Age, growth and mortality of common two-banded seabream, Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817), in the eastern Adriatic Sea (Croatian coast)

Abstract

Age, growth and mortality were analysed for the common twobanded seabream, Diplodus vulgaris, collected in the eastern Adriatic (Croatian coast) from commercial fishery catches by ÔtramataÕ fishing (2005)(2006) to obtain growth estimation. The oldest female was estimated to be age 11, the oldest male age 10 years. The von Bertalanffy growth parameters estimated by reading scales were: L ¥ = 48.60 cm (SE = 1.101), K = 0.112 (SE = 0.005) and t 0 = )2.366 (SE = 0.060) for all specimens; L ¥ = 51.96 cm (SE = 2.153), K = 0.095 (SE = 0.007) and t 0 = )2.837 (SE = 0.120) for females and L ¥ = 56.25 cm (SE = 2.662), K = 0.084 (SE = 0.067) and t 0 = )2.920 (SE = 0.117) for males. The overall sex ratio was 1.22 : 1 in favour of males. Total mortality, corresponding to the slope of the descending limb of the catch curve, was Z = 0.81 per year for females and Z = 0.85 per year for males. Exploitation ratios were E = 0.68 for females and E = 0.73 for males.

Spatial variation in demography of an estuarine teleost: implications for population and fishery assessments

“…These results suggest that females grew faster and attained greater FLs than males (a previous study on A. australis did not discriminate between genders; Pollock 1982). This result is consistent with reports on many other Sparidae (Morison et al 1998, Pajuelo & Lorenzo 2000, Pajuelo et al 2006, Alós et al 2010), but gender-related growth patterns in contrast to this are apparent within the family (Pajuelo & Lorenzo 2003, Brouwer & Griffiths 2004, Dulčić et al 2011) and can be confounded due to the prevalence of protandric hermaphroditism displayed by several species, including A. australis (Pollock 1982, Buxton 1993, Pajuelo & Lorenzo 2000, Abou-Seedo et al 2003, Pajuelo et al 2006). Further work is required to determine the levels and effects of hermaphroditism on s exspecific growth rates of A. australis.…”

“…Estimated longevity of A. australis was influenced by estuary, with fish not exceeding 14 yr in LM, but attaining 21 yr in SGB and 22 yr in CR. Observed longevity did not differ greatly between genders (19 compared with 22 yr for males and females, respectively), which is concordant with reports of other Sparidae (Sarre & Potter 2000, Dulčić et al 2011. Sparids display a diverse range of longevities, with the recorded maximum ages of some estuarine/coastal species elsewhere exceeding 40 yr (Horn 1986, Buxton & Garratt 1990.…”

Reproductive biology, age and growth of the two-banded seabream Diplodus vulgaris (Pisces: Sparidae) in the Gulf of Gabès, Tunisia

“…The oldest fish was 9 years old in the Gulf of Gabès, 8 in Gulf of Lion (Man-Wai, 1985), 4 in Spain (Gordoa & Moli, 1997) and 11 in Croatia (Dulčić et al , 2010).…”

The Effect of Different Habitat Types and Ontogenetic Stages on the Diet Shift of a Critically Endangered Fish Species, Coreius guichenoti (Sauvage and Dabry de Thiersant, 1874)

“…In this study, we defined the individuals in the IV–VI stages as fully mature individuals and the other stages as immature individuals [ 29 ]. In addition, scales from all collected fish were extracted from the area below the dorsal fin and above the lateral line as the age-determining materials [ 30 ]. The scales were first cleaned with water and NaOH, placed between two slides and then observed in the field using a SZ61TR stereo microscope (Olympus, Japan) to determine the age of each fish [ 30 ].…”

“…In addition, scales from all collected fish were extracted from the area below the dorsal fin and above the lateral line as the age-determining materials [ 30 ]. The scales were first cleaned with water and NaOH, placed between two slides and then observed in the field using a SZ61TR stereo microscope (Olympus, Japan) to determine the age of each fish [ 30 ]. After removing the skins and scales, muscle tissues were taken from below the dorsal fin.…”