Age and growth in southern bluefin tuna, Thunnus maccoyii (Castelnau): Direct estimation from otoliths, scales and vertebrae

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“…Ho wever, in the current study, vertebrae provided age estimates similar to those from otoliths only up to age 5 (between-reader agreement, 84.07%), and consistently underestimated the age of A. brama after age 11. These results are similar to those of Gunn et al (2008), who reported that age estimates of Thunnus maccoyii from vertebrae and otoliths matched closely up to age 10, but the counts diverged for older individuals. As reported by Hill, Calliet, and Radtke, (1989) for blue marlin (Makaira nigricans Lacepede) and Khemiri, Gaamour, Zy lberberg, Meunier, and Ro mdhane (2005) for Boops, we found that the rings on vertebral centra were not very clear and showed numerous minute marks unrelated to cyclic events .…”

“…Otoliths were superior to the other examined structures in all criteria used to (Hammers & Miranda, 1991;Phelps et al, 2007;Gunn et al, 2008;Ma et al, 2011). Otoliths are often used as a benchmark to compare age estimates fro m other structures (Niewinski & Ferreri, 1999).…”

“…Because the vertebrae had bi-concave centra, they were cut in half along the dorsal-ventral axis. Half of each vertebra was placed at the optimal angle in order to make all of the rings visible (Gunn et al, 2008).…”

Growth Characteristics and Reproduction of Comber, <I>Serranus Cabrilla</I> (Actinopterygii, Perciformes, Serranidae), in the Aegean Sea

“…and the fishing activities on The absence of older ages group can be explained their rarity in the population and our randomly samplings. In addition, this may be caused by the difference in the readability of opaque zones among otoliths and/or counting skills of readers (Gunn et al 2008). …”

Life history characteristics of the protogynous parrotfish Calotomus japonicus from northwest Kyushu, Japan

“…For many species, it has been reported that otoliths are more suitable calcareous structures than scales for the purpose of age determinations (e.g., Sadovy et al 1992;Gunn et al 2008;Robillard et al 2009). The compression of rings on the margin of the scales of older fish often makes estimation of age very difficult and tends to lead to underestimation of age in older fish.…”