Abstract
Characterization of the morphometric traits of crustacean larvae is the basis for comparative works in many fields, including ecology, fisheries and aquaculture. Often, field sampled specimens will be stored in preservative before being sorted in the laboratory. Length changes are significant in fish larvae stored in different preservatives. However, no comparative study has been reported in crustacean larvae. This work investigates the effect of different measuring techniques, preservation methods and storage duration on the morphometric measurements of mud crab Scylla olivacea and the giant freshwater prawn Macrobrachium rosenbergii larvae. Measurements did not differ significantly when measured with stereo microscope or advanced research microscope. Different storage methods (70% ethanol, 95% ethanol and 10% neutral buffered formalin) did not result in inconsistency in the total length (TL) and dorsal spine (DS) of S. olivacea larvae, and the rostral spine (RS) of M. rosenbergii larvae. TL of M. rosenbergii larvae was significantly shorter when stored in 95% ethanol. Significant shrinkage of crustacean larvae was observed during the first few days after immersion in preservatives.