Biodiversity and Evolution of Digeneans of Fishes in the Southern Ocean

• Main Authors: Faltýnková, A. (Anna), Georgieva, S. (Simona), Kostadinova, A. (Aneta), Bray, R. A.
• Format: Book Part
• Language: English
• Published: 2017
• Subjects: antarctic ice-sheet; pine island bay; weddell sea; phylogenetic analysis; notothenia-coriiceps; opecoelid trematode; macvicaria gibson; west antarctica; Antarc*; Antarctic; Antarctica; Ice Sheet; Pine Island; Pine Island Bay; Ross Sea; Scotia Sea; Southern Ocean; Weddell Sea; West Antarctica
• Online Access: https://doi.org/10.1007/978-3-319-46343-8_5; http://hdl.handle.net/11104/0280399

The digenean fauna of fishes found in the Southern Ocean is described based on a database derived from the literature and new observations. A total of 60 digenean species allocated to 28 genera in ten families have been described or reported from fishes in the three provinces of the Southern Ocean, i.e. the Sub-Antarctic Islands, the Scotia Sea and the Continental High Antarctic (Province 61) The most prevalent digenean families are the Opecoelidae, the Lepidapedidae and the Hemiuridae. Digeneans have been reported from 76 fish species of 41 genera in 13 families. The fish family with the highest number of records of digeneans is the Nototheniidae with the Channichthyidae, Bathydraconidae and Artedidraconidae also frequently infected. The taxonomic diversity in the Continental High Antarctic Province and the Scotia Sea Province is higher than that of the Sub-Antarctic Islands. It was found that these data suggest that digeneans in fishes of the Southern Ocean typically exhibit low levels of host-specificity. The faunas of Weddell Sea and the distantly separated Ross Sea are highly similar, suggesting that, in geological terms, the regions had been recently connected by a collapse of the West Antarctic Ice Sheet. Phylogenetic inferences derived from 28S rDNA sequences for newly collected Antarctic representatives of the three commonest families are presented and discussed. It was found that the Hemiuridae could only be considered monophyletic if the family Lecithasteridae is included within it. In the Opecoelidae it was found that the genus Macvicaria is polyphyletic and that the two Antarctic species included formed a clade isolated from other putative congeners. In the Lepidapedidae, the Antarctic species clustered with related worms from deep-sea species.