Jump to content

Cranchiidae

From Wikipedia, the free encyclopedia

Cranchiidae
Cranchiid squid juvenile found in Antarctica
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Oegopsida
Superfamily: Cranchioidea
Family: Cranchiidae
Prosch, 1847[1]
Subfamilies
Synonyms

The family Cranchiidae comprises the approximately 60 species of glass squid, also known as cockatoo squid, bathyscaphoid squid, cranch squid, or simply cranchiids.[2] The common name "glass squid" derives from the transparent bodies of most species. Cranchiid squid occur in surface and midwater depths of open oceans around the world. Cranchiid squid spend much of their lives in partially sunlit shallow waters, where their transparency provides camouflage.[dubious – discuss]

Like most squid, the juveniles of cranchiid squid live in surface waters, descending to deeper waters as they mature. Some species live over 2 km below sea level. The body shape of many species changes drastically between growth stages, and many young examples could be confused for different species altogether.[citation needed] The family ranges in mantle length from 10 cm (3.9 in) to over 3 m (9.8 ft), in the case of the colossal squid, which is the largest invertebrate alive.[3]

The type genus of the family, Cranchia, is named for English naturalist John Cranch.[4][5] Cranchiid squid are of no interest to commercial fisheries.[citation needed]

Description

[edit]

The family is characterised by an enlarged mantle and short arms that bear two rows of suckers or hooks, with the third pair of arms often enlarged. Eye morphology varies widely, ranging from large and circular to telescopic and stalked. A large, fluid-filled coelomic cavity containing ammonia solution is used to aid buoyancy.[6][7] This buoyancy system is unique to the family and is the source of their common name "bathyscaphoid squid", after their resemblance to a bathyscaphe. The only organ that is typically visible through the transparent tissues is a cigar-shaped digestive gland, a cephalopod analogue of the liver; this organ is usually held in a vertical position to reduce its silhouette. Many species are bioluminescent and may possess light organs on the lower tip of their digestive gland and on the undersides of their eyes, used to cancel their shadows and evade predators.[8][9][additional citation(s) needed] Cranchiids have lower activity levels and metabolic rates than other families of squid, being more sedentary.[10][7]

Diet

[edit]

Cranchiids occupy a variety of trophic levels, with some species relying heavily on mesopelagic crustaceans such as copepods and small fishes; cranchiids as a whole may prey on a broad variety of species.[10] Recent research using fatty acid and stable isotope analyses has shown that smaller cranchiids in the Benguela Upwelling System feed at mid to lower trophic levels, whereas larger, more muscular squid such as Todarodes and Abraliopsis occupy higher trophic positions; the ecological niche of cranchiids has even been compared to those of planktonic siphonophores.[10] Early juveniles may also exploit productive surface waters for faster growth before transitioning to deeper zones.[11] Due to their lower activity levels, the family is thought to be comprised of ambush predators.[7]

Migration

[edit]

As they develop, glass squids often exhibit a two-phase life cycle: juveniles in the epipelagic layers, then migrating into bathypelagic waters as adults.[11][additional citation(s) needed] By remaining translucent and harnessing specialized buoyancy mechanisms involving ammonia retention, cranchiids reduce energy expenditure and adapt to low-light deep-sea habitats[12]. This vertical migration strategy is thought to minimize predation risk while maximizing feeding opportunities.[citation needed]

Genera

[edit]
Cranchiid squid, Operation Deep Scope Expedition, 2004. The image on the bottom was taken with a polarising filter.

The family contains two subfamilies (both established by Georg Johann Pfeffer) and about 15 genera:[13]

References

[edit]
  1. ^ Julian Finn (2016). "Cranchiidae Prosch, 1847". World Register of Marine Species. Flanders Marine Institute. Retrieved 26 February 2018.
  2. ^ Mark Norman & C.C. Lu (2000). "Preliminary checklist of the cephalopods of the South China Sea" (PDF). The Raffles Bulletin of Zoology (Supplement No. 8): 539–567. Archived from the original (PDF) on March 31, 2012.
  3. ^ Rosa, Rui; Lopes, Vanessa M.; Guerreiro, Miguel; Bolstad, Kathrin; Xavier, José C. (30 March 2017). "Biology and ecology of the world's largest invertebrate, the colossal squid (Mesonychoteuthis hamiltoni): a short review" (PDF). Polar Biology. 40 (9): 1871–1883. doi:10.1007/s00300-017-2104-5. S2CID 15480545.
  4. ^ David M. Damkaer (2002). "Adding pages". The Copepodologist's Cabinet: A Biographical and Bibliographical History, Volume 1. Memoirs of the American Philosophical Society, Volume 240. American Philosophical Society. pp. 131–155. ISBN 978-0-87169-240-5.
  5. ^ White, Adam (1857). A Popular History of British Crustacea; Comprising a Familiar Account of Their Classification and Habits. Lovell Reeve. pp. 249–250.
  6. ^ Clarke, MR; Denton, EJ; Gilpin-Brown, JB (1979). "On the use of ammonium for buoyancy in squids". J Marine Biology Association United Kingdom. 59: 259–276. doi:10.1017/S0025315400042570.
  7. ^ a b c "Functional traits explain trophic allometries of cephalopods". Animal Ecology. 89 (11): 2692-2703. 7 September 2020. doi:10.1111/1365-2656.13333. Retrieved 20 March 2025.
  8. ^ Mark Norman 2000. Cephalopods: A World Guide. Hackenheim, ConchBooks, p. 156.
  9. ^ Richard E. Young and Katharina M. Mangold (1922-2003). "Cranchiid Buoyancy". The Tree of Life Web Project. Retrieved March 14, 2012.{{cite web}}: CS1 maint: numeric names: authors list (link)
  10. ^ a b c Kremer, Kira Izabela; Hagen, Wilhelm; Oesterwind, Daniel; Duncan, Sabrina; Bode-Dalby, Maya; Dorschner, Sabrina; Dudeck, Tim; Sell, Anne F. (2025-01-28). "Trophic ecology of squids in the Benguela Upwelling System elucidated by combining stomach content, stable isotope and fatty acid analyses". Marine Biology. 172 (2): 32. doi:10.1007/s00227-024-04592-2. ISSN 1432-1793.
  11. ^ a b Arkhipkin, Alexander (1996-01-01). "Age and growth of planktonic squids Cranchia scabra and Liocranchia reinhardti (Cephalopoda, Cranchiidae) in epipelagic waters of the central-east Atlantic". Journal of Plankton Research. 18 (9): 1675–1683. doi:10.1093/plankt/18.9.1675. ISSN 0142-7873.
  12. ^ Voight, J. R.; and O'Dor, R. K. (1995-01-01). "A review of ammonia‐mediated buoyancy in squids (cephalopoda: Teuthoidea)". Marine and Freshwater Behaviour and Physiology. 25 (1–3): 193–203. doi:10.1080/10236249409378917. ISSN 1023-6244. {{cite journal}}: |first2= missing |last2= (help)CS1 maint: multiple names: authors list (link)
  13. ^ Richard E. Young and Katharina M. Mangold (1922-2003) (2008). "Cranchiidae Prosch, 1847. Bathyscaphoid squids". The Tree of Life Web Project. Retrieved March 14, 2012.{{cite web}}: CS1 maint: numeric names: authors list (link)
  14. ^ "WoRMS - World Register of Marine Species - Parateuthis tunicata Thiele, 1921". www.marinespecies.org. Retrieved 2023-04-12.
[edit]
Retrieved from "https://en.wikipedia.org/w/index.php?title=Cranchiidae&oldid=1281410828"