Turkish Journal of Fisheries and Aquatic Sciences									        			
									        				2012, Vol 12, Num, 1									        				      (Pages: 157-164) 
									        			
									        	
			
			
			
													
			        							
									        			
			
												
										    	
											        			 
											        						
											        								Histological Study on Reproductive Pattern and Sex Reversal of Dusky Grouper Epinephelus guaza in Natural Environment of Antalya Bay of Mediterranean in Turkey 
											        						
											        			
											        			 
												        				
													        					Mehmet Rüştü Özen 1 ,Beytullah Ahmet Balcı 1 												        			    
 
											        			
											        			 
											        					
											        					1 Suleyman Demirel University, Egirdir Fisheries Faculty, 32500, Egirdir-Isparta-TURKEY 
											        			
											        		
		
											        															        				
													        			DOI : 
													        				10.4194/1303-2712-v12_1_18 
													        			
												        													        			
											        														        					
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											        				In this study, gonadal changes of dusky grouper Epinephelus guaza L.1758 were investigated by histo-anatomically according to sexual maturity in Antalya Bay of Eastern Mediterranean in Turkey. The specimens (n=104) were captured monthly by spear-fishing from their natural sites. The gonads of them were dissected as soon as and fixed in 10 % neutral buffered formaldehyde and Bouin’s solution. They were embedded in paraffin blocks after several histo-chemical processes. Sectioned tissue samples at 5μm were stained by Haematoxylin-eosin and Mallory trichrome techniques. Mainly four different stages which were immature stage, mature female stages (from F1 to F6), transitional stages (from T1 to T3), and mature male stages (from M1 to M3) were observed according to gonadal development. However GSI (Gonadosomatik indeks) is the most common used to quantify spawning time in fish; the RGI (Relative gonadal index) was found more appropriate than GSI for the fish. Dusky groupers spawned in June and September in Antalya Bay. 
 
											        			
											        			
		
											        			
											        			Keywords : 
											        				Dusky grouper, Epinephelus guaza, Reproductive pattern, Protogynous hermaphroditism, Sex reversal