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

Abstract

Summary 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.

Reproductive variables of Hypleurochilus fissicornis (Quoy & Gaimard, 1824) (Pisces: Blenniidae) on rocky intertidal zones in the South-western Atlantic

“…Our results revealed that the breeding season for H. fissicornis spans five months as has been observed for some blennies that inhabit temperate zones, (e.g. Aidablennius sphinx, Carrassón & Bau, 2003, Lipophrys pholis, Shackley & King, 1977Carvalho et al, 2017 andIstiblennius enosimae, Sunobe et al, 1998).…”

“…Blennies live more than two years and sometimes up to 10 years (e.g. Lipophrys pholis; Dunne, 1977;Carvalho et al, 2017). The breeding season spans two months or more in temperate areas, with several spawning events (Qasim, 1956;Santos, 1992).…”

Age and Growth of Japanese Anchovy (Engraulis japonicus, Temminck & Schlegel, 1846) in Coastal Waters around Shandong Peninsula, China

“…For Japanese anchovy, a translucent band appears before the opaque band, and each opaque band was identified as an annulus ring [46]. The formation of annulus was proven to occur between May and September, with predominant occurrences in June and August, as indicated by marginal increment analysis [46][47][48][49]. This suggests that the timing of annual ring formation in anchovies corresponds with their spawning period, indicating a correlation between annulus formation and spawning events.…”