MORPHOLOGICAL CHARACTERISTICS AND DIFFERENCE ON ZOEA LARVAE OF MACROBRACHIUM MALCOLMSONII AND MACROBRACHIUM ROSENBERGII

From hatching to metamorphosis for larvae of Macrobrachium malcolmsonii, the larvae had experienced the molting process twelve times accompany with changes of Morphology and appendage characteristics. Through microscopic observation and photography on 30 samples from Z1 to Z12 larvae, the results showed that there were big differences in compound eye between Z1 and Z2. The main characters were located on the telson between Z3 and Z2, Z4 and Z5. There was proleg germination occurred on abdomen of Z6. The morphological variations between Z7 and Z8 lain in changes of antennule inner and outer flagellum appendage. The main periodical standards to discriminate Z9 and Z12 were morphology of periopods, proleg and rostrum. Therefore, it could provide biological basis in different zoea stages of Macrobrachium malcolmsonii by means of observation on morphological variations such as the inner and outer flagellum of the first antennule, flagellum and antennal scale of the second antenna, rostrum, dorsal spur, compound eye, the first and second legs on the carapace, pleopod, telson, tail fan from Z1 to Z12 larvae, as well as determination of morphometric character of the larvae such as the number of segments, quantity of seta during the period from Z1 to Z12 stages. In addition, morphological variations of zoea larvae of Macrobrachium malcolmsonii have been compared with Macrobrachium rosenbergii, which could provide reference to identify these two kinds of zoea larvaes by measuring the number of antennal flagellum segmentation.