Biogeography and adaptations of torquaratorid acorn worms (Hemichordata: Enteropneusta) including two new species from the Canadian Arctic

• Published in: Canadian Journal of Zoology
• Main Authors: Jabr, Noura, Archambault, Philippe, Cameron, Christopher B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2018
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Arctic; Baffin Bay; Canada; Pacific; Osborn; Melville Sound; Viscount Melville Sound; Pawson; Baffin; North Atlantic
• Online Access: http://dx.doi.org/10.1139/cjz-2017-0214; http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjz-2017-0214; http://www.nrcresearchpress.com/doi/pdf/10.1139/cjz-2017-0214

The enteropneust family Torquaratoridae, discovered in 2005, has the fewest species of the four living families. It is composed of seven species that live on the cold, deep-sea floor. Torquarator bullocki Holland, Clague, Gordon, Gebruk, Pawson and Vecchione, 2005 was the first species described and collected from the Northeastern Pacific. Two new species of Torquaratoridae were collected from the Eastern Pacific and described as Tergivelum baldwinae Holland, Jones, Ellena, Ruhl and Smith, 2009 and Allapasus aurantiacus Holland, Kuhnz and Osborn, 2012. A further three species have been collected from the North Atlantic: Yoda purpurata Priede, Osborn, Gebruk, Jones, Shale, Rogacheva and Holland, 2012, Allapasus isidis Priede, Osborn, Gebruk, Jones, Shale, Rogacheva and Holland, 2012, and Tergivelum cinnabarinum Priede, Osborn, Gebruk, Jones, Shale, Rogacheva and Holland, 2012. The latest Torquaratoridae species was collected from the Russian Arctic in 2013. We add two new species to the Torquaratoridae from Baffin Bay and Viscount Melville Sound, in the eastern Arctic of Canada. Terminstomo arcticus gen. nov. and sp. nov. was collected at a depth of 505 m and is characterized by lacking a heart and a stomochord that extends from the posterior end of the proboscis through the entire length of the collar. Allapasus fuscus sp. nov. was collected from a depth of 444 m and is characterized by a typhlosole process along the dorsal midline of the collar buccal cavity.