Japetella diaphana

Japetella diaphana
Illustration from 1910
Model at the Natural History Museum in London, England
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Amphitretidae
Genus: Japetella
Species:
J. diaphana
Binomial name
Japetella diaphana
(Hoyle, 1885)

Japetella diaphana, also known as the midwater octopus,[2][3] is a species of pelagic deep-sea octopus from the subfamily Bolitaeninae in the family Amphitretidae. It inhabits the mesopelagic and bathypelagic zones of all three major oceans,[4] and is known for its transparent body and bioluminescence.[5] The midwater octopus is also noted for its high tolerance to hypoxia, and is able to live in a wide range of oxygen levels.[6]

Taxonomy

Japatella diaphana belongs to the phylum Mollusca, in the class of Cephalopoda and the subclass Coleoidea. Within Coleoidea, it is part of the order Octopoda in the Incirrata suborder. It belongs to the family Amphitretidae and the subfamily Bolitaeninae.

The genus Japetella, of which Japatella diaphana is the type species, is commonly referred to as the 'midwater octopus'.[7]

Anatomy and morphology

Japetella diaphana is characterized by its small, gelatinous body and distinctive bioluminescence, which play roles in communication and predator avoidance.[5]. Its adaptations, including a luminescent oral ring composed of light-generating photocytes and hypoxic metabolic strategies, are well-suited to deep-sea environments, where visual predator-prey interactions are constrained by light availability.[8][9]

Illustration from 1910 of Japetella diaphana's arms and mouth

Specimens of Japetella diaphana collected from the Pacific Ocean near the Hawaiian Islands have displayed mantle lengths of 35–80 mm (1.4–3.1 in),[10] while mature specimens obtained in the northeast Pacific and central and eastern Atlantic have displayed longer mantle lengths of 53–144 mm (2.1–5.7 in), body masses ranging from 18–235 g (0.63–8.29 oz), and a series of growth increments in their beaks ranging from 21 to 207. Each growth increment takes over 24 hours to form.[4] Japetella diaphana displays a longer-than-average lifespan compared to octopus species living in the neritic zone.[4] The species also exhibits physiological traits and plasticity that allow it to tolerate hypoxic conditions at warmer temperatures, unlike most ectotherms.[6]

Distribution and habitat

Japetella diaphana is found in tropical and subtropical oceans worldwide, including the Atlantic, Pacific, and Indian Oceans.[6] Unlike most octopuses, which are benthic,[11] Japetella diaphana is pelagic, inhabiting both the mesopelagic and bathypelagic oceanic zones.[4][6] The species is the most widespread deep-sea cephalopod in the Mexican Pacific, and has been sampled in 11 stations off the west coast of Mexico during the TALUD III-XVI-B research cruises.[12] Its presence has also been recorded in the Gulf of California, Monterey Bay (California), the North Atlantic, and near the Cape Verde archipelago.[4] In the Sargasso Sea, it is primarily found in the southern area, where its distribution is influenced by oceanographic features such as temperature gradients and water currents.[13]

Japetella diaphana undergoes diurnal vertical migration (DVM), moving between depths in response to light availability.[8] It is also known for ontogenetic vertical migration, where juveniles start their life at shallower depths (approximately 200 m (660 ft)) and gradually descend to deeper depths as they mature; brooding females are often found at depths exceeding 700–1,000 m (2,300–3,300 ft).[6]

Japetella diaphana is particularly abundant in regions with deep-water oxygen minimum zones (OMZs), including the Eastern Tropical North Pacific (ETNP) off the coast of Mexico and Central America. It is well-adapted to the hypoxic conditions present in these zones.[6] Despite its hypoxia tolerance, the species avoids the most extreme hypoxic zones, instead populating the more oxygenated waters surrounding these areas.[6]

Diet

Japetella diaphana is an opportunistic ambush predator, relying on its translucent body to avoid detection and its bioluminescent characteristics (including a photophore surrounding the mouth of mature females)[10] to lure prey such as zooplankton and small crustaceans. Specimens of Japetella diaphana collected off the west coast of Mexico contained crustacean remains in their stomachs, suggesting a diet composed mainly of copepods and amphipods.[12] Japetella's ability to switch between prey types based on availability may be essential for its survival in resource-scarce environments.

Reproduction

Illustration from 1910 of Japetella diaphana larvae

Japetella diaphana's reproductive strategy is characterized by synchronous ovulation, with mature females spawning approximately 2,000 eggs.[14] A brooding female was found at 1,352 m (4,436 ft) in the Gulf of California carrying 1,419 eggs in the pre-organogenetic stage; each egg had a diameter of approximately 2.5 mm.[4] Immature and maturing females can have as many as 4,000 oocytes, but a significant portion of these cells undergo resorption before reaching full maturity. The octopus broods its eggs within its arm crown, holding them in front of the mouth. This behavior likely restricts the octopus's ability to feed.[14] It is estimated that embryonic development takes about 731 days in cold deep-sea conditions (4.5 °C (40.1 °F).[14]

A large, bioluminescent circumoral photophore is found on mature females.[5][10] It lies beneath a transparent outer layer, forming a thick ring around the mouth with blood vessels and muscle fibers passing directly through the structure. One female specimen collected near the Hawaiian islands had a yellow photophore measured at 1.5 mm deep by 3 mm wide (0.05 in by 0.12 in). The photopore had short, extended lobes that gave it a flower-like appearance.[10] This organ originates from a muscular ring that undergoes cellular proliferation during the early stages of development, followed by gradual degeneration of the muscle tissue. Its photocytes have a uniform cytoplasm with small mitochondria, granular aggregates, and microtubular or microfibrillar bundles.[5] The organ may play a role in attracting mates, particularly in the low-light environments of the deep sea.[10][15]

Threats

Japetella diaphana is a host for the protist Hochbergia moroteuthensis, a large unicellular parasite commonly found in midwater cephalopods.[16] Remotely operated vehicles (ROVs) in the Monterey Submarine Canyon have observed the presence of the parasite in 7% of sampled J. diaphana individuals.[17]

References

  1. ↑ Allcock, L. (2014). "Japetella diaphana". IUCN Red List of Threatened Species. 2014 e.T162986A960411. doi:10.2305/IUCN.UK.2014-3.RLTS.T162986A960411.en.
  2. ↑ "Midwater octopus". Monterey Bay Aquarium Research Institute. Retrieved 28 July 2026.
  3. ↑ Bush, Stephanie (2007-08-10). "Squid science: Field notes from Stephanie Bush". University of California Museum of Paleontology. Retrieved 28 July 2026. Thanks to these trawls I also obtained ink from the midwater octopus Japetella diaphana.
  4. 1 2 3 4 5 6 Schwarz, Richard; Piatkowski, Uwe; Robison, Bruce H.; Laptikhovsky, Vladimir V.; Hoving, Henk-Jan (2020-10-01). "Life history traits of the deep-sea pelagic cephalopods Japetella diaphana and Vampyroteuthis infernalis". Deep Sea Research Part I: Oceanographic Research Papers. 164 103365. Bibcode:2020DSRI..16403365S. doi:10.1016/j.dsr.2020.103365. ISSN 0967-0637.
  5. 1 2 3 4 Herring, P. J.; Dilly, P.N.; Cope, Celia (1987). "The morphology of the bioluminescent tissue of the cephalopod Japetella diaphana (Octopoda: Bolitaenidae)". Journal of Zoology. 212 (2): 245–254. doi:10.1111/j.1469-7998.1987.tb05987.x. ISSN 0952-8369.
  6. 1 2 3 4 5 6 7 Birk, Matthew A.; Mislan, K. A. S.; Wishner, Karen F.; Seibel, Brad A. (2019-06-01). "Metabolic adaptations of the pelagic octopod Japetella diaphana to oxygen minimum zones". Deep Sea Research Part I: Oceanographic Research Papers. 148: 123–131. Bibcode:2019DSRI..148..123B. doi:10.1016/j.dsr.2019.04.017. ISSN 0967-0637.
  7. ↑ "F01-Octopus_Japetella". Earth Negotiations Bulletin. International Institute for Sustainable Development. Retrieved 28 July 2026.
  8. 1 2 Seibel, BA; Thuesen, EV; Childress, JJ (2000). "Light-limitation on predator-prey interactions: consequences for metabolism and locomotion of deep-sea cephalopods". The Biological Bulletin. 198 (2): 284–298. doi:10.2307/1542531. ISSN 0006-3185. JSTOR 1542531. PMID 10786948.
  9. ↑ Herring, P.J. (1987-06-01). "The morphology of the bioluminescent tissue of the cephalopod Japetella diaphana". Journal of Zoology. 212 (2). doi:10.1111/j.1469-7998.1987.tb05987.x. Retrieved 28 July 2026.
  10. 1 2 3 4 5 Robison, Bruce H.; Young, Richard Edward (1981). "Bioluminescence in Pelagic Octopods". Pacific Science. 35 (1): 39–44. ISSN 0030-8870.
  11. ↑ Counter, Rosemary (2023-06-16). "Is Ursula from 'The Little Mermaid' an octopus? Sort of". National Georgraphic. Retrieved 28 July 2026. Most squids spend their time jetting around in open water, whereas most [octopuses] are benthic, which just means they live at the bottom.
  12. 1 2 Urbano, Brian; and Hendrickx, Michel E. (2019-01-02). "Offshore cephalopods (Mollusca: Cephalopoda) collected off the west coast of Mexico during the TALUD cruises". Molluscan Research. 39 (1): 13–28. Bibcode:2019MollR..39...13U. doi:10.1080/13235818.2018.1495799. ISSN 1323-5818.
  13. ↑ Lischka, Alexandra; Piatkowski, Uwe; Hanel, Reinhold (2017-01-17). "Cephalopods of the Sargasso Sea: distribution patterns in relation to oceanography". Marine Biodiversity. 47 (3): 685–697. Bibcode:2017MarBd..47..685L. doi:10.1007/s12526-016-0629-4. ISSN 1867-1616.
  14. 1 2 3 Schwarz, Richard; Hoving, Henk-Jan; Noever, Christoph; Piatkowski, Uwe (2019-07-11). "Life histories of Antarctic incirrate octopods (Cephalopoda: Octopoda)". PLOS ONE. 14 (7) e0219694. Bibcode:2019PLoSO..1419694S. doi:10.1371/journal.pone.0219694. ISSN 1932-6203. PMC 6622534. PMID 31295339.
  15. ↑ Lonsdale, Peter (1981). "Drifts and ponds of reworked pelagic sediment in part of the southwest Pacific". Marine Geology. 43 (3–4): 153–193. Bibcode:1981MGeol..43..153L. doi:10.1016/0025-3227(81)90180-8. ISSN 0025-3227.
  16. ↑ Stenvers, Vanessa (2022-05-18). "ROV observations reveal infection dynamics of gill parasites in midwater cephalopods". Scientific Reports. doi:10.1038/s41598-022-11844-y. PMC 9117243. PMID 35585085. Retrieved 28 July 2026.
  17. ↑ Stenvers, Vanessa I.; Sherlock, Rob E.; Reisenbichler, Kim R.; Robison, Bruce H. (2022-05-18). "ROV observations reveal infection dynamics of gill parasites in midwater cephalopods". Scientific Reports. 12 (1): 8282. Bibcode:2022NatSR..12.8282S. doi:10.1038/s41598-022-11844-y. ISSN 2045-2322. PMC 9117243. PMID 35585085.
This page is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.