西部和中部北太平洋海域灰鲭鲛.pptx

Age and growth analysis of the shortfin mako, Isurus oxyrinchus, in the western and central North Pacific Ocean;Shortfin Mako ;Introduction;Biology;r-organisms ;Characteristic ;Distribution ;Sustainable Development ;Materials and methods;Sample collection;Fig. 1 Sampling locations for the shortfin mako (Isurus oxyrinchus) in the western and central North Pacific Ocean. Each point denotes a position where samples were collected.;Fig. 2 Length frequency of the specimen used for the analysis;species.wikimedia.org/.../Images/test ;DL, TL, FL with PCL;Step;Vertebral processing;Four techniques to enhance vertebral growth bands;Method of age determination;The shadowing method;Fig. 3 Half of a vertebral centrum with lateral illumination from fiber-optic sources. The triangles indicate a convex structure or growth band. This example is from a 137 cm PCL female, with a vertebral centrum radius of 9.5 cm, and an estimated age of 4.6 years;Age determination ;CR with PCL;Fig. 6 Age-bias plot of 275 shortfin mako vertebral counts from two independent readings by the first author. The open and solid mark indicate the observed counts and the mean counts assigned by the second count for all fish which was assigned a given count in the first count up to 12, respectively. The vertical bars for the solid mark up to the first count of 11 indicate the 95% confidence interval. The one to one equivalence line is also represented.;;Assuming that annuli (convex structures) are formed soon before or after 1 December, age in years was calculated as follows:;Lt = PCL at time t (cm) L0 = size at birth (cm)(74 cm TL) (Joung and Hsu 2005) L∞ =asymptotic length (cm) K = brody growth constant (year?1).;Results;the allometric equation for regression analysis;Akaike’s Information Criterion;The estimated growth equations;The estimated S.E. of L∞ for females was larger than that for males, while S. E. of K for males was larger than for females;Discussion;Growth ;Growth band formation;Fig. 8 Compariso