Stauroteuthis gilchristi

Stauroteuthis gilchristi
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Stauroteuthidae
Genus: Stauroteuthis
Species:
S. gilchristi
Binomial name
Stauroteuthis gilchristi
(Robson, 1924)[2]
Synonyms
  • Chunioteuthis gilchristi
    (Robson, 1924)[2]
  • Cirroteuthis gilchristi
    Robson, 1924

Stauroteuthis gilchristi is a species of small pelagic octopus found at great depths in the south Atlantic Ocean. It is believed to be one of a very small number of octopuses to exhibit bioluminescence, like its sister taxon Stauroteuthis syrtensis.[3]

Description

Stauroteuthis gilchristi has a secondary web, a small mantle aperture and a vestigial, U-shaped shell supporting the fins. The arms are fringed with long cirri but these do not extend as far as the tip. There is no radula. It can be distinguished from the otherwise similar Stauroteuthis syrtensis by the larger suckers. Only a few specimens have been examined, and from these it seems that there is no sexual dimorphism. However, this may not be the case, as most specimens so far collected have been either males or immature females.[4][5]

Distribution

Stauroteuthis gilchristi is found in deep waters in the southern Atlantic Ocean. The type specimen was taken from near South Africa and is the only specimen recovered from that locality. A small number of individuals have since been recovered from near South Georgia. There is a certain difference between these and the holotype in that the cirri start further up the arm in the South Georgia specimens, and it is possible that there are in fact two different species, one on each side of the Atlantic.[4] More recently, evidence has been found of the presence of this species in the southern Indian Ocean,[6] and off Macquarie Island (south of Australia),[7] and it may therefore have a circum-polar distribution throughout the Southern Ocean.

Ecology

In a study, the stomach contents of a top predator in sub-antarctic waters, the Patagonian toothfish (Dissostichus eleginoides), were examined in order to see what octopuses and squid formed part of the diet. These could be identified by the undigested remains of their beaks. In waters around the Crozet Islands, 53 beaks of S. gilchristi were found among a total of 1725 cephalopod beaks, and this cirrate octopus formed 3% of the diet of the toothfish. This study extended the range of S. gilchristi into the southern Indian Ocean.[6]

References

  1. ^ Lyons, G.; Allcock, L. (2014). "Stauroteuthis gilchristi". IUCN Red List of Threatened Species. 2014: e.T163328A998805. doi:10.2305/IUCN.UK.2014-3.RLTS.T163328A998805.en. Retrieved 20 November 2021.
  2. ^ a b Stauroteuthis gilchristi (Robson, 1924) World Register of Marine Species. Retrieved 2011-10-06.
  3. ^ Johnsen, S.; E.J. Balser; E.C. Fisher; E.A. Widder (1999). "Bioluminescence in the deep-sea cirrate octopod Stauroteuthis syrtensis Verrill (Mollusca: Cephalopoda)" (PDF). The Biological Bulletin. 197 (1): 26–39. doi:10.2307/1542994. JSTOR 1542994. PMID 28296499. Archived from the original (PDF) on 2011-03-05.
  4. ^ a b Stauroteuthis gilchristi (Robson 1924) The Tree of Life Web Project. Retrieved 2011-10-06.
  5. ^ Collins, Martin A. & Camila Henriques (2000). "A revision of the family Stauroteuthidae (Octopoda: Cirrata) with redescriptions of Stauroteuthis syrtensis and S. gilchristi". Journal of the Marine Biological Association of the UK. 80 (4): 685–97. doi:10.1017/S0025315400002514. S2CID 85406750.
  6. ^ a b Cherel, Yves; Guy Duhame & Nicolas Gasco (2004). "Cephalopod fauna of subantarctic islands: new information from predators" (PDF). Marine Ecology Progress Series. 266: 143–56. Bibcode:2004MEPS..266..143C. doi:10.3354/meps266143.
  7. ^ Verhoeff, Tristan Joseph (2023-07-20). "A new species of Stauroteuthis (Octopoda: Cirrata) and further novel cirrate octopods from Australian waters". Molluscan Research: 1–20. doi:10.1080/13235818.2023.2232534. ISSN 1323-5818. S2CID 260017318.