Determination of the Spawning Time and Changes in the Reproduction Cycle of Ribbon Fish, Trichiurus lepturus, According to the Hepatosomatic Index and Gonadosomatic Index

Abstract

The ribbon fishes, belonging to the family Trichiuridae, are one of the most important protein resources in the Indian Ocean. A considerable density of the dominant species of this family, Trichiurus lepturus has been observed in the Oman Sea. During the conducted cruises in the northern part of the Oman Sea, Gonadosomatic index (GSI) and Hepatosomatic index (HSI) were estimated according to the size of the female groups of Trichiurus lepturus. GSI increases significantly from September to next April (P <0.05). Polymodal egg size frequency revealed prolong spawning time by the females. The HSI fluctuations are good indications for this type of reproductive behavior.