New Antarctic deep-sea weird leech (Hirudinida: Piscicolidae): morphological features and phylogenetic relationships

Abstract

A new fish leech Ambulobdella shandikovi n. g., n. sp. (Hirudinida: Piscicolidae), a parasite of Whitson's grenadier Macrourus whitsoni (Regan) (Macrouridae: Gadiformes) collected in the Ross Sea at depths from 1,221 to 1,433 m, is described and compared with related taxa based on morphological and molecular characters. Ambulobdella shandikovi n. sp. is characterised by prominent segmental tubercles on the venter and dorsal segmental tubercles, an uncommon appearance of its anterior sucker with ear-like edges and an inner membrane around the mouth-pore, well-developed musculature and a unique combination of features of the reproductive and digestive systems. The presence of uncommon tubercles can be attributed, in part, to temporary associations of A. shandikovi n. sp. with its fish hosts and a need for well-developed sensory and locomotory organs. A certain locomotory function of ventrolateral tubercles of A. shandikovi n. sp. is hypothesised and discussed. Further deep-sea surveys are obviously needed to shed light on the behaviour and mode of locomotion of this species.

Not that many leech species after all: Myzobdella lugubris and Myzobdella patzcuarensis (Annelida: Hirudinida) are the same species

“…These subfamilies were proposed in the basis on the absence or presence of a single, or two pairs of pulsatile vesicles, respectively. So far, only members of Pontobdellinae have been recovered as a monophyletic group in phylogenetic studies (Williams & Burreson, 2006 ; Utevsky & Utevsky, 2018 ).…”