Short Spicules Research Articles

Three new species of free-living nematodes from inter-tidal sediments in southern New Zealand

Abstract Three new species are described from sheltered intertidal sediments of Papanui Inlet, southern New Zealand. Microlaimus falciferus n. sp. is characterised by a cuticle with two lateral alae, the presence of pores between the cephalic setae, a strongly sclerotised and non-compartmentalised mouth cavity and scythe-shaped spicules with two sub-lateral pre-cloacal setae. This is the first species of the family Microlaimidae described as having lateral differentiation of the cuticle. Microlaimus falciferus n. sp. can also be differentiated from other Microlaimus species by the presence of two types of porids, i.e., pores and short hollow setae, as all other species of the genus possess only one type of porid (when present). Aponema subtile n. sp. is characterised by its slender form, relatively long tail, presence of longitudinal bars and lateral grooves on the cuticle and groups of short setae in the pre- and post-cloacal regions. It is similar to A. torosum in the structure of the male sexual organs but differs from the latter in the following ways: higher a values (30-40 vs 17-27); longer tail (5.4-7.8 vs 4-5 anal body diam. long) and a weakly sclerotised pharyngeal bulb that is never angular in appearance. Sabatieria annulata n. sp. is most similar to the cosmopolitan species S. punctata, the main difference being the absence of punctations in S. annulata n. sp. Sabatieria annulata n. sp. also has shorter spicules (34-36 vs 41-54 μm) and shorter gubernacular apophyses (14-16 vs 20-24 μm) than S. punctata.

Three new species of free-living nematodes of the family Comesomatidae from the delta of the Mekong River, Vietnam (Nematoda, Monhysterida)

Sabatieria parvula sp. n., Dorylaimopsis tumida sp. n. and Paracomesoma curvatum sp. n. from the delta of the Mekong River (Vietnam) are described and illustrated. Sabatieria parvula sp. n. differs from S. parabyssalis Wieser, 1954 and S. stekhoveni Vitiello, 1970 in the slenderer body, longer tail and narrowed labial region. Dorylaimopsis tumida sp. n. differs from D. mediterranea Grimaldi de Zio, 1968 in the shorter body, longer cephalic setae, shorter spicules and absence of striation of spicules. Paracomesoma curvatum sp. n. differs from P. longispiculum (Timm, 1961) in the longer body, shorter cephalic setae, longer stoma and spicules, and structure of cuticle areolation.

Two new species of Philometra (Nematoda: Philometridae) parasitic in the perciform fish Cynoscion nebulosus (Sciaenidae) in the estuaries of South Carolina, USA

Two new nematode species of Philometra Costa, 1845, P. carolinensis sp. n. and P. cynoscionis sp. n., are described from the spotted seatrout, Cynoscion nebulosus (Cuvier) (Sciaenidae, Perciformes) in estuaries on the Atlantic coast of South Carolina, USA. Philometra carolinensis (males and gravid and subgravid females) parasitic in the host's ovary is most similar to P. lateolabracis (Yamaguti, 1935) in female morphology, but distinctly differs from it in possessing conspicuously short spicules (81-87 microm long) with heavily sclerotized distal parts, the gubernaculum bearing a reflected dorsal barb, and in the length ratio of the gubernaculum and spicules (1:1.23-1.42) in the male. Philometra cynoscionis (only gravid females) found subcutaneously in the host's tissue (lateral to the ascending process of the premaxilla and also posteromedial to the length of each maxilla) is characterized mainly by the presence of cephalic papillae arranged in two circles (8 large papillae in outer circle and 6 small papillae in inner circle), the absence of caudal projections, the body size (length of gravid female 20-33 mm) and the location in the host.

New Host Records, Redescriptions and New Species of Labiostrongylinea (Nematoda: Chabertiidae) from Macropodid Marsupials, with a Revised Host-Parasite Checklist

SummaryNew host records: from Macropus rufogriseus for Labiosimplex clelandi, M. robustus for Ls. aridus, Thylogale stigmatica for Ls. thetidis, and M. parma for Ls. bancrofti are reported. On re-examination of all material, Labiosimplex quasibancrofti was found to be morphologically indistinguishable from Ls. australis and is therefore a synonym of Ls. australis. A new species of Labiomultiplex, described from a single female from M. parma, is differentiated by the shape of the lateral lips and Lm. kimberleyensis is redescribed from additional material collected from the type-host, Onychogalea fraenata, from Queensland. Two new species of Labiosimplex are described from macropodid marsupials from central Australia. Labiosimplex centralis sp. nov. from the stomach of Petrogale lateralis differs from the most similar of its congenors, Ls. thomasae (both lacking a gubernaculum), in having shorter spicules, a shorter dorsal lobe of the bursa, and in the form of the dorsal ray. Labiosimplex territoriensis sp. nov. from the stomach of M. antilopinus differs from all its congenors in having large multi-lobed oesophago-intestinal diverticula. A new species, Labiostrongylus arnhemensis sp. nov. from the stomach of M. bernardus from the Northern Territory, differs from its congenors in a suite of characters including the position of the deirids, the shape of the oesophago-intestinal diverticula, the length of the dorsal lobe of the bursa, the morphology of the genital cone and gubernaculum and the length of the female tail. A revised host-parasite checklist, including Labiostrongylinea from the island of New Guinea together with those occurring in Potoroidae, is given.

A new species of Pterothominx Freitas, 1959 (Nematoda: Capillariidae) parasitising psittacine birds (Psittaciformes)

A new species, Pterothominx (Pterothominx) moraveci n. sp. (Trichinelloidea: Capillariidae) is described from an Australian parrot, Barnardius zonarius Shaw (Psittacidae: Psittaciformes), imported from Germany and kept in captivity in the Czech Republic. Males of the new taxon differ from all other species of the subgenus Pterothominx Freitas, 1959, which mainly parasitise galliform birds, in having a shorter spicule (0.925-1.338; mean 1.050 mm), a shorter body length and a different form of armed spicular sheath and bursa. Females differ in having the smallest eggs (40-50 x 20-25; mean 48 x 23 microm) and in other morphometrical characters. From the species P. (P.) totani (Linstow, 1875), which parasitises charadriiform birds, the new species differs in its smaller number of stichocytes (females 42-46, mean 44; versus 50-54), different form of the bursa and praebursal alae, and other characters. This is the only species of Pterothominx that parasitises psittacine birds.

Graphidioides subterraneusn. sp. (Nematoda: Trichostrongyloidea) from the South American subterranean rodentCtenomys talarumThomas, 1898 (Rodentia: Octodontidae)

A new nematode species, Graphidioides subterraneus n. sp., found in the stomach of C. talarum from Argentina is described. The new species more closely resembles G. mazzai Lent & Freitas, 1935, parasite of Galea leucoblephara from Argentina, and G. kravetzi Sutton & Durette-Desset, 1995, parasite of Holochilus brasiliensis from Uruguay. It can be distinguished by shorter spicules, by the shape of the gubernaculum, by shorter uterine branches, and by a different number of ridges of the synlophe all along the body.

Differentiation of Cylicocyclus gyalocephaloides of Equus burchelli from Cylicocyclus insigne of Equus caballus (Strongyloidea: Nematoda)

Abstract Specimens of Cylicocyclus insigne (Boulenger, 1917) from Equus caballus and Cylicocyclus gyalocephaloides Ortlepp, 1938 from Equus burchelli were studied to determine whether they should be recognized as separate species. Both are relatively large species with broader than deep buccal capsules with thick, concave walls and a distinct basal external ring; a large esophageal funnel without a thick cuticular lining; and an excretory pore and cervical papillae at or near the junction of the esophagus and intestine. Although the specimens of C. gyalocephaloides are as long or longer than C. insigne, the former have a longer esophagus, males have shorter spicules and a longer gubernaculum, and females have a shorter vagina. In addition, the dorsal papillae of the genital cone of C. gyalocephaloides are more slender than those of C. insigne and bilateral spines present on the genital cones of C. insigne were not found on the available specimens of C. gyalocephaloides. It was concluded that sufficient mo...

A new entomopathogenic nematode, Steinernema robustispiculum n. sp. (Rhabditida: Steinernematidae), from Chumomray National Park in Vietnam

Steinernema robustispiculum n. sp. (Rhabditida: Steinernematidae) was isolated from woodland in Chumomray National Park, Sason, Sathay, Kontum, Vietnam. Its morphology, morphometrics, cross-hybridisation and the ITS-rDNA sequence analysis revealed that S. robustispiculum clearly differs from other known Steinernema spp. As in the cases of S. intermedium (Poinar, 1985), S. robustispiculum has very robust spicules, but it can be distinguished by the longer tail of the infective juvenile, lower E%, shorter spicules, the shape of the spicules, the number of genital papillae in the caudal region and the presence of a mucron on the male tail. S. robustispiculum has a lateral field resembling that of S. sangi Phan, Nguyen & Moens, 2001, but can be distinguished by a higher E%, higher D%, smaller length to width ratio of the spicules and the morphology of both the spicule head (manubrium) and the dorsal lobe of the spicule. The morphometrics of infective juveniles of S. robustispiculum are similar to those of S. monticolum Stock, Choo & Kaya, 1997; these species can be distingusihed by the position of the excretory pore, the smaller length to width ratio of the spicules, and the length and morphology of the spicule head (manubrium). The phylogenetic relationships within Steinernema Travassos, 1927, including the newly sequenced Vietnamese species S. robustispiculum n. sp., S. loci Phan, Nguyen & Moens, 2001, S. thanhi Phan, Nguyen & Moens, 2001 and S. sangi, are presented based on analyses of the ITS-rDNA. The ITS RFLP profiles obtained from 17 different restriction enzymes are also presented.

Hysterothylacium winteri sp. n. (Nematoda: Anisakidae), a parasite of Chilean rock cod, Eleginops maclovinus (Perciformes: Eleginopidae), from South Chile.

Hysterothylacium winteri sp. n. (Nematoda: Anisakidae) was collected from the intestine of a marine-estuarine fish, Eleginops maclovinus (Valenciennes) (Perciformes: Eleginopsidae), from Abtao in the Gulf of Ancud, Chile. Sixteen (51.6%) out of 31 fish were infected; the intensity was 1-10 (mean 4) worms/host. The new species belongs to the group of congeners possessing one double pair of postanal papillae. By possessing a lateral pair of phasmids situated near the tip of tail, H. winteri most closely resembles Hysterothylacium habena. The new species can be distinguished by the lip flanges forming broadly rounded points and the equal, short spicules (320-400 microm long) representing 0.9-1.7% of body length.

Oxyonchus Longisetosus n. sp. Oxyonchus Evelynae n. sp. and Oxyonchus Culcitatus Wieser, 1959 (Thoracostomopsidae: Enoplida: Nematoda) from Australian Ocean Beaches, Together with Observations on the Variability of Taxonomic Characters and a Key to Species of the Genus Oxyonchus

Two new species of Oxyonchus are described and O. culcitatus Wieser, 1959, is re-described from the coast of eastern Australia. All three were collected from between the tide-marks from sandy beaches. Oxyonchuslongisetosus n.sp. is distinguished from other species of the genus by the combination of very long cephalic setae, low arched mandibles and stout ` comma-shaped' spicules. Oxyonchus evelynaen.sp. also possesses long cephalic setae and `comma-shaped' spicules but has higher rectangular mandibles. Oxyonchus culcitatus shares the long cephalic setae and low arched mandibles with O. longisetosus but has thin semi-circular spicules. Other described species have relatively shorter cephalic setae, rectangular mandibles and short stout spicules. A key to the identification of 14 valid species of Oxyonchus is provided. Several other early descriptions are considered species inquirenda because they are based on inadequate material, usually single females or juveniles. Scanning electron photomicrographs illustrate the head and buccal structures more clearly than they can be seen by light microscopy.

Two species of Acuaria Bremser, 1811 (Nematoda: Acuarioidea: Acuariidae) in passerine birds from the Area de Conservacion Guanacaste, Costa Rica.

Two species of Acuaria were collected from passerine birds from the Area de Conservacion Guanacaste, Costa Rica. Acuaria mayori Lent, Freitas and Proenca, 1945, was collected from Myiarchus nuttingi. Specimens from Costa Rica differ from the original description by having a spicule ratio of 1:1.5-1.7 versus 1:1.43-1.47, as well as shorter spicules and female tails. Acuaria wangi n. sp. in Hylophylax naevioides and Gymnopithys leucaspis resembles A. alii, A. crami, A. cyanocitta, A. minuta, A. pattoni, and A. cissae by having cordons extending posteriorly to the anterior portion of the glandular esophagus. The new species differs from A. alii by having 4 pairs of preanal and 6 pairs of postanal papillae rather than 2 pairs of preanal and 7 pairs of postanal papillae, a shorter left spicule, a spicule ratio of 1:1.6-1.8 versus 1:1.1 and in having spicules with blunt rather than pointed distal ends. Acuaria crami and A. minuta differ from A. wangi by having 7 pairs of postanal papillae and spicule ratios of 1:1.6-1.8 versus 1:1.3 in A. crami and 1:1.1 in A. minuta; in addition, A. minuta has spatulate-shaped spicules and a tricupsid-shaped distal end of the right spicule. The new species can be distinguished from A. pattoni by having a longer left spicule and a spicule ratio of 1:1.6-1.8 versus 1:1 and from A. cissae by having a shorter left spicule and a spicule ratio of 1:1.6-1.8 versus 1:2.5-2.7. Acuaria wangi is similar to A. cyanocitta, which has similarly shaped spicules, including a very pointed distal end of the left spicule, but differs in body length, in having shorter spicules, in the arrangement of postanal papillae, and in having smaller eggs.

Four new species of Dorylaimida (Nematoda) from New Zealand

Four new nematode species belonging to the families Aporcelaimidae, Qudsianematidae and Leptonchidae (Dorylaimida) are described from native vegetation in New Zealand. Makatinus silvaticus n. sp. is 2.3–2.7 mm long and has characteristically narrow lateral hypodermal chords, a lip region set‐off by a slight depression, a 25–27 μm long odontostyle, and a pharyngo‐intestinal junction with a disc. The females have a longitudinal vulva and characteristically shaped vaginal sclerotisation; the males have large spicules and 11–12 ventromedian supplements. Hulqus zelandicus n. sp. females are 0.9–1.0 mm long and have a set‐off lip region, a 7–9 μm long odontostyle, wine‐glass‐shaped amphids with small apertures, a monoopisthodelphic gonad, a posteriorly directed vagina and a long filiform tail; males are unknown. Proleptonchus attenuatus n. sp. is 1.5–1.9 mm long and slender and has a set‐off lip region, a 7.5–8.5 μm long odontostyle, and an elongate pharyngeal bulb; the female has a pseudomonodelphic gonad, the posterior branch being reduced to a vestigial oviduct and traces of an ovary; the males have short spicules. Capilonchus capitatus n. sp. is 1.7–2.2 mm long and slender and has a set‐off lip region with a prominent labial disc, a 9.0–9.5 μm long, attenuated odontostyle with fine lumen and aperture, and a pharyngeal bulb set‐off by a constriction; the female has a pseudomonodelphic gonad, the posterior branch being reduced to a vestigial oviduct and traces of an ovary; the males have dorylaimoid spicules and five ventromedian supplements.

The African Rhigonematoidea (Nematoda: Rhigonematida). 2. Six new species of Rhigonema Cobb, 1898 (Rhigonematidae)

AbstractSix new species of Rhigonema are described from the gut of various African diplopods. Rhigonema fecundum sp. n., from South Africa, is characterised by medium to fairly long body length, finely pilose anterior region, posterior margin of cephalic collar smoothly fused to body contour, Type 2 genital tract with a long ovejector, presence of a long, closely adpressed, vulval flap, tail shape in both sexes, broad spicules of medium length and complement of 23 copulatory papillae of which three pairs are subdorsal or sublateral in position. Rhigonema oxydesmi sp. n., from Oxydesmus platycercus concolor, Zaire, is characterised by medium body length, slightly projecting cephalic collar, finely pilose anterior region, Type 2 female genital tract with a long ovejector, presence of a short, adpressed, vulval flap, tail shape in both sexes, medium length spicules with a hamate capitulum and complement of 23 copulatory papillae, three pairs of which are subdorsal or sublateral in position. Rhigonema peziphorum sp. n., from Sphaerotherium selindum, Zimbabwe, is characterised by medium body length, prominently projecting cephalic collar, finely pilose anterior region, Type 1 female genital tract with a medium length ovejector, rather large eggs, absence of a prominent vulval flap, presence of a spermatophore, tail shape in both sexes, unusually short spicules with a weakly hamate capitulum and complement of 23 copulatory papillae. It is the only known Rhigonema species to form a spermatophore. Rhigonema rostrellum sp. n., from Ivory Coast, is characterised by medium body length, finely pilose anterior region, Type 2 genital tract with a very long ovejector, presence of a closely adpressed vulval flap, tail shape in both sexes, broad spicules of medium length and complement of 23 copulatory papillae of which three pairs are subdorsal or sublateral in position. Rhigonema spicatum sp. n., from Congoromus flabellatus, Zaire, is characterised by medium body length, slightly projecting cephalic collar, densely pilose anterior region, Type 2 female genital tract with a long ovejector, presence of an adpressed vulval flap, tail shape in both sexes, relatively short spicules with a hamate capitulum and complement of 23 copulatory papillae. Rhigonema xiphiurus sp. n., from Oxydesmus sicarius, Zaire, is characterised by medium body length, projecting cephalic collar, coarsely pilose anterior region with bristly microtrichs, microtrichs extending down body to beyond vulval level in female and a similar relative position in the male, Type 2 female genital tract with a long ovejector, elongate female tail, convex conoid male tail with an exceptionally well developed subulate projection, very short spicules and disposition of the 23 copulatory papillae, three pairs of which are dorsal or sublateral in position. A synopsis of the other eight nominal species of African Rhigonema is appended.

The African Carnoyidae (Nematoda: Rhigonematida). 3. Four new species of Brumptaemilius Dollfus, 1952

Four new species of the genus Brumptaemilius Dollfus, 1952 are described from the intestine of various spirostreptid diplopods. B. antoinettae sp. n., from South Africa, is characterised by features of the male copulatory apparatus and area rugosa: two regular subventral rows of 75 (60-85) lobate, tuberculate papillae; postcloacal field of imbricate transverse rows of spines; form and disposition of subventral fields of rugosities; ventral region of tail non-rugose posterior to last pair of postcloacal papillae; spicules about 372 (338-390) μm long and with ca 44 (36-48) transverse striae; male tail spike ca 1.2 times as long as gubernaculum and female lateral alae terminating ca halfway between vulva and anus. B. imbricatus sp. n., from Zimbabwe and South Africa, is characterised by: the form of the male area rugosa, i.e., two subventral rows of tuberculate papillae bearing small lobe-like tips, a well developed postcloacal field of imbricate spines and rugosities not extending on to ventral region of subulate portion of tail; medium spicules 271 (259-287) μm long with 43 (38-49) transverse striae; subulate portion of tail rather long, 2.3 (2.1-2.6) times as long as gubernaculum; spermatophore present; lateral alae starting in anterior half of corpus in male and at anterior margin of corpus bulb in female. B. nigelus sp. n., from Nigeria and Togo, is characterised by: the form of the area rugosa, in particular that of the spine field array on the posterior cloacal lip, the extension of the rugose area on to the ventral region of the tail spike and tuberculate papillae with crown-like tips arranged as four, irregular rows anteriorly, becoming two, more regular rows posteriorly; relatively short spicule length of 215 (195-230) μm with 24 (21-29) transverse striae; subulate portion of male tail ca 1.7 times the gubernaculum length; presence of a spermatophore with a short, sinuate peduncle; lateral alae starting in vicinity of corpus/isthmus junction in both sexes. B. ugandae sp. n., from Uganda, is principally characterised by: features of the area rugosa, including the relatively few subventral tuberculate papillae arranged more or less in two rows, the shield-shaped field of imbricate spines on the posterior cloacal lip and the non-rugose ventral region at the base of the tail spike; subulate portion of male tail ca 1.6 (1.5-1.7) times the gubernaculum length; medium length spicules of 304 (266-331) μm with 21 (19-22) transverse striae; male lateral alae starting well posterior to the basal bulb and presence of a spermatophore with peduncle inserted into vulva. The type of the genus, B. sclerophorus Dollfus, 1952 is discussed and added to the list of species inquirendae.

Spinitectus osorioi n. sp. (Nematoda: Cystidicolidae) from Chirostoma spp. (Osteichthyes: Atherinidae) in Lake Pátzcuaro, Michoacán, México.

Spinitectus osorioi (Nematoda: Cystidicolidae) is described from the freshwater atherinids Chirostoma estor and Chirostoma attenuatum from Lake Pátzcuaro in the Mesa Central, Michoacán State, México. This nematode is characterized by a conspicuous protuberance on the ventral surface of the distal end of the long spicule that distinguishes it from its congeners in North America and in the neotropics. In addition, the species can be readily distinguished from 4 of the 5 nominal species of North American freshwater Spinitectus by the absence of either a terminal barb or heel on the short spicule and from Spinitectus mexicanus by the spination. Previous records of Spinitectus carolini from Chirostoma spp. in México (Lakes Pátzcuaro and Zirahuén) refer to S. osorioi, and the species appears to be specific to Chirostoma spp. The geological history of the Mesa Central drainages and the historical biogeography of freshwater atherinids in this region suggest that the origin of S. osorioi may be associated with either the marine history of their hosts or with host-switching from more distantly related freshwater hosts after colonization of freshwater environments by atherinids.

The African Carnoyidae (Nematoda: Rhigonematida). 1. Brumptaemilius brevispiculus sp. n. from Ghana with observations on copulatory plugs and spermatophore development

AbstractBrumptaemilius brevispiculus sp. n. from the gut of a spirostreptid diplopod from Ghana is described and illustrated with the aid of SEM. The species is characterised by the structure of the male area rugosa, particularly the ventral extension of the rugosities on to the tail spike and the transverse rows of imbricate spines in the postcloacal region, the tail spike ca 1-1.5 gubernaculum length long, the very short spicules bearing relatively few transverse striae, the form and disposition of the copulatory papillae and the presence of an external, pedunculate spermatophore. It is distinguished from the other nominal species in the genus, including all of the ten species inquirendae, principally by a combination of the unusually short spicules, the form of the area rugosa, vulval position and the extent of the lateral alae in both sexes. The development of copulatory plugs and spermatophores within the African Carnoyidae is discussed. Simple copulatory plugs exist in Gilsonema and Waerebekeia, but specialised spermatophores occur in Afrocarnoya and Brumptaemilius. The most complex spermatophore is found in Brumptaemilius and comprises an oval structure containing sperm connected by a hollow peduncle to the vulval/vaginal region of the female, the peduncle being inserted under the anterior vulva lip and firmly cemented into position by a copulatory plaque. This is only the second report of spermatophore development within the Nematoda.

Longidorus camelliae n. sp. (Nematoda: Longidoridae) associated with ornamental cultivars of Camellia japonica L. growing in a nursery at Fuyang, Zhejiang Province, eastern China.

A description is provided of Longidorus camelliae n. sp., a bisexual species associated with ornamental cultivars of Camellia japonica L. growing in Fuyang, Zhejiang Province, eastern China. The species is characterised by its small body length (1.83-3.54 mm), narrow (6-10 microm), anteriorly flattened, continuous head region, non-bilobed amphidial pouches, medium odontostyle length (80-91, microm) and elongate, conoid tail (32-39 microm; c' = 1.1-1.4). Males are characterised by having short spicules (44-48 microm) and a row of seven supplements. The species has only three juvenile development stages.

Microsculpture and phylogenetic significance of the spermatheca of black flies (Diptera: Simuliidae)

The highly varied spermatheca of black flies provided an under-studied character system for phylogenetic reconstruction of the Simuliidae. Scanning electron microscopy of the spermatheca of 17 simuliid species elucidated folds and spicules on the inner surface; callosities, anastomosing ridges, and minute tubercles on the outer surface; and an intricately fluted spermathecal duct. The spermatheca of Parasimulium crosskeyi, the most plesiomorphic taxon, had a slightly wrinkled inner surface and an outer surface with acutely raised polygonal ridges. Species hypothesized to be among the basal lineages of the simuliids (e.g., Helodon susanae and Prosimulium magnum) had an irregularly folded inner spermathecal surface, but their relationships were not well resolved on the basis of information about the spermatheca. More evolutionarily derived species, including a number of species in the genus Simulium, had short or filiform spicules on the inner surface of the spermatheca. Although the use of a single character system, the spermatheca, did not fully resolve relationships among Simuliidae, its utility as a rich source of phylogenetic information was demonstrated.

Some anisakid nematodes from marine fishes of Japan and the North Pacific Ocean

A recent collection of anisakid nematodes from marine fishes from Japan and the North Pacific Ocean comprised a total of seven species of two genera; six of them (Raphidascaroides nipponensis Yamaguti, 1941, Hysterothylacium aduncum aduncum (Rudolphi, 1802), H. auctum (Rudolphi, 1802), H. cornutum (Stossich, 1904), H. marinum (Linnaeus, 1767) and H. physiculi sp. n.) parasitize fishes as adults, whereas one (Hysterothylacium sp.) occurred as larvae encapsulated in the host's abdominal cavity. Hysterothylacium physiculi sp. n. from the intestine of the gadiform fish Physiculus maximowiczi (Herzenstein) (family Moridae) from the western North Pacific (Kamaishi Bay, Honshu) is characterized mainly by shape of the lips, presence of well developed lateral alae starting some distance posterior to base of the lips, a short caecum, and markedly short (324-416mum) spicules. SEM study of R. nipponensis, type species of the genus, did not confirm the presence of dentigerous ridges on the lips. All species are briefly described and illustrated and some taxonomic problems are discussed. Several new host and geographical records are presented.

Paraquimperia Africana n. sp (Nematoda : Quimperiidae), a new intestinal parasite of the eel Anguilla mossambica Peters, in South Africa.

A new seuratoid nematode of the family Quimperiidae, Paraquimperia africana n. sp., is described from the small intestine of the longfin eel, Anguilla mossambica Peters, from the Eastern Cape Province, South Africa. The new species is characterized mainly by the presence of a ventral sucker in mature males, short spicules (147-171 microm), the number and arrangement of caudal papillae, the postesophageal position of the excretory pore, and by the slender female tail. In this new species, a variability in the number (3-5 pairs) of subventral preanal papillae was observed. Paraquimperia africana is the first representative of the genus in Africa. In view of recent reports, Paraquimperia aditum (Mueller, 1934) is considered a junior synonym of Paraquimperia tenerrima (Linstow, 1878). Paraquimperia xenentodonia Gupta and Bakshi, 1984 is considered a species inquirenda.