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A disease of freshwater fishes caused by Tetrahymena corlissi Thompson, 1955, and a key for identification of holotrich ciliates of freshwater fishes

Tetrahymena corlissi , a free-living protozoan, apparently caused the death of large numbers of guppies ( Poecilia reticulatus ) and occasionally other fishes, in aquaria and hatcheries at several locations. Apparently the disease occurs when the fish and protozoan populations are both at a high level of density. The signs include white spots and epidermal damage. Histologically, T. corlissi could be seen in skin, muscle, and viscera; in some there was marked inflammation, in others there was little tissue reaction. A key is presented for the identification of invasive fish ciliates: Chilodonella , Hemiophrys , Ichthyophthirius , Ophryoglena , and Tetrahymena .

Journal of Parasitology

Thin-section electron microscopy of mature Myxosoma cerebralis (Myxosporidea) spores

The morphology of purified, mature Myxosoma cerebralis spores was examined by thin-section electron microscopy. Surface architecture corresponded closely to that described in an earlier scanning electron microscopy study of this organism (Lom and Hoffman, 1971). A uniformly thick spore wall is composed of finely granular, electron-lucent material. Intrawall "valvoplasm" at the sutural border region contains small, light spheroidal profiles with dense centers situated in a background matrix; such structures are absent in the intermediate wall areas. Ovoid polar capsules contain complex filamentous profiles within the peripheral matrix region. Individual filaments appear twisted into S-shaped configurations and contain moderately electron-opaque material within their lumina.

Journal of Parasitology

Polypodium sp. (Coelenterata) infection of paddlefish (Polyodon spathula) eggs

Parasitism of fish by coelenterates is rare and the first North American infection was reported in sturgeon (Hoffman et al., 1974, J Parasitol 60: 548-550). In the USSR parasitism of sturgeon (Acipenser sp.) eggs by the coelenterate Polypodium hydriforme Ussov 1885 has long been reported and investigated [Raikova, 1959, in Parasites of Freshwater Fish and the Biological Basis for their Control. Bull State Sci Res Inst Lake and River Fish. XLIX. Eng. transl. No. TT61-31056, O. T. S., U. S. Dep. Commerce, Washington, D. C., 1962, 235 p.: Raikova, 1973, (Proc Second Internat Symp on Cnidaria), Seto Marine Biological Laboratory 20: 165-173]. This report represents the first known infection of Polypodium in the paddlefish (Polyodon spathula).

Journal of Parasitology

New host and geographical records for the leech Acanthobdella peledina Grube 1851 (Hirudinea, Acanthobdellidae)

A total of four leeches (Acanthobdella peledina), parasitizing four specimens of the least cisco (Coregonus sardinella), were found during July and August 1977. The hosts and parasites were collected during a fishery survey by the U.S. Fish and Wildlife Service in the North Slope waters of Naval Petroleum Reserve, Alaska. Two host fishes were collected from the Chipp River (70035' latitude, 155012' longitude) and two from an unnamed, landlocked lake (69054' latitude, 153o23' longitude). The Chipp River collection site is about 130 km southeast of Barrow, and the unnamed lake about 200 km southeast of Barrow. The leeches, which were fixed in situ with neutral formalin, appeared to have penetrated the integument and were embedded in subcutaneous tissues and white muscle at the base of the pelvic fins. The specimens were cylindrical and about 23 mm long and 2-3 mm wide. Color before fixation was olive-green. The five anterior segments each had four pairs of hooked setae at the ventral surface. Our identification was based on a description in Bykhovskaya-Pavlovskaya et al., 1962, Key to parasites of freshwater fish of the USSR (Transl. from Russian), NTIS TT-64-11040.

Journal of Parasitology

Feather mites of the greater sandhill crane (Grus canadensis tabida)

New taxa are described from Grus canadensis tabida: Brephosceles petersoni sp. n. (Alloptidae); Pseudogabucinia reticulata sp. n. (Kramerellidae); Geranolichus canadensis sp. n., and Gruolichus wodashae, gen. et sp. n. (Pterolichidae). Observations on resource partitioning by these mites are given.

Indiana, Wisconsin

The parasitic coelenterate, Polypodium hydriforme Ussov, from the eggs of the American acipenseriform Polyodon Spainthula

No significant differences in macro- and micromorphology were found between the parasitic stolon and free-living polyps of Polypodium sp. obtained from infected eggs of the North American acipenseriform fish Polyodon spathula and corresponding developmental stages of Polypodium hydriforme Ussov, parasitic in the Volga sterlet ( Acipenser ruthenus ). Therefore, both the American and the European forms of Polypodium belong to the species P. hydriforme Ussov.

Missouri

The white pelican (Pelicanus erythrorhynchos) as a host of Pelecanectes apunctatus (Acarina: Hypoderidae)

Several species of nymphs from the family Hypoderidae have been reported from pelecaniform birds (Cerny, 1969, Folia Parasit. (Praha) 16:271-274; Pence, 1972, J. Med. Ent. 9: 435-438; Pence and Courtney, 1973, J. Parasitol. 59: 711-718); however, there are no records from the white pelican, Pelecanus erythrorhynchos . I report here the occurrence of hypopi from this host species.

Texas

Increased population densities of Amblyomma americanum (Acari: Ixodidae) on Long Island, New York

Lone star ticks, A mblyomma americanum comprised a significantly greater proportion of total ticks flagged on eastern Long Island and Fire Island, New York, in 1986 and 1990 than in samples reported by other authors from the 1940s (when A. americanum was not collected by flagging or from hosts) and the 1970s. Therefore, population densities of A. americanum apparently have increased in recent years on southeastern Long Island, where this species now is distributed widely.

Journal of Parasitology

Haemoproteus iwa n. sp. in great frigatebirds (Fregata minor [Gmelin]) from Hawaii: Parasite morphology and prevalence

We describe a new species of Haemoproteus Kruse, 1890 from great frigatebirds ( Fregata minor [Gmelin]) captured on Tern Island-French Frigate Shoals and Laysan Island in Hawaii. Parasite prevalence on Laysan Island (35%) was not significantly different than that of Tern Island (36%). On Laysan, prevalence was highest in juveniles (52%), followed by adult males (29%) and adult females (19%). Prevalence on Tern was 36% both for adult females and juveniles, and 28% for adult males. Parasitemia was low (mean < 2 parasites/10,000 red blood cell). Parasitized red cells had significantly greater areas than unparasitized cells. We named this parasite Haemoproteus iwa after the Hawaiian name for frigatebirds (iwa). This is the first documentation of a hemoparasite from tropical pelagic seabirds in Hawaii and the first description of an endemic hemoparasite in the archipelago.

Hawai'i

Description and epizootiology of Babesia poelea n. sp. in brown boobies (Sula leucogaster (Boddaert)) on Sand Island, Johnston Atoll, Central Pacific

We describe a new species of piroplasm from brown boobies (Sula leucogaster) on Sand Island, Johnston Atoll National Wildlife Refuge, central Pacific. Mean parasitemia in adults and chicks was less than 1%, with the parasitemia in chicks significantly greater than in adults. There was no significant relation between the age of chicks and the degree of parasitemia. Parasitized red cells and red cell nuclei were significantly smaller than those of unparasitized cells, and infected birds appeared clinically normal. Prevalence of the parasite in chicks (54%) was significantly greater than in adults (13%), and the geographic distribution of parasitized chicks was skewed toward the eastern end of Sand Island. On the basis of morphologic characteristics, we named it Babesia poelea. The specific name is a concatenation of the Hawaiian names for dark (po'ele) and booby ('a). This is the second documentation of an endemic avian hemoparasite in seabirds from the central Pacific.

Johnston Atoll

Pathogenicity of entomopathogenic fungus Metarhizium anisopliae (Deuteromycetes) to Ixodes scapularis (Acari: Ixodidae)

The entomopathogenic fungus Metarhizium anisopliae is highly pathogenic to the black-legged tick, Ixodes scapularis. Spore concentrations of 108/ml for engorged larvae and 107/ml for engorged females resulted in 100% tick mortality, 2 wk post-infection. The LC50 value for engorged larvae (concentration to kill 50% of ticks) was 107 spores/ml. Metarhizium anisopliae shows considerable potential as a microbial control agent for the management of Ixodes scapularis.

Journal of Parasitology

Acanthocephala of the bald eagle (Haliaeetus leucocephalus) in North America

Examination of bald eagles (Haliaeetus leucocephalus) collected from several locations in North America contributed new information concerning the acanthocephalan fauna of this host. Representatives of Arythmorhynchus brevis, representing a new host record, were collected from eagles in Florida, New Hampshire, and Wisconsin. Plagiorhynchus sp. was collected from an eagle in Florida. Corynosoma strumosum was collected from an eagle in Alaska. Andracantha phalacrocoracis, representing a new host record, was collected from an eagle in Alaska. Southwellina hispida, representing a new host record, was collected from eagles in Maine and Virginia. The occurrence of gravid or mature females of A. brevis, Plagiorhynchus sp., and S. hispida suggests that the bald eagle may serve as a competent definitive host for these species.

Alaska, Florida, Maine, New Hampshire, Virginia, W

Spatial distribution of larval Ixodes scapularis (Acari:Ixodidae) on Peromyscus leucopus and Microtus pennsylvanicus at two island sites

Larval blacklegged ticks, Ixodes scapularis , were collected from white-footed mice, Peromyscus leucopus , on Prudence Island (where Microtus pennsylavanicus were not captured) and from meadow voles, M. pennsylvanicus , on Patience Island (where P. leucopus was absent) in Narragansett Bay, Rhode Island from June to October 1992. Ixodes scapularis larvae were also collected by flagging in the vicinity of host captures. On both islands, the relative density of larvae changed from July to September in samples from hosts, but not in flagging samples. Consequently, different sampling techniques can give different assessments of tick populations. Larvae were highly aggregated on both of the host species throughout the sampling period. As the mean relative density of larvae increased in the environment (based on flagging samples), larvae on the hosts became more dense and more crowded. Increased densities of larvae in the environment were not correlated with increased patchiness in the distribution of larvae among host animals on either island. Changes in the spatial distribution of larval I. scapularis on each host species had similar trends as larval densities and distributions within the environment. These results suggest that M. pennsylvanicus can serve as an alternative host for immature I. scapularis in a P. leucopus -free environment and have similar distributional characteristics.

Journal of Parasitology

Some myxosporidia found in Pacific Northwest salmonids

During the histological examination of a group of wild and hatchery salmonids undescribed sporazoans were frequently observed. This was not unexpected, since Myxosporidia are typical fish parasites (Kudo, 1920). Myxidium were observed in kidney tubules, Cholromyxum in glomeruli, and Myxobous in the spinal cord and on epidermal scales. The present paper will deal with the description and indentification of these unclassified Myxosporodia.

Oregon, Washington