Redescription of cystacanths of Corynosoma pseudohamanni Zdzitowiecki, 1984 (Acanthocephala: Polymorphidae) from paratenic fish hosts

Cystacanths of Corynosoma pseudohamanni Zdzitowiecki, 1984 (Palaeacanthocephala: Polymorphidae) are redescribed on the basis of specimens recovered from three species of Antarctic notothenioid fish, Trematomus bernacchii Boulenger, Gobionotothen gibberifrons (Lönnberg) and Notothenia coriiceps Richardson, collected from the Prince Gustav Channel, Antarctica. The cystacanths' morphometry and their internal anatomy including trunk muscles were studied using light and scanning electron microscopy (SEM). The characteristic features of this species such as the length of proboscis and the number of hooks (i.e. 260 hooks arranged in 20 rows with 13 hooks each, including two basal hooks) were confirmed and the intraspecific variability was evaluated. Sexual dimorphism was manifested in the shape of the hindtrunk, and the distribution and extent of the somatic armature only. SEM observations of internal anatomy revealed the detailed organization of trunk musculature.