Reproductive biology of the blue jack mackerel,Trachurus picturatus(Bowdich, 1825), off the Canary Islands

Abstract

Summary The reproductive cycle of the blue jack mackerel, Trachurus picturatus, had not been described for the Canary Islands. Between March 2005 and March 2006 monthly samples of T. picturatus were collected randomly at the central fishery wharf from the commercial catches of purse‐seiners in Tenerife Island waters (Canary Islands). Some 2472 specimens were analysed, with total lengths from 10.4 to 31.9 cm. Although females outnumbered males in summer, males were more abundant in the sex ratio (1.36 : 1). Based on the monthly evolution of the gonado‐somatic index and the proportion of mature individuals, the spawning season occurred between January and April, peaking in February. Lengths at first maturity (LFM) were calculated from the maturity ogives by the Gompertz model for all specimens (22.79 cm), for males (21.20 cm) and for females (23.05 cm). In this area the minimum legal size for T. picturatus is actually smaller than the length at first maturity and should be revised to avoid depletion of the stock.

Metazoan parasites of blue jack mackerelTrachurus picturatus(Perciformes: Carangidae) from Portuguese mainland waters

“…This could reflect annual changes in growth and condition of this species, which, especially in the Portuguese continental shelf, is likely to benefit from an increase in food availability in spring/summer due to the occurrence of upwelling and consequent increase in primary production and plankton availability (Arístegui et al , 2009). Blue jack mackerel reproduces in winter (Jurado-Ruzafa & Santamaría, 2013; Garcia et al , 2015). Many fish species follow annual cycles with distinct periods of feeding and reproduction, and successful reproduction is often heavily dependent on adequate energy reserves, which need to be acquired prior to the start of the reproductive season (Lloret et al , 2014); in contrast, during the reproductive season there is often a reduction in feeding intensity, as seen for example in the horse mackerel, T. trachurus (Jardas et al , 2004).…”

“…The blue jack mackerel grows quickly in the first 3 years of life, after which growth slows down (Vasconcelos et al , 2006). In the Azores, it reaches sexual maturity at 4–5 years, and may live to 18 years of age (Garcia et al , 2015); whereas in Madeira and the Canary Islands maturity is reached earlier and longevity seems to be curtailed, with no specimens older than 9 years occurring in Madeira (Vasconcelos et al , 2006; Jurado-Ruzafa & Santamaría, 2013). It feeds mainly on crustaceans and small fish, especially snipefish, Macroramphosus spp.…”

Life history parameters of blue jack mackerel Trachurus picturatus (Teleostei: Carangidae) from north-east Atlantic

“…In the Macaronesian region, the main catches are those from multi-species artisanal fleets using purse seine nets (Vasconcelos et al, 2006;Jurado-Ruzafa & Santamaría, 2013). In the Azores, T. picturatus is the only species of the genus Trachurus that occurs in the region, and is exploited by various fleets and métiers.…”

Genetic diversity and population structure of the blue jack mackerel Trachurus picturatus across its western distribution

“…In recent years, there were several attempts to clarify the population structure of T. picturatus using different methods, but these studies were done regionally and only focussed on the western part of its distribution. Several authors have studied the growth and reproduction of individuals from the Azores (Garcia et al, ; Isidro, ), Madeira (Vasconcelos et al, ; Vasconcelos et al, ) and Canaries (Jurado‐Ruzafa & Santamaría, , ). These studies found similar reproductive seasons but different growth rates among the sampling locations.…”