title: Chlorophycean parasite on a marine fish, Sillago japonica (Japanese sillago).
abstract: A green spotted Japanese sillago (Sillago japonica) was caught by a fisherman and brought to the laboratory for pathological inspection. The green spots were abundant on the lateral line and more extensively so within the mouth cavity. In both sites, green spots were embedded within the fish flesh and formed 2-3mm dome-shaped colonies. SEM revealed these colonies to harbor numerous unknown cells with small, surface warts (ornamentations). Molecular analysis showed the cells were Desmodesmus (D. komarekii), a common freshwater coccoid green alga found in ponds and rivers worldwide. It is uncertain how the host fish came to be infected with the alga which was not merely attached externally but embedded within the flesh and inside the mouth cavity. This is the first case of parasitic form of coccoid green algae in marine fish and provides new insights into the variable nature of green algae.
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8528, Japan. Electronic address: kazkoike@hiroshima-u.ac.jp.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
authors.forename: Noriko
authors.initials: N
authors.lastname: Akai
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Liao
authors.forename: Shota
authors.initials: S
authors.lastname: Ikeda
authors.forename: Sadaaki
authors.initials: S
authors.lastname: Yoshimatsu
mesh_terms: D000818:Animals; D001483:Base Sequence; D000460:Chlorophyta / Q000145:classification* / Q000166:cytology / Q000235:genetics; D048028:DNA, Algal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005393:Fish Diseases / Q000469:parasitology* / Q000473:pathology; D005399:Fishes; D007564:Japan; D053403:Lateral Line System / Q000469:parasitology; D008969:Molecular Sequence Data; D009055:Mouth / Q000469:parasitology; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D048028:DNA, Algal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012337:RNA, Ribosomal, 18S
keywords: Algal parasite; Desmodesmus; Fish disease; Green alga; Japanese sillago