The finding of Exorchis oviformis (Trematoda: Cryptogonimidae) in the southern Maritime Territory

Some new data on the expansion, host-animals, biology and morphology of different developmental stages of the trematode Exorchis oviformis in the southern Prymorye are given. It was revealed, that the first intermediate host of that species is Stenothyra (S.) recondita. Different species of freshwater fishes play a role of a second intermediate host. The definitive host of E. oviformis is a bullhead (Parasilurus asotus).     

Genetic connectivity between north and south Mid-Atlantic Ridge chemosynthetic bivalves and their symbionts

Transform faults are geological structures that interrupt the continuity of mid-ocean ridges and can act as dispersal barriers for hydrothermal vent organisms. In the equatorial Atlantic Ocean, it has been hypothesized that long transform faults impede gene flow between the northern and the southern Mid-Atlantic Ridge (MAR) and disconnect a northern from a southern biogeographic province. To test if there is a barrier effect in the equatorial Atlantic, we examined phylogenetic relationships of chemosynthetic bivalves and their bacterial symbionts from the recently discovered southern MAR hydrothermal vents at 5°S and 9°S. We examined Bathymodiolus spp. mussels and Abyssogena southwardae clams using the mitochondrial cytochrome c oxidase subunit I (COI) gene as a phylogenetic marker for the hosts and the bacterial 16S rRNA gene as a marker for the symbionts. Bathymodiolus spp. from the two southern sites were genetically divergent from the northern MAR species B. azoricus and B. puteoserpentis but all four host lineages form a monophyletic group indicating that they radiated after divergence from their northern Atlantic sister group, the B. boomerang species complex. This suggests dispersal of Bathymodiolus species from north to south across the equatorial belt. 16S rRNA genealogies of chemoautotrophic and methanotrophic symbionts of Bathymodiolus spp. were inconsistent and did not match the host COI genealogy indicating disconnected biogeography patterns. The vesicomyid clam Abyssogena southwardae from 5°S shared an identical COI haplotype with A. southwardae from the Logatchev vent field on the northern MAR and their symbionts shared identical 16S phylotypes, suggesting gene flow across the Equator. Our results indicate genetic connectivity between the northern and southern MAR and suggest that a strict dispersal barrier does not exist.     

Gelatinous zooplankton (ctenophores,salps and medusae): an important food resource of fishes in the temperate SW Atlantic Ocean

This study quantifies the occurrence of gelatinous zooplankton in the stomach contents of fishes from the southwest Atlantic Ocean (33°–55°S). More than 69,000 fish stomachs belonging to 107 species were examined. A total of 39 fishes were documented as consumers of gelatinous zooplankton, 23 of which were newly discovered. Three gelatinous organism consumption categories are recognized: (1) very frequent consumers (10 species, six of which were exclusive); frequent consumers (five species); and occasional consumers (26 species). Three types of gelatinous prey (ctenophores, salps and medusae) were found in the stomach contents of fishes. Ctenophores were consumed at high levels across almost the entire continental shelves of Argentina and Uruguay. Salps were frequent prey on the slope and southern shelf. In contrast, medusae were consumed in coastal areas, slopes and the southern shelf. Classification methods (group average sorting of the Bray–Curtis similarity measures based on log (X?+?1)-transformed percentage data) determined six areas where fishes predated on gelatinous organisms. SIMPER (similarity percentages) analysis determined which fishes contributed more to the consumption of gelatinous organisms. Results revealed that two fish species (Stromateus brasiliensis and Squalus acanthias) had high gelatinous zooplankton predation rates throughout the entire study area, while another six species (Patagonotothen ramsayi, Helicolenus dactylopterus lahillei, Macrourus holotrachys, Merluccius hubbsi, Schroederichthys bivius, and Macruronus magellanicus), while widely distributed, seemed to have specific areas where consumption occurred. This study not only provides new knowledge about the importance of gelatinous zooplankton in the diet of numerous fishes, but might also be valuable for planning and managing local fisheries.     

Stomach contents of long-finned pilot whales (Globicephala melas) from southern Chile

The widely distributed long-finned pilot whale (Globicephala melas) has been reported off the Chilean coast, from Iquique (20°12′S) south to Navarino Island (55°15′S; 67°30′W), but little is known about its biology or ecology in the region. Here, we report on the prey of this species, identified by stomach content analyses from animals stranded on Holget Islets, Beagle Channel, southern Chile in August 2006. The stomachs of seven individuals (six females and one male) contained cephalopod remains. The prey composition found in these southern Chilean pilot whales was similar to that described in other parts of the world and the Southern Ocean. This is the first report on the feeding habits of this species from Chile.     

Infection by anisakid nematodes contracaecum spp. in the Mayan cichlid fish 'Cichlasoma (Nandopsis)' urophthalmus (Gunther 1862)

Larval nematodes that parasitize the Mayan cichlid fish 'Cichlasoma (Nandopsis)' urophthalmus (Günther 1862) in southern Florida were identified as Contracaecum spp. (Nematoda: Anisakidae, Anisakinae). The objective of this study was to determine whether infection intensity and prevalence of these parasites differ between a brackish water and freshwater habitat or through ontogeny in the freshwater habitat only. The nematodes were removed from the abdominal cavity of the fishes and counted. Infection intensity was compared between habitats using analysis of covariance and evaluated through ontogeny using Spearman rank order correlation. Prevalence was compared between habitats and between adults and juveniles from the freshwater habitat using a z-test. Although infection intensity did not differ between habitats, infection prevalence was greater at the freshwater site (FWS). Both the prevalence and intensity of nematode infection increased through ontogeny at the FWS, and no nematode was found in fishes that were smaller than 93 mm standard length. Thus, the parasites appear to accumulate during the lifetime of the fishes.     

A new species of Paracapillaria (Nematoda: Capillariidae) from the intestine of the toad Duttaphrynus melanostictus (Anura) from the Malayan Peninsula

A new species of parasitic nematode, Paracapillaria malayensis n. sp. (Capillariidae), is described from the small intestine of the toad Duttaphrynus melanostictus imported from the Malayan Peninsula to the Czech Republic. The new species differs from the only other congeneric species, Paracapillaria spratti, mainly in the shape and structure of the spicular proximal end (with a lobular rim), smaller eggs (45-51 x 21-24 microm), longer spicule (336 microm), and the number (37-38) of stichocytes in gravid females; whereas P. spratti parasitizes frogs of the Microhylidae in Papua New Guinea, P. malayensis is a parasite of Bufonidae in the Malayan Peninsula. Other Paracapillaria spp. are parasites of fishes, birds, or mammals and they mostly differ from P. malayensis in the structure of eggs and some other morphological features.     

Larval stages of the Antarctic dragonfish Akarotaxis nudiceps (Waite, 1916), with comments on the larvae of the morphologically similar species Prionodraco evansii Regan 1914 (Notothenioidei: Bathydraconidae)

The notothenioid family Bathydraconidae is a poorly understood family of fishes endemic to the Southern Ocean. There is especially little information on Akarotaxis nudiceps, one of the deepest-dwelling and least fecund bathydraconid species. Using genetic and morphological data, we document and describe the larval stages of this unique species, offer a novel characteristic to distinguish it from the morphologically similar bathydraconid Prionodraco evansii and use the sampling locations to infer a possible spawning area of A. nudiceps along the western Antarctic Peninsula. These results provide important baseline information for locating, identifying and studying the biology of A. nudiceps, an important component of the Southern Ocean ecosystem.     

Ornithodoros (Alectorobius) spheniscus n. sp. [Acarina: Ixodoidea: Argasidae: Ornithodoros (Alectorobius) capensis group], a tick parasite of the Humboldt penguin in Peru

Ornithodoros (Alectorobius) spheniscus n. sp., described from wild-caught and laboratory-reared females, males, nymphs, and larvae parasitizing the Humboldt Penguin, Spheniscus humboldti Meyen, is the fifth species of the Ornithodoros (Alectorobius) capensis group to be recognized in the Neotropical Region. A related Peruvian species, Ornithodoros (Alectorobius) amblus Chamberlin, also parasitizes S. humboldti but is recorded from a wider range of marine birds breeding on the Pacific coast and offshore islands, where the birds congregate to feed on the rich fish fauna usually produced by the Humboldt current. Differential criteria are provided for the new species, O. (A.) amblus, and Ornithodoros (Alectorobius) yunkeri Keirans, Clifford, and Hoogstraal of the Galapagos. These 3 members of the O. (A.) capensis group parasitize marine birds associated with the Humboldt current in western South America and the Galapagos. Persons visiting Humboldt Penguin breeding sites in caves and on barren coastal ledges are eagerly attacked by nymphal and adult O. (A.) spheniscus and suffer afterward from pruritus and slowly-healing blisters. The O. (A.) spheniscus life cycle required 128 to 193 days in the laboratory and, as typical of bird-parasitizing members of the subgenus Alectorobius, the first nymphal instar did not feed.     

Parasitic copepods of fishes: a new genus of the Hatschekiidae from New Caledonia,and new records of the Pennellidae,Sphyriidae and Lernanthropidae from the South Atlantic and South Pacific

A new genus and species of the Hatschekiidae, Laminohatschekia synaphobranchi, is described from an eel caught off New Caledonia. It is characterised by its long ribbon-like trunk and by the possession of three pairs of biramous legs. The pennellid Sarcotretes scopeli is redescribed from a macrourid also taken off New Caledonia. Sarcotretes lobatus is recognised as a synonym of S. scopeli. Phrixocephalus carcellesi is described in detail for the first time, from the stomach contents of a King Shag caught in the Falkland Islands. A wide range of individual variability in holdfast structure was noted in P. carcellesi. A new species, Peniculisa bellwoodi, is described from Pomacentrus amboiensis collected at Lizard Island on the Great Barrier Reef. The sphyriid Lophoura cornuta is redescribed from a synaphobranchid eel caught off New Caledonia and both sexes of a lernanthropid, Aethon morelandi, are redescribed from Nemadactylus macropterus in southern Australia.     

Competition, resource partitioning and coexistence of an endoparasitoid Encarsia perniciosi and an ectoparasitoid Aphytis melinus of the California red scale

Abstract. 1. Laboratory experiments and field studies were conducted to explain the coexistence of an endoparasitoid, Encarsia perniciosi Tower, and an ectoparasitoid, Aphytis melinus DeBach, both of which were introduced into California to control the California red scale, Aonidiella aurantii (Mask.).
2. Encarsia parasitized all scale stages but it preferred first and second instar scales. This is in contrast to Aphytis melinus , in which previous studies have shown that it parasitizes second and third instar females and second instar males but prefers third instar female scales. Encarsia developed most rapidly when it parasitized an early second instar and slowest when it parasitized the mature female scale. However, on early second instar scales it was about 80% as fecund as a wasp that emerged from a mature female scale.
3. Second instar scales parasitized by Encarsia were accepted by Aphytis as readily as unparasitized scales.
4. Encarsia did not distinguish between unparasitized hosts and those previously parasitized by Aphytis.
5. Encarsia always outcompeted by Aphytis when both species parasitize the same host.
6. Encarsia prefers scale on stems whereas Aphytis prefers those on leaves and fruits. This, too, may be a result of interspecific competition with Aphytis.
7. The partitioning of the scale resource by the two species explains why they coexist in coastal southern California but it does not explain why Encarsia disappeared from citrus groves in the inland valleys coincident with the introduction of Aphytis melinus into southern California.     

Feline cuterebrosis caused by a lagomorph-infesting Cuterebra spp. larva

Native species of rodents and lagomorphs in the Americas are the typical hosts of Cuterebra spp. larvae. Although these bot flies are relatively host specific, they occasionally parasitize other native and introduced mammals (including domestic animals and humans), an affliction termed cuterebrosis. Cuterebra spp. larvae generally cause benign, subcutaneous lesions (warbles), but when infesting domestic cats, they can invade the eyes, respiratory tract, and cerebral tissues, causing severe, and in some cases fatal, injury. Despite more than 2 dozen published reports of feline cuterebrosis, the type (rodent- or lagomorph-infesting) or species parasitizing domestic cats has rarely been determined. Here, I identify a larva removed from a kitten in southern Wisconsin as belonging to a lagomorph-infesting Cuterebra species, most likely C. abdominalis, based especially on features of the cuticular platelets covering its exterior, and its geographic location. This seems to be only the third substantiated report of feline cuterebrosis in more than 50 yr in which a larva has been identified beyond "Cuterebra spp." In each case, lagomorph-infesting species were involved, suggesting that domestic cats may not be susceptible to rodent-infesting Cuterebra species. However, because these studies are limited in number and geographic area, additional research is required to establish the spectrum of Cuterebra species involved in feline cuterebrosis.     

A new species of Capillostrongyloides (Nematoda: Capillariidae) parasitizing the horsefish, Congiopodus peruvianus (Pisces: Congiopodidae), from Argentina

A new species of parasitic nematode, Capillostrongyloides congiopodi n. sp. (Capillariidae), is described based on specimens collected from the gall bladder of the horsefish, Congiopodus peruvianus Cuvier and Velenciennes (Congiopodidae, Scorpaeniformes), from the Patagonian Shelf, Argentina (45-48 degrees S; 60-64 degrees W). Among the 9 species described so far in the genus, the new species most closely resembles C. norvegica Moravec and Karlsbakk, 2000, by the presence of its conspicuously elevated anterior vulvar lip in females; however, it is readily distinguished from it by having a larger body size, larger eggs with protruding polar plugs, the shape and length of the spicule, and mainly by the general morphology of the caudal bursa of males. In addition, the site of infection, i.e., stomach versus gall bladder. This is the first Capillostrongyloides species reported from fishes in the southern Atlantic Ocean.     

Marine flora of the Iles Eparses (Scattered Islands): A longitudinal transect through the Mozambique Channel

The diversity of marine macrophytes of small islands in the South Western Indian Ocean region has been poorly documented and little or no information is available for the Iles Eparses (or Scattered Islands) in the Mozambique Channel. We present the first species checklist for the three largest islands of the Iles Eparses: Europa, Juan de Nova and Glorioso. Overall, with a total of 321 marine macrophyte species recorded (incl. 56% Rhodophyta, 27% Chlorophyta, 15% Phaeophyceae and 2% Magnoliophyta; Europa: 134 spp., Juan de Nova: 157 spp. and Glorioso: 170 spp.) these islands harbour 23.5% of the total species recorded for the Mozambique Channel region. We report 36 new records for the Mozambique Channel including 29 undescribed new and cryptic species. Our results highlight a decrease in species richness southward in the Channel. Because of their longitudinal arrangement between the northern and the southern ends of the Channel and their central position, Europa, Juan de Nova and Glorioso Islands represent data points of particular biogeographical interest and could be critical ‘stepping stones’ for connectivity in the highly dynamic Mozambique Channel region.     

Pauciconfibula patagonensis sp. nov. (Monogenea: Microcotylidae) parasitizing the horsefish, Congiopodus peruvianus (Pisces: Congiopodidae), from the Patagonian Shelf, Argentina

Pauciconfibula patagonensis sp. nov. (Monogenea: Microcotylidae), parasite of gill filaments of the horsefish, Congiopodus peruvianus (Congiopodidae) collected in the Patagonian Shelf, Argentina, is described and illustrated. The new species is characterized by having intestinal caeca not confluent and entering into the haptor, vitelline follicles extending from the genital pore to near the posterior portion of haptor, two parallel rows each comprised of 16-20 microcotylid clamps in the haptor, 25-43 testes and a fusiform egg with one very long tangled polar filament. P. patagonensis is the only member of the genus known to parasitize a scorpaeniform host and represents the first record of a representative of this genus in the southern Atlantic Ocean.     

Molecular phylogeny of gill monogeneans (Platyhelminthes, Monogenea, Dactylogyridae) and colonization of Indo-West Pacific butterflyfish hosts (Perciformes, Chaetodontidae)

We investigated the phylogenetic relationships among monogenean parasites of the Chaetodontidae (butterflyfishes) from the Indo-West Pacific Ocean. Molecular phylogenies of selected taxa within the Dactylogyridae, including the ancyrocephaline parasites of butterflyfishes, based on two nuclear and one mitochondrial gene fragments (complete 18S rDNA, partial 28S rDNA (D1-D3), and partial 16S rDNA) were reconstructed using parsimony, maximum likelihood and Bayesian inference methods. Our results show the non-monophyletic nature of the monogenean fauna of butterflyfishes. The group is divided into two independent lineages. The first clade contains species of the genera Aliatrema and Euryhaliotrematoides , which parasitize Chaetodontidae exclusively. The second contains species of Haliotrema , a generalist group of parasites. The positions of several other species of the Ancyrocephalinae, including freshwater species, at the base of the two clades, provide strong evidence that the monogenean fauna did not result from a single colonization event, but rather that they have colonized their butterflyfish hosts independently at least twice.     

New Host and Locality Records for the Ixodes Auritulus (Acari: Ixodidae) Species Group, with a Review of Host Relationships and Distribution in the Neotropical Zoogeographic Region

New Neotropical records are presented for ticks belonging to the Ixodes auritulus Neumann, 1904, species group, together with a review of hosts and localities from which members of this complex have previously been collected. The range of the I. auritulus species group is now understood to include Colombia, and 15 bird species are listed as new hosts. From Guatemala to southern Argentina and Chile, specimens of the I. auritulus group have been found on birds belonging to the orders Ciconiiformes, Columbiformes, Falconiformes, Galliformes, Passeriformes, Piciformes, Procellariiformes and Tinamiformes. Passeriform birds are probably the principal hosts, sustaining tick populations throughout the Neotropics. Collection data have yielded four areas – southern South America (from 56° S to 51° S), southern Brazil (25° S–22° S), south-central Peru (14° S–10° S) and Central America (10° N–15° N) – where the I. auritulus group appears to commonly parasitize birds, but additional collections may show that the range of this complex is less discontinuous than currently perceived. Several morphological differences are described for ticks within and among these areas, but it is still unclear whether the I. auritulus group comprises more than one species.     

Molecular and morphometric evidence for separate species of Uncinaria (Nematoda: Ancylostomatidae) in California sea lions and northern fur seals: hypothesis testing supplants verification

California sea lions (Zalophus californianus) and northern fur seals (Callorhinus ursinus) are each believed to host distinct hookworm species (Uncinaria spp.). However, a recent morphometric analysis suggested that a single species parasitizes multiple pinniped hosts, and that the observed differences are host-induced. To explore the systematics of these hookworms and test these competing hypotheses, we obtained nucleotide sequences of nuclear ribosomal DNA (D2/D3 28S, D18/D19 28S, and internal transcribed spacer [ITS] regions) from 20 individual hookworms parasitizing California sea lion and northern fur seal pups where their breeding grounds are sympatric. Five individuals from an allopatric population of California sea lions were also sampled for ITS-1 and D18/D19 28S sequences. The 28S D2/D3 sequences showed no diagnostic differences among hookworms sampled from individual sea lions and fur seals, whereas the 28S D18/D19 sequences had one derived (apomorphic) character demarcating hookworms from northern fur seals. ITS sequences were variable for 7 characters, with 4 derived (apomorphic) states in ITS-1 demarcating hookworms from California sea lions. Multivariate analysis of morphometric data also revealed significant differences between nematodes representing these 2 host-associated lineages. These results indicate that these hookworms represent 2 species that are not distributed indiscriminately between these host species, but instead exhibit host fidelity, evolving independently with each respective host species. This evolutionary approach to analyzing sequence data for species delimitation is contrasted with similarity-based methods that have been applied to numerous diagnostic studies of nematode parasites.