Identification of Larva of Pinctada martensi

Abstract

Larval shell equivalve, nearly oval in shape, slightly contracted anteriorly ; umbo projecting prominently, with 13-15 well marked concentric growth lines on the surface of shell ; ligament slender, situating internally at the central part of provinculum, which is small, reduced anteriorly with 4 teeth of rectangular shape, shallowly divided each into 2 parts at their tips, excepting a posterior tooth in each valve ; lateral hinge system reduced to a small flange on the left valve without any lateral teeth ; larva having a pair of eye-spots, dark in color without apical flagellum on the velum. Length of valve 245μ on an average of 15 specimens ; prodissoconch 253±16μ on an average of 100 individuals.