Parasites Of Freshwater Fishes Research Articles

Four New Species of Trichodina Ehrenberg, 1830 (Ciliophora: Trichodinidae) from Bangladeshi Fish

During surveys of the trichodinid parasites in freshwater and estuarine fishes in Chittagong Division, Bangladesh four new species of the genus Trichodina were investigated and morphologically studied. These are: Trichodina aplocheilusi sp. n. from Aplocheilus panchax, Trichodina chittagongensis sp.n. from Labeo bata, Trichodina kaptaiensis sp. n. from Chanda nama and Trichodina siddiquae sp. n. from Heteropneustes fossilis. Taxonomic and morphometric data for these trichodinids based on wet silver nitrate impregnated specimens are presented.

Alien parasites of freshwater fishes in Lake Biwa

Alien parasites of freshwater fishes in Lake Biwa

Biogeography of helminth parasites of freshwater fishes in Mexico: the search for patterns and processes

AbstractAim To uncover and describe patterns of biogeography of helminth parasites in freshwater fishes of Mexico, and to understand processes that determine them. Three predictions about host‐specificity, faunal exchange in transitional areas, and the biogeographical ‘core’ fauna, are evaluated, all of which follow from a fundamental hypothesis: that parasites show characteristic associations with particular host clades. The parasite fauna of the southern Mexican cichlids and of the fishes of the Mesa Central are examined as case studies that reflect Neotropical and Nearctic historical influences.Location The region covered in this study includes most of Mexico, with emphasis on six biogeographical areas: the Yucatán Peninsula (area 1), the Grijalva‐Usumacinta drainage (area 2), the Papaloapan and Pánuco drainages (area 3), the Balsas drainage (area 4), the Lerma‐Santiago drainage (area 5), and the Bravo drainage (area 6).Methods A parasite data base containing all the records of helminth parasites of freshwater fishes of Mexico was filtered to extract records of adult helminth parasites in freshwater fishes from the six biogeographical areas designated in this study. Jaccard's similarity coefficients and cluster analyses (using upgma) were used to analyse the extent of faunal similarity between the designated biogeographical areas and between host (fish) families. Taxonomic composition of parasite assemblages in different host groups was also qualitatively compared from summary data. These data were used to test the three main predictions.Results To date, 184 species of helminths (120 as adults) have been recorded from 127 freshwater fishes in Mexico (almost 33% of the total fish diversity of Mexico). Of these parasite species, 69 are digenetic flukes, 51 are nematodes, 33 are monogeneans, 25 are tapeworms, and only six are acanthocephalans. The data and analyses from the six biogeographical areas corroborate the predictions that: (1) the adult parasite fauna is largely circumscribed by higher levels of monophyletic host taxa (families, orders, etc.), and that this pattern is independent of areas; (2) areas within a certain biogeographical region, and consequently with similar fish composition (e.g. areas 1, 2 and 3) have more similar parasite faunas compared to areas with less similar fish faunal composition; and (3) ‘core’ parasite faunas persist to some extent in transitional areas with limited host‐sharing.Main conclusions Helminth biodiversity in Mexican freshwater fishes is determined by the historical and contemporary biogeography of their hosts. Host lineage specificity, mainly at the level of the host family, appears to be an important factor in the distribution of the parasites. Most fish families (Characidae, Cichlidae, Pimelodidae, Ictaluridae, Catsotomidae, Goodeidae, Atherinidae) possess their own characteristic ‘core’ helminth fauna, with limited host‐sharing in transitional areas (e.g. areas 3 and 4). A re‐evaluation of the helminth fauna of Mexican cichlids questions the hypothesis that cichlids lost parasites during the colonization of Mexico from South America. The evidence supports the idea that they acquired new parasites by host switching, possibly from marine or brackish‐water percomorphs. In contrast, the parasite fauna of the Mesa Central remains enigmatic and reflects the region's history of endemicity with historical marine and Nearctic connections.

TWO NEW NEMATODE SPECIES, ORIENTATRACTIS CAMPECHENSIS N. SP. AND ORIENTATRACTIS CHIAPASENSIS N. SP. (NEMATODA: ATRACTIDAE) FROM CICHLID FISHES IN SOUTHERN MEXICO AND NICARAGUA

Two new nematode species, Orientatractis campechensis n. sp. and Orientatractis chiapasensis n. sp. (Atractidae, Cosmocercoidea), are described from the intestine of cichlid fishes collected in localities of southeastern Mexico and Nicaragua. These atractid nematodes are characterized by the presence of a cephalic end armed with 4 marked, Y-shaped, well-sclerotized pieces, consisting of 2 "horns" extending outward and downward and immediately below a single-horned structure. Both new species differ from the other 2 species of Orientatractis (Orientatractis leiperi and Orientatractis levanhoai) mainly in the body measurements, presence of a vulvar appendix, lengths of spicules and of the gubernaculum, distribution of caudal papillae, and the number of anterior sclerotized structures. Morphological and biometrical variations were evident among specimens from different hosts and localities, with the larger organisms being collected from Vieja bifasciata and Cichlasoma pearsei. Orientatractis campechensis and O. chiapasensis represent the first 2 species of this genus parasitizing freshwater fishes; the other species have been found in amphibians and reptiles.

Helminth Parasites of Freshwater Fishes of the Pánuco River Basin, East Central Mexico

This study presents results from a survey of helminth parasites of fishes in the Panuco River basin, in the states of San Luis Potosi, Hidalgo, Queretaro and Guanajuato, all in east central Mexico. Seventeen freshwater fish species (n = 1,019) were examined for helminths between May 1997 and September 1998. Thirty-one helminth species were collected: 11 allogenic species, mostly Nearctic in origin, and 20 autogenic species. Two anthropogenically introduced species were recorded. The most prevalent and widespread helminth taxon was Posthodiplostomum minimum (metacercariae). The helminth fauna of fishes of the Panuco River is dominated by trematodes (12 species) and nematodes (11 species) accompanied by a few monogenean (4 species), cestode (3 species), and acanthocephalan (1 species) taxa. Most of the helminth taxa reported have been reported from other regions of Mexico. Thus, the helminth parasite fauna of fishes of the Panuco River basin are not exclusive, including a primordially autogenic Neotropical species component mixed with a mainly allogenic, globally distributed Nearctic species component. The regional freshwater fish helminth fauna is associated with the ichthyofaunanal composition of the basin. The nematode family Rhabdochonidae displays high species richness in this hydrological basin of Mexico.

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.

Water Quality, Stocking Density and Parasites of Freshwater Fish in Four Selected Areas of Bangladesh

Water Quality, Stocking Density and Parasites of Freshwater Fish in Four Selected Areas of Bangladesh

Helminth Parasites of Freshwater Fishes of the Ayuquila River, Sierra de Manantlán Biosphere Reserve, West Central Mexico

This study presents results from the first survey of the helminth parasites of fishes in the Ayuquila River, Sierra de Manantlan Biosphere Reserve, in the states of Jalisco and Colima, west central Mexico. Twenty-eight helminth species were collected from 14 freshwater fish species in July 2000 and February 2001. No helminth species collected is exclusive to the Ayuquila River: 11 are allogenic species, mostly Nearctic in origin, and 17 are autogenics. Three introduced species were recovered. Saccocoelioides sogandaresi (Trematoda) was the most prevalent and widespread helminth recovered. The fish helminth fauna of the Ayuquila River is dominated by trematode and nematode species with only a few monogenean and acanthocephalan species. The fauna exhibits considerable overlap with that reported for other freshwater basins in Mexico, and all helminths recovered have been reported previously from Mexico.

A checklist of metazoan parasites recorded in freshwater fish from Turkey

A checklist of the metazoon parasites of freshwater fish in Turkey has been compiled from parasitological studies done in Turkey between 1964 and 2003. The parasite species list is arranged by phylum and class, providing parasite species name and author, host fish, location of host fish capture and author and date of published record. The host list consists of all parasite species listed by host species. One hundred and thirteen parasite species are listed from 41 host species belonging to 26 genera.

Parsimony Analysis of Endemicity (PAE) of Mexican hydrological basins based on helminth parasites of freshwater fishes

AbstractAim The distributional patterns of helminthological fauna of freshwater fishes were analysed to postulate a general hypothesis on the relationships of some Mexican hydrological systems.Location Eight hydrological systems of central and eastern Mexico were studied and compared with records from Nicaragua.Methods A Parsimony Analysis of Endemicity (PAE) was applied to the presence/absence of ninety‐two helminth parasite taxa (Monogeneans, Digeneans, Cestodes, Acanthocephalans and Nematodes) of freshwater fishes, from eight Mexican hydrological systems, using the Hennig86 program.Results The results represent the first attempt for a biogeographical analysis through application of the PAE method to the distributional patterns of helminth parasites of freshwater fishes in Mexico. A single most parsimonious cladogram was obtained, which grouped all the Neotropical systems in accordance with previous proposals based on other plant and animal taxa.Main conclusions The most basal systems were Santiago and Lerma basins, which exhibited Nearctic affinities. The remaining areas of the cladogram showed Neotropical affinities. All the southeastern systems were grouped in a clade with the Nicaragua system, providing support for a ‘Mesoamerican province’ based on helminth parasites of cichlids. The cladogram also suggests that the treatment of the Lerma‐Santiago basin as a single biogeographical unit is inaccurate and that they should be treated as separate systems.

Morphological and phylogenetic studies of marine Myxobolus spp. from mullet in Ichkeul Lake, Tunisia.

Six species of the genus Myxobolus (Myxozoa) from the marine environment were collected from two species of mullet (Mugil cephalus and Liza ramada) in Ichkeul Lake, Tunisia. Four of these species were described previously (Myxobolus bizerti, Myxobolus ichkeulensis, Myxobolus spinacurvatura, and Myxobolus episquamalis) and two (Myxobolus exiguus and Myxobolus muelleri) are redescribed. The small subunit ribosomal (18S rDNA) sequences of these six myxozoans were obtained and compared to traditional criteria used in the identification and taxonomy of myxozoan species (such as spore morphology, host specificity, and tissue tropism). A distance analysis of 1,600-1,700 base pairs of the 18S rDNA of the six species indicates that they formed a monophyletic group separate from Myxobolus spp. found as parasites of freshwater fish. The sequence analyses also confirm that these morphologically different Myxobolus spp. that infect mullet represent different species. Lastly, M. exiguus and M. muelleri, which were found in the same host, exhibit clear differences in spore morphology but sequencing of two different regions of the 18S rDNA show they are closely related. These results demonstrate the utility of DNA sequence data in providing more detailed relationships among the Myxobolus species based upon existing morphological taxonomic approaches. We suggest that future descriptions of Myxobolus spp. provide both careful spore descriptions as part of the traditional criteria but also 18S rDNA sequence data that will aid in situations where morphological details may be absent or misleading.

Problemas na classificação dos Proteocefalídeos (Cestoda) da América do Sul. Uma nova classificação para o grupo

The taxonomy of the Order Proteocephalidea, parasites of freshwater fishes, amphibia and reptilia, is being reapraised. The taxa of proteocephalids parasitizing fishes from South American rivers are evaluated on utilizing morphological characters, with the help of phylogenetic systematics. The Woodland´s classification divides the South American proteocephalids into two groups, Proteocephalidae and Monticellidae, depending on the position of vitellaria and gonads in medullar or cortical parenchyma of proglottids. With the intention to propose modifications in the classification, we discuss the trees that resulted from phylogenetic analysis. The conclusions are that the actual taxonomy of the group, based on the papers of Woodland (1933-1935), can not be supported by these analyses; consequently, it is suggested the supression of Monticellidae and its subfamilies. It is accepted only one family, Proteocephalidae, with five subfamilies: Proteocephalinae Mola, 1929, Corallobothriinae Freze, 1965, Sandonelliinae Khalil, 1960, Gangesiinae Mola, 1929 and Acanthotaeniinae Freze, 1963. The monticellid species were transferred to Corallobothriinae or Proteocephalinae, depending on the presence or not of a metascolex

Observations on Babesiosoma mariae (Apicomplexa: Dactylosomatidae) from the Okavango Delta, Botswana.

Observations on Babesiosoma mariae (Apicomplexa: Dactylosomatidae) from the Okavango Delta, Botswana.

Detection of Opisthorchis viverrini in experimentally infected bithynid snails and cyprinoid fishes by a PCR-based method.

A PCR procedure for the detection of Opisthorchis viverrini in experimentally infected bithynid snails and cyprinoid fishes was developed. This procedure was based on primers designed from a pOV-A6 specific probe sequence giving a 330 base-pair product. The detection was accomplished in host tissue homogenates to which a single cercaria or metacercaria was introduced. PCR can detect as little as a single cercaria artificially inoculated in a snail or a single metacercaria artificially inoculated in a fish sample. The method gave a 100% positivity rate for all infected snails or fishes. The method did not yield a 330 base-pair amplified product with other digenean fluke DNAs such as Haplorchis taichui, Centrocestus spp., Echinostoma malayanum, Fasciola gigantica, animal schistosomes, Paragonimus heterotremus or Haplorchoides spp. The assay has great potential for application in epidemiological surveys of both snail and fish intermediate hosts as well as for investigation of foodborne parasites in freshwater fishes.

Myxozoan communities parasitizing Notropis hudsonius (Cyprinidae) at selected localities on the St. Lawrence River, Quebec: possible effects of urban effluents.

Late summer myxozoan infra- and component communities parasitizing 73 Notropis hudsonius at 5 sites on the St. Lawrence River upstream and downstream from the island of Montreal are described from study of histological sections of individual fish. Community membership included Myxobolus sp. A (intracellular in striated muscle fibers), Myxobolus sp. B (intracellular in striated muscle fibers), Myxobolus sp. C (brain), and Thelohanellus notatus (Mavor, 1916) Kudo, 1929 (loose connective tissue), all of which are histozoic myxobolids displaying strict tissue specificity for trophozoite development. Mean infracommunity richness in fish at the separate localities was estimated to be 0.4 +/- 0.5 to 1.3 +/- 0.7, with a maximum richness of 3 in any 1 fish. Component community richness in host samples was 2 to 4. It is argued that these are relatively high levels of diversity for freshwater fish parasites but that the values are probably conservative because of the study of only portions of individual fish. The percentage of fish infected with myxozoans of any species and infracommunity richness was significantly greater below the island of Montreal compared with above it. It is suspected that increased oligochaete populations at these sites, resulting from sewage-caused organic enrichment of sediments, may have accounted for the observed increased prevalence of infection.

Redescriptions of two echinostomes from freshwater fishes, with comments on Singhia Yamaguti, 1958 and Caballerotrema Prudhoe, 1960 (Digenea: Echinostomatidae).

The type-species of Singhia and Caballerotrema (Digenea: Echinostomatidae), parasites of freshwater fishes which have previously been assigned to the subfamily Singhiinae Yamaguti, 1958, are redescribed. One of the specimens of the type-series of Caballerotrema brasiliense Prudhoe, 1960 was identified as C. aruanense Thatcher, 1980. C. arapaimense Thatcher, 1980 is considered a species inquirenda. Himasthla piscicola Stunkard, 1960 is transferred to Caballerotrema as C. piscicola n. comb. The generic diagnoses of Singhia and Caballerotrema are redefined and Singhia is re-allocated to the Echinostomatinae Looss, 1899, the Singhiinae becoming a synonym of the latter.

Chromosome analysis of Proteocephalus osculatus (Cestoda: Proteocephalidea)

The cestode order Proteocephalidea Mola, 1928 is dominated by the cosmopolitan genus Proteocephalus Weinland, 1858, which includes about 40% of its nominal species. Proteocephalus spp. are found in freshwater fishes, amphibians, and reptiles (Freze V.I. 1965: Proteocephalideans – Tapeworm Helminths of Fish, Amphibians and Reptiles. Essentials of Cestodology, Vol V. Publ. House Nauka, Moscow, 540 pp., in Russian; Brooks D.R. 1978: Syst. Zool. 27: 312-323; Brooks D.R., Hoberg E.P., Weekes P.J. 1991: Proc. Biol. Soc. Wash. 104: 651-668). There is presently a lack of agreement on the taxonomic status of many Proteocephalus species. Brooks et al. (Brooks et al. 1991, op. cit.) have suggested that various species currently assigned to Proteocephalus may be more closely related to a variety of different groups than to each other. The recent comparative studies based on morphological features and molecular systematic analysis have demonstrated a general uniformity among most Proteocephalus spp. in Europe (Scholz T., Hanzelova V. 1998: Tapeworms of the Genus Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidae), Parasites of Fishes in Europe, Academia, Praha, 118 pp.; Zehnder M.P., Mariaux J. 1999: Int. J. Parasitol. 29: 1841-1852). On the other hand, a high degree of intraspecific morphological variability has recently been found to occur within Palaearctic Proteocephalus spp. (Hanzelova V., Spakulova M. 1992: Folia Parasitol. 39: 307-316; Anikieva L.V. 1993: Parazitologiya 27: 260-268; Anikieva L.V. 1995: Parazitologiya 29: 505-510; Hanzelova V., Snabel V., Kral’ova I., Scholz T., D’amelio S. 1999: Can. J. Zool. 77: 1450-1458). Due to the presence of high intraspecific variability and the scarcity of taxonomically useful morphological characters, cytogenetics may be a useful tool to differentiate species and clarify their phylogenetic relationships. Proteocephalus osculatus (Goeze, 1782) is a specific parasite of the European wels (Silurus glanis L.) and is distributed throughout its host’s Eurasian range (Freze 1965, op. cit.; Dubinina M.N. 1987: Class Cestoda Rudolphi, 1808. In: O.N. Bauer (Ed.), Key to the Parasites of Freshwater Fishes. Vol 3. Publ. House Nauka, Leningrad, pp. 5-76, in Russian). This study provides the first description of the karyotype of P. osculatus based on the analysis of colchicinetreated mitotic chromosomes. Ten specimens of P. osculatus used for karyological exami-nation were recovered from the gut of European wels (S. glanis) caught in Curonian Bay near Ventė settlement (Lithuania) in June 1999. Whole living specimens were placed in 0.01% colchicine in physiological solution for 3-4 h at room temperature. Fixation involved three changes (20 min each) of a freshly prepared solution of ethanol-acetic acid (3 : 1). Each slide was made from a single individual using a cellular suspension air-drying technique (Petkeviciūtė R., Ieshko E.P. 1991: Int. J. Parasitol. 21: 11-15). Slides were stained directly with 4% Giemsa in phosphate buffer (pH 6.8) for 40 min. Metaphase plates, suitable for karyological analysis, were photographed, and photomicrographs were used for construction of karyotypes. Seven well-spread metaphase plates were chosen for karyometric analysis. The classification of chromosomes followed that of Levan et al. (Levan A., Fredga K., Sandberg A. 1964: Hereditas 52: 201-220). When a centromere position was on the borderline between two categories, two chromosome categories were listed. From 10 specimens of P. osculatus, 79 mitotic plates were obtained where the chromosomes were spread well enough to be counted, and of these, 70 contained 18 chromosomes. All other values were lower than 18 and were attributed either to aneuploidies or, more likely, to loss of chromosomes during slide preparation. The chromosomes of P. osculatus were relatively small. Their mean absolute length ranged from 1.02 μm to 3.26 μm (Table 1), and the mean total length of the haploid set (TCL) was 17.49 μm. The first pair of homologues was noticeably larger than the remaining pairs which decreased in size fairly gradually (Fig. 1). According to centromeric index values, chromosomes 1, 7, and 9 were subtelocentric, pairs 2, 5, and 8 submetacentric, pair 3 metacentric, 4 subtelo-submetacentric, and 6 submeta-metacentric. Within the order Proteocephalidea, chromosome morphology has been described for three Proteocephalus spp.: P. percae, P. exiguus, and P. macrocephalus (Spakulova M., Hanzelova V. 1992: Folia Parasitol. 39: 324-326; Petkeviciūtė R. 1993: Biology (Vilnius) 1: 47-48; Hanzelova V., Snabel V., Spakulova M., Kral’ova I., Fagerholm H-P. 1995: Can. J. Zool. 73: 1191-1198; Scholz T., Spakulova M., Snabel V., Kral’ova I., Hanzelova V. 1997: Syst. Parasitol. 37: 1-12). The same chromosome number (2n = 18) has been found, but with some differences in chromosome morphology. A different chromosome number (2n = 14) was reported for another proteocephalidean, Acanthotaenia multitesticulata, but without any details of karyotype morphology (Vijayaraghavan S., Subramanyam S. 1980a: Z. Parasitenkd. 63: 65-70). The diploid chromosome numbers in Cestoda range from 6 in Microsomacanthus spp. (Hymenolepididae) (Petkeviciūtė R., Regel K.V. 1994: J. Helminthol. 68: 53-55) to 28 in Nematotaenia dispar (Nematotaeniidae) (Vijayaraghavan S., Subramanyam S. 1980b: Riv. Parassitol. 41: 371-375). ChroFOLIA PARASITOLOGICA 48: 159-161, 2001

On the phylogenetic positions of the Caryophyllidea, Pseudophyllidea and Proteocephalidea (Eucestoda) inferred from 18S rRNA

A phylogenetic analysis of tapeworms (Eucestoda) based on complete sequences of the 18S rRNA genes of 43 taxa (including new sequences of 12 species) was carried out, with the emphasis on the groups parasitising teleost fish and reptiles. Spathebothriidea and Trypanorhyncha (the latter group being paraphyletic) appeared as basal groups of the Eucestoda but their position was not stable. The tetrafossate orders (Litobothriidea, Lecanicephalidea, Tetraphyllidea, Proteocephalidea, Nippotaeniidea, Tetrabothriidea and Cyclophyllidea) were well separated from the remaining groups. Results supported polyphyly of the Pseudophyllidea formed by two distinct clades: one with diphyllobothriids (Diphyllobothrium, Schistocephalus, Spirometra and Duthiersia) and another including Abothrium, Probothriocephalus, Eubothrium and Bothriocephalus. The former pseudophyllidean clade formed a separate branch with the Caryophyllidea (Khawia and Hunterella) and Haplobothriidea (Haplobothrium), the latter taxon being closely related to either caryophyllideans or diphyllobothriids in different analyses. Proteocephalideans formed a monophyletic group in all analyses and constituted a clade within the Tetraphyllidea thus rendered paraphyletic. Within the Proteocephalidea, the Acanthotaeniinae (Acanthotaenia from reptiles in Africa) and Gangesiinae (Gangesia and Silurotaenia from silurid fish in the Palearctic Region) were separated from parasites of freshwater fish and mammals. The family Proteocephalidae was found to be paraphyletic due to the placement of a monticelliid species, Monticellia sp., in a clade within the former family. The genus Proteocephalus appeared as an artificial assemblage of unrelated taxa which is congruent with previous molecular analyses.

Enteric Helminths of Perch (Perca fluviatilis L.) and Yellow Perch (Perca flavescens Mitchill): Stochastic or Predictable Assemblages?

Component communities of perch (Perca fluviatilis L) in Eurasia and the North American yellow perch (Perca flavescens Mitchill) were examined to determine the nature of their parasite communities. The scale of this investigation is continental and includes data collected across the distribution of each host species. Data were compiled from the literature and from 5 sample sites in North America. Four parasite species were found to occur frequently in the helminth component communities of P. flavescens. The cestodes Bothriocephalus cuspidatus and Proteocephalus pearsei, the digenean Crepidostomum cooperi, and the nematode Dichelyne cotylophora comprised a suite of species of which some or all occurred in most samples. Similarly, a group of 4 predictable parasite species was identified for P. fluviatilis in Eurasia, the digenean Bunodera luciopercae, the nematode Camallanus lacustris, the cestode Proteocephalus percae, and the acanthocephalan Acanthocephalus lucii. Specificity was not a requirement for predictability. Despite geographical isolation for millions of years, and different fish species interactions within and between continents, the predictability of these parasite assemblages indicates they are shaped by a biology, especially feeding patterns, common to both perch species. This is evidence that parasite assemblages comprised of nonhost-specific parasites in freshwater fishes are not merely stochastic assemblages but have key components that are predictable at this broad continental scale.

Experimental Infection of Striped Marshfrog Tadpoles (Limnodynastes peronii) by Ichthyophthirius multifiliis

Ichthyophthirius multifiliis, or white spot, is a well known and widely distributed parasite of freshwater fish. However, it is not know whether it can infect other aquatic vertebrates such as amphibians. This study uses a series of laboratory-based experiments to demonstrate that I. multifiliis can infect the tadpole stage of an amphibian, the striped marshfrog (Limnodynastes peronii) of Eastern Australia. The tadpoles did not appear to develop ichthyophthiriasis at low parasite levels (200 parasites per tadpole), but at high parasite levels (2,000 parasites per tadpole) 100% of the tadpoles developed ichthyophthiriasis. This is the first time that it has been demonstrated that I. multifiliis can infect a nonpiscine vertebrate host.