Age, growth and sex of the shanny, Lipophrys pholis (Linnaeus, 1758) (Teleostei, Blenniidae), from the NW coast of Portugal.

Age, growth, sex and gonadal maturation of the shanny, Liphorys pholis, were determined in specimens caught in a rocky intertidal area in northern Portugal in order to provide essential ecological data on the species. This study represents the first available reference in the literature for L. pholis in a southern European location. Totals of 251 individuals (115 females, 99 males, 37 undetermined; total length: 30-172 mm) were collected seasonally (November 2013, March, June, and September 2014) in a northern Portuguese rocky beach (Póvoa do Varzim: 41°23′47.79″N; 08°46′45.48″W) using fine-mesh aquarium fishnets during low tides. Marginal increment analysis showed that one translucent and one opaque zone was formed each year in the sagittal otoliths. Ages of L. pholis ranged from 0 to 6 years. Males were larger and older than females. The von Bertalanffy growth equation parameters considering all individuals were L∞ = 184 mm, K = 0.26 mm/year, t0 = −1.34. The annual variation of the fish condition and hepatosomatic indexes appeared to be related to the mobilization of the somatic reserves prior to reproduction. Maximum gonadosomatic index for males and females coincided with the breeding seasons (November and March). The sex ratio was close to 1:1, all maturity stages included. Furthermore, some stages of sexual development in males and females were observed during the same season, and several germinal cells were also observed at the same time within a single ovary or testis, indicating that L. pholis is an asynchronous and multiple spawner. Maturation for both sexes appears to be around 70 mm TL and prior to reaching 1 year of age. [ABSTRACT FROM AUTHOR]