Age, Growth and Age Composition estimation of Painted Lizardfish, Trachinocephalus myops(Bloch and Schneider,1801), in the Southern Taiwan Strait

• Main Authors: Jeng,Kuen-Jong, 鄭坤忠
• Other Authors: Lee,Ying-Chou
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/72795340269318355951

碩士 === 國立臺灣大學 === 漁業學系 === 84 === Age,growth and age composition of Trachinocephalus myops were estimated by Walford-plot method and iterated age-length key algorithm(IALK),the results were as follows:(1) The vertebral character showed:(a)the larger the fork length, the more the ring count;(b)relative positions of ring radius in all vertebrae of the same specimen were analogous;(c)relative positions of ring radius were analogous in different specimen with same rings;(d)the frequency and mean ring radius were significantly different between neighboring ring groups. Base on above results, the present study made sure that the vertebra was an effective age character.(2)There were significant difference between sexes for the relationship between fork length(L;cm) and centrum radius(R;1/15mm), the equations were estimated as follows: Male:L=2.4166+1.0439R;Female:L=2.7489+1.0 369R.(3)The von Bertalanffy growth equation for fork length(cm) were estimated as follows:Male:Lt=54.77{1-exp[-0.1113(t+2.5909) ]};Female:Lt=65.38{1-exp[-0.0865(t+2.8151)]}.(4)There were significant difference between sexes for the relationships between natural logarithmic boby weight(W;g) and fork length (L; cm), the equations were estimated as follows:Male:W=0.006822 L^3.1673 ; Female:W=0.007767L^3.1364.(5)The annulus was formed once a year in the period from March to May.(6)Reproductive period of female are in March-April and July-September, and male are in February-April and August-November.(7)According to 1932 speciemens, sex ratio was 0.24, which was significant different from 0.5 by Chi-square test, and the difference increased with fork length or age.(8)The age composition estimations showed that there were 7 age groups in 1994, 7 age groups in 1995 and 6 age groups in 1996. The major catch group appeared at age 2 in 1994,age 0 in 1995 and age 1 in 1996, respectively.