Biochemical Composition during the Embryonic Development and Freshly Hatched Zoea of Macrobrachium idella idella (Hilgendorf, 1898)

Abstract

IntroductionThe females of most decapods extrude their eggs and carry them under the abdomen until hatching. The eggs are rich in yolk substances that are used as embryonic development progresses [1][2][3][4][5]. The utilization of yolk substances closely correlates with the embryonic development. Protein is one of the main components of yolk, plays an important role in both morphogenesis and energy supply in embryos [2,3]. Lipid in the eggs of the most of the crustacean is one of the main energy sources that the females stored. During the embryonic development stages, lipid is not only a kind of energy source, but also components of biological membranes and pigments of compound eyes [4,5]. There is no information available on the biochemical composition during embryonic development and freshly hatched zoea of crustaceans in general and palaemonid prawn, Macrobrachium idella idella in particular. So the present study is designed to know the biochemical changes in the embryonic and freshed hatched first zoeal stages of edible prawn, Macrobrachium idella idella. Materials and Methods CollectionThe prawn, Macrobrachium idella idella was collected from Ponanthittu (Lat.11°28`50.50º N; Long. 79°45`28.23º E) waters which is located 2 km south to Parangipettai and connected with Vellar estuary. The prawns were caught by the fisherman with the help of trap, line and hand-net and scoop net. The specimens were collected from fisherman as the sizes of the collected specimens were ranged from 30 to 125 mm in length. Totally 210 specimens were collected and transported to the laboratory in live condition by keeping them in bucket containing freshwater and aeration. After reaching the laboratory they were washed carefully with distilled water to remove dust and algal particles and ice killed.The freshly collected berried females during the months of November and December 2006 were segregated into four arbitrary stages as described by Aubson and Patlan, Sumitra and Easterson, Rodriguez (1977) and Rodriguez (1985), respectively [6][7][8][9]. The color and diameter of the eggs were noted before segregation and small clumps of eggs was snipped from random locations in each clutch using sharp scissors. All the developing embryos were examined with a MEIJI binocular dissecting microscope (100X) to ensure that only viable embryos were sampled and the color of the embryo were also observed. The diameter of the eggs was measured using a micrometer mounted in the ocular of a dissecting microscope. Eggs were classified into 4 stages based on the following characteristic features. Characteristic features of different egg stagesEgg stage-I: The eggs were opaque, greenish, round or oval in shape. The diameter of the egg was found to be 0.45 mm. Egg stage -II:The eggs were translucent, light green in color, oval with a narrow peri-vitelline space at one end and small transparent plate (the blastoderm) were easily distinguished. The diameter of the egg was calculated as 0.57 mm. Egg stage-III:The eggs were translucent, brownish-yellow in c...