaces are preferred by some species. Prevalences for species range from 57 to 100%.     

Two new species of Rhizorhina (Copepoda: Siphonostomatoida) from leptostracan and tanaidacean hosts

Summary

Two new species of parasitic copepods from the North Atlantic, Rhizorhina leptostracae associated with Nebaliella caboti, and Rhizorhina tanaidaceae from Leviapseudes hanseni, are described. Leptostracans and tanaids are new host groups for this genus. The systematic position of Rhizorhina is discussed.     

Hairworms found in Scottish agricultural land,with descriptions of two new species of Gordionus Muller (Nematomorpha: Gordiidae)

Three species of Nematomorpha were found in a survey of the ground beetles of Scottish agricultural land, Gordionus violaceus (Baird) and two undescribed new species, G. linourgos sp. nov. and G. diligens sp. nov. The morphology of all three species is studied with the aid of SEM, and the characteristics of the cuticle and the male terminal lobes described in detail. All species were found to be parasitic in ground beetles of the family Carabidae, in nine different species (Nebria brevicollis (Fabricius), Harpalus latus (Linnaeus), four species of Pterostichus, and three species of Calathus). Gordionus violaceus is also reported to be a parasite of the spider Arctosa alpigena (Lycosidae). Up to four specimens were found in the same host, typically one adult and several juvenile forms. Parasitized hosts had severe alterations of their reproductive, digestive and secretory systems. The three species of Gordionus were mostly found in grasslands and coniferous forest, most abundantly in June and July.     

Gorgonolaureus muzikae sp. nov. (Crustacea: Ascothoracida) parasitic on a Hawaiian gorgonian,with special reference to its protandric hermaphroditism

Summary

Twenty-five specimens of a new ascothoracid parasite, Gorgonolaureus muzikae were found within cortical galls on specimens of a bathyal Hawaiian gorgonian, Placogorgia sp. These represent the first ascothoracid known from Hawaii. G. muzikae differs from its congener G. bikiniensis primarily in its larger size and details of setation. Five developmental stages are described and illustrated: the mature female, young female, late protander, protander, and nauplius. The protander is compared to species of Synagoga, and the characters distinguishing the two genera are specified. Sexuality in Ascothoracida is reviewed, and the life cycle of G. muzikae is reconstructed as follows: eggs and larvae are brooded within the carapace of a mature female; a bivalved, free-swimming male stage is postulated; after inseminating one or more established females it settles permanently on a host gorgonian; as the protandric male changes into a female, the carapace valves fuse and expand dorsally, the first and second antennae, thoracopods, penis, and abdomen become reduced, the dorsum of the second thoracomere becomes produced into a ‘horn’, and seminal receptacles appear in the thoracopods. The functional morphology of the second antennae, dorsal horn, and thoracopods is discussed, and it is suggested that G. muzikae may filter feed rather than be totally parasitic. The possibility that the large coxal setae represent vestigial epipods is discussed. Aspects of ecology, demography, and host specificity are briefly summarized. Wagin's (1976) biogeographical model of the provenance of Gorgonolaureus, based on outdated information, is rejected.     

Biogeography of amphipods (Crustacea: Amphipoda: Gammaridae) from the central Zagros Mountains,Iran, with descriptions of two new species

Seven species of gammarid amphipods were studied in the relatively small province of Charmahal-Va-Bakhteyari in the central Zagros Mountains, Iran. Of these, four are previously known (Gammarus proiectus, G. komareki, G. syriacus and G. balutchi), one is a new record for the region (G. pseudosyriacus) and two are new species (G. lordeganensis and G. bakhteyaricus). From the taxonomic point of view, head microsculpturing characters were found to be reliable as discriminating sets of characters useful in species identification. Habitat diversification and climatic fluctuations appear to be the main factors for species diversity of the area, and the Zagros Mountains act as a geographical barrier to species distribution.     

Freshwater sponges of the West Indies: Discovery of Spongillidae (Haplosclerida,Spongillina) from Cuba with biogeographic notes and a checklist for the Caribbean area

The paper reports the first finding of freshwater sponges from the Greater Antilles. Spongillidae belonging to four species of the genera Ephydatia, Anheteromeyenia, and Radiospongilla were found in a variety of freshwater habitats in western Cuba. Anheteromeyenia cheguevarai nov. sp. is described. Morphological traits of sponges from West Cuba were characterized by light microscopy and scanning electron microscopy and compared to the spongillofauna of the Nearctic and Neotropical regions and the pan‐Caribbean area. The specific richness and the discovery of a new species suggest a high diversity of the Antillean freshwater sponges although the investigated area of Cuba is relatively small.     

Host selection by a kleptoparasitic spider

Argyrodes globosus (Keyserling, 1884) is a small kleptoparasite spider that steals prey from the web of web-building spiders. In coffee plantations in the south of Mexico it was observed to parasitize five species: Gasteracantha cancriformis (Linnaeus, 1785) and Verrucosa arenata (Walckenaer, 1841) (Araneidae), Leucauge mariana (Keyserling, 1881) and Leucauge venusta (Walckenaer, 1841) (morphologically indistinguishable species) and Leucauge argyra (White, 1841) (Tetragnathidae). G. cancriformis was more frequently parasitized than the other hosts. An analysis of web diameter for each host species indicated that for L. mariana/venusta, L. argyra and V. arenata the kleptoparasite was associated with webs of a certain size range (23-33cm diameter) although a far larger range of web sizes was available (17-50cm diameter). The average size of the web of G. cancriformis (~23cm) appeared to be close to the preferred size for the kleptoparasite and this, together with an apparent absence of host aggression, may explain the prevalence of A. globosus with this host. For the parasite, web size choice may involve a tradeoff among diverse factors including prey capture rate, ease of access to the web and aggressive behaviour by the host.     

Community composition of laelapine mites (Acari: Laelapidae) associated with the nests and fur of Cerradomys subflavus (Wagner, 1842)

Knowledge about the role of the nest environment in the life cycle of laelapine mites associated with neotropical small mammals is unclear because nests have rarely been collected. Here we use infestation data to make predictions about host–mite ecology and examine the nests of the host to assess the validity of these predictions. Spool-and-line method was used to track Cerradomys subflavus nests. We found that: the structure of mite populations infesting the body of C. subflavus, was strongly biased toward the reproductive female stage; recaptured hosts were re-infested with laelapine mites at different rates; and female hosts were not more highly infested than males. We found strong evidence of nidicoly with both, Gigantolaelaps vitzthumi and Androlaelaps fahrenholzi. The G. vitzthumi was more abundant in the nests of female rodents and with both these mite species, we encountered males and immature mites in the nests, although not in the host fur.     

Fly parasitism in Papuan frogs,with a discussion of ecological factors influencing evolution of life‐history differences

Dipteran parasitism of frogs in the Papuan region is described and aspects of the ecological interaction are detailed. The fly involved, Batrachomyia krausi, is the largest known member of an otherwise Australian genus. Larvae of this species develop in the lateral lymph sacs of frogs of the genus Rana, feed on host blood tissues, occur with high incidence and moderate intensity, yet exhibit minimal virulence. Minimal virulence and high infestation rate seen in this host–parasite system contrast with those reported for Australian congeners. These differences are hypothesized to derive from interaction of the large size of the Papuan parasite with its phylogenetically constrained life‐history. Differences in virulence exhibited between parasitic chloropids versus calliphorids and sarcophagids are discussed as consistent with ecological predictions based on parasite transmission dynamics.     

A review of the genus Scyracepon Tattersall, 1905 (Crustacea: Isopoda: Bopyridae), with description of a new species from China

The parasitic isopod genus Scyracepon Tattersall, 1905 is recorded from China for the first time, and a new species, Scyracepon distincta, is described from the host Jonas distinctus (Brachyura: Corystidae). Females of the new species can be distinguished from those of the other six species of Scyracepon by their subequal mid-dorsal projections on pereomeres 6 and 7 (lacking on other pereomeres) and pleonal segments with medial but not lateral fusion. Males of the new species have the first two pleomeres free, pleomeres 3–5 fused, and bear midventral tubercles on all pereomeres and the first pleomere. This is the first record of any species of Corystidae bearing parasitic isopods. Remarks on, and a key to, the seven known species of Scyracepon are provided.     

Larval anisakid nematodes from four species of squid (Cephalopoda: Teuthoidea) from the central and western North Pacific Ocean

Third-stage larvae of two species of the genus Anisakis, A. simplex (Rudolphi, 1809) and A. physeteris Baylis, 1923, and those of two types of Lappetascaris sp. are described from four species of squids from the central and western North Pacific Ocean. Larvae of Lappetascaris sp. Type A were 15-33 mm long and occurred individually free in the mantle musculature of squids, whereas those of Lappetascaris sp. Type B were considerably smaller, only 3–7 mm long, and were found in capsules on the stomach wall, each capsule containing up to 50–60 larvae. It is not known whether both larval types are conspecific or belong to two different Lappetascaris species. Anisakis simplex and A. physeteris larvae were found in Onychoteuthis borealijaponica Okada and Gonatopsis borealis Sasaki, and O. borealijaponica, respectively, whereas Lappetascaris sp. Type A and Type B larvae from Thysanoteuthis rhombus Troschel, Ommastrephes bartramii (LeSueur), Onychoteuthis borealijaponica and G. borealis, and O. bartramii, respectively. The findings represent several new host records and all these parasites are reported for the first time from squids in the central North Pacific Ocean.