Abstract
A new parasitic species of eulimid gastropod, Haliella seisuimaruaesp. nov., is described from bathyal (728–978 m) waters off the Pacific coasts of Japan. It shows the closest resemblance to the type species H. stenostoma from the North Atlantic and Barents Sea in having a tall shell with an almost straight outer lip, but differs in having a junction of the parietal wall and columellar lip at 38% of the aperture height from the suture (33% in H. stenostoma), a slightly wider aperture and a more curved and extended columellar lip. The holotype of H. seisuimaruaesp. nov. was found attached to an irregular sea urchin, Brissopsis sp. cf. luzonica (Spatangoida: Brissidae). This represents the first direct observation of parasitic ecology and echinoderm host for the genus Haliella. A new replacement name, Eulima tsushimensisnom. nov., is proposed here for Eulima stenostoma A. Adams, 1861, which is preoccupied by Eulima stenostoma Jeffreys, 1858 (type of Haliella).
Highlights
Snails of the family Eulimidae (Caenogastropoda: Vanikoroidea) are exclusive parasites of echinoderms including all five classes of the phylum, namely Asteroidea, Crinoidea, Echinoidea, Holothuroidea and Ophiuroidea
Several unnamed congeners have been reported from bathyal depths around Japan (Hasegawa 2001, 2005, 2009; Hasegawa and Okutani 2011). None of these named or unnamed species have previously been collected in situ on their hosts, whereas bycatch in the same trawl/dredge hauls suggests they might parasitize on brittle stars (Warén 1984) or irregular sea urchins (Warén in Hasegawa 2009)
The holotype of Haliella seisuimaruae sp. nov. (Fig. 3) was collected with a 2-m wide beam trawl from a muddy bottom at an depth of 641–727 m, off Tanabe, Wakayama, Honshu Island, Japan, on the No 1803 research cruise of T/V “Seisui-maru”. This specimen was found attached to the dorsal side of an irregular sea urchin, Brissopsis sp. cf. luzonica (Fig. 1)
Summary
Snails of the family Eulimidae (Caenogastropoda: Vanikoroidea) are exclusive parasites of echinoderms including all five classes of the phylum, namely Asteroidea (sea stars), Crinoidea (sea lilies and feather stars), Echinoidea (sea urchins), Holothuroidea (sea cucumbers) and Ophiuroidea (brittle stars; Warén 1984). Deep-sea eulimids tend to be detached from the host when they are collected with bottom sediment and other benthos by such destructive gears as a biological dredge and a beam trawl (see Schiaparelli et al 2007; Takano et al 2018) These result in a lack of host information for a number of eulimid species and even genera (Warén 1984; Bouchet and Warén 1986; Hori and Matsuda 2017). Several unnamed congeners have been reported from bathyal depths around Japan (Hasegawa 2001, 2005, 2009; Hasegawa and Okutani 2011) None of these named or unnamed species have previously been collected in situ on their hosts, whereas bycatch in the same trawl/dredge hauls suggests they might parasitize on brittle stars (Warén 1984) or irregular sea urchins (Warén in Hasegawa 2009). This represents the first direct observation of parasitic ecology and echinoderm host for the genus Haliella
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
