Abstract
Otolith increment age estimates for a deepwater species, Allocyttus verrucosus, were validated by comparison with the results from Pb-210:Ra-226 radiometric analysis. Transverse sectioning and subsequent grinding of otoliths to a thickness of similar or equal to 0.2 mm revealed increments which provided age estimates for a range of fish sizes, Age estimates ranged from 7 yr for an immature fish of 15.2 cm total length (TL) to 130 yr for a female fish of 36.5 cm TL. Age at maturity was estimated as 28 yr for females and 24 yr for males. In comparison, radiometric analysis of whole otoliths, using a single linear otolith-mass growth-rate model suggested maximum ages of 130 to 170 yr for fish of 34 to 35 cm TL. Radiometric ages were also recalculated using a two-phase otolith-mass growth-rate model in which the growth rate was assumed to slow after maturity to 90% of the pre-maturity rate. This reduced the maximum age to 132 +/- 15 yr for a mean fish length of 34.5 cm. Age at maturity for females was estimated at 34 yr. The similarity between age estimates from otolith-increment counts and radiometric analysis strongly supports the accuracy of results from both methods, and encourages further use of such comparisons as an alternative to traditional validation techniques.
| Original language | English |
|---|---|
| Pages (from-to) | 29-38 |
| Number of pages | 10 |
| Journal | Marine Biology |
| Volume | 123 |
| Issue number | 1 |
| Publication status | Published - Jul 1995 |
Keywords
- PSEUDOCYTTUS-MACULATUS
- THALASSOMA-BIFASCIATUM
- SMOOTH OREO
- MURRAY COD
- BLACK OREO
- GROWTH
- LONGEVITY
- PISCES
- REEF
- PERCICHTHYIDAE