A new peronosporomycete, Halioticida noduliformans gen. et sp. nov., isolated from white nodules in the abalone Haliotis spp. from Japan

Abstract

A new peronosporomycete, Halioticida noduliformans gen. et sp. nov., isolated from white nodules in the abalone Haliotis spp. from Japan Abstract Four strains belonging to the Peronosporomycetes (formerly Oomycetes) were isolated from white nodules found on the mantle of three species of abalone. In artifi cial seawater, the four isolates formed fragments such as in the genus Haliphthoros, but the protoplasm constriction was weaker, and fragments were longer, with smaller spaces between them, than those of Haliphthoros. The four strains form one or more discharge tubes from each zoosporangium. The four strains were similar, but not identical, to the genus Haliphthoros based on morphological characteristics. As a result, the four isolates were classifi ed in a new genus and species, Halioticida noduliformans gen. et sp. nov. Phylogenetic analysis of the D1/D2 region of the large subunit ribosomal RNA gene (LSU rDNA) was performed, and the four isolates showed 100%-99.8% concordance. In the phylogenetic tree, the four isolates were not classifi ed in the subclass Peronosporomycetidae, Saprolegniomycetidae, or Rhipidiomycetidae. However, the four isolates formed a new clade with genera Haliphthoros and Halocrusticida in Peronosporomycetes. Within this new clade, the four isolates, Haliphthoros spp. and Halocrusticida spp., were grouped in their respective independent subclades. These results showed that these were the new genus and species from the morphological characteristics.

Intracellular eukaryotic pathogens in brown macroalgae in the Eastern Mediterranean, including LSU rRNA data for the oomycete Eurychasma dicksonii

“…Observation of filamentous brown algal hosts by microscopy resulted in the detection of Eury chasma dicksonii (E. P. Wright) Magnus and 2 intracellular pathogens identified as members of the genus Anisolpidium. Furthermore, we report here the first gene sequences of large subunit ribosomal RNA (LSU rRNA) for E. dicksonii, which has re cently been used to delineate early-branching oomycete clades (Muraosa et al 2009, Macey et al 2011. The LSU rRNA gene sequence information from E. dicksonii isolates originating from the Pacific, South and Northeast Atlantic Ocean and the Aegean Sea not only confirms the identification of the Greek pathogen with molecular tools, but also underscores the monophyly of Eurychasma on a global scale.…”

“…However, currently sequence information on different marker genes is in many instances restricted and fragmentary, which especially holds true for the basal oomycetes (e.g. Hakariya et al 2009, Muraosa et al 2009, Sekimoto et al 2009 Sparrow 1960). Members of the Sphacelariales show apical growth patterns (Katsaros 1995).…”

First Report of Achlya oblongata Infection in Freshwater‐Reared Asian Seabass Lates calcarifer

“…(), and Muraosa et al. (, ), the edges of hyphae that had been growing for 48–72 h and incubated at 25°C in GY broth were cut and frozen at −85°C. Next, the mycelia were homogenized by Micro Smash (Tomy Seiko Co. Ltd) with the addition of zirconia beads.…”

11 Hyphochytriomycota, Oomycota and Perkinsozoa (Super-group Chromalveolata )

“…Both H. heterospora and M. vermicola have been recorded several times from terrestrial species of Rhabditis , while G. latitubus is the only nematode parasite known from a single marine isolate. Halioticida is a recentlyerected and monotypic genus, with H. noduliformis isolated from white nodules found on the mantle of three species of abalones (Muraosa et al 2009). …”