台灣近海扁紅?與紅瓜?形態測定學之研究

Abstract

Seventeen samples consisting of 789 specimens of red scad anu nine samples consisting of 309 specimens of round scad, collected at monthly interval from the waters off Nanfangao and Kaohsiung were employed in the study. The resalts are as fallow: 1. Red Scad: (一) Meristic characters: A. The number of vertebrae and the number of the first dorsal spines of all specimens were 24 and 8 respectively with only two and one exceptions. B. Although the variation of the number of the second dorsal fin rays was a bit greater than the vanriation of the number of anal fin rays, the differences of both characters between female and male, among months and between the two areas are not significant. (二) Non-meristic characters: A. The difference between female and male is insignificant. B. There is a fairly good linear relationship between each character and fork length of every sample. C. Of all the characters, the more useful ones are the lengths that from snout to the insertion of the second dorsal fin, snout to the insertion of the first dorsal fin, snout to the insertion of the anal fin and head length. D. The result of the analysis of covariance indicates the possibility of intermingle between Nanfangao and Kaohisiung area, while the former is more simple with less intermingle. 2. Round scad: (一) Meristic characters: A. There are no variation in the number of vertebrae and the number of the first dorsal spines were 24 and 8 respectively. B. There are no significant difference tat the number of the second dorsal fin rays between female and male, among months and between the two areas. C. Although there are no significant differences in the number of anal fin rays between female and male and between the two areas, there is a significant difference among months. It is possibly due to the existance of more than two populations and the intermingle between the two areas. (二) Non-meristic characters: A. There are no significant difference between female and male. B. There is a fairly good linear reiationship between each character and fork length of every sample. C. Of all the characters, the more useful onces are the lengths that from snout to the insertion of the second dorsal fin, snout to the insertion of the anal fin, snout to the insertion of the first dorsal fin and head length. D. The geological variation seem to be more significant than the monthly variation. This possibly due to the fork length of the sample of the Kaohsiung is dominantly larger than that of Nanfangae.