Age and growth of the Spanish chub mackerel Scomber colias off southern Spain: a comparison between samples from the NE Atlantic and the SW Mediterranean

Abstract

Age and growth of the Spanish chub mackerelResumen.-Se analiza la edad y los patrones de crecimiento del estornino Scomber colias en aguas del sur de España, procedentes de dos áreas diferentes, costa Atlántica y Mediterráneo occidental, en el periodo comprendido entre octubre de 2003 y septiembre de 2004. La relación longitud-peso viene dada por la ecuación TW=0,0015 TL 3,5289 (r 2 = 0,99, donde TW= peso total en g, TL=longitud total en mm). La edad se determinó mediante la lectura (conteo e interpretación) de los anillos de crecimiento de otolitos sagitta en 221 ejemplares capturados por la flota comercial andaluza y durante las campañas oceanográficas de prospección de recursos marinos. En los otolitos, anualmente fueron depositados dos anillos, uno opaco y otro hialino. La zona opaca se formó principalmente en primavera y verano, mientras que la zona hialina se formó en otoño e invierno. La relación existente entre el radio del otolito y la longitud del pez, se describe mediante la ecuación: TL = 43,881 * OR 1,245 (r 2 = 0,93, donde OR= radio del otolito). Los parámetros de la curva ajustada de crecimiento de von Bertalanffy fueron estimados para los dos sexos de forma conjunta así como para todo el periodo de estudio (L ∞ = 43 cm, K = 0,27 para el Golfo de Cádiz, y L ∞ = 40 cm, K = 0,37 para el Mar de Alborán, donde L ∞ se define como la talla máxima teórica, y K como la rapidez con la que la curva se torna asintótica). No se han encontrado diferencias de crecimiento entre las distintas áreas de estudio, lo que sugiere que el Estrecho de Gibraltar no supone una barrera geográfica para el normal desarrollo del ciclo vital de esta especie. Por otro lado, gracias a las condiciones medioambientales similares del Mar de Alborán y del Golfo de Cádiz, el Estrecho de Gibraltar es una vía de comunicación importante que permite la existencia de un flujo larval entre el Atlántico y el Mediterráneo.Palabras clave: Scombridae, otolito, parámetros de von Bertalanffy, Estrecho de Gibraltar Abstract.-This paper studies the age and growth patterns of the Spanish chub mackerel Scomber colias off southern Spain collected from two different areas, Atlantic coast and Western Mediterranean, from October 2003 to September 2004. The length-weight relationship was given by TW=0.0015 TL 3.5289 (r 2 = 0.99, where TW= total weight in g, TL= total length in mm). Age was determined by interpreting and counting growth rings on the sagitta otoliths of 221 individuals caught by the commercial Andalusian fleet and during fisheries research surveys. Two rings, one opaque and one hyaline, were laid down each year on the otoliths. The opaque zone was formed during spring and summer and the hyaline one during autumn and winter. The otolith radius-length of the fish relationship was described by the equation: TL = 43.881 * OR 1.245 (r 2 = 0.93, where OR= otolith radius). The parameters of the fitted von Bertalanffy growth curve were estimated for sex combined for the whole period (L ∞ = 43 cm, K = 0.27 for the Gulf of Cadiz, and L ∞ = 40 cm, K =...

Age and growth of Atlantic chub mackerel (Scomber colias) in the Northwest Atlantic.

“…Information on individual growth dynamics is essential for the assessment of exploited stocks (Ballagh et al, 2011). The demographic characteristics of S. colias have been described from populations in the Northeast Atlantic (Martins 1996;Lorenzo and Pajuelo, 1996;Carvalho et al, 2002;Vasconcelos et al, 2011;Velasco et al, 2011;Jurado-Ruzafa et al, 2017), Mediterranean Sea (Perrotta et al, 2005;Bayhan, 2007;Velasco et al, 2011), and Southwest Atlantic (Perrotta et al, 2005), but have not been described for the stock in the Northwest Atlantic. These studies indicate that considerable geographic variation exists in parameter estimates of Atlantic chub mackerel growth that describe length-at-age (Table 1) and weight-at-length (Table 2) among locations.…”

“…Gear type used in commercial harvest varies widely and includes purse-seine (Martins 1996;Lorenzo and Pajuelo, 1996;Carvalho et al, 2002;Sinovčić et al, 2004;Vasconcelos et al, 2011;Velasco et al, 2011), beach seine (Sinovčić et al, 2004), commercial trawl (Martins 1996;Santos et al, 2002;Velasco et al, 2011;Jurado-Ruzafa et al, 2017), hook and line (Martins 1996;Carvalho et al, 2002;Velasco et al, 2011), longline (Santos et al, 2002;Moutopoulos and Stergiou 2002), traps (Santos et al, 2002), and a variety of other net types (Martins 1996;Carvalho et al, 2002;Santos et al, 2002;Moutopoulos and Stergiou 2002;Mendes et al, 2004). Sample sizes used to describe the length-at-age relationship ranged from 98 (Velasco et al, 2011) to 2 191 individuals (Vasconcelos et al, 2011) and 46 (Moutopoulos and Stergiou 2002) to 4 599 individuals (Jurado-Ruzafa et al, 2017) to describe the weight-at-length relationship. Sample collection also took place during different years and seasons (Martins 1996;Lorenzo and Pajuelo, 1996;Carvalho et al, 2002;Santos et al, 2002;Moutopoulos and Stergiou, 2002;Sinovčić et al, 2004;Mendes et al, 2004;Perrotta et al, 2005;Vasconcelos et al, 2011;Velasco et al, 2011;…”

“…Sample sizes used to describe the length-at-age relationship ranged from 98 (Velasco et al, 2011) to 2 191 individuals (Vasconcelos et al, 2011) and 46 (Moutopoulos and Stergiou 2002) to 4 599 individuals (Jurado-Ruzafa et al, 2017) to describe the weight-at-length relationship. Sample collection also took place during different years and seasons (Martins 1996;Lorenzo and Pajuelo, 1996;Carvalho et al, 2002;Santos et al, 2002;Moutopoulos and Stergiou, 2002;Sinovčić et al, 2004;Mendes et al, 2004;Perrotta et al, 2005;Vasconcelos et al, 2011;Velasco et al, 2011;Jurado-Ruzafa et al, 2017). The majority of studies describing sex-specific length-at-age (Lorenzo and Pajuelo, 1996;Kiparissis et al, 2000;Perrotta et al, 2005;Bayhan 2007;Vasconcelos et al, 2011;Velasco et al, 2011) and weight-at-length (Lorenzo and Pajuelo, 1996;Kiparissis et al, 2000;Santos et al, 2002;Bayhan 2007;Vasconcelos et al, 2011;Velasco et al, 2011) relationships do not report significant differences between sexes, with few exceptions.…”

“…Sample collection also took place during different years and seasons (Martins 1996;Lorenzo and Pajuelo, 1996;Carvalho et al, 2002;Santos et al, 2002;Moutopoulos and Stergiou, 2002;Sinovčić et al, 2004;Mendes et al, 2004;Perrotta et al, 2005;Vasconcelos et al, 2011;Velasco et al, 2011;Jurado-Ruzafa et al, 2017). The majority of studies describing sex-specific length-at-age (Lorenzo and Pajuelo, 1996;Kiparissis et al, 2000;Perrotta et al, 2005;Bayhan 2007;Vasconcelos et al, 2011;Velasco et al, 2011) and weight-at-length (Lorenzo and Pajuelo, 1996;Kiparissis et al, 2000;Santos et al, 2002;Bayhan 2007;Vasconcelos et al, 2011;Velasco et al, 2011) relationships do not report significant differences between sexes, with few exceptions. Differences in sex-specific mean growth parameter estimates for the length-at-age relationship were reported in the Adriatic Sea, however it was not reported whether these differences were statistically significant (Čikeš Keč and Zorica, 2012).…”

Morphometric and meristic variation in the Atlantic chub mackerel Scomber colias Gmelin, 1789 from the Moroccan coast

“…Meristic characters are the number of discrete countable structures, independent of size and stable during growth and the morphometric characters are continuous characters describing aspects of body shape (Ihssen et al, 1981;Turan 2004;Erguden et al, 2009;Tarkeshwar et al, 2012) and are often been used to delineate stocks ( Turan et al, 2006). So far, many studies have been carried out on chub mackerel, dealing with different aspects of biology such as diet, age, growth, reproduction and morphometry, along both Mediterranean and Atlantic coasts and most of them are related to S. japonicus (Baird, 1977;Carvalho et al, 2002;Perrotta et al, 2005;Bayhan, 2007;Cikes et al, 2011;Velasco et al, 2011;Wahbi et al, 2015;Ait Talborjt and El Ouizgani, 2016;Allaya et al, 2016). Such data available for S. colias from the Moroccan Atlantic Ocean are very scanty, even though the species form a commercial fishery in the region.…”