Biology of Shortfin Mako Shark (Isurus oxyrinchus Rafinesque, 1810) from the Eastern Mediterranean

Abstract

Shortfin mako, Isurus oxyrinchus Rafinesque, 1810, is one of the commercially and recreationally important shark species in the world. Still knowledge on its biology and status is limited in the eastern Mediterranean. Three individuals were caught from Turkish waters. Two individuals (one female and one male) stomach contents, morphological measurements and female’ gonad histology were studied. According to the results from macroscopic examination and gonad histology, the female was a Stage 1-immature, and smallest female ever recorded from Turkish waters. In addition, phylogenetic network of mitochondrial haplotypes was constructed for all three individuals. The phylogenetic network analysis supported that the species having a metapopulation as mentioned in previous studies. Since every information is critical for development of conservation actions aiming endangered species, we believe that our study will contribute to the limited knowledge on I. oxyrinchus biology and reproduction habits in Eastern Mediterranean.

Keywords

• Isurus oxyrinchus,conservation biology,ecology,Eastern Mediterranean

Doğu Akdeniz'den Kısa Yüzgeçli Mako Köpekbalığının (Isurus oxyrinchus Rafinesque, 1810) Biyolojisi

Öz

Kısa yüzgeçli mako köpekbalığı, Isurus oxyrinchus Rafinesque, 1810, dünyadaki ticari ve sportif açıdan önemli olan köpekbalığı türlerinden biridir. Türün, Doğu Akdeniz'deki biyolojisi ve durumu konusundaki bilgiler hala sınırlıdır. Çalışmada, Türkiye kıyılarından üç birey yakalanmıştır. Yakalanan iki bireyin (bir dişi ve bir erkek) morfolojik ölçümleri yapılmış, mide içeriği ve dişi gonad histolojisi incelenmiştir. Makroskopik inceleme ve gonad histolojisi sonuçlarına göre; dişi birey, aşama-1 (olgunlaşmamış) safhasında ve şimdiye kadar Türk sularından kaydedilen en küçük dişi bireydir. Ayrıca, her üç birey için filogenetik mitokondriyal haplotip ağ oluşturulmuştur. Yapılan bu filogenetik ağ analizi, önceki çalışmalarda belirtildiği gibi bir metapopülasyona sahip türlerin desteklendiğini göstermektedir. Her bilgi, nesli tükenmekte olan türlere yönelik koruma eylemlerinin geliştirilmesi için kritik öneme sahiptir. Çalışmamızın, Doğu Akdeniz'deki I. oxyrinchus biyolojisi ve üreme alışkanlıkları hakkındaki sınırlı bilgiye katkı yapacağına inanmaktayız. 

Anahtar Kelimeler

• Isurus oxyrinchus,koruma biyoloji,ekoloji

Kaynakça

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