New tentacled leech Ceratobdella quadricornuta n. g., n. sp. (Hirudinida: Piscicolidae) parasitic on the starry skate Raja georgiana Norman from the Scotia Sea, Antarctica

Abstract

A new fish leech Ceratobdella quadricornuta n. g., n. sp. (Hirudinida: Piscicolidae), a parasite of the Antarctic skate Raja georgiana Norman (Rajiformes: Rajidae) collected between the Falkland Islands and South Georgia Island in the Scotia Sea, is described and compared with related genera. Ceratobdella quadricornuta is characterised by an uncommon appearance of its anterior sucker bearing four well-developed tentacles and a unique combination of features of the reproductive and digestive systems: crop and intestine equally developed, posterior crop caeca separated; accessory glands, conductive tissue and external copulatory area lacking; common part of ejaculatory ducts (common atrium) voluminous and muscular, male copulatory bursa short, small ovisacs opening into female copulatory bursa (vagina).

Leeches in the extreme: Morphological, physiological, and behavioral adaptations to inhospitable habitats

“…Megaliobdella szidati is a very large leech (up to 34 cm in length) covered in magnificent papillae that easily distinguish it from all other leeches and occurs in the Southern Oceans south of 35° latitude ( Meyer and Burreson, 1990 ). Ceratobdella quadricornuta is one of the ‘tentacled’ leeches and possesses four well-developed finger-like tentacles surrounding the oral sucker, presumably sensory structures, and parasitizes the Antarctic starry skate Raja georgiana in the Scotia Sea ( Sawyer, 1972 ; Utevsky and Gordeev, 2015 ). Ambulobdella shandikovi has limb-like dorsal and ventrolateral tubercles, considered most likely to be sensory structures but could play a role in locomotion ( Utevsky and Utevsky, 2018 ).…”