Age and growth of dolphinfish, Coryphaena hippurus, off Puerto Rico

Dolphinfish, Coryphaena hippurus, off Puerto Rico were sampled over an 8-mo nth period to study age and growth from daily increments recorded in the sa gittae. A total of 121 otoliths were analyzed. Growth was rapid and nonline ar. No significant differences in growth rate were observed based on sex or on location of capture (north or south coast). The von Bertalanffy growth parameters were L-infinity = 1457 mm FL, K = 2.19/yr, and t(0) = -0.046 yr. With these values, extrapolated growth over the first year averaged 3.6 mm FL/day. An existing hypothesis of two separate stocks (north and south) in the vicinity of Puerto Rico predicts that fish from the north coast caught primarily in the winter would show a much slower growth rate than fish from the south coast caught primarily in the spring. The absence of growth diff erences between coasts does not match this prediction; however previous gro wth estimates for the northern stock may have been underestimated. On the b asis of these results, the stock structure and migration pattern of dolphin fish are likely to be more complicated than originally postulated.