Redescription of Camallanus hypophthalmichthys Dogel and Akhmerov, 1959 (Nematoda: Camallanidae) and its first record from fishes in China

The nematode Camallanus hypophthalmichthys Dogel and Akhmerov, 1959 is redescribed from specimens collected from the intestine of the bighead carp Aristichthys nobilis, from Liangzihu Lake (Yangtze River basin), Hubei Province, central China. The light and scanning electron microscopical examination made it possible to study in detail the morphology of this so far little-known species and to confirm its validity. The main specific features of C. hypophthalmichthys distinguishing it from the most similar Camallanus spp. is the presence of 3 small caudal processes on the male tail tip, 13-16 longitudinal ridges on the inner surface of the valve of the buccal capsule, and the arrangement of preanal and postanal genital papillae in the male. This finding represents a new host record, the first record of this parasite in the Yangtze River basin, and the first documented record of C. hypophthalmichthys from China. Camallanus hypophthalmichthys is considered a specific intestinal parasite of fishes of the cyprinid Hypophthalmichthyinae.     

Survival activity and penetration of the first stage larvae of Camallanus oxycephalus Ward and Magath, 1916

The survival, activity and the ability to penetrate the gut wall of the intermediate host were studied for the first stage larvae of Camallanus oxycephalus. Survival was affected by temperature and salinity. The penetration efficiency decreased in a logarithmic relationship with larval age and was more rapid at 25°C than at 20°C. Larval activity rates decreased in a linear relationship with age. Activity was shown to be the most important factor in penetration of the copepod gut wall. These processes were compared with Ancylostoma and Haemonchus larvae. A fundamental difference is believed to exist in the decline of activity rates between Camallanus and Ancylostoma and Haemonchus. This difference is related to the life cycles of the three nematodes.     

Molecular characteristics of Camallanus Spp. (Spirurida: Camallanidae) in fishes from China based on its rDNA sequences

In the paper, we explored the intra- and interspecific evolutionary variation among species of Camallanus collected from different fish species in various regions of China. We determined the internal transcribed spacers of ribosomal DNA (ITS rDNA) sequences of these nematodes. The divergence (uncorrected p-distance) of ITS1, ITS2, and ITS rDNA data sets confirmed 2 valid species of Camallanus in China, i.e., C. cotti and C. hypophthalmichthys. The 2 species were distinguished not only by their different morphologies and host ranges but also by a tetranucleotide microsatellite (TTGC)n present in the ITS1 region of C. cotti. Phylogenetic analyses of the nematodes disclosed 2 main clades, corresponding to different individuals of C. cotti and C. hypophthalmichthys from different fish species in various geographical locations, although the interior nodes of each clade received poor support.     

A new enteric nematode of Camallanus (Nematoda: Camallanidae) from Jiyu Island of Amoy (Taiwan Strait)

A new enteric nematode, Camallanus jiyuensis n. sp., is described from the intestine of the shokihaze goby, Tridentiger barbatus (Günther, 1861), collected from the beach of Jiyu Island, Amoy, southeast of China. The new species differs from its congeners mainly in the following combination of characters. The body is rather small in size, with 2 squarish, chitinized thickenings on the anterior border of the buccal capsule. The prongs of the trident are unequal. The nerve ring is near the posterior end of tridents. Cervical papillae are located in the middle of muscular esophagus. The excretory pore is located in the posterior third of muscular esophagus. Twelve pairs of pedunculate caudal papillae are present, of which 7 pairs are preanal and 5 are postanal. Spicules are similar, but subequal in length; the right and the left account for 9.8% and 8.9% of body length, respectively. The vulva does not protrude conspicuously from body surface and is located postequatorially.     

Occurrence of Ergasilus megaceros Wilson, 1916, in the sea lamprey and other fishes from North America

Ergasilus megaceros (Copepoda: Ergasilidae) was recovered from the nasal fossae (lamellae) of the olfactory sac in 1 (1.8%) of 56 sea lampreys, Petromyzon marinus Linne, 1758, collected in May 2002 from the Cheboygan River, Michigan. Although the sea lamprey is a new host record for E. megaceros, this fish species may not be a preferred host because of its low prevalence. Ergasilus megaceros is the second ergasilid species reported from the sea lamprey in North America. This is the third report of an ergasilid species infecting the nasal fossae of fishes in North America, with E. rhinos being the only other species reported from this site.     

The taxonomy of Capillaria spp. (Nematoda: Trichuroidea) in North American freshwater fishes

Summary The Capillaria spp. from North American freshwater fishes are redescribed. These are: Capillaria catastomi from Catastomus commersoni, Cyprinus carpio, Cyprinus carpio × Carassius auratus hybrid (carp × goldfish) and Coregonus clupeaformis; Capillaria salvelini from Salvelinus fontinalis, S. namaycush, Salmo salar and Oncorhynchus kisutch and Capillaria catenata from Lepomis gibbosus. A key to identification of the above is included. C. bakeri is considered a nomen dubium.     

Species of Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidae) from cyprinid fishes in North America

A taxonomic study of Proteocephalus species parasitizing cyprinid fishes in North America, namely Proteocephalus ptychocheilus Faust, 1920 and Proteocephalus cobraeformis Haderlie, 1953, has demonstrated their conspecificity with Proteocephalus torulosus (Batsch, 1786), a common parasite of cypriniform fishes (Cyprinidae and Cobitidae) in the Palaearctic Region. Proteocephalus ptychocheilus and P. cobraeformis are considered junior synonyms of P. torulosus.     

Larval and adult morphology ofCamallanus anabantis Pearse, 1933 andC. kulasirii (Yeh, 1960) (Nematoda: Camallanidae) from freshwater fishes,with notes on the validity of some related forms

Larvae and adults ofCamallanus anabantis andC. kulasirii, recovered from the West Bengali freshwater fishes,Anabas testudineus andOphicephalus punctatus, respectively, are described on the basis of detailed morphological studies under the light microscope. Larval forms collected fromA. testudineus are deemed to be of the third and fourth stages when compared with those from experimental studies of the life cycle ofC. anabantis. Moreover, the present fourth stage female larvae are similar to the females ofC. pearsei, both morphologically and metrically.C. pearsei is, therefore, believed to represent the fourth stage female larvae ofC. anabantis. Similarly, adult males and females recovered fromO. punctatus closely resembleC. kulasirii andC. fernandoi, respectively. The larval forms from this host are fourth stage and can be distinguished as males and females, but both possess a buccal capsule bearing beaded longitudinal ridges similar to that of adult males. The late fourth stage (just prior to the final moult) female larva is, however, found to possess a buccal capsule transitional between that of the adult male and female and also betweenC. kulasirii andC. fernandoi. C. fernandoi is, therefore, presumed to represent the females ofC. kulasirii. However,C. pearsei andC. fernandoi are regarded, for the present, asspecies inquirendae.     

Redescription of Testudotaenia testudo (Magath, 1924) (Eucestoda: Proteocephalidea), a parasite of Apalone spinifera (Le Sueur) (Reptilia: Trionychidae) and Amia calva L. (Pisces: Amiidae) in North America and erection of the Testudotaeniinae n. subfam.

Testudotaenia testudo (Magath, 1924) is redescribed from the intestine of the softshell turtle Apalone spinifera (Le Sueur) (Trionychidae) and the bowfin Amia calva Linnaeus (Amiidae) from Reelfoot Lake, Tennessee, United States. A new subfamily, the Testudotaeniinae, is erected. The new taxon differs from all proteocephalidean subfamilies in the position of the genital organs in relation to the longitudinal internal musculature, i.e. the testes are cortical, rarely medullary; the ovary is partly medullary, with cortical lobes; the vitelline follicles are mainly medullary, with some follicles in the cortex; and the uterus is cortical. A key to the subfamilies of the order Proteocephalidea Mola, 1928 is provided. The most characteristic features of T. testudo are the precocious uterine aperture, the presence of internal uterine pores (as previously described for Proteocephalus paraguayensis (Rudin, 1917)), the eggs laid unripe, the very long strobila (up to 970 mm), and the presence of an anterior circular musculature in the suckers, which is considered as a good differential character. Three other species were found in Amia calva: Proteocephalus perplexus La Rue, 1911, P. ambloplitis (Leidy, 1887) and a new, undescribed form. Sequences of the partial nuclear 28S rRNA gene of specimens of T. testudo from Apalone spinulifera and Amia calva confirm the conspecificity of samples from these two very distinct hosts, which may represent a capture phenomenon. As the subfamily Adenobrechmoinae Bursey, Goldberg & Kraus, 2006 and the genus Adenobrechmos Bursey, Goldberg & Kraus, 2006 are based on the presence of an apical organ, a character which reflects a rather common convergence, we consider the Adenobrechmoinae to be a junior synonym of the Proteocephalinae La Rue, 1911 and Adenobrechmos a junior synonym of Ophiotaenia La Rue, 1911. Adenobrechmos greeri Bursey, Goldberg & Kraus, 2006 thus becomes Ophiotaenia greeri (Bursey, Goldberg & Kraus, 2006) n. comb.     

Redescription of the freshwater amphipod Hyalella faxoni from Costa Rica (Crustacea: Amphipoda: Hyalellidae)

Hyalella faxoni Stebbing, 1903 from Costa Rica is redescribed. The species was previously in the synonymy of Hyalella azteca (Saussure, 1858). The morphological differences between these two species are discussed.     

Bryocamptus pilosus n. sp. (Copepoda: Harpacticoida) from North America

A new species of Bryocamptus from North America, B. pilosus n. sp., is described and illustrated. Some remarks are made on the occurrence of a specific piliform seta on the ventral side of the caudal ramus in the vejdovskyi species group.