Growth model for the endangered cyprinid fish Tribolodon nakamurai based on otolith analyses

Abstract

A growth model for the endangered cyprinid fish Tribolodon nakamurai was derived following otolith analyses of 16 wild and 53 reared specimens. The asteriscus was the most appropriate to measure size among three otolith elements, and its height OH mm was used as size index of otolith. Standard length L cm was best back‐calculated using the Gompertz model, L = 70.0·exp[–exp{−0.553 (OH – 2.73)}]. Translucent zones on the lapilli, analyzed from 5‐year‐old‐reared fish, were regarded as winter slow‐growing zones. The ages of 10 wild specimens of 37.0–48.1 cm standard length were calculated as 7–10 years by counting the translucent zones on the lapilli. Age t was best back‐calculated using the allometry model, t = 1.33·OH1.37. The growth trajectory of T. nakamurai followed a slender S curve, three typical growth models, von Bertalanffy, Logistic and Gompertz, and Richards’ model, which is a general formula of the above three, being fitted using the maximum likelihood method. The Gompertz model, Lt = 60.2·exp[–exp{−0.258(t − 4.68)}], was found by Akaike's information criterion (AIC) to be the statistically most acceptable growth model.

Comparison of non-linear growth models to describe the growth curve in West African Dwarf sheep

“…The Gompertz and Von Bertalanffy models showed the best fit in Morkaraman and Awassi lambs (Topal et al, 2004); Gompertz model in Suffolk sheep . In fish population, the Gompertz model has been considered as the best fit according to AIC lowest value (Tsangridis and Filippousis, 1994;Imai et al, 2002).…”

Otolith Sr : Ca ratios of the freshwater and anadromous cyprinid genus Tribolodon

“…Two specimens of T. brandtii and T. hakonensis were from Russia, 1 specimen grow linearly in proportion to body growth (Imai et al, 2002), the earlier increase in the Sr : Ca ratio in Russian specimens (Hk-4 and -5) than in Japanese specimen (Hk-3) may indicate that the former migrated to the sea at a smaller size than the latter. Because T. hakonensis from the Asian continent is usually anadromous , the data on the Korean specimen (Hk-2) show a rare instance of fluvial T. hakonensis.…”

“…Four specimens of T. nakamurai from the Mogami River, Yamagata Prefecture, northern Japan, showed relatively stable ratios, indicating a fluvial life mode. On the other hand, the ratio increased once in only one specimen of T. nakamurai from the Koyoshi River of Akita Prefecture, suggesting the possibility that it was born in the Mogami River, the nearest major habitat of this species, and accidentally migrated to the Koyoshi River through the sea.Key words Far Eastern dace · Tribolodon · Migration · Anadromy · Otolith Sr : Ca ratio of T. hakonensis from Korea, and the remaining specimens from Japan.The asteriscus otolith was used for analysis because the sagittal otolith of Tribolodon is small and needle shaped and not suitable for analysis (Imai et al, 2002). The dried otolith was embedded in epoxy resin, cut near the core utilizing a diamond cutting disk, mounted on a glass slide, and then ground to expose the core using aluminum oxide paste (0.3 µm).…”

“…The asteriscus otolith was used for analysis because the sagittal otolith of Tribolodon is small and needle shaped and not suitable for analysis (Imai et al, 2002). The dried otolith was embedded in epoxy resin, cut near the core utilizing a diamond cutting disk, mounted on a glass slide, and then ground to expose the core using aluminum oxide paste (0.3 µm).…”

Age and growth of chub mackerel (Xcomber japonicus) in the East China and Yellow Seas using sectioned otolith samples

“…where σ 2 is the variance of the normal distribution (Imai et al, 2002). The parameters were estimated by maximizing the log-likelihood lnl (p 1 , …, p m , σ 2 ) (Tokai, 1997).…”