J. G. Van As

Trichodinid ectoparasites of cichlid and cyprinid fishes in South Africa and Israel

SummaryThree new and seven known species of trichodinid ectoparasites (Ciliophora: Peritricha) were identified from cichlid and cyprinid fishes collected from fish ponds, natural and man-made lakes, rivers and streams in South Africa and Israel. The new species described are: Trichodina centrostrigata n.sp., T. minuta n.sp. and Tripartiella cichlidarum n.sp. The known species, of which comparative descriptions are given and intraspecific variability discussed, are: Trichodina acuta Lom, 1961, T. heterodentata Duncan, 1977, T. mutabilis Kazubski & Migala, 1968, T. nigra Lom, 1960, T. pediculus Ehrenberg, 1838, T. reticulata Hirschmann & Partsch, 1955 and Trichodinella epizootica (Raabe, 1950). ac]19820916

Trichodinid ectoparasites (Ciliophora: Peritrichida) of freshwater fishes of the Zambesi River System, with a reappraisal of host specificity.

Over a period of five years parasitological surveys were carried out on the freshwater fish fauna in the eastern Caprivi which included the upper Zambesi River, a section of the Chobe and Kwando Rivers, and vast swampy areas. This area is well known for its wide variety of indigenous fish and has so far not been influenced in any way by introduced alien fish species. In these surveys 45 different fish species of 12 families were examined. This paper reports on the parasites of the generaTrichodina andHemitrichodina of the eastern Caprivi. A total of 15 species of parasites were recorded of which nine are new species described here-in. The list of host records of known species are expanded and an evaluation of host specificity based on information recorded in this survey as well as previously published data from southern Africa is provided.

Trichodinid ectoparasites (Ciliophora: Peritrichida) of wild and cultured freshwater fishes in Taiwan, with notes on their origin

During 1988 parasitological surveys were carried out on the freshwater fish fauna on the island of Taiwan in 12 localities that included fishery stations, reservoirs, fish markets as well as natural rivers and swamps. A total of 28 fish species were examined, representing 14 families. This paper reports on the parasites of the genus Trichodina (Ciliophora, Peritrichida) of Taiwan. Fourteen trichodinid species were recorded of which five are new. Trichodinids collected in this study can be divided into four categories, based on their host association and possible region of origin. The first category includes trichodinids with an African origin, T. centrostrigeata Basson, Van As & Paperna, 1983, T. heterodentata Duncan, 1977, T. compacta Van As & Basson, 1989 and possibly T. canton n. sp. The second category is species with an Eurasian origin and includes T. acuta Lom, 1961, T. modesta Lom, 1970, T. mutabilis Hirschmann & Partsch, 1955, T. nigra Lom, 1961 and T. nobilis Chan, 1963. The third category comprises one species, T. maritinkae Basson & Van As, 1990, with an Afro-Asian distribution. The last category is composed of new species that are most likely native to Asia: these are T. matsu n. sp., T. mandarin n. sp., T. wulai n. sp. and T. pagoda n. sp.

Host specificity of trichodinid ectoparasites of freshwater fish

Ciliophorons of the family Trichodinidoe comprise seven genera, all of which are commensolists or parasites - mainly on aquatic hosts such as other ciliophorans, coelenterates, planctonic crustaceans, molluscs, echinoderms, amphibians and fish. Although the first species of this family, Trichodina pediculus, was described from material collected from Hydra, most literature concerns the trichodinids of fish-particularly cultured freshwater fish. These ciliophorans have been implicated in severe disease and mortalities of fish, causing severe economic losses in various parts o f the world. In spite o f the confused taxonomy o f the Trichodinidae, it now appears that they fall into four distinct groups representing a line of specialization towards a more exclusive niche on the host fish. The more opportunistic species, with a broad host range, tend to be larger skin parasites, while the more specialized are smaller and usually only parasitize the gills o f their specific host.

Trichodinids (Ciliophora: Peritrichia) from a calanoid copepod and catfish from South Africa with notes on host specificity

A case study is presented in which a trichodinid infestation was found on Clarias gariepinus (Burchell, 1822) larvae in a hatchery. Upon examination of copepods in the water system, it was found that they too hosted this trichodinid species. After following the infestation for some time it was found that the trichodinids on the catfish disappeared, whilst the infestation on the calanoid copepods persisted. It was concluded that the trichodinid originated from the copepods and could not establish a viable infestation on the catfish larvae. Specimens of catfish fry from the same farm, however, hosted a different trichodinid which is described as a new species. After analysis of published information, it was concluded that the trichodinid from these calanoid copepods belongs to the same species as described by different authors from various localities from Eurasia. In order to provide a specific identification of this trichodinid, a literature review is presented. In a discussion of host specificity, it is concluded that the trichodinid involved is specific to planktonic copepods and cannot establish an infestation on fish.

Differential diagnosis of the genera in the family Trichodinidae (Ciliophora: Peritrichida) with the description of a new genus ectoparasitic on freshwater fish from southern Africa

A trichodinid ectoparasite was collected from mormyrid fish in the Olifants River System, South Africa. A new genus, Hemitrichodina, is described to accomodate these trichodinid ciliophorans of which the blades are reduced and with an adoral spiral of more than 360°, but less than two full turns. A differential diagnosis of the genera within the family Trichodinidae is presented.

The digestive system of the fish ectoparasite Dolops ranarum (Crustacea: Branchiura)

Reconstructions from serial sections reveal that the digestive system consists of a pharynx esophagus, crop, midgut, and rectum. Two main stems from the branched enteral diverticula are connected to the lateral regions of the crop by right rind left arms. Glandular tissue surrounds the enteral diverticula proximally. A strong sphincter separates the crop and midgut, whereas the midgut and rectum are separated by a weak sphincter. Cuboidal epithelium lines the pharynx, esophagus, crop, and rectum, whereas cuboidal and club‐shaped epithelia line the midgut. The cuboidal cells possess elongated nuclei and numerous vacuoles, suggesting that absorption takes place in the midgut.

Trichodinid (Ciliophora; Peritricha) gill parasites of freshwater fish in South Africa

SummaryTrichodinella epizootica (Raabe, 1950) and seven new species of trichodinid ectoparasites (Ciliophora: Peritricha) were identified from both wild and pond fishes collected during an extensive survey of fish ponds, rivers and lakes in the Transvaal, South Africa. The new species are Tripartiella clavodonta n. sp., T. lechridens n. sp., T. leptospina, n. sp., T. macrosoma n. sp., T. nana n. sp., T. orthodens n. sp. and Trichodinella crennulata n. sp.

A TAXONOMIC STUDY OF SESSILE PERITRICHIANS OF A SMALL IMPOUNDMENT WITH NOTES ON THEIR SUBSTRATE PREFERENCES

SUMMARY A taxonomic study of the sessile peritrichians (Ciliophora: Peritricha) was carried out on material collected from plants and animals, as well as inanimate substrates, experimentally placed into West-dene Dam, Johannesburg. A total of 15 species, representing the genera Carchesiwn, Voorticella, Apiosoma, Epistylis, Opercularia, Scyphidia, Cothurnia and Vaginicola were identified. Four new species are described and comparative descriptions of the known species given. Substrate preference and specificity are discussed. Peritrichians associated with fish, were not only found to be morphologically distinct, but also specific to their piscean substrates.

A redescription of Dolops ranarum (Stuhlmann, 1891) (Crustacea: Branchiura)

The branchiuran ectoparasite Dolops ranarum (Stuhlmann, 1891) was described almost one hundred years ago. This descriptional though valid is incomplete. A redescription is given. New information was obtained with light and scanning electron microscopy. Morphometric values are included and a species diagnosis is presented.