Family SPIRULIDAE
Compiler and date details
July 2001 - C.C. Lu, National Chung Hsing University, Taichung, Taiwan
Introduction
The family Spirulidae d'Orbigny, 1826 is monotypic. Individuals rarely exceed 4.5 cm in mantle length (ML). The sole species, named Nautilus spirula by Linné in 1758, was transferred to the newly erected genus Spirula by Lamarck in 1801. The family Spirulidae has been credited to Owen (1836) by many authors, including Chun (1903), Voss (1977), Clarke and Trueman (1988). A review of literature reveals that d'Orbigny in fact was the first to use the family name 'Spirulees' in 1826. The current latinised spelling of 'Spirulidae' began with Owen (1836). This fact was mentioned by Naef (1922). According to the International Code of Zoological Nomenclature (1999), Art. 11.7.2, the family Spirulidae should be attributed to d'Orbigny, 1826, not Owen, 1836. Peron (1804) published the first record of this species from the Australian region: a figure of Spirulea prototypos. Lamarck, in 1816, re-named the same specimen as Spirula australis and in 1822 again re-named this same specimen as Spirula peronii. Angas (1865) reported on a beached specimen from near Port Jackson under the name Ammonia laevis. Brazier (1892) synonymised all these names under Spirula peroni and Hoyle (1909) recognised Spirula spirula as the valid name of the species.
Spirula spirula is found in the tropical and subtropical regions of all three major oceans. In Australian waters the animals have been captured in oceanic waters from Queensland to Tasmania, the Great Australian Bight and Western Australia. Shells have been collected from beaches around Australia.
Live specimens of Spirula spirula take on a vertical position, head downwards, when at rest. They can swim downwards, head first, propelled by fluttering movements of the fins which stretch up vertically and aided by the current created by the backwards-pointing funnel (Schmidt 1922). In dashes Spirula spirula employs the typical jet propulsion method of cephalopods (Kerr 1931), involving muscles of the mantle, funnel arms and fins.
No direct observation has been made on feeding activities of Spirula spirula. The digestive system of S. spirula is similar to that of other coleoids, except that the animal lacks a radula (Kerr 1931).
Owen (1880) and Kerr (1931) reported on the reproductive system of Spirula spirula in detail. The ventral arms of mature male are modified into hectocotyli. The right arm is larger and thicker than the left arm: in the preserved specimen, the margins of the aboral surface are rolled aborally to form prominent flanges; the lateral sides are smooth and prominent, the oral surface lacks suckers, and the distal end terminates in a spoon-like organ, the extreme tip of which extends into a sharp point flanked by a pair of claw-like points. The left ventral arm is more slender than its counterpart and lacks flanges; the tip is modified into a very complex organ of unknown function. Hectocotylisation first occurs at a mantle length (ML) of 2.0 cm (Kerr 1931; Bruun 1943).
The spermatophore structure of Spirula is not particularly different from that of other cephalopods (Kerr 1931).
The eggs are small. The largest ovarian eggs are about 1.7 mm (Chun 1915) and the newly hatched young are about 4.2 mm (Naef 1923). Animals attain sexual maturity at about 30 mm ML (Schmidt 1922). The smallest young known, presumably newly hatched, have a ML of about 1.5 mm, with two chambers (Lu et al. 1992).
Little is known about the life history of Spirula. No pelagic eggs have been identified. Bruun (1943) reported the capture of juveniles at about 1000 m to 1750 m and suggested that the females possibly lay eggs on the bottom on the continental slope (Bruun 1943, 1955). Clarke (1970) suggested that in the North Atlantic, Spirula spirula hatches mainly in June or July and the animals grow to maturity after 12 to 15 months, after which time mating and egg laying take place. The life span is estimated to be about 18 to 20 months.
Spirula spirula is found in the open ocean. Bruun (1955) suggested that water temperature is the dominant factor in its distribution: all catches were made in the region where the water temperature at 400 m is 10°C or higher.
The animals undergo diel migration. During the day they live at depths greater than 550 m with the centre of population at 600 to 700 m. During darkness, most of the population is found at a depth shallower than 300 m. Evidence suggests that the young larvae do not migrate immediately after hatching. They appear to adopt migratory behaviour during early growth, but then change behaviour in old age, when they appear to stay in deep water even at night (Clarke 1969). The animal controls its buoyancy by regulating the pressure of gas contained in the shell (Denton et al. 1967; Denton & Gilpin-Brown 1971).
Diagnosis
The internal calcareous-chambered shell is spirally coiled or ram's horn-shaped, located in the posterior end of animal. The adult shell contains over 30 chambers. The mantle is cylindrical, thin and muscular. The funnel-mantle locking cartilage is simple and straight. The arms are short and connected by a deep web. The paired, small fins are round, and attached transversely to the posterior end of the mantle, almost perpendicular to the longitudinal axis of the body. The anterior margin of the mantle has three pronounced projections on the dorsal midline and ventro-laterally on each side of the funnel-mantle locking cartilages. The large eyes are equipped with muscular eyelids, as in oegopsids. The length of arms increases from dorsal arms ventrally and each arm bears four to six rows of small suckers. The two long tentacles have non-expanded clubs bearing numerous small suckers in 16 rows. All but the ventral arms are connected with a web. A large photophore is located between the fins. In males both ventral arms are hectocotylised.
General References
Angas, G.F. 1865. On the marine molluscan fauna of the Province of South Australia, with a list of all the species known up to the present time, together with remarks on their habitats and distribution, etc. Proceedings of the Zoological Society of London 1865: 155-"180" (=190)
Bruun, A. Fr 1943. The biology of Spirula spirula (L). Dana Reports 24: 1-44 2 pls
Chun, C. 1903. Aus den Tiefen des Weltmeeres. Jena : Gustav Fischer 544 pp.
Chun, C. 1915. Die Cephalopoden. II. Teil: Myopsida, Octopoda. Jena : Verlag von Gustav Fischer. [English Translation (1975). 436 pp. Roper, C.F.E. & Roper, I.H. (eds). Jerusalem: Israel Program for Scientific Translation English Translation (1975). 436 pp. Roper, C.F.E. & Roper, I.H. (eds). Jerusalem: Israel Program for Scientific Translation CHECK, 1914 IN TEXT]
Clarke, M.R. 1969. Cephalopoda collected on the SOND cruise. Journal of the Marine Biological Association of the United Kingdom 49: 961-976
Clarke, M.R. 1970. Growth and development of Spirula spirula. Journal of the Marine Biological Association of the United Kingdom 50: 53-64
Clarke, M.R. & Trueman, E.R. 1988. Introduction. pp. 1-10 in Clarke, M.R. & Trueman, E.R. (eds). Paleontology and Neontology of Cephalopods. The Mollusca. Vol. 12. San Diego; London : Academic Press.
d'Orbigny, A. 1826. Tableau méthodique de la classe des Céphalopodes. Annales des Sciences Naturelles, Paris 7: 96-169
Denton, E.J., Gilpin-Brown, J.B. & Howarth, J.V. 1967. On the buoyancy of Spirula spirula. Journal of the Marine Biological Association of the United Kingdom 47: 181-191
Denton, E.J. & Gilpin-Brown, J.B. 1971. Further observations on the bouyancy of Spirula. Journal of the Marine Biological Association of the United Kingdom 51: 363-373
Hoyle, W.E. 1909. A catalogue of recent Cephalopoda. Second Supplement, 1897–1906. Proceedings of the Royal Physical Society of Edinburgh 17: 254-299
Kerr, J.G. 1931. Notes upon the Dana specimens of Spirula and upon certain problems of cephalopod morphology. Dana Reports 8: 1-36
Lu, C.C. 2001. Cephalopoda. pp. 129-308 in Wells, A. & Houston, W.W.K. (eds). Zoological Catalogue of Australia. Vol. 17.2 Mollusca: Aplacophora, Polyplacophora, Scaphopoda, Cephalopoda. Melbourne : CSIRO Publishing, Australia xii 353 pp. [Date published 3 July 2001] [194]
Naef, A. 1922. Die Fossilen Tintenfische. Jena : Verlag von Gustav Fischer 322 pp.
Naef, A. 1923. Die Cephalopoden, Systematik. Fauna und Flora des Golfes von Neapel 35 1: 1-863
Owen, R. 1836. Descriptions of some new or rare Cephalopoda, collected by Mr George Bennett, Corr. Memb. Z.S. Proceedings of the Zoological Society of London 1835: 19-23
Owen, R. 1880. On the external and structural characters of the male Spirula australis, Lam. Proceedings of the Zoological Society of London 1880: 352-354
Schmidt, J. 1922. Live specimens of Spirula. Nature (London) 110: 788-790
Voss, G.L. 1977. Classification of recent cephalopods. pp. 575-579 in Nixon, M. & Messenger, J.B. (eds). The Biology of Cephalopods. London : Academic Press.
History of changes
| Published | As part of group | Action Date | Action Type | Compiler(s) |
|---|---|---|---|---|
| 12-Feb-2010 | (import) |