BIOCHEMICAL AND MOLECULAR STUDIES ON SOME SPECIES OF MULLET FISH

Abstract

This study was carried out during the period from the year 2015 to 2020 in the dry Genetics lab (Genetics department - Central laboratory for aquaculture research - Agriculture research center), the Agricultural Genetic Engineering Research Institute (AGERI), Agriculture Research Center (ARC), Giza, Egypt and the Department of Genetics, Faculty of Agriculture, Cairo University. The present investigation was conducted with the two main objectives: (1)To assess the genetic diversity among the four mullet species using morphological assessment, biochemical markers (SDS-PAGE) and molecular markers (SCoT and ISSR). (2) To identify and sequencing the unique markers related to some morphological traits which can differentiate among the four studied species. The results could be summarized as the follows: 1- The genetic diversity among the four mullet species based on the morphological characterization

In the present investigation forty-eight samples of mullet species namely Mugil cephalus, Liza ramada, Valamugil sihilil and Liza garana fish were collected from four different Governorates in Egypt (Alexandria, Ismailia, Port Said and Damietta), twelve samples for each species within the same family were investigated. Seventeen morphometric characters ,total length (TL ), standard length (ST), fork length (FL), head length(HL) , distance of first dorsal fin (D1) , distance of second dorsal fin (D2) , distance of ventral fin (DV), distance of central of anus (DCA) , distance of anal fin (DA) , maximum body height (MBH) , eye diameter (ED) , caudal peduncle depth (CPD), dorsal fin length (DFL), snout length (NL), head depth (HD), width (W), pectoral fin length (PecFL) = tail length, body weight (BW) and condition factor (CF) was calculated that equal, CF =100w/l for each fish sample were measured. The ANOVA test revealed that out of the seventeen morphometric characters four traits (head length (HL), distance of first dorsal fin (DL), fork length (FL) and body weight (BW)) showed significant difference (p<0.05) among the four species. The HL character ranged from 2.83cm in Valamugil sihilil (Alex.) to 5.83 cm in Mugil cephalus (Alex.). Concerning the DL the highest value (12.50 cm) was displayed by Mugil cephalus (Ism.) While, the lowest value (4.30 cm) exhibited by Valamugil sihilil (Alex.). The D2 character ranged from 7.67 to 18.33 cm Mugil cephalus (Ism.) and Valamugil sihilil (Alex.), and the body weight (BW) ranged from 24.30 to 303.70 gm in Valamugil sihilil (Alex.) and Mugil cephalus (Ism.), respectively. Meanwhile, the remaining morphometric characters (13) revealed no significant differences (p<0.05) among the four mullet species.