Cytogenetic studies on five Red Sea reef fish species Larabicus quadrilineatus, Hemigymnus melapterus,
Thalassoma rueppellii, Thlassoma lunare and Gomphosus caeruleus of the family Labridae (Perciformes)
were carried out; all samples were collected from Hurghada, on the Egyptian Red Sea coast. All the
specimens showed a diploid chromosome number of 2n=48, they were also identical in the karyotype (all
acrocentric), and in the Fundamental number FN=48. The RAPD-PCR analysis were carried out by using
eight primers OPA12, 5`-TCGGCGATAG-3, OPA14,5`-TCTGTGCTGG-3`, OPA15, 5`-TTCCGAACCC-
3`, OPA17,5`- GACCGCTTGT – 3`, OPA18 5`-AGGTGACCGT-3`, OPA19 5`-CAAACGTCGG-
3`,OPA20,5`-GTTGCGATCC-3` and OPO11,5`- GACAGGAGGT- 3`.
The results were extremely useful to improve the importance of using RAPD-PCR in genetic analysis
among the species which are identical in chromosome number and karyotype.