Journal of the Marine Biological Association of the United Kingdom

Short Communications

Age, Growth and Sex Ratio of the Azorean Rock-Pool Blenny, Parablennius Sanguinolentus Parvicornis

Ricardo Serrão Santosa1, Richard D. M. Nasha2 and Stephen J. Hawkinsa2

a1 Universidade dos Açores, Departamento de Oceanografia e Pescas, PT-9900 Horta (Açores), Portugal

a2 University of Liverpool, Port Erin Marine Laboratory, Isle of Man, IM9 6JA

The age and population structure of Parablennius sanguinolentus parvicornis (Valenciennes) (Pisces: Blenniidae) from the Azores have been studied. Total length and weight relationships are given for each sex. Age study was based on otoliths readings. The von Bertalanffy growth function was applied to describe the growth in total length with age. At the end of the first year mean (±SD) total length was significantly different in males (7.1 ±1.5 cm) and females (6.1 ±1.2 cm). One-year-old males participate in reproduction as satellites, whereas females do not. The implications of this in early growth rate of the males is discussed. During the two most important months of the reproductive season (i.e. June and July), the sex ratio was significantly biased towards males, particularly in the larger size classes.