Promachoteuthis sulcus

Promachoteuthis sulcus is a species of promachoteuthid squid. It is distinguished from related taxa on the basis of several morphological features: Nuchal fusion between the head and mantle, much larger size of arm-suckers compared to club-suckers, greater width of tentacle-base than arm-base, a recessed club-base, and the presence of an aboral tentacle-groove.^[1]

Promachoteuthis sulcus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	Oegopsida
Family:	Promachoteuthidae
Genus:	Promachoteuthis
Species:	P. sulcus
Binomial name
Promachoteuthis sulcus Young, Vecchione & Roper, 2007

Promachoteuthis sulcus is known from a single specimen caught by the German research vessel R/V Walther Herwig in an open net off Tristan da Cunha, southern Atlantic Ocean (36°49′S 12°17′W), at a depth of 1,750–2,000 m (5,740–6,560 ft).^[1]