Shell growth and chamber formation of aquarium-reared Nautilus pompilius (Mollusca, Cephalopoda) by X-ray analysis

• Published in: Journal of experimental zoology. Part A, Comparative experimental biology Comparative experimental biology, 2004-12, Vol.301A (12), p.930-937
• Main Authors: Westermann, Bettina, Beck-Schildwächter, Ingrid, Beuerlein, Knut, Kaleta, Erhard F., Schipp, Rudolf
• Format: Article
• Language: English
• Subjects: Age Determination by Skeleton; Aging - physiology; Animals; Body Weights and Measures; Cephalopoda; Marine; Mollusca - growth & development; Nautilus; Nautilus pompilius; Radiography
• ISSN: 1548-8969; 1932-5223; 1552-499X; 1932-5231
• DOI: 10.1002/jez.a.116

Observations on the growth rate of aquarium maintained Nautilus pompilius in different developmental stages, i.e. juveniles (shell length about 8.75 cm), late juveniles (≈10 cm), and early adolescent (≈13.5 cm), indicate that this species is fully grown at an age of 7.3–8 years. The age calculations are based on two different computations: (1) the measurement of the increase of the shell length per day and (2) the formation of new septa in time intervals of 150±5 days, as demonstrated by X‐ray analyses. After N. pompilius hatches, its shell grows about 139 mm to reach full growth and approximately 28 septa are formed. With an increase of the shell length of 0.052 mm per day, it takes about 2,673 days (7.3 years) to reach maturity. Provided that the process of chamber formation follows an exponential function, these computations result in ≈2,925 days (8 years) to reach full maturity. Supposing that N. pompilius may live for several years after onset of maturity like Nautilus belauensis, the total life span for this species may exceed 11–12 years. J. Exp. Zool. 301A:930–937, 2004. © 2004 Wiley‐Liss, Inc.