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Summary A new nematode species, Philometroides khalili n. sp. (Philometridae), is described from female specimens recovered from the operculum of the freshwater cyprinid fish Labeo rosae Steindachner (Cyprinidae, Cypriniformes) caught in the Bubi River, Zimbabwe. Based on light and scanning electron microscopical examination, the new species mainly differs from the only other African congeneric species P. africanus Moravec et Van As, 2001 in the body shape (filiform), length of gravid female (56 - 71 mm), in possessing a large oesophageal gland with a conspicuously large cell nucleus and in the shape (transversely oval), size (up to 33 - 36 μm high) and distribution of cuticular bosses. From other congeners it differs by a combination of morphological and biometrical features

Examination of 385 specimens of the Acanthodactylus pardalis group from eastern Libya, Egypt and Israel confirmed the occurrence of two allopatric species in this area: Acanthodactylus pardalis (Lichtenstein, 1823) distributed in Egypt And eastern Libya and a hitherto undescribed species endemic to the Negev (Israel). The species differ most markedly in body size, hemipenial structure, colouration and details of sexual dichromatism. Other significant differences involve scalation and biometrics. A simple method for artefact-free use of discriminant analysis in multivariate classification is presented. Redescription of A. pardalis (Lichtenstein, 1823), description of a new species Acanthodactylus beershebensis sp.n. and corrected geographical ranges of the two species are provided. Both species, each endemic to a small area, appear to be markedly endangered by habitat destruction.

L'evolution saisonniere de l'helminthe Bathybothrium rectangulum (Bloch, 1782), parasite du barbeau (Barbus barbus), a ete etudiee d'avril 1992 a juin 1993 dans la riviere Jihlava (bassin du Danube), Republique tcheque. Bien que les cestodes soient presents chez le poisson tout au long de l'annee, leur maturation est marquee par un net caractere saisonnier - nouvelles infestations (recrutement) en ete (juillet), croissance et maturation en automne et hiver; les vers porteurs d'oeufs murs quittent le poisson-hote de mai a juillet. Les poissons les plus petits (taille ≤ 35 cm) ont ete plus souvent infestes par les cestodes que les plus grands, encore que le pic d'intensite soit maximal pour les poissons longs de 35,5 a 40 cm.

A new collection of adult anisakid nematodes from the intestine of the catfish Rhamdia guatemalensis from two cenotes (= sinkholes) and a cave in the Yucatan Peninsula, southeastern Mexico, has shown that they are conspecific with those inadequately described as Dujardinia cenotae Pearse, 1936. The female is redescribed and the male is described for the first time. The morphology of this species shows that it belongs to the genus Hysterothylacium. This is the only Hysterothylacium species recorded from freshwater fishes in Mexico and it may well be endemic to cenotes and caves of the Yucatan Peninsula.

A new nematode species, Paracapillaria epinepheli, is described from the stomach of the marine fish Epinephelus morio (Valenciennes), the red grouper, (Serranidae, Perciformes) from coastal waters of the Gulf of Mexico in Yucatan, southeastern Mexico. It is characterised mainly by its small body (body length of male and female 2.73–3.22 mm and 5.94–6.35 mm, respectively), number (31–36) and structure of the stichocytes, length of the spicule (0.180–0.195 mm), structure of the male caudal bursa (considerably reduced), structure and size of the eggs (size 0.057–0.063 × 0.027–0.030 mm), and by their site within the host. It is the second Paracapillaria species known to occur in the marine and estuarine fishes of the Gulf of Mexico.

The undoped and doped (Si, N, In) GaAs single crystals are grown by horizontal Bridgman technique. The etch pit density (EPD) profiles were measured in transverse direction for each crystal. It was found that the shape of EPD profiles differs in dependence on the used dopant.

The isovalent doping of GaAs single crystals prepared by Horizontal Bridgman method is examined. Attention is given to the influence of In and N doping on the crystal growth and electrical parameters of GaAs single crystals. It was found that In and N doping does not alter the electrical properties of GaAs crystals. The critical value of indium concentration in the melt was determined to be about 1×1021 cm−3 in the case of GaAs: In crystal growth.

Single crystals of GaAs doped with In and N were grown by the horizontal Bridgman method. The influence of isovalent doping on the crystal growth was investigated. The single crystals were examined by means of the chemical etching of dislocations, electrical measurements and optical measurements. Die mit Indium und Stickstoff dotierten GaAs-Einkristalle wurden nach dem horizontalen Bridgman-Verfahren (HB) gezuchtet. Der Einflus der Isovalentdotierungen wurde an der Kristallzuchtung studiert. Elektrische und optische Messungen wurden durchgefuhrt und auch die Versetzungsdichten (EPD) nach dem Atzverfahren gemessen.

An examination of a sample of benthic invertebrates collected from the Upper San Marcos River in southwestern Texas, USA in September 1999 revealed that the nymph of the ephemeropteran Tricorythodes curvatus served as natural intermediate host of the nematode Rhabdochona kidderi texensis (Nematoda: Rhabdochonidae), an intestinal parasite mainly of the Rio Grande perch (Cichlasoma cyanoguttatum) in this locality; the prevalence of the parasite's third- and fourth-stage larvae in mayflies was 6.8% with the intensity of 1-2 larvae per nymph. Live R. kidderi texensis eggs collected from nematodes recovered from C. cyanoguttatum in Texas were transported to the Czech Republic, where they were used to experimentally infect nymphs of the palaearctic mayfly species Paraleptophlebia submarginata; the development of infective third- and fourth-stage larvae in this experimental intermediate host was completed after approximately 10 days at 19 degrees C. Infected nymphs were fed to aquarium-reared fishes, four Cichlasoma nigrofasciatum and one Oreochromis niloticus, of which only three of the former became infected. The last (fourth) moult of a male nematode was observed in C. nigrofasciatum 23 days p.i. and adult males and gravid females with not fully mature (non-embryonated) eggs in uteri on days 40 and 51 p.i. The prepatent period of R. kidderi texensis is approximately two months.

The silicon doped GaAs single crystals were grown by means of a horizontal Bridgman method. The relation between the free carrier concentration and silicon concentration determined by chemical analysis was examinated. Die mit Silicium doped GaAs single crystals were grown by means of a horizontal Bridgman-Verfahren (HB) gezuchtet. Die Beziehung wurde zwischen der Konzentration der freien Trager und der durch die chemische Analyse festgelegten Konzentration des Siliciums gefunden.

Five species of adult nematodes, unidentifiable nematode larvae, and three species of acanthocephalans, were found in freshwater ornamental fishes newly imported into Germany from Brazil, Colombia, Indonesia, Malaysia, Nigeria, Peru, Sri Lanka and Thailand. The following species were identified: Adult Nematoda: Pseudocapillaria tomentosa, Capillariidae gen. sp., Dichelyne hartwichi sp. n., Procamallanus (Spirocamallanus) pintoi and Spinitectus allaeri; Acanthocephala: Pseudogorgorhynchus arii gen. et sp. n., Neoechinorhynchus sp. and Pallisentis sp. The nematode Dichelyne hartwichi sp. n. (male only) from the intestine of Chelonodon fluviatilis (Hamilton) from Thailand is characterised mainly by the presence of minute cuticular spines on the tail tip, length of spicules (510 microns) and arrangement of caudal papillae. The acanthocephalan Pseudogorgorhynchus arii sp. n. from the intestine of Ariopsis seemanni (Günther) from Colombia represents a new genus Pseudogorgorhynchus gen. n., differing from other genera of the Rhadinorhynchidae mainly in possessing a small proboscis armed with markedly few (18) hooks arranged in six spiral rows. Spinitectus macheirus Boomker et Puylaert, 1994 and Spinitectus moraveci Boomker et Puylaert, 1994 are considered junior synonyms of Spinitectus allaeri Campana-Rouget, 1961.

Examinations of 29 specimens of the catfish Liobagrus reini Hilgendorf (Siluriformes: Amblycipitidae), a species endemic to Japan, collected from the Sho River, Toyama Prefecture, in central Honshu, revealed the presence of four species of helminth parasites: Plagioporus honshuensis sp. n. (Trematoda), Rhabdochona coronacauda Belouss, 1965, R. japonica Moravec, 1975 and Mexiconema liobagri sp. n. (all Nematoda). The new opecoelid trematode P. honshuensis is characterized mainly by the extent of vitelline follicles, the size ratio of the suckers (1 : 1.7-2.1), the situation of testes near the middle of the body and by the structure, size and shape of the cirrus sac. Allopodocotyle Pritchard, 1966 is considered a junior synonym of Plagioporus Stafford, 1904. The males of R. japonica are described for the first time and conspecific females are redescribed; this species is a specific parasite of L. reini. The principle hosts of R. coronacauda are cyprinids and, therefore, its finding in the catfish may indicate an accidental infection; L. reini represents a new host record. M. liobagri (only females were found) from the host's abdominal cavity is the second known species of this dracunculoid genus, being characterized by the position of the excretory pore and the number (1) of caudal processes in the female. The recorded helminths are briefly described and illustrated and problems of their systematic status are discussed.

The nematode Rhabdochona anguillae Spaul, 1927, a specific intestinal parasite of the European eel, Anguilla anguilla (L.), is redescribed and illustrated from specimens collected from eels of the Sousa River, northern Portugal (prevalence 20%, intensity 2-13). The species is characterized by the presence of 14 anterior teeth in the prostom, small non-bifurcate deirids, absence of lateral preanal papillae, by the length (0.460-0.660 and 0.130-0.150 mm) and the shape of spicules, fairly large (0.041-0.054 x 0.025-0.030 mm) mature eggs without filaments, and by the bluntly pointed to rounded tip of the tail. Its morphological features are discussed in relation to other congeneric species. This nematode has hitherto been recorded only from eels in southern Europe (Portugal, Spain, Bulgaria).

A new nematode, Crocodylocapillaria longiovata n. gen. and n. sp., is described from the stomach of wild and farmed young crocodiles, Crocodylus johnstoni Krefft, and Crocodylus porosus Schneider, from northern Australia and Papua New Guinea; it is undoubtedly identical with the nematodes previously reported as Capillaria sp. from Crocodylus novaequineae Schmidt from Irian Jaya, Indonesia. This capillariid species represents a new genus, being characterized mainly by the presence of elongate eggs with unusually long protruding polar plugs, a well developed vulvar appendage, a weakly sclerotized spicule, proximal and distal parts of the spicular sheath with spines, and the male posterior end with 2 large lateral caudal lobes and a pair of papillae near the cloacal opening. The body length of C. longiovara males and females is 5,576-7,208 microm and 8,609-14,008 microm, respectively, the spicule is 276-369 microm long; the size of the egg proper is 48-60 x 15-21 microm, length of polar plugs 15-18 microm. Neocapillaria Yi and Guitang, 1994, a junior homonym of Neocapillaria Moravec, 1987, is re-named Sinocapillaria nom. n. and placed as a synonym of Pseudocapillaria Freitas, 1959. Indocapillaria De and Maity, 1995 is retained as a subgenus of Pseudocapillaria because of the possession of a vulvar appendage in the type species. Neocapillaria Moravec, 1987 remains a subgenus of Capillaria Zeder, 1800. A key to genera of the Capillariidae from poikilotherm vertebrates is provided; C. longiovata is the first capillariid species described from the digestive tract of crocodiles.

Third-stage larvae of the nematode Serpinema trispinosum (Leidy, 1852) were collected from the intestine of the freshwater cichlid, Cichlasoma urophthalmus (Günther), from a small lake in Yucatan, Mexico. This is the first record of Serpinema larvae from fishes, and their presence may reflect the importance of fishes as paratenic hosts of turtle parasites in this genus.

A new nematode genus and species, Lucionema balatonense gen. et sp. n., is described from the swimbladder of the European pikeperch, Stizostedion lucioperca (L.), from Lake Balaton in Hungary; a new dracunculoid family Lucionematidae fam. n. is established to accommodate it. The hitherto monotypic family Lucionematidae shows affinities with the families Skrjabillanidae and Daniconematidae, differing from them mainly in having simple oesophagus without external oesophageal glands and the vulva situated near the middle of body; from the first family also in the absence of the buccal capsule and the bursa-like caudal alae in the male. The genus Lucionema gen. n. is characterized mainly by the presence of 8 cephalic papillae in two circlets, absence of spicules, presence of the copulatory plate, only 2 pairs of postanal papillae in the male, and by the distal part of the monodelphic uterus forming a posteriorly directed coil. The body length of L. balatonense females is 1074-1782 microns, that of the only available male 770 microns. A key to the families of the Dracunculoidea is presented.

The present paper comprises a systematic survey of nematodes of the superfamily Seuratoidea collected from fishes of the Paraná River, southern Brazil, in 1992-1995. The following species were recorded: Neoparaseuratum travassosi Moravec, Kohn et Fernandes, 1992, Spectatus sp., Seuratoidea gen. sp. larvae, Cucullanus brevispiculus Moravec, Kohn et Fernandes, 1993, C. pinnai pinnai Travassos, Artigas et Pereira, 1928, C. pinnai pterodorasi subsp. n., C. rhamphichthydis sp. n., C. zungaro Vaz et Pereira, 1934, and Dichelyne pimelodi sp. n. C. pinnai pterodorasi (type host Pterodoras granulosus) differs from C. p. pinnai in the shape of the oesophagus and in the position of the nerve ring. C. rhamphichthydis (only females) (type host Rhamphichthys rostratus) is characterized mainly by the postoesophageal position of the excretory pore and deirids, complex structure of the cuticular lining of oesophastome and by markedly narrow body, whereas D. pimelodi (one male) (type host Pimelodus sp.) by the length of spicules (1.46 mm), postoesophageal position of the excretory pore and deirids and by the arrangement of genital papillae. Most species are briefly described (females of C. brevispiculus and Seuratoidea gen. sp. larvae for the first time) and illustrated and some problems concerning their taxonomy, hosts and geographical distribution are discussed.

The present paper comprises a systematic survey of helminths from 202 red groupers, Epinephelus morio (Valenciennes) (Pisces: Serranidae), the most important commercial marine fish in the region, collected from ten localities off the Yucatan Peninsula in the Gulf of Mexico during 1994-1996; two more helminth species were recorded from E. morio earlier. Thirty species of helminths were found: Monogenea 1, Cestoda 3, Trematoda 17, Nematoda 8, Acanthocephala 1. Of them, 15 species were adults, whereas 15 species were larval stages parasitizing piscivorous elasmobranch and teleostean fishes, birds and marine mammals as adults. A new didymozoid trematode, Allonematobothrium yucatanense sp. n., is described from the fins of this host. Most findings represent new host- and geographical records. Philometra margolisi, a nematode parasitizing the gonads, is undoubtedly the most important parasite affecting the reproduction of the host, endangering E. morio in aquaculture. Larval anisakid nematodes (Anisakis, Pseudoterranova, Hysterothylacium) recorded from the red grouper in the region of the southern Gulf of Mexico are important from the viewpoint of public health.

The present paper comprises a systematic survey of nematodes found in 88 specimens of 24 species of freshwater fishes in Venezuela in 1992 and 1994. The following 13 species of nematodes were recorded: Adults; Guyanema longispiculum Moravec, Prouza et Royero, 1996, Guyanema sp., Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas et Pereira, 1928, P. (S.) krameri (Petter, 1974) comb. n., P.(S.) pintoi (Kohn et Fernandes, 1988) comb, n., Procamallanus (Spirocamallanus) sp., Raphidascaris (Sprentascaris) mahnerti (Petter et Cassone, 1984). Larvae: Anisakidae gen. sp., Brevimulticaecum sp., Contracaecum sp. Type 1, Contracaecum sp. Type 2, Contracaecum sp. Type 3, Eustrongylides sp. All these parasites are reported from Venezuela for the first time and all findings represent new host records. Brevimulticaecum larvae are reported from fishes for the first time. Almost all parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. A new name, Terranova diazungriai nom.nov. is proposed for T. caballeroi Díaz-Ungría, 1968 (a junior homonym of T. caballeroi Barus et Coy Otero, 1966).

The development of the nematode Procamallanus (Spirocamallanus) neocaballeroi (Caballero-Deloya, 1977), an intestinal parasite of the characid fish, Astyanax fasciatus (Cuvier) in Mexico, was studied in the experimental copepod intermediate host, Mesocyclops sp. After the copepod's ingestion of free first-stage larvae of the nematode, these penetrate into the haemocoel of the intermediate host; they moult twice (on the 3rd and 4-5th day p.i. at 21-22 degrees C) before they attain the third, infective stage. The third-stage larva already possesses the large buccal capsule subdivided into an anterior broad portion with eight spiral thickenings (as observed in lateral view) and a narrow posterior portion, and its tail tip bears three conical processes. The definitive host acquires infection by feeding on infected copepods; in the intestine of this fish, the nematode larvae undergo two more moults (on the 10th and 14-15th day p.i. at 25-32 degrees C) before attaining their maturity. The prepatent period is approximately two months.

Two types of third-stage nematode larvae (most of which were encapsulated) were collected from the abdominal cavity and liver of the freshwater fishes Etheostoma fonticola, Etheostoma lepidotum, Cichlasoma cyanoguttatum, Lepomis auritus, Lepomis sp., and Gambusia affinis in Texas and are referred to the genus Falcaustra. This is the first record of Falcaustra larvae from fishes, and their presence may reflect the importance of fishes as paratenic hosts of turtle parasites in this genus.

Examination of a total of 581 fish specimens of 15 species from 39 cenotes (sinkholes) in the Yucatan Peninsula, southeastern Mexico, revealed the presence of 10 species of adult trematodes. These were as follows: Saccocoelioides sogandaresi Lumsden, 1963, Saccocoelioides sp. (family Haploporidae), Cichlasotrema ujati Pineda et Andrade, 1989 (Angiodictyidae), Crassicutis cichlasomae Manter, 1936 (Homalometridae), Magnivitellinum simplex Kloss, 1966 (Macroderoididae), Stunkardiella minima (Stunkard, 1938) (Acanthostomidae), Oligogonotylus manteri Watson, 1976 (Cryptogonimidae), Genarchella tropica (Manter, 1936), G. astyanactis (Watson, 1976), and G. isabellae (Lamothe-Argumedo, 1977) (Derogenidae). Saccocoelioides sogandaresi is reported from Mexico for the first time. Poecilia velifera and P. latipunctata for S. sogandaresi, Cichlasoma octofasciatum for C. cichlasomae, Cichlasoma friedrichstahli and C. meeki for O. manteri, and C. meeki, C. octofasciatum and Gobiomorus dormitor for G. isabellae represent new host records. Most species found are described and figured and their host range and distribution are discussed.

A new nematode species, Pseudocapillaria yucatanensis sp. n., is described from the intestine of the freshwater pimelodid catfish Rhamdia guatemalensis (Günther) from cenotes (= sinkholes) in Yucatan, Mexico. It differs from other three related species parasitizing freshwater fishes mainly in possessing the spicule with a simple rim of its proximal end and a non-expanded distal end, in the length of the spicule (0.218-0.295 mm), and the size (0.050-0.060 x 0.025-0.030 mm), shape and structure of eggs, and also in the host types and geographical distribution. Pseudocapillaria yucatanensis is the first known autochtonous species of Pseudocapillaria parasitizing freshwater fishes in Mexico.

The present paper comprises a systematic survey of adult nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southeastern Mexico, in 1993-1994. Examinations of a total of 533 fishes (17 species) originating from 39 cenotes from the Mexican states of Yucatan and Quintana Roo revealed the presence of the following nine nematode species: Rhabdochona (Rhabdochona) kidderi, Procamallanus (Spirocamallanus) rebecae, P. (S.) neocaballeroi, Philometroides caudata, Hysterothylacium cenotue. Pseudocapillaria yucatanensis, Paracapillaria rhamdiae, P. teixerafreitasi and Capillostrongyloides sp. (only females). Four species (R. kidderi, P. rebecae, P. neocaballeroi and Capillostrongyloides sp.) are briefly described and illustrated and some problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Taxonomic changes include Procamallanus (Spirocamallanus) neocaballeroi (Caballero-Deloya. 1977) comb. n. and Procamallanus (Spirocamallanus) rebecae (Andrade-Salas, Pineda-López et García-Magaña, 1994) comb. n. The nematode fauna of fishes in cenotes of the Yucatan Peninsula shows its appurtenance to the Neotropical fauna with close affinities with that of fish nematodes from South America, but with a considerable degree of endemism.

This paper comprises a systematic survey of larval nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southern Mexico, in 1993-1994. Larvae of the following nine species were recorded: Physocephalus sexalatus, Acuariidae gen. sp., Spiroxys sp., Falcaustra sp., Hysterothylacium cenotae, Contracaecum sp. Type 1, Contracaecum sp. Type 2, Goezia sp., and Eustrongylides sp. Larvae of P. sexalatus are recorded from fishes (Rhamdia guatemalensis) for the first time. The larvae are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Adults of these larvae are parasitic in piscivorous fishes, reptiles, birds and mammals (definitive hosts). Fishes harbouring the larvae of these parasites serve as paratenic hosts, being mostly an important source of infection for the definitive hosts.

Capillaria (Hepatocapillaria) cichlasomae sp. n., parasitic in the liver of the cichlid Cichlasoma urophthalmus (Günther) from a small freshwater lake ("aguada") Xpoc in Yucatan, Mexico, is described. The parasite is characterized mainly by its small body size (male 1.8 mm, female 4.5 mm), the structure of the stichosome (markedly short stichocytes in one row) and the male (the presence of a pair of small subventral postanal papillae) and female (anus distinctly subterminal) caudal ends, and by the size and structure of the spicule (spicule 0.068-0.085 mm long, with marked transverse grooves on surface) and eggs (size 0.053-0.058 x 0.023 mm, with protruding polar plugs). This is the second known Capillaria species from the liver of fish and the first one from the liver of a freshwater fish.

Enscapsulated third-stage nematode larvae collected from the abdominal cavity of the Trinidadian hylid frog Hyla minuta are referred to the rare anisakid genus Brevimulticaecum. These are the first specimens of Brevimulticaecum from a tropical frog, and their presence may reflect the importance of amphibians as intermediate or paratenic hosts of reptilian parasites.

Trichospirura amphibiophila n. sp. (Nematoda) is described from the abdominal cavity (encapsulated near the liver) of the frog Eleutherodactylus martinicensis (Anura: Leptodactylidae) from the island of La Désirade in the French Antilles. It is characterized by the length of its spicules (459 microns and 90 microns) and their length ratio (1:5), by the presence of deirids and 7 pairs of caudal papillae in the male (2 preanal and 5 postanal), and by the site of localization (abdominal cavity) in the host. Trichospirura amphibiophila is the first known species of the genus parasitizing amphibians.

The development of the nematode Syncuaria squamata (Linstow, 1883), a gizzard parasite of cormorants, was experimentally studied in the ostracod Notodromas monacha. After the eggs of this nematode have been swallowed by the ostracod, the toothed first-stage larvae of the parasite are released and penetrate through the intestinal wall into the haemocoel of the crustacean. Before attaining the infective third stage, the larvae moult twice in the body of the intermediate host (9-11 and 13-15 days after infection at water temperatures of 20-22 degrees C). The fishes Alburnoides bipunctatus, Noemacheilus barbatulus, Oncorhynchus mykiss and Poecilia reticulata were for the first time recorded as suitable experimental paratenic hosts of S. squamata third-stage larvae in which a slight growth of larvae may occur. The first recorded natural paratenic host of this nematode was tench, Tinca tinca, originating from a South-Bohemian pond where cormorants occur. Paratenic hosts are apparently the main source of S. squamata infection for cormorants.

Examination of freshwater fishes from the Paraná River in southern Brazil during March 1992, revealed the presence of two new, previously undescribed species of the genus Goezia: G. brasiliensis sp. n. is described from the stomach of Brycon hilarii (family Characidae) (type host) and the intestine of Pseudoplatystoma coruscans (Pimelodidae) and it is characterized mainly by the length (0.802 mm) of spicules, number and arrangement of male caudal papillae (10 pairs of preanals and 4 pairs of postanals) and body measurements (male 11 mm, female 10-16 mm); the main characteristics of G. brevicaeca sp. n., described from the stomach of Brycon hilarii, are a short anterior intestinal caecum reaching anteriorly only to the posterior end of oesophagus, comparatively short spicules (0.367 mm), number of male caudal papillae (20 pairs of preanals and 4 pairs of post-anals) and an elongate, rather long body (male 17 mm, female 23 mm).

Daniconema anguillae Moravec et Køie, 1987 larvae measuring 1.64-1.76 mm were occasionally found in considerable numbers in the fins and subcutaneous connective tissue of approximately 50% of eel Anguilla anguilla (L.) sampled from Lake Balaton, Hungary. The larvae were noted for their slender body, very long tail with a rounded tip, a densely transversely striated cuticle, and the presence of boring tooth and large kidney-shaped amphids on the cephalic end. The larvae could easily be recovered from the above mentioned organs by placing them into isotonic saline solution. No disease signs or pathological changes attributable to the larval infection could be observed. The only histological indication of host reaction was the appearance of macrophages adhering to the body surface of larvae and of cells with spherical nucleus in areas around the larvae. A possible life cycle pattern of D. anguillae is discussed.

An examination of a sample of European eels, Anguilla anguilla (L.), collected from Lake Bracciano near Rome in 1993, the only known European locality with the occurrence of the introduced swimbladder nematode Anguillicola novaezelandiae Moravec et Taraschewski, 1988, revealed for the first time the presence of two Anguillicola species, A. novaezelandiae and A. crassus. In view of the investigations carried out by current authors in Bracciano Lake in the years 1982-1992, it is apparent that the latter species has been introduced into the lake quite recently, where it quickly became a dominant species. The development of A. novaezelandiae was experimentally studied in the copepod intermediate host, Cyclops strenuus, for the first time. The copepods were infected with nematode second-stage larvae at 21-22 degrees C; fully developed infective third-stage larvae were obtained 13 days p.i. The general morphology of individual larval stages of A. novaezelandiae was similar to that of larvae of the related species A. crassus.

The authors present the case of a 18-year-old patient who reported deteriorated vision and mobile dark shadows on the left eye. Examination revealed in the vitreous body an extremely mobile filiform, worm-like formation, white in colour, of the size of an arteriole, about 9 mm long. In the course of hospitalization the formation was isolated by surgery of the pars plana vitrectomy and subjected to detailed helminthological examination. The worm was identified as Dirofilaria repens (Reillet et Henry 1911) and described in detail. The presented finding is the first finding of this parasite in this country and at the same time the first finding of this parasite in Czechoslovakia.

From October 1985 until July 1987, the bionomy of the trematode Allocreadium isoporum (Looss, 1894) was studied in the Rokytná River (the Danube basin), Czechoslovakia. While clams of the genera Sphaerium Scopoli and Pisidium Pfeiffer apparently serve as its first intermediate hosts, mayfly larvae Ephemera danica Müll. were found (prevalence 8%, intensity 1-5 metacercariae per mayfly) to be the only second intermediate host of A. isoporum in the locality. The most important definitive host is chub, Leuciscus cephalus (L.), in which the seasonal dynamics of A. isoporum occurrence and maturation was followed. The parasite exhibits here a distinct seasonal cycle of maturation which is shown mainly by quantitative changes in the ratio of young to mature worms containing eggs. The trematodes containing eggs occur almost throughout the year, but mainly in the spring and early summer (maximum in May), and after the oviposition they leave the host. New infections are acquired by chub all the year round. This seasonal periodicity is determined by ecological factors, mainly the temperature regime in the locality. A isoporum infections in chub in this locality are dependent on the body size of host fishes; the highest degree of A. isoporum infection occurs in fishes 20-25 cm long, the prevalence decreasing somewhat in larger fishes; infection is associated with changes in the food composition of chub of different size groups.

A reexamination of the type specimens of Thominx platyrrhinorum Barus, 1961, described from the small intestine of the monkey Cebus capucinus from a zoo in Czechoslovakia, has revealed that it belongs to the genus Aonchotheca López-Neyra, 1947. The minute refractile formations on the surface of the proximal part of the spicular sheath, originally described as spines in this species, are also present in Aonchotheca annulosa parasitizing murid rodents. Since there are no substantial morphological or biometrical differences between these two species, as indicated by the description of A. annulosa specimens originating from Apodemus sp. from Czechoslovakia, T. platyrrhinorum is considered to be a synonym of A. annulosa (Dujardin, 1845). Another synonym of the latter is the species originally described as Thominx sadovskoi (sic) (= sadovskajae) Morozov in Skryabin et al. 1957. Armocapillaria Gagarin et Nazarova, 1966, earlier considered a synonym of Pterothominx Freitas, 1959, is now reerected as a subgenus of Aonchotheca López-Neyra, 1947. Armocapillaria moschiferi and Capillaria brochieri are transferred to Aonchotheca as A. (A.) moschiferi (Gagarin et Nazarova, 1966) comb. n. and A. (A.) brochieri (Justine, 1988) comb. n.

A new nematode species, Huffmanela schouteni sp. n., has been established on the basis of its egg morphology and biological characters (adult nematodes are unknown). The dark-shelled eggs of this histozoic parasite occur in masses in the abdominal cavity, serose covers of internal organs and in the liver of the flying fishes Hirundichthys affinis Günther (type host) and Cypselurus cyanopterus Cuvier et Valenciennes in Curaçao. The eggs of H. schouteni sp. n. differ from those in other congeneric species mainly in the absence of small spines on the surface of the transparent envelope enclosing the egg proper, measurements (size of eggs 0.069-0.075 x 0.027-0.030 mm) and their localization in the host. A key to Huffmanela species based on egg morphology has been provided.

In 1989, samples of some freshwater fishes collected in Vientiane Province (R. Mekong basin) in Laos were examined for helminths. This material comprised 11 species of parasitic nematodes (7 adults and 4 larvae), including 3 species new to science: Camallanus (Camallanus) hampalae sp. n. from Hampala macrolepidota, Procamallanus (Punctocamallanus) punctatus sp. n. from Mystus rhegma and Mystus sp., and Rhabdochona (Globochona) equispiculata sp. n. from Hampala macrolepidota and H. dispar. Zeylanema Yeh, 1960 is considered a subgenus of the genus Camallanus, Dentocamallanus subgen. n. (type species C. (D.) sweeti (Moorthy, 1937)) is proposed for the species of Paracamallanus with teeth in the buccal capsule, and Punctocamallanus subgen. n. (type species P. (P.) punctatus sp. n.) for the species of Procamallanus with the buccal capsule ornamented with punctations. The name Rhabdochona wangi nom. nov. is proposed for R. bagarii Wang et Guo, 1983 (a homonym to R. bagarii Gupta et Srivastava, 1982) and Camallanus gomtii Gupta et Verma, 1978 is newly synonymized with Neocamallanus ophiocephali (Pearse, 1933). All the nematodes are recorded from Laos for the first time. The parasites are briefly described and illustrated and some problems concerning their taxonomy and geographical distribution are discussed.

An examination of a small sample of four species of frogs (Cophixalus riparius, Phrynomantis humicola, Ph. stictogaster, Ph. wilhelmana) from Papua New Guinea yielded altogether 5 species of nematodes, 2 of them being new to science. These include: Cosmocercella phrynomantisi sp. n. (type host Ph. humicola), Spinicaudinae gen. sp., Parathelandros andersoni sp. n. (type host C. riparius), Oswaldocruzia bakeri, and Paracapillaria spratti. C. phrynomantisi sp. n. differs from congeneric species mainly in the length of spicules (0.180 mm) and the character, arrangement and number of caudal papillae in the male, while P. andersoni sp. n. is characterized mainly by the presence of four well developed spines on the male tail. Pseudocapillaria spratti is redescribed in detail and it is transferred to Paracapillaria as P. spratti (Moravec et Sey, 1986) comb. n. Capillaria combesi Chabaud et Knoepffler, 1985 is transferred to Amphibiocapillaria Moravec, 1982 and Capillaria petiti Justine et Bain, 1987 to Pseudocapillaria Freitas, 1959. A survey of the endohelminths (excluding Hirudinea) hitherto reported from New Guinea amphibians is presented.

The paper comprises a list of the cestode, trematode and acanthocephalan type specimens deposited in the helminthological collection of the Institute of Parasitology, Czechoslovak Academy of Sciences, in Ceské Budĕjovice. These materials include a total of 7 species of cestodes, 16 species of trematodes, and 5 species of acanthocephalans.

Large numbers of anisakid nematodes identified as Raphidascaris (Sprentascaris) hypostom (Petter et Cassone, 1984) were collected from the stomach and intestine of armoured catfishes P leco stomus albopunctatus, P. commersoni, P. derbyi, and Ancistrus cirrhosus (all representing new host records) from the three water reservoirs, Salto Osório, Salto Santiago and Passo Fundo, in southern Brazil. Another closely related species, R. (S.) mahnerti (Petter et Cassone, 1984), was recorded from the intestine of the armoured catfish Loricaria laticeps of the Paraná River. Since these are the first records of these parasites since their original descriptions, they are briefly redescribed and illustrated. The genus Sprentascaris Petter et Cassone, 1984, in which both these species were originally placed, is now considered only a subgenus of Raphidascaris Railliet et Henry, 1915 and, therefore, all Sprentascaris species are transferred to the latter genus as Raphidascaris (Sprentascaris) mahnerti (Petter et Cassone, 1984) comb. n., R. (S.) pimelodi (Petter et Cassone, 1984) comb. n., and R. (S.) hypostomi (Petter et Cassone, 1984) comb. n.