title: An Anomalous Hatchery-Reared Biwa Rock Catfish, Silurus lithophilus (Teleostei: Siluridae),with an Adipose Fin-Like Projection.
abstract: An anomalous individual with an adipose fin-like projection was discovered during seedling production of Biwa rock catfish, Silurus lithophilus (Teleostei: Siluridae). The external shape of the projection resembled an adipose fin, but soft rays were clearly observed within it. The projection was proximally supported by a series of pterygiophores and by 14 soft rays. The projection can be explained as: I, homologous with a primitive adipose fin, which occurred as a result of localized ontogenetic reversion; II, an extra fin that occurred as a result of abnormal expression of a regeneration mechanism; III, a remnant of a dorsal fin and/or a second dorsal fin; and IV, an inversion phenomenon of the polarity in the formation process of the anal fin.
authors.affiliation: Faculty of Agriculture, Kinki University, Nakamachi, Nara 631-8505, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kitagawa
authors.affiliation: Faculty of Agriculture, Kinki University, Nakamachi, Nara 631-8505, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hosoya
mesh_terms: D058500:Animal Fins / Q000002:abnormalities*; D000818:Animals; D017756:Aquaculture; D002397:Catfishes / Q000002:abnormalities*; D005393:Fish Diseases / Q000151:congenital* / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography; D013131:Spine / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology
keywords: artificial breeding; dysplasia; endemic species; evolution; fin-ray