The parasitic ciliate causing shrimp black gill (sBG) infections in penaeid shrimp has been identified. The sBG ciliate has a unique life cycle that includes an encysted divisional stage on the host's gills. The ciliature of the encysted trophont stage has been determined and is quite similar to that of the closely related apostomes Hyalophysa bradburyae and H. chattoni. Hyalophysa bradburyae is a commensal ciliate associated with freshwater caridean shrimp and crayfish, while H. chattoni is a common commensal found on North American marine decapods. Based on 18S rRNA gene sequence comparisons, the sBG ciliate is more closely related to the marine species H. chattoni than to the freshwater species H. bradburyae. The unique life cycle, morphology, 18S rRNA gene sequence, hosts, location, and pathology of the sBG ciliate distinguish this organism as a new species, Hyalophysa lynni n. sp.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.ejop.2020.125673 | DOI Listing |
Eur J Protistol
April 2021
Department of Life Sciences, Natural History Museum, London, UK. Electronic address:
Denis Lynn (1947-2018) was an outstanding protistologist, applying multiple techniques and data sources and thus pioneering an integrative approach in order to investigate ciliate biology. For example, he recognized the importance of the ultrastructure for inferring ciliate phylogeny, based on which he developed his widely accepted classification scheme for the phylum Ciliophora. In this paper, recent findings regarding the evolution and systematics of both peritrichs and the mainly marine planktonic oligotrichean spirotrichs are discussed and compared with the concepts and hypotheses formulated by Denis Lynn.
View Article and Find Full Text PDFOecologia
December 2020
Department of Ecology and Evolution, University of Salzburg, Hellbrunnerstrasse 34, 5020, Salzburg, Austria.
Temporal heterogeneity in nutrient availability is known to increase phytoplankton diversity by allowing more species to coexist under different resource niches. Spatial heterogeneity has also been positively correlated with species diversity. Here we investigated how temporal and spatial differences in nutrient addition together impact biodiversity in metacommunities varying in the degree of connectivity among the patches.
View Article and Find Full Text PDFEur J Protistol
August 2021
University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria. Electronic address:
I studied a Brazilian population of Holophrya teres (Ehrenberg, 1834) Foissner, Berger and Kohmann, 1994, using live observation, morphometry, silver impregnation, and scanning electron microscopy. This showed a fair similarity with European populations, especially in having a large (about 13 × 5 μm in vivo) micronucleus pyriform in broad-side view and cuneate in narrow-side view. Several new structures were discovered, viz.
View Article and Find Full Text PDFEur J Protistol
April 2020
University of Georgia, Skidaway Institute of Oceanography, Savannah, GA, 31411, United States.
The parasitic ciliate causing shrimp black gill (sBG) infections in penaeid shrimp has been identified. The sBG ciliate has a unique life cycle that includes an encysted divisional stage on the host's gills. The ciliature of the encysted trophont stage has been determined and is quite similar to that of the closely related apostomes Hyalophysa bradburyae and H.
View Article and Find Full Text PDFEur J Protistol
February 2017
Universität Salzburg, FB Organismische Biologie, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria. Electronic address:
Using standard methods, we describe the morphology and ontogenesis of a possibly very rare ciliate, Stylonychia (Metastylonychia) nodulinucleata nov. subgen (basionym: Stylonychia nodulinucleataShi and Li, 1993), isolated from soil of the Murray River floodplain in Australia. Further, we provide an English translation of the Chinese original description.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!