Siphonophorae

Not to be confused with Siphonophorida.

Siphonophorae
(A) Rhizophysa eysenhardtii scale bar = 1 cm, (B) Bathyphysa conifera 2 cm, (C) Hippopodius hippopus 5 mm, (D) Kephyes hiulcus 2 mm (E) Desmophyes haematogaster 5 mm (F) Sphaeronectes christiansonae 2 mm, (G) Praya dubia 40 m (130 ft), (H) Apolemia sp. 1 cm, (I) Lychnagalma utricularia 1 cm, (J) Nanomia sp. 1 cm, (K) Physophora hydrostatica 5 mm
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Hydrozoa
Subclass: Hydroidolina
Order: Siphonophorae
Eschscholtz, 1829
Suborders[1]
Synonyms
  • Siphonophora Eschscholtz, 1829

Siphonophorae (from Greek siphōn 'tube' + pherein 'to bear'[2]) is an order within Hydrozoa, which is a class of marine organisms within the phylum Cnidaria. According to the World Register of Marine Species, the order contains 175 species described thus far.[3]

Siphonophores are highly polymorphic and complex organisms.[4] Although they may appear to be individual organisms, each specimen is in fact a colonial organism composed of medusoid and polypoid zooids that are morphologically and functionally specialized.[5] Zooids are multicellular units that develop from a single fertilized egg and combine to create functional colonies able to reproduce, digest, float, maintain body positioning, and use jet propulsion to move.[6] Most colonies are long, thin, transparent floaters living in the pelagic zone.[7]

Like other hydrozoans, some siphonophores emit light to attract and attack prey. While many sea animals produce blue and green bioluminescence, a siphonophore in the genus Erenna was only the second life form found to produce a red light (the first one being the scaleless dragonfish Chirostomias pliopterus).[8][9]

  1. ^ Schuchert, P. (2019). "Siphonophorae". World Hydrozoa Database. Retrieved 2019-01-27 – via World Register of Marine Species.
  2. ^ "Siphonophora". Lexico. Archived from the original on 2020-10-22. Retrieved 2020-03-10.
  3. ^ Cite error: The named reference WoRMS was invoked but never defined (see the help page).
  4. ^ Mackie, G. O.; Pugh, P. R.; Purcell, J. E. (1988-01-01), Blaxter, J. H. S.; Southward, A. J. (eds.), Siphonophore Biology, Advances in Marine Biology, vol. 24, Academic Press, pp. 97–262, doi:10.1016/s0065-2881(08)60074-7, ISBN 9780120261246, retrieved 2023-04-08
  5. ^ Cite error: The named reference :7 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference :2 was invoked but never defined (see the help page).
  7. ^ Dunn, Casey W. (December 2005). "Complex colony-level organization of the deep-sea siphonophore Bargmannia elongata (Cnidaria, Hydrozoa) is directionally asymmetric and arises by the subdivision of pro-buds". Developmental Dynamics. 234 (4): 835–845. doi:10.1002/dvdy.20483. PMID 15986453. S2CID 8644671.
  8. ^ Cite error: The named reference :4 was invoked but never defined (see the help page).
  9. ^ "Siphonophores | Smithsonian Ocean". ocean.si.edu. Retrieved 2021-06-18.