Description of Pomphorhynchus spindletruncatus n. sp. (Acanthocephala: Pomphorhynchidae) from freshwater fishes in northern Iraq,with the erection of a new pomphorhynchid genus,Pyriproboscis n. g., and keys to genera of the Pomphorhynchidae and the species of Pomphorhynchus Monticelli, 1905

The status of species of Pomphorhynchus Monticelli, 1905 is examined and 23 species are recognised as valid. These include P. spindletruncatus n. sp., which is described herein from two species of freshwater fishes in northern Iraq, Aspius vorax Heckel and Barbus xanthopterus (Heckel) (Cyprinidae). Only one other species, P. yunnanensis Wang, 1981, has a spindle-shaped trunk similar to that of P. spindletruncatus, but is distinguished from it by a distinctly different proboscis armature. A key separating the new taxon from other species of Pomphorhynchus is included. P. heronensis Pichelin, 1997 is reassigned to a new pomphorhynchid genus, Pyriproboscis n. g., based on its unique proboscis shape and armature, short proboscis receptacle and tubular cement glands. A key to the genera of the Pomphorhynchidae is also included.     

Acanthocephala from lake fishes in Wisconsin: ecology and host relationships of Pomphorhynchus bulbocolli (Pomphorhynchidae)

Pomphorhynchus bulbocolli Linkins in Van Cleave, 1919, was considerably more common in fishes of the river-connected Tichigan Lake than of the landlocked Silver Lake, southeastern Wisconsin. It is reported from 17 species of principal, accessory, and occasional definitive hosts (new record in Moxostoma carinatum) and from 13 species of paratenic hosts (new records in Amia calva, Ictalurus punctatus, Lepomis cyanellus, and Pomoxis nigromaculatus). Infection patterns were influenced by fish species, feeding behavior, temperature, availability of intermediate host, type of water body, fish movement, and changes in fish host community. Host roles are not fixed but are often interchangeable. A seasonal cycle in prevalence, intensity, and maturation was evident, with greatest abundance and maturation during summer and recruitment during summer and autumn. Recruitment of new infections, development, and release of eggs, however, occurred all year. Sex ratio changed from near equal in new infections to one more highly in favor of females in older adults. Female fish were considerably more frequently and heavily infected than males. No relationship with fish age (size) was evident. Worms were mostly attached in posterior intestinal locations but initial establishment sites correlated with temperature. Translocation of P. bulbocolli due to competitive exclusion in concurrent infections was not observed. The significance of extraintestinal larval forms in the cycle of transmission was noted.     

The description of Paralongicollum nemacheili n. gen., n. sp. (Acanthocephala: Pomphorhynchidae) from freshwater fishes in Kazakh S.S.R

Paralongicollum nemacheili n. gen., n. sp. is described from Salmo gairdneri Richardson and Nemacheilus stoliczkai Steindacher in Lake Kul'say in the basin of Lake Balkhash, Kazakh S.S.R. Its long uniformly cylindrical neck and nonfiliform proboscis distinguish it from the other 3 genera of the family. Tenuiproboscis Yamaguti, 1935, has a filiform proboscis. The neck of Pomphorhynchus Monticelli, 1905, has a bulb anteriorly, and that of Longicollum Yamaguti, 1935, is spirally twisted with expansions. A key to the genera of Pomphorhynchidae is provided. The relatively longer necks in juveniles than in larger worms probably enhance the establishment of new infections. A large proportion of worms had extensive body wall deformities. Longicollum sergenti (Choquette and Gayot, 1952) Golvan, 1969, is relegated to the new genus Paralongicollum.     

Hysterothylacium patagonense n. sp. (Nematoda: Anisakidae) from freshwater fishes in Patagonia,Argentina, with a key to the species of Hysterothylacium in American freshwater fishes

A new anisakid nematode, Hysterothylacium patagonense n. sp., is described from the intestine of the temperate bass Percichthys trucha (Cuvier & Valenciennes), a freshwater fish from Lake Aluminé, Patagonia, Argentina. It is characterised mainly by the absence of lateral alae, the length ratio of the caecum and ventricular appendix (1:0.9–1.8), the length of the spicules (0.952–1.292 mm) and the presence of minute spines on the tip of the tail. In the same locality and in Lake Huechulafquen, advanced third-stage and fourth-stage larvae of this parasite were also recorded from the digestive tract of the introduced salmonids, Salvelinus fontinalis (Mitchell), Oncorhynchus mykiss (Walbaum) and Salmo trutta L. This is the second Hysterothylacium species described from freshwater fishes in South America. A key to Hysterothylacium species parasitising American freshwater fishes is provided.     

A new species of Pomphorhynchus (Acanthocephala: Palaeacanthocephala) in freshwater fishes from central Chile

This study describes a new species of Pomphorhynchus collected from Percilia gillissi Girard, 1855 from the Za?artu canal, between the sister basins of the Itata and Laja rivers, in central Chile. Pomphorhynchus moyanoi n. sp. is characterized by an asymmetrical, well-differentiated subspherical bulb and 12-14 longitudinal rows of 13-14 hooks; the third and the fourth hook in each row are stout. Among South American species, P. moyanoi n. sp. shows some similarities to the Chilean species P. yamagutii Schmidt & Hugghins, 1973, but it differs in having a longer neck, larger bulb, and different proboscis armature arrangement. Pomphorhynchus moyanoi n. sp. differs from P. patagonicus Ortubay, Ubeda, Semenas & Kennedy 1991, in the bulb shape (protuberances), number of rows, fourth hook size and basal hook size. Pomphorhynchus moyanoi n. sp. also differs from P. sphaericus in the arrangement of hooks (number of rows and hooks per row), length and width of the proboscis, neck width, and symmetry of the bulb.     

Acanthocephaloides cyrusi n. sp. (Acanthocephala: Arhythmacanthidae) from southeast African teleost fishes

A new species,Acanthocephaloides cyrusi, is described from the fishesSolea bleekeri andPomadasys commersoni from Lake St. Lucia, Natal, South Africa. It is distinguished from the other species in the genus by the more marked sexual dimorphism in length, the arrangement of hooks, the proboscis with the longest hooks at the anterior-most extremity and the greater size of the proboscis hooks and body spines. An acanthella, which may represent this species, was found in the tanaidApseudes digitalis.     

Pilum pilum gen. et sp. n. (Acanthocephala: Echinorhynchidae) from freshwater fishes of the southeastern United States.

Pilum pilum gen. et sp. n. is described from the warmouth, Lepomis gulosus (Cuvier); brown bullhead, Ictalurus nebulosus (Lesueur); yellow bullhead, I. natalis (Lesueur); redbreast sunfish, L. auritus (Linnaeus); bluegill, L. macrochirus Rafinesque; spotted sunfish, L. punctatus (Valenciennes); and redfin pickerel, Esox americanus (Gmelin), from the Alabama River Drainage, brown bullhead from the Mobile Bay Drainage in Alabama, and pirate perch, Aphredoderus sayanus Gilliams, from an Atlantic Coast drainage in Georgia. The new genus most closely resembles the genus Acanthocephalus; it differs from this genus in having a distinctive pear-shaped proboscis, a long neck, and hooks which abruptly differ in size.     

First record of Pomphorhynchus laevis (Acanthocephala) in fishes from Northern Ireland

During the spring and summer of 1999, Pomphorhynchus laevis was recovered from rainbow trout Oncorhynchus mykiss raised in a Northern Ireland fish farm and from a European eel Anguilla anguilla from the Erne catchment, Ireland. These records appear to be independent of each other. They are the first reports of P. laevis from fish in Northern Ireland.     

Seasonality of recruitment and reproduction of Acanthocephalus tumescens (Acanthocephala) in fishes from Lake Moreno (Patagonia, Argentina)

The seasonality of recruitment and reproduction of Acanthocephalus tumescens at the component population level was investigated in Lake Moreno (Patagonia, Argentina). Seasonal samples of the principal fish host species were taken between spring 1999 and spring 2000. Prevalence, mean intensity, coefficient of dispersion, sex ratio, proportion of maturity stages of females, and percentages of the 2 sources of infection in the stomach of fishes were calculated. Overall prevalence, mean intensity, and coefficient of dispersion showed the same pattern of seasonal changes. The seasonal feeding patterns of fishes affect the occurrence of A. tumescens, producing 1 peak in spring and the other peak in autumn. The lower temperature in winter delay reproductive processes after the autumn period of recruitment.     

Echinorhynchus trachyrinci n. sp. (Acanthocephala: Echinorhynchidae) from macrourid fishes of the northeast Atlantic

Echinorhynchus trachyrinci n. sp. (Palaeacanthocephala: Echinorhynchidae) is described from Trachyrincus scabrus (Rafinesque) (Macrouridae: Trachyrincinae) (type-host) and T. murrayi Günther from the northeast Atlantic. The most important diagnostic features of this species are: the number of longitudinal rows of hooks 17–22; the number of hooks per row 17–22+; the maximum length of hook blade 38–52m; the proboscis width 139–224m; and the proboscis length to width ratio 3.9–6.4:1. E. trachyrinci n. sp. is differentiated from E. gadi, E. malacocephali, E. longiproboscis, E. petrotschenkoi, E. melanoglaeae, E. theragrae and E. sebastolobi. Metechinorhynchus malacocephali Parukhin, 1985 is transferred to Echinorhynchus as E. malacocephali n. comb     

A comparative study of the host-parasite relationship of Pomphorhynchus patagonicus (Acanthocephala) in two species of fish from Lake Rosario (Chubut, Argentina).

Some aspects of the host-parasite relationships of Pomphorhynchus patagonicus (Acanthocephala) in 2 fish species from Lake Rosario (Chubut, Argentina) were studied. The fish species Patagonina hatcheri (Atherinidae) is autochthonous, and Oncorhynchus mykiss (Salmonidae) is introduced. The host species appears to influence attachment, size, sexual maturity, and distribution of parasites along the digestive tract. In P. hatcheri, an effective major host, parasites are attached firmly to the wall of the gut, well developed, attain a greater size, and a large proportion of females is gravid with ripe eggs. In O. mykiss, an unsuccessful host, there were many unattached parasites that were small and not well developed; gravid females were rare and never had ripe eggs.     

Observations on two Rhabdochona species (Nematoda: Rhabdochonidae) from freshwater fishes in Argentina, including description of Rhabdochona fabianae n. sp

Helminthological examination of specimens of the freshwater fishes Bryconamericus iheringi Boulenger, 1887 (Characidae) and Jenynsia multidentata (Jenyns, 1842) (Anablepidae), collected from Medina River, Province of Tucuman, Argentina, revealed the presence of 2 species of parasitic nematodes, Rhabdochona fabianae n. sp. and Rhabdochona acuminata (Molin, 1860) (Rhabdochonidae). Rhabdochona fabianae n. sp. was characterized by the presence of 16 anterior teeth in the prostom and filamented eggs in females. Rhabdochona acuminata was recorded for the first time in the north of Argentina.     

Argentinochondria patagonensis n. gen., n. sp. (Copepoda: Chondracanthidae) parasitic on Genypterus brasiliensis (Pisces: Ophidiidae) from Patagonia, Argentina

Argentinochondria patagonensis n. gen., n. sp. (Copepoda: Chondracanthidae) is described from adult specimens recovered from the smooth kingklip Genypterus brasiliensis Reagan, 1903, from San Jorge Gulf, Patagonia, Argentina. The new genus is placed in the Chondracanthinae. Females of the new genus differ from other members of this subfamily in having 2 pairs of modified legs, a bulbose head, a long neck region, and a trunk devoid of processes. Males have usual chondracanthid form, oral appendages as in female, except a longer paragnath, fewer teeth on maxilla, and 2 pairs of reduced legs.     

Pseudocapillaria (Discocapillaria) margolisi n. subg., n. sp. (Nematoda: Trichuroidea) from freshwater fishes of West Bengal,India

A new nematode,Pseudocapillaria (Discocapillaria) margolisi n. subg., n. sp., from the freshwater fishesPuntius conchonius, P. sophore andAmblypharyngodon mola of West Bengal, India is described. The presence of a ventral lobe-like elevation with two papillae and the absence of a dorsal cuticular membrane on the male tail are referred to as distinguishing features of the new subgenus. The parasite is also characterised by small body size, short and non-annulated stichocytes, a distinctly expanded and folded lobular rim of the proximal end of the spicule, and eggs with protruding polar plugs, all features in which it differs distinctly from other species of the genusPseudocapillaria.     

Duplaccessorius andinus n. gen., n. sp. (Dactylogyridae: Ancyrocephalinae) from the gills of Percichthys trucha (Perciformes: Percichthyidae) in Patagonia, Argentina

During a parasitological survey of Patagonian freshwater fishes, specimens of a new species of Monogenea were collected from the gills of Percichthys trucha (Perciformes: Percichthyidae). This species is described as the only member of a newly proposed genus of Ancyrocephalinae. Duplaccessorius n. gen. (Dactylogyridae, Ancyrocephalinae) is characterized by hooks with 2 subunits, gonads in tandem, a coiled male copulatory organ with counterclockwise rings, an accessory piece formed by 2 distinct parts, and a nonsclerotized sinistrolateral vagina with a funnel shape vestibule. Duplaccessorius andinus n. sp. infects the gills of P. trucha (Cuvier and Valenciennes, 1840) from Andean Patagonian lakes, being the first species of Ancyrocephalinae described from a South American percichthyid.     

New species of Ergasilus von Nordmann, 1832 (Copepoda: Ergasilidae) from the gills of freshwater fishes in Patagonia,Argentina

Systematic Parasitology - A new parasitic copepod, Ergasilus yandemontei n. sp., is described based on 10 adult females collected from the gills of the atherinid silverside Odontesthes hatcheri...     

Steganoderma szidati n. sp. (Trematoda: Zoogonidae) from Galaxias maculatus (Jenyns) and G. platei Steindachner in Patagonia,Argentina

Steganoderma szidati n. sp. is described from the intestine of two freshwater fishes, Galaxias maculatus and G. platei (Galaxiidae), from Andean lakes in Patagonia, Argentina. This freshwater zoogonid species fits in the genus Steganoderma (sensu Bray, 1987) because of the length of the caeca and the position of the vitelline follicles. The new species is characterised by possesing 6-13 vitelline follicles situated between the anterior margin of the ventral sucker and the poterior margin of the testis. The gonads are in the anterior hindbody and the ovary is anterior to the right testis. The cirrus has two conspicuous spines at its distal end, and the seminal vesicle always exhibits a constriction. The excretory vesicle never reaches the level of the posterior margin of the testes.