Morphometric variation in red-spot prawn ( Metapenaeopsis barbata) in different geographic waters off Taiwan

Abstract

Morphometric variation was used to elucidate the stock structure of red-spot prawn ( Metapenaeopsis barbata) in adjacent waters off Taiwan. Five samples were separately collected from Keelung, Tashi, Taichung, Putai, and Cheding. The 10 measurements made for each individual were size-standardized by Burnaby’s method and resulting measurements submitted to canonical variate analysis; the square of Manhattan distance (Manhattan D 2) between population centroids values were then calculated using canonical scores. Dendrograms were constructed by three different clustering methods using Manhattan D 2 values. A randomization test was used to test the significance of morphometric variation between different groups derived from cluster analysis. A sexual dimorphism for red-spot prawn was found by ANCOVA, so analyses were separately performed by sex. Five sampling areas were clustered into two groups by each sex, the first group included Keelung; the second group included Tashi, Taichung, Putai, and Cheding. Randomization tests showed that morphometric variation between these two groups was significant for each sex. There appear to be at least two morphologically distinguishable stocks of red-spot prawn in adjacent waters off Taiwan. The utility of morphometric measurements for discriminating stock of red-spot prawn is demonstrated, but further verification of the stock structure may be essential.