Length–weight and length–length relationships of the bluefin tuna,Thunnus thynnusL., in the Turkish part of the eastern Mediterranean Sea

Abstract

Summary This study describes length–weight (LWR) and length–length relationships (LLR) of bluefin tuna (BFT), Thunnus thynnus, in the eastern Mediterranean (Levantine Sea). Fulton’s condition factor (K) was also calculated for each standard length class for both sexes. A total of 363 specimens, 175 males and 188 females, were caught by purse‐seine from late winter to early summer 2003 off Antalya Bay, Turkey. Fork length values of 175 BFT males were between 114 and 250 cm with an average of 159.3 cm ± 2.14, and between 116 and 256 cm with an average of 163 cm ± 2.26 in 188 females. LWRs indicated positive allometric growth in both males and females. The coefficient b ranged from a minimum 3.32 for males to a maximum of 3.35 for females. Results indicated that the LLRs were highly correlated (r2 > 0.99, P < 0.001). K values ranged from 1.45 to 2.11 (mean: 1.56 ± 0.12) in males and from 1.43 to 2.14 (mean: 1.69 ± 0.06) in females.

Determination ofLmaxfor Atlantic Bluefin Tuna,Thunnus thynnus(L.), from Meta-Analysis of Published and Available Biometric Data

“…Fifty-three years after the publication of Akyüz and Artüz (1957), Percin and Akyol (2009) published an L-W equation for ABFT in Turkish waters of the Aegean Sea (Y = 0.0000028X 3.34 ), by which a bluefin tuna of 725 kg would measure 330 cm, the same length that had been sampled by Akyüz and Artüz (1957) in Istanbul. Hamre et al (1971) carried out further sampling in the market of Istanbul in 1967 and 1968 and measured bluefin tuna of 320 cm.…”

“…of K have been found of between 1.4(dos Santos et al, 2004;Aguado and García, 2005) and 1.5-1.6(Chapman et al, 2011;Rodríguez-Roda, 1964) for wild ABFT in a low fattening condition following spawning, up to 2.0-2.1 for fish in the spawning phase(Rodríguez-Roda, 1964;Percin and Akyol, 2009), ≥2 for wild bluefin tuna in the active growth phase(Golet and Lutcavage, unpublished data, cited by Chapman et al, 2011), and 2.3 for farm fattened fish…”

On the Variability of the Length–Weight Relationship for Atlantic Bluefin Tuna,Thunnus thynnus(L.)

“…En los dos casos (almadrabas de Marruecos y de España) el valor medio del factor de condición (K) de las muestras seleccionadas es > 2, que según Rodríguez-Roda (1964) and Percin and Akyol (2009) El modelo EAST es la última adaptación hecha por los dos autores a los modelos publicados por Rodríguez-Marín et al (2013.…”

“…In the two cases (traps of Morocco and Spain) the mean value of the condition factor (K) of the selected samples was > 2, which, according to Rodríguez-Roda (1964) and Percin and Akyol (2009) The set of the three databases (N=673) will hereinafter be referred to as ALM+GBYP. The model EAST is the last adaptation made by the two authors to the models published by Rodríguez-Marín et al (2013;.…”

Geographic variation of body morphology of the Atlantic bluefin tuna, (Thunnus thynnus, Linnaeus, 1758)

“…To date, the morphological features of the Atlantic bluefin tuna have been analyzed using traditional morphometric approaches (Aguado‐Giménez and García‐García, ,b; Percin and Akyol, ; Tičina et al., ; Addis et al., ), but they have never been studied using GMMs. Thus, the aim of this study was to determine whether the landmark‐based geometric morphometric approach to describing body shape is useful for discriminating between populations of Atlantic bluefin tuna.…”