Age and growth of John Dory, Zeus faber (Linnaeus, 1758), in the East China Sea

Abstract

The age and growth of John Dory, Zeus faber , collected in the East China Sea between April 1999 and March 2001 was determined from vertebral centra. Length frequencies of males and females differed, and all fish >400 mm total length (TL) were female. The zonation pattern on the centrum surface was distinct, and a set of translucent bands (annuli) was visible. The precision of age estimates was relatively high for all ages. Monthly changes in the frequency of appearance of a translucent band on the outer margin of the centrum, and in the marginal increments, indicate that ring marks form once annually, between December and March. John Dory grow rapidly in their first year and more slowly thereafter. Male fish had 1–13 ring marks, females 1–15. Using the observed TLs at age, the growth of male John Dory can be expressed as TL _t =446.7 [1−exp{−0.128 (t+1.465)}] and that of females as TL _t =580.2 [1−exp{−0.112 (t+0.772)}]. Females seemingly grow faster and live longer than males, most fish older than 10 years being female.