Opisthoteuthis chathamensis

Opisthoteuthis chathamensis, commonly known as the roughy umbrella octopus,^[2] is a species of cirrate octopus restricted to demersal habitats surrounding the Chatham Rise in New Zealand.^[3]

Opisthoteuthis chathamensis
Conservation status
Critically Endangered  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	Octopoda
Family:	Opisthoteuthidae
Genus:	Opisthoteuthis
Species:	O. chathamensis
Binomial name
Opisthoteuthis chathamensis O'Shea 1999

on, description & threats

Chatham Rise, the type locality of O. chathamensis

Specimens have been recorded solely on soft sediments from 900–1,438 metres (2,950–4,720 ft) deep.^[1][4] The type locality of O. chathamensis is near the Chatham Islands at 44°44'S, 77°15'W, 1,180 m (3,870 ft). The species is known only from this area of the Chatham Rise and off the eastern and.^[5] O. chathamensis reaches a maximum length of 18 cm (7.1 in) TL, and a mantle length of 5.4 cm (2.1 in).^[4] They are described as having subequal arms with around 41-45 suckers in males and 45-55 suckers in females.^[5] Their oral surface and the webbing between their tentacles is maroon and the suckers are a pale cream.^[6] O. chathamensis is listed as Critically Endangered by the IUCN due to a 70% decrease in population size in recent years, and has not been seen since 1999, when it was a common bycatch species. In addition, their longevity, low fecundity and slow growth (especially embryonic development which lasts 1.4-2.6 years among other species in the genus) has made them particularly susceptible to population declines and slow recoveries.^[1][7]