Parasitic protozoa from marine and euryhaline fish of Newfoundland and New Brunswick. I. Peritrichous ciliates

Abstract

Trichodina elizabethae n. sp. (which is commonly hyperparasitized by the suctorian Endosphaera engelmanni Entz), T. galyae n. sp., and T. domerguei (Wallengren) saintjohnsi n. subsp. are described from Newfoundland waters; the first two from the radiated shanny and lumpfish respectively, and the last from the mailed sculpin, lumpfish, and shorthorn sculpin. T. jarmilae n. sp. parasitizes the sea raven in the Bay of Fundy, New Brunswick. In both provinces, T. cottidarum Dogiel, sensu lato, occurs on shorthorn and longhorn sculpins. Two species of fish from brackish pools (the threespine stickleback in both areas; the mummichog in the Bay of Fundy) are often heavily parasitized by T. tenuidens Fauré-Fremiet. All the ciliates referred to were collected from the gills of their hosts, only two of which bore peritrichs other than trichodinids. One of these, Caliperia brevipes Laird, is found on the little skate in the Bay of Fundy and has been described elsewhere. The other, Scyphidia arctica Zhukov, is now reported from the longhorn sculpin in Newfoundland. Only five (16%) of 31 species of marine fish from Newfoundland bore trichodinids, as compared with nine (35%) of 26 from New Brunswick. However, four of the latter group had extremely light or sporadic infestations. Three of the rest, showing high incidence and heavy to extremely heavy infestations, were sculpins (Cottidae), as were three of the five Newfoundland hosts. Thus, while information is accumulating to suggest that marine fish trichodinids find optimum environmental conditions where mean seawater temperatures are not extreme (neither very warm nor very cold), certain fish are evidently more prone to infestation than others. This may well be due to varying ecological vulnerability to parasitization rather than to the operation of host specificity, an important question which, like that of environmental tolerances, merits early experimental attention. The paper includes a list of 61 species of Trichodina and the closely related Tripartiella and Trichodinella now known from marine and euryhaline fish, their validity being assessed on the basis of technique and the taxonomic criteria used.

Description of Trichodina hippoglossi n. sp. from farmed Atlantic halibut larvae Hippoglossus hippoglossus

“…Lom & Dykova 1992). However, in aquaculture, with high host densities and abnormal environments, these protozoans may become pathogens and cause mortality.…”

“…Of these, only 2 species were characterised as well established: Trichodina borealis Shulman & Shulman-Albova, 1953, which has been reported from several flatfish species (e.g. Platishthys flesus L., Hippoglossoides platessoides Fabr., Pleuronectes platessa L.) (Raabe 1958, Lom & Laird 1969, MacKenzie 1969, Calenius 1980, and T. raabei Lom, 1962, which has been described from P. flesus in the Black Sea (Lom 1962). Additionally, Pearse (1972) has presented morphometric data for Trichodina sp.…”

First Record of the Parasitic Ciliate Trichodina truttae Mueller, 1937 on Chum Salmon Fry (Oncorhynchus keta) from Japan.

“…Ciliates belonging to the family Trichodinidae are common and occasionally pathogenic para sites of freshwater and marine fishes (Lom and Hoffman, 1964;Lom and Laird, 1969;Hoffman, 1978). In Japan, trichodinid infections fre quently occur on cultured freshwater and ma rine fishes, but taxonomic and pathological studies of this group have been very few (Egusa, 1978).…”

Progress of co-infections of Trichodina cooperi and T. murmanica parasitising farmed Atlantic cod Gadus morhua juveniles in Iceland

“…It has been described from wild and cultured cod Gadus morhua in Atlantic Canadian waters (Poynton & Lom 1989, Khan 2004, the Barents and White Seas (Polyanskiy 1955, Shtein 1976, Karasev et al 1996 and Chukotka (Siberia) (Zhukov 1964), from saithe Pollachius virens from the Barents and White Seas (Polyanskiy 1955, Karasev et al 1996 and from various other non-gadoids such as winter flounder Pseudopleuronectes americanus in Canadian waters (Barker et al 2002), Cyclopterus sp., Triglops murrayi and Myoxocephalus scorpius from Grand Banks in Atlantic Canada (Lom & Laird 1969) White Sea (Shtein 1976), Pholis gunellus and Myoxocephalus scorpius from the Barents Sea (Shtein 1973) and Acanthopagrus macrocephalus from the Yellow Sea in South East China (Xu et al 1999). Yet, the only known host for T. cooperi is Atlantic cod G. morhua.…”