Table 3. Recaptured Nautilus measurements, growth rate and age estimates.

Animal	M/F	Recapture interval (days)	Shell length (mm)	Initial circ. (mm)	Circ. Growth (mm)	Growth rate (mm/day)	Relative annual growth (%)	Age estimate (yrs)
1616	m	169	119	404.6	6.76	0.040	3.6	23.6
1179	m	174	122	414.8	5.63	0.032	2.6	30.0
1363	m	272	123	418.2	4.92	0.018	1.6	53.1
1347	m	294	127	431.8	16.82	0.057	4.9	18.6
477	m	484	118	401.2	30.93	0.064	5.8	16.0
397	m	535	107	362.1	59.30	0.111	11.5	9.3
697	m	616	125	423.3	44.00	0.071	6.2	15.8
274	m	904	106	361.4	79.38	0.088	8.8	12.1
1912	m	799	112	379.4	52.64	0.066	6.5	15.5
723	m	1024	112	380.8	51.80	0.051	4.8	19.8
1992	f	301	114	387.6	17.21	0.057	5.3	16,5
2156	f	204	131	445.4	10.88	0.053	4.4	20.4
1426	f	379	118	401.2	22.27	0.059	5.3	16.8
1535	f	231	124	421.6	20.27	0.088	7.6	12.2
1928	f	674	102	346.8	44.70	0.066	6.9	13.8

Size and growth data for ten male and five female recaptured Nautiluses which were immature at both first capture and recapture times. The mean circumferential (circ.) growth rate of 0.0614±0.023 mm day⁻¹; range = 0.018 to 0.111 mm day⁻¹) provides an age estimate of 20+ years.