Species of cephalopod known as the ram's horn squid
Spirula
Temporal range: Miocene–Recent[1]
PreꞒ
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
Dorsal view of female
Ventral view of female (chromatophores of mantle missing)
Conservation status
Least Concern (IUCN 3.1)[2]
Scientific classification
Domain:
Eukaryota
Kingdom:
Animalia
Phylum:
Mollusca
Class:
Cephalopoda
Order:
Spirulida
Family:
Spirulidae Owen, 1836
Genus:
Spirula Lamarck, 1799
Species:
S. spirula
Binomial name
Spirula spirula
(Linnaeus, 1758)
Synonyms
Nautilus spirula Linnaeus, 1758
Spirula spirula is a species of deep-water squid-like cephalopod mollusk. It is the only extant member of the genus Spirula, the family Spirulidae, and the order Spirulida. Because of the shape of its internal shell, it is commonly known as the ram's horn squid[3] or the little post horn squid. Because the live animal has a light-emitting organ, it is also sometimes known as the tail-light squid.
Live specimens of this cephalopod are very rarely seen because it is a deep-ocean dweller. The small internal shell of the species is, however, quite a familiar object to many beachcombers. The shell of Spirula is extremely light in weight, very buoyant, and surprisingly durable; it very commonly floats ashore onto tropical beaches (and sometimes even temperate beaches) all over the world. This seashell is known to shell collectors as the ram's horn shell or simply as Spirula.
Side view of a Spirula shell
Ventral view; the siphuncle and the last septum of the phragmocone are visible
^Hayward, B.W. (1977). "Spirula (Sepioidea: Cephalopoda) from the Lower Miocene of Kaipara Harbour, New Zealand (note)" (PDF). New Zealand Journal of Geology and Geophysics. 19: 145–147. doi:10.1080/00288306.1976.10423557.
^Barratt, I. & Allcock, L. (2012). Spirula spirula. The IUCN Red List of Threatened Species. Version 2014.2.
^Norman, M. 2000. Cephalopods: A World Guide. Hackenheim, ConchBooks.
Spirulaspirula is a species of deep-water squid-like cephalopod mollusk. It is the only extant member of the genus Spirula, the family Spirulidae, and...
Spirulida is an order of cephalopods comprising one extant species (Spirulaspirula) and several extinct taxa. Oldest representative: Carboniferous, though...
mineralized coleoids (Spirula, Sepia, and Metasepia) as a clade; however, others do recover this more parsimonious-seeming clade, with Spirula as a sister group...
Cyclostrema spirula is a species of sea snail, a marine gastropod mollusk in the family Liotiidae. Examination (Warén & Bouchet 1988) of the holotype...
floating objects, such as drifting wood, buoyant shells of organisms such as Spirula, or man-made flotsam. Examples include goose barnacles and the bryozoan...
ten-limbed cephalopods (including squid, bobtail squid, cuttlefish, and Spirula) as well as in the eight-limbed cirrate octopuses and vampire squid. Many...
polyplacophorans (or chitons), and cephalopods (such as nautilus and spirula). These shells are very often the most commonly encountered, both in the...
modified internal shell, which is porous and is made of aragonite. Except for spirula, they are the only coleoid cephalopods with a shell with a phragmocone...
supplement, despite its name Spirulina (suborder), a group of cephalopods Spirula, the only extant member of that suborder Spiralinella, a genus of very...
org". Archived from the original on 2017-08-12. Retrieved 2006-12-12. "spirula.nl". Archived from the original on 2020-09-19. Retrieved 2012-08-15. {{cite...
Abraliopsis; the pygmy cuttlefish Sepia pulchra; and the ram's horn squid, Spirulaspirula. The octopod superfamily Argonautoidea is characterised by markedly...
extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and Spirula. In the case of the cuttlefish, the siphuncle is indistinct and connects...
chitinous beak, although the radula is reduced in octopuses and absent in Spirula.: 110 The cephalopod radula rarely fossilizes: it has been found in around...
common mathematical characteristics of a wide range of shells from Helix to Spirula; and Henry Nottidge Moseley described the mathematics of univalve shells...
between 95 and 210 microns. Oncicola signoides (Meyer, 1932) Oncicola spirula (Olferas, 1819) South American species that is common in captive primates...
Cyclostrema atomus) Dekker, H. & Orlin, Z. (2000). Checklist of Red Sea Mollusca . Spirula. 47 Supplement : 1-46 To World Register of Marine Species...
themed issue per year. The name "Vita Malacologica" is Latin, meaning "malacological life". "Vita Malacologica". www.spirula.nl. Retrieved 2017-07-23....
Invasie van rugschilden van Sepia pharaonis langs de kust van Israel". Spirula (in Dutch). 335: 127–129. Retrieved 20 February 2018. English abstract...
include other nautiloids and the subclass Ammonoidea. Cuttlefish, squid, spirula, vampire squid, and cirrate octopuses have small internal shells. Females...
natural and artificial. Jellyella eburnea is common on shells of the squid Spirula (which become detached from the soft body of the squid after death) and...
in Amsterdam (Zoölogisch Museum Amsterdam). He was also involved with Spirula, the Dutch malacological journal. Especially the "Field Guide shells" (Veldgids...
Familie. Med Bemaerkninger om de to beslaegtede former Sepiolidea D'Orb. og Spirula Lmk. Det Kongelige Danske videnskabernes selskabs skrifter; Naturvidenskabelig...
accepted. Among Mollusca, he described not only the pearly nautilus but also Spirula (1850) and other Cephalopoda, both living and extinct, and it was he who...
Side view of a Spirula shell
Ventral view; the siphuncle and the last septum of the phragmocone are visible
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