AGE, GROWTH AND SEX-RATIO OF THE AZOREAN ROCK-POOL BLENNY, PARABLENNIUS-SANGUINOLENTUS-PARVICORNIS

The age and population structure of Parablennius sanguinolentus hrs pa rvicornis (Valenciennes) (Pisces: Blenniidae) from the Azores have bee n studied. Total length and weight relationships are given for each se x. Age study was based on otoliths readings. The von Bertalanffy growt h function was applied to describe the growth in total length with age . At the end of the first year mean (+/-SD) total length was significa ntly different in males (7 . 1 +/-1 . 5 cm) and females (6 . 1 +/-1 . 2 cm). One-year-old males participate in reproduction as satellites, w hereas females do not. The implications of this in early growth rate o f the males is discussed. During the two most important months of the reproductive season (i.e. June and July), the sex ratio was significan tly biased towards males, particularly in the larger size classes.