ASPECTS OF THE REPRODUCTIVE-BIOLOGY OF PETROLISTHES-LAEVIGATUS (GUERIN, 1835) (DECAPODA, ANOMURA, PORCELLANIDAE) .3. EFFECTS OF STARVATION AND DIFFERENT TYPES OF DIET ON LARVAL DEVELOPMENT UNDER LABORATORY CONDITIONS

Early developmental stages of the Chilean porcellanid crab Petrolisthe s laevigatus were reared in the laboratory at 13 degrees C and 20 degr ees C to test both starvation vulnerability and the suitability of dif ferent diets for the larvae. The experimental design included a starva tion control, a mixed diet (Artemia sp. with Isochrysis sp.), a phytop lankton (Isochrysis sp.) and an Artemia sp. diet. Only individuals fed with Artemia sp. or the mixed diet were able to complete larval devel opment. Larvae cultivated at 13 degrees C and 20 degrees C reached the megalopal stage after a mean of 39.7 days and 21.5 days, respectively . Duration of both zoeal stages was significantly shorter at 20 degree s C; however, no such differences were detected for the megalopal stag e. Newly-hatched larvae survived starvation for up to 13 days, and all megalopae died in the absence of food within 10 days. An algal diet d id not allow the molt to the second instar; however, larvae survived l onger than in the starvation control. Since the mixed diet provided al l developmental stages with a better survival than the Artemia sp. die t, we conclude that phytoplankton as a single food source does not all ow successful development. However, diatoms may be an important additi onal energy source in the natural diet of P. laevigatus. We compare ou r data with regressions for estimating development times of other porc ellanid zoeae and megalopae. Furthermore, we discuss our results and b ehavioral observations regarding the megalopal stage of P. laevigatus in relation to possible transport mechanisms and settlement strategies .