The ciliate Orchitophrya cf. stellarum and other parasites and commensals of the northern pacific seastar Asterias amurensis from Japan (original) (raw)
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Castration and mortality in Pisaster ochraceus parasitized by Orchitophrya stellarum (Ciliophora)
Diseases of Aquatic Organisms, 1991
A s w e y of the sex-ratio and gonadal index of sea stars Pisaster ohraceus (Brandt, 1835) at 2 sites on the southern coast of British Columbia, Canada, revealed an e~izootic disease affectina the testes. The disease reduced the proportion of males and their reproductive potential in the ~owulations studied. Examination of diseased testes revealed the presence of a parasitic ciliate, Orchitophrya stellarum Cepede, 1907, that has not previously been reported from the Pacific Ocean. The more virulent nature of the parasite in P. ochraceus, as compared with its Atlantic and Mediterranean hosts, may indicate the recent introduction of the parasite into the Pacific.
Journal of Eukaryotic Microbiology, 2008
The morphology and infraciliature of Orthodonella sinica n. sp. and Apokeronopsis wrighti n. sp., isolated from the coastal water off Hong Kong, were investigated in living and stained specimens. Orthodonella sinica n. sp. is diagnosed as: a marine Orthodonella 150-310 Â 40-80 mm in vivo; with a dominant beak-like projection at the anterior end; about 70 somatic kineties; 84-126 dikinetids in the synhymenium; one contractile vacuole in the posterior one-fourth of cell, near the left margin; one conspicuous dorsal suture. Apokeronopsis wrighti n. sp. is diagnosed as: an Apokeronopsis about 150-230 Â 35-55 mm in vivo; dark-reddish blood-cell-shaped cortical granules grouped in three rows on the ventral side and two rows on the dorsal side; 23-35 cirri in the right mid-ventral rows (MVR) and 23-32 cirri in the left MVR; six to eight buccal, two frontoterminal, 30-42 left marginal, and 32-43 right marginal cirri; 21-30 transverse cirri extending anteriorly beyond the level of mid-body; consistently three dorsal kineties. The separation of A. wrighti n. sp. and its highly similar congeners Apokeronopsis crassa and Apokeronopsis bergeri was supported by comparison of their SSrRNA gene sequences.
Journal of Invertebrate Pathology, 2013
Outbreaks of an unidentified ciliate have occurred on several occasions in blue crabs from Chesapeake Bay held during winter months in flow-through systems. The parasite was initially thought to be Mesanophrys chesapeakensis, but molecular analysis identified it as Orchitophyra stellarum, a facultative parasite of sea stars (Asteroidea). We investigated the host-parasite association of O. stellarum in the blue crab host. Crabs were inoculated with the ciliate, or they were held in bath exposures after experimentally induced autotomy of limbs in order to determine potential mechanisms for infection. Crabs inoculated with the ciliate, or exposed to it after experimental autotomy, rapidly developed fatal infections. Crabs that were not experimentally injured, but were exposed to the ciliate, rarely developed infections; thus, indicating that the parasite requires a wound or break in the cuticle as a portal of entry. For comparative purposes, fiddler crabs, Uca minax, were inoculated with the ciliate in a dose-titration experiment. Low doses of the ciliate (10 per crab) were sometimes able to establish infections, but high intensity infections developed quickly at doses over 500 ciliates per crab. Chemotaxis studies were initiated to determine if the ciliate preferentially selected blue crab serum (BCS) over other nutrient sources. Cultures grown on medium with BCS or fetal bovine serum showed some conditioning in their selection for different media, but the outcome in choice experiments indicated that the ciliate was attracted to BCS and not seawater. Our findings indicate that O. stellarum is a facultative parasite of blue crabs. It can cause infections in exposed crabs at 10-15°C, but it requires a portal of entry for successful host invasion, and it may find injured hosts using chemotaxis.
Acta protozoologica
The living morphology and infraciliature of three heterotrichous ciliates from the north China sea, Condylostentor auriculatus , Condylostoma minutum Bullington, 1940 and C. spatiosum Ozaki and Yagiu in Yagiu, 1944, were investigated using protargol impregnation and in vivo observations. Based on the Qingdao population, an improved diagnosis of the poorly defined Condylostentor Jankowski, 1978 is suggested: free-swimming Stentoridae with deep, prominent vestibular cavity, apical boarder with conspicuous ventral groove; ciliature in Stentor-like pattern, i.e. ventral suture and contrast zone of somatic kineties present; adoral zone almost closed but interrupted on ventral side by a deep cleft, vestibulum kineties on vestibular cavity wall; paroral membrane present. A redescription of Condylostentor auriculatus, the type species, is also supplied. Condylostoma minutum is investigated for the first time using silver impregnation and an improved diagnosis is given based on three populations. New information about some details of the oral apparatus is supplied for a third species, Condylostoma spatiosum. characters can be used for species separation. Furthermore the infraciliature of many nominal species remains unknown thus the identification of these organisms is often difficult (Dragesco