Pomphorhynchus patagonicus n. sp. (Acanthocephala: Pomphorhynchidae) from freshwater fishes of Patagonia, Argentina

Pomphorhynchus patagonicus n. sp. is described from Lake Rosario, Chubut Province, Argentina. It is characterized by a long neck forming an asymmetrical bulb with 2 well differentiated dorsal protruberances and 14 alternating rows of 13 and 14 proboscis hooks, each row with a stout fourth hook. It most closely resembles Pomphorhynchus sebastichthydis Yamaguti, 1939, from Japan, but differs in the bulb protruberances and in having more rows of hooks and more hooks per row and in the shapes of the fourth and basal hooks. Among American species P. patagonicus shows some similarities to Pomphorhynchus yamagutii Schmidt and Hugghins, 1973, from Chile, but differs with respect to the longer neck, bulb protruberances, and proboscis armature. Pomphorhynchus patagonicus is endemic to Patagonia, where its definitive type host is the endemic fish Patagonina hatcheri (Atherinidae) and its intermediate host the endemic freshwater amphipod Hyalella patagonica. It has been found also in autochthonous fishes belonging to the families Galaxiidae and Percichthyidae and in introduced salmonid fishes.     

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.     

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.     

A key to the species of Acanthocephala parasitic in British freshwater fishes

We present methods for the collection, fixation, preservation and examination of the acanthocephalans parasitic in British freshwater fishes. An illustrated key to the species is provided.     

A new Acanthocephala Breizacanthus ligur sp. n. (Palaeacanthocephala: Arhythmacanthidae Yamatugi, 1935) parasite of some species of benthic fishes from the Ligurian Sea]

Breizacanthus ligur sp.n. is described and figured from several benthic fishes from the Ligurian Sea. The host species are: Argentina sphyraena, Chlorophthalmus agassizi, Gadiculus argenteus, Phycis blennoides, Coelorhynchus coelorhynchus, Capros aper, Callionymus phaeton, Helicolenus dactylopterus. The parasites were considered as belonging to the family Arhythmacanthidae Yamaguti, 1935 and to the genus Breizancanthus Golvan, 1969. Breizancanthus ligur differs from the only two known species of the genus B. irenae and B. chabaudi for the number of longitudinal rows of hooks and-or numbers of hooks in each longitudinal row, arrangment of cement glands, length of body and lenght of male genital apparatus ratio, lenght of female genital apparatus and shape of embroyophore.     

Three new Procamallanus (Spirocamallanus) species from freshwater fishes in Mexico

The following 3 new species of Procamallanus (Spirocamallanus) are described from the intestines of freshwater fishes in Mexico, all belonging to the morphological group characterized by the presence of wide caudal alae, 3 pairs of subventral preanal papillae, and unequal spicules in the male: Procamallanus (Spirocamallanus) jaliscensis n. sp. (type host: Agonostomus monticola) and Procamallanus (Spirocamallanus) gobiomori n. sp. (hosts: Gobiomorus maculatus [type host], Gobiomorus polylepis and Eleotris picta) from 2 rivers in Jalisco State, western Mexico, and Procamallanus (Spirocamallanus) mexicanus n. sp. (type host: Cichlasoma geddesi) from Xalapa District, Veracruz State (Gulf of Mexico region), southeastern Mexico. Procamallanus jaliscensis is characterized by the length of the spicules (606-900 microm and 282-354 microm), number (15-16) of spiral ridges in the buccal capsule, and the digit-like protrusion with 1 terminal cuticular spike on the female tail; P. mexicanus by the length of the spicules (456-480 microm and 231-233 microm), number (10-12) of spiral ridges in the capsule, and the shape of the female tail (conical with a suddenly narrowed distal part, without any terminal spikes); and P. gobiomori by the length of spicules (318-348 microm and 156-192 microm), number (8-10) of spiral ridges and by the digit-like protrusion with 2 terminal cuticular spikes on the female tail.     

Two new species of Ascarophis (Nematoda: Cystidicolidae) in marine fishes from Chile

In this study, we describe 2 new species of Ascarophis van Beneden, 1871 (Nematoda: Cystidicolidae), found in fishes from southern Chile. Ascarophis carvajali n. sp. was found in Austrolycus depressiceps and Patagonotothen cornucola, whereas Ascarophis draconi n. sp. was taken from Champsocephalus gunnari. These new Ascarophis species differ from other species in a combination of several morphometric and morphological characteristics. Although A. carvajali n. sp. was morphologically close to Ascarophis minuta, the new species has a larger ratio between glandular and muscular esophagus, filaments on both egg poles, and a shorter right spicule than A. minuta. Ascarophis draconi n. sp. was morphologically similar to Ascarophis adioryx and Ascarophisfiliformis. However, A. adioryx has eggs without filaments, a smaller ratio between glandular and muscular esophagus length, and a smaller ratio between left and right spicule lengths in contrast to A. draconi n. sp., whereas A. filiformis has a shorter glandular esophagus and left spicule length than A. draconi n. sp. Only 1 Ascarophis species has been recorded in a single fish from Chile (i.e., Ascarophis sebastodis in Sebastes capensis). Consequently, this study constitutes not only new species and records of Ascarophis in fishes from Chile, but also new records for the Pacific coast of South America.     

A discussion on the Heteracanthocephalidae Petrochenko, 1956 (Acanthocephala: Palaeacanthocephala)

Several heteracanthocephalid specimens were recovered from the flatfish Rhombosolea leporina (Günther), a host of Heteracanthocephalus peltorhamphi (Baylis, 1944) Petrochenko, 1956 from New Zealand. Unlike H. peltorhamphi, these new specimens have trunk spines. Measurements and proboscis armament of the new specimens are consistent with the worms being Aspersentis minor Edmonds & Smales, 1992 originally described from the Australian flounder Rhombosolea tapirina Günther. A review of the family Heteracanthocephalidae Petrochenko, 1956 was undertaken to assess the validity of its four genera and eight species. The validity of Aspersentis megarhynchus (Linstow, 1892) Golvan, 1960 (syn. Echinorhynchus megarhynchus Linstow, 1892) is questioned. E. megarhynchus is not considered to be an heteracanthocephalid and is relegated to a species inquirenda. A. megarhynchus (Linstow, 1892) of Golvan (1960) nec E. megarhynchus Linstow, 1892 is considered a synonym of A. austrinus Van Cleave, 1929. The monotypic genus Heteracanthocephalus Petrochenko, 1956 is proposed as a synonym of Aspersentis Van Cleave, 1929 because there appear to be insufficient morphological differences between them. Aspersentis peltorhamphi n. comb. is proposed for Heteracanthocephalus peltorhamphi. The monotypic genus Sachalinorhynchus Krotov & Petrochenko in Petrochenko, 1956 is considered valid, but the other heteracanthocephalid genus, Bullockrhynchus Chandra, Rao & Shyamasundari, 1985, also monotypic, is not. B. indicus Chandra, Rao & Shyamasundari, 1985 possesses more features resembling rhadinorhynchids than heteracanthocephalids but only females are known, and therefore the genus and species cannot be placed. There are currently four valid species of Aspersentis and one of Sachalinorhynchus.     

A new species of Allocreadium (Trematoda: Allocreadiidae) from freshwater fishes in the Danjiangkou Reservoir in China

A new species of Allocreadium, Allocreadium danjiangensis n. sp., is described from the intestine of several species of freshwater fish, including Abbottina rivularis (Basilewsky, 1855), Sarcocheilichthys nigripinnis nigripinns (Güther, 1873), Gnathopogon argentatus (Sauvage et Dabry 1874), Opsariichthys uncirostris bidens (Gunther, 1873), and Erythroculter mongolicus mongolicus (Basilewsky, 1855) (Cyprinidae) from the Danjiangkou Reservoir in central China. The main morphological characters of the new species are as follows: vitelline follicles numerous, extending from the level of acetabulum to posterior extremity, distributed over both sides around the ceca; cirrus sac relatively large, developed, lying obliquely anterior to the acetabulum, extending from the level of the intestinal bifurcation to the central level of acetabulum, and overlapping left or right cecal; and ovary much smaller than testes, generally close to or even overlapping the anterior border of anterior testis. Observation by scanning electron microscopy shows only 2 kinds of tegumental formations, i.e., papillae and tubercles, instead of 3 types of tegumental formations, i.e., papillae, bosses, and minute sensor receptors observed on other species of the Allocreadiidae. The tegumental striations of the present species vary on the different parts of the body. In addition, a new structure, identified as the "groove" with a tonguelike tubercle, was observed on the inner wall of acetabulum.     

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.     

A new species of erigeron (Compositae: Astereae) from Chile

Erigeron campanensis, sect.Erigeron, is described as new from Central Chile (Cerro Campana, near Valparaiso). It is most similar toE. fasciculatus, from which it differs in leaf shape, leaf arrangement, pubescence of leaves, stems, and phyllaries, and stigmatic branches, of disc florets.     

Two new species of Moniliformis (Acanthocephala: Moniliformidae) from Malaysia

Moniliformis tarsii n. sp. was found in Tarsius bancanus. It is unique in possessing 11-12 longitudinal rows of 6-7 hooks each. Hooks 2 and 3 are conspicuously enlarged, 41-55 microns long. Moniliformis echinosorexi n. sp. differs from all other species in having 12-15 rows of 11-13 hooks that are 34-36 microns long, and in having a proboscis receptacle 1.2-2.0 mm long. Several new host records for M. moniliformis are presented.     

A new species of Brachygasterina Macquart from Chile (Diptera: Muscidae)

The genus Brachygasterina Macquart is Neotropical, with six species recorded from Argentina, Chile, Ecuador and Colombia. A new species was found among an extensive unidentified muscid material from South America in the collection of the California Academy of Sciences collection (San Francisco, California, U.S.A.). Brachygasterina maculata, new species, from Santiago, Chile, is here described and illustrated, and its position in the genus Brachygasterina is discussed.     

Histopathology in Leuciscus cephalus (Pisces: Cyprinidae) resulting from infection with Pomphorhynchus laevis (Acanthocephala).

The histopathology present in Leuciscus cephalus Risso 1826 from the River Po, naturally infected with the acanthocephalan Pomphorhynchus laevis Müller 1776, was studied and described. The parasite was only found within the host's digestive tract, and a density of 10 P. laevis per square centimeter was common. On histological examination it was noticed that both male and female parasites penetrated deeply through all the layers of the host digestive tract by means of their slender neck, bulb and proboscis; thus the bulb and proboscis become encapsulated beneath the serosa and mesentery. As a result, the presence of a capsule was noticed on the external surface of the host digestive tract. P. laevis caused local damage to the intestinal wall, and the parasite elicited an intense host reaction. The response of L. cephalus at the attachment site of the acanthocephalan was hyperplasia of host connective tissue, with cellular infiltration. In a few hosts, the presence of a fibrous nodule on the outer surface of the alimentary canal was observed.     

Differential influence of Pomphorhynchus laevis (Acanthocephala) on brain serotonergic activity in two congeneric host species

The physiological mechanisms by which parasites with complex life cycles manipulate the behaviour of their intermediate hosts are still poorly understood. In Burgundy, eastern France, the acanthocephalan parasite Pomphorhynchus laevis inverses reaction to light in its amphipod host Gammarus pulex, but not in Gammarus roeseli, a recent invasive species. Here, we show that this difference in manipulation actually reflects a difference in the ability of the parasite to alter brain serotonergic (5-HT) activity of the two host species. Injection of 5-HT in uninfected individuals of both host species was sufficient to inverse reaction to light. However, a difference in brain 5-HT immunocytochemical staining levels between infected and uninfected individuals was observed only in G. pulex. Local adaptation of the parasite to the local host species might explain its inability to manipulate the behaviour and nervous system of the invasive species.     

Two new species of bucephalids (Digenea: Bucephalidae) parasitic in freshwater fishes of Argentina

Two new species of bucephalids (Digenea: Bucephalidae) were found parasitizing freshwater fishes of Argentina. Prosorhynchoides cambapuntaensis sp. n. from Salminus maxillosus (Characidae) is characterised by the tegument covered with two kinds of spines, scale-like spines anteriorly and fine spines posteriorly; uterine loops reaching the vitelline arch in the pre-oral region; and the Laurer's canal short, opening dorsally immediately posterior to the ovary. Rhipidocotyle santanaensis sp. n. from Acestrorhynchus pantaneiro (Acestrorhynchidae) is characterised by the rhynchus with two lateral projections; the testes arranged in tandem or slightly diagonal; and the vitelline follicles forming an arch in the pre-oral region.     

Two new species and one new record of Clavella (Copepoda: Lernaeopodidae) from inshore fishes of Antofagasta,Chile

Summary Clavella applicata n. sp. and C. caudata n. sp. are described and illustrated. Both species are parasitic on the fins (the latter also on the inner surface of the operculum) of Anisotremus scapularis (Tschudi), an inshore teleost fish from Antofagasta, Chile. Both new species can be distinguished from their congeners, and from each other, by various details of their appendages. C. caudata is unique in possessing modified uropods. The dorsal position of these appendages suggest that the Clavella-branch of Lernaeopodidae is related more closely to the Charopinus-branch than to Brachiella-branch of the family. C. parva Wilson, 1912, is recorded for the first time from Chilean waters, where it was found on the caudal fin of Mugiloides chilensis (Molina). ac]19840504     

A new species of freshwater triclad (Platyhelminthes: Tricladida) from Australia

A new species of freshwater triclad, Romankenkius libidinosus sp. nov. , is described from New South Wales, Australia. The species is characterized by a large adenodactyl and unique genito-intestinal connections, and represents the first record of the genus Romankenkius outside Tasmania. The taxonomic and phylogenetic implications of several morphological features of the new species are discussed in the light of a previous phylogenetic study.     

Phylogenetic relationships of Palaeacanthocephala (Acanthocephala) inferred from SSU and LSU rDNA gene sequences

The Palaeacanthocephala is traditionally represented by 2 orders, Echinorhynchida and Polymorphida, with 10 and 3 families, respectively. To test the monophyly of the class, these 2 orders, and certain families, phylogenies were inferred using nuclear small-subunit (SSU) and large-subunit (LSU) ribosomal DNA sequences obtained for 29 species representing 10 families, 2 other classes of acanthocephalans, and 3 rotifer outgroups. Phylogenetic relationships were inferred by analyzing combined SSU and LSU sequences using maximum parsimony (MP) and maximum likelihood (ML) methods. Parsimony and ML trees inferred from combined analysis of these rDNA data strongly supported monophyly of Palaeacanthocephala and provided good resolution among species. Neither Polymorphida nor Echinorhynchida was monophyletic. Gorgorhynchoides bullocki (Echinorhynchida) was nested within the 6 species representing Polymorphida, and this clade was nested within species representing Echinorhynchida. Three of 4 palaeacanthocephalan families that could be evaluated were not monophyletic, and this finding was strongly supported. These results indicate that the family level classification of palaeacanthocephalans, which is mainly based on combinations of shared characters (not shared derived characters), needs to be reevaluated with respect to comprehensively sampled phylogenetic hypotheses.