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Rupture strength and flow rate of Nautilus siphuncular tube

Published online by Cambridge University Press:  08 April 2016

John A. Chamberlain Jr.  and
William A. Moore Jr.
John A. Chamberlain Jr.
Affiliation:
Department of Geology, Brooklyn College of the City University of New York, Brooklyn, New York 11210 and Osborn Laboratories of Marine Sciences, New York Aquarium, New York Zoological Society, Brooklyn, New York 11224
William A. Moore Jr.
Affiliation:
Department of Geology, Brooklyn College of the City University of New York, Brooklyn, New York 11210
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Abstract

The siphuncular tube is a key component of the buoyancy control and mechanical strength systems in both Nautilus and fossil cephalopods. We measured the rate of hydrostatically induced fluid flow across the tube wall and tube rupture strength of Nautilus pompilius at hydrostatic pressures in the range of 10–85 bars. We found that in fresh, undecayed tubes, rupture occurs at pressures of about 80–85 bars. This is equivalent to the strength of the shell proper and to the depth limit of the live animal. The siphuncular tube is neither markedly stronger, nor weaker, than the shell. Siphuncle rupture strength is constant in the last 20 chambers of the shell despite a strong decrease in the siphuncle strength index (ratio of tube thickness to radius). The notion that strength index gives an accurate indication of tube strength is therefore in error. This suggests that the geometry of the siphuncular tube can not be straightforwardly used as an index of living depth in fossil cephalopods. Rupture occurs at the siphuncle-septum contact. The junction of the tube to its mechanical supports is thus weaker than the tube itself. Measured flow rates are in the range of 1–20 ml/h/chamber. Flow rates increase linearly with applied pressure and in successively larger chambers as a result of size-related variation in surface area and thickness of the tube wall. Rates of osmotic pumping in live animals are up to three orders of magnitude lower than hydrostatically induced flow rates across the siphuncular tubes of empty shells. Pumping capacity of live animals is apparently limited by functional constraints of the osmotic pump rather than by the fluid conductance properties of the tube wall. Living depth in evolving cephalopod lineages may be limited ultimately by physiologic or chemical restrictions of the osmotic pumping mechanism rather than by mechanical strength of the shell or siphuncle.

Type
Articles
Information
Paleobiology , Volume 8 , Issue 4 , Fall 1982 , pp. 408 - 425
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Chamberlain, J. A. Jr. 1978a. Permeability of the siphuncular tube of Nautilus: its ecologic and paleoecologic implications. Neues Jahrb. Geol. Palaontol., Mh. 3:129–142.Google Scholar
Chamberlain, J. A. Jr. 1978b. Mechanical properties of coral skeleton: compressive strength and its adaptive significance. Paleobiology. 4:419–435.CrossRefGoogle Scholar
Chamberlain, J. A. Jr. 1981. Hydromechanical design of fossil cephalopods. Pp. 289–336. In: House, M. R. and Senior, J. R., eds. The Ammonoidea. Syst. Assoc. Spec. Vol. 18. Academic Press; New York.Google Scholar
Chamberlain, J. A. Jr., Ward, P. D., and Weaver, J. S. 1981. Post-mortem ascent of Nautilus shells: implications for cephalopod paleobiogeography. Paleobiology. 7:494–509.CrossRefGoogle Scholar
Collins, D. H. and Minton, P. 1967. Siphuncular tube of Nautilus. Nature 216:916–917.Google Scholar
Collins, D. H., Ward, P. D., and Westermann, G. E. G. 1980. Function of cameral water in Nautilus. Paleobiology. 6:168–172.CrossRefGoogle Scholar
Denton, E. J. and Gilpin-Brown, J. B. 1966. On the buoyancy of the pearly Nautilus. J. Mar. Biol. Assoc. U.K. 46:723–759.CrossRefGoogle Scholar
Erben, H. K., Flajs, G., and Siehl, A. 1969. Die Fruhontogenetische Entwicklung der Schalenstruktur ectocochleater Cephalopoden. Palaeontographica. Abh. A. 132:1–54.Google Scholar
Greenwald, L., Cook, C. B., and Ward, P. 1982. The structure of the chambered Nautilus siphuncle: the siphuncular epithilium. J. Morphol. 172:5–22.Google Scholar
Greenwald, K., Ward, P., and Greenwald, O. 1980. Cameral liquid transport and buoyancy control in the chambered Nautilus (Nautilus macromphalus). Nature. 286:55–56.Google Scholar
Kanie, Y., Fukuda, Y., Nakayama, H., Seki, K., and Hattori, M. 1980. Implosion of living Nautilus under increased pressure. Paleobiology. 6:44–47.CrossRefGoogle Scholar
Mutvei, H. 1956. A preliminary report on the structure of the siphonal tube and on the precipitation of lime in the shells of fossil nautiloids. Ark. Mus. Geol. 2:179–190.Google Scholar
Mutvei, H. 1967. On the microscopic shell structure in some Jurassic ammonoids. Neues. Jahrb. Geol. Palaontol., Abh. 129:157–166.Google Scholar
Mutvei, H. 1972. Ultrastructural studies on cephalopod shells. I. The septa and siphonal tube in Nautilus. Bull. Geol. Inst., Univ. Uppsala. N.S. 3:237–261.Google Scholar
Obata, I., Tanaba, K., and Fukada, Y. 1980. The ammonite siphuncular wall: its microstructure and functional significance. Bull. Nat. Sci. Mus., Ser. C. 6:59–72.Google Scholar
Raup, D. M. and Takahashi, T. 1966. Experiments on strength of cephalopod shells. Geol. Soc. Am. Annu. Meet. 1966. Abstr.173.Google Scholar
Saunders, W. B. and Wehman, D. A. 1977. Shell strength of Nautilus as a depth limiting factor. Paleobiology. 3:83–89.Google Scholar
Tanabe, K. 1979. Palaecological analysis of ammonoid assemblages in the Turonian Scaphites facies of Hokkaido, Japan. Palaeontology. 22:609–630.Google Scholar
Wainwright, S. A., Biggs, W. D., Currey, J. D. and Gosline, J. M. 1976. Mechanical Design in Organisms. 423 pp. John Wiley & Sons; New York.Google Scholar
Ward, P. 1979. Cameral liquid in Nautilus and ammonites. Paleobiology. 5:40–49.Google Scholar
Ward, P. 1982. The relationship of siphuncle size to emptying rates in chambered cephalopods: implications for cephalopod paleobiology. Paleobiology. 8:426–433.CrossRefGoogle Scholar
Ward, P., Greenwald, L., and Greenwald, O. 1980. The buoyancy of the chambered Nautilus. Sci. Am. 243:190–203.Google Scholar
Ward, P., Greenwald, L., and Magnier, Y. 1981. The chamber formation cycle in Nautilus macromphalus. Paleobiology. 7:481–493.Google Scholar
Ward, P., Greenwald, L., and Rougerie, F. 1980. Shell implosion depth for living Nautilus macromphalus and shell strength of extinct cephalopods. Lethaia. 13:182.Google Scholar
Ward, P. and Martin, A. W. 1978. On the buoyancy of the pearly Nautilus. J. Exp. Zool. 205:5–12.CrossRefGoogle Scholar
Ward, P. and Martin, A. 1980. Depth distribution of Nautilus pompilius in Fiji and Nautilus macromphalus in New Caledonia. Veliger. 22:259–264.Google Scholar
Ward, P., Stone, R., Westermann, G. E. G., and Martin, A. 1977. Notes on animal weight, cameral fluids, swimming speed, and color polymorphism of the cephalopod Nautilus pompilius in the Fiji Islands. Paleobiology. 3:377–388.Google Scholar
Westermann, G. E. G. 1971. Form, structure, and function of shell and siphuncle in coiled Mesozoic ommonoids. Life Sci. Contrib. R. Ont. Mus. 78:1–39.Google Scholar
Westermann, G. E. G. 1973. Strengh of concave septa and depth limits of fossil cephalopods. Lethaia. 6:383–403.CrossRefGoogle Scholar
Westermann, G. E. G. 1975. Architecture and buoyancy of simple cephalopod pragmocones and remarks on ammonites. Palaontol. Zeitschr. 49:221–234.Google Scholar
Westermann, G. E. G. 1977. Form and function of othroconic cephalopod shells with concave septa. Paleobiology. 3:300–321.Google Scholar
Westermann, G. E. G. 1979. Decomposition and diagenesis of the ammonoid siphuncle. Syst. Assoc. Symp. on the Ammonoidea, York, England. 11.Google Scholar
Westermann, G. E. G. and Ward, P. 1980. Septum morphology and bathymetry in cephalopods. Paleobiology. 6:48–50.Google Scholar
Zar, J. H. 1974. Biostatistical Analysis. Prentice Hall, Inc.; Englewood Cliffs, N.J.Google Scholar