Age, growth and reproductive characteristics of gold striped amberjack 1 Seriola lalandi in the waters off western Kyushu, Japan

Figures & data

Fig. 1  The location of Seriola lalandi commercially caught in the waters off western Kyushu. The size of circle indicates the number of fish caught at each site in the present study. The total number of collected specimens of gold striped amberjack was 164.

Fig. 2  Photograph of centrum of Seriola lalandi with three ring marks (A, FL = 758 mm, female), two ring marks (B, FL = 710 mm, female) and one ring mark (C, FL = 586 mm, male), and a schematic figure (D) of the measurement region on the centrum shown in (A). Black arrows and grey areas in (D) indicate ring marks and the opaque zone, respectively. F, focus; CR, centrum radius; rn, ring radius of the boundary from an opaque zone to a translucent zone; MI, marginal increment.

Fig. 3  Photomicrographs of testes at different developmental stages in Seriola lalandi: (A) spermatogonia proliferation stage; (B) early spermatogenesis stage; (C) late spermatogenesis stage; (D) functional maturation stage; (E) post-spawning stage. sg, spermatogonial; st, spermatid; sz, spermatozoon. Scale bar equals 100 µm.

Fig. 4  Photomicrographs of ovaries at different developmental stages in Seriola lalandi: (A) immature stage; (B) developing stage; (C) vitellogenic stage; (D-E) mature stage; (F) spawning stage; (G) resting stage. at, atretic oocyte; ey, early yolk oocyte; gvm, germinal vesicle migration oocyte; hy, hydration oocyte; ly, late yolk oocyte; my, mid-yolk oocyte; pn, perinucleolus oocyte; pof, postovulatory follicle. Scale bar equals 100 µm.

Fig. 5  Monthly changes in (A) frequency of appearance of an opaque zone on the outer margin of the centrum and in the (B) marginal increments (MI) of centrum in Seriola lalandi. Open and closed circles indicate the specimens with translucent and with opaque zones on the outer margin, respectively. Number of fish examined each month is indicated.

Fig. 6  Relationship between age and fork length. Fitted curve indicates the von Bertalanffy growth curve for Seriola lalandi.

Fig. 7  Monthly changes in the gonadosomatic index (GSI) of male (n=60) and female (n=78) Seriola lalandi. Vertical bars denote the standard error.

Fig. 8  Monthly changes in the frequency of occurrence of various maturity stages of (A) testes and (B) ovaries in Seriola lalandi. For males, Sp, spermatogonial proliferation stage; Es, early spermatogenesis stage; Ls, late spermatogenesis stage; Fm, functional maturation stage; Ps, post-spawning stage, and for females, Im, immature stage; D, developing stage; Vi, vitellogenic stage; M, mature stage; Sp, spawning stage; Re, resting stage. The numbers over each column represent the number of fish examined.

Fig. 9  Relationships between (A) the five maturation stages of testes and gonadosomatic index (GSI); (B) the five maturation stages of testes and fork length; (C) the six maturation stages of ovaries and GSI; (D) the six maturation stages of ovaries and fork length of Seriola lalandi. Refer to Figs. 3 and 44 for each testis and ovarian stage, respectively. n, number of fish examined.