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Morphological variability of otolith organs in three congeneric Pagellus species

Bostanci Derya, Yedier Serdar, Türker Dilek, Işmen Ali

Oceanological and Hydrobiological Studies

2024

Vol. 53, No. 1

88--101

Morphological features of sagittal otoliths in Pagellus acarne, P. bogaraveo, and P. erythrinus samples collected from the Aegean Sea were used to assess the variability both between Pagellus species and between otolith pairs employing scanning electron microscopy (SEM) and contour shape analysis. Twenty-one otolith morphological characters were compared in detail using SEM analysis. Twelve of these characters differ between Pagellus species and are suitable for distinguishing between the three congeneric Pagellus species. Wavelet functions of otolith contour shape were compared for six Pagellus groups. The wavelet functions obtained from the contour shape analysis showed high variability in the antero-dorsal, postero-dorsal, and antero-ventral regions of otoliths among the six groups analyzed. The results of principal component analysis (PCA) of the wavelet data provided a clear distinction between the groups under study. Cluster analysis supported the PCA results and basically divided them into two main branches. One of these branches contained only P. erythrinus, while P. acarne and P. bogaraveo were present in the other branch. This is the first study to provide detailed morphological characters and wavelet analysis of left- and right-side otoliths in these three congeneric Pagellus species from the Aegean Sea.

Reproductive biology of Penaeus kerathurus (Forskål, 1775) (Decapoda: Penaeidae) in the Sea of Marmara, Turkey

Ihsanoglu Mukadder Arslan, Daban Ismail Burak, Işmen Ali, Cabbar Koray, Yığin Cahide Çiğdem

Oceanological and Hydrobiological Studies

2021

Vol. 50, No. 1

33--37

One of the economically important species is Penaeus kerathurus (Forskål, 1755), which is widespread in the Mediterranean ecosystem. This paper presents results of research on reproductive biology of Penaeus kerathurus in the Sea of Marmara. A total of 1404 specimens were dissected to determine the maturity stages, reproduction time, and length at first reproduction. The female-to-male ratio was 1:0.9. A high percentage of mature females was determined in April, May and July. Moreover, the value of the gonadosomatic index (GSI) decreased after July. The spawning period was observed between April and July, and its intensity increased in July. The carapace length at first sexual maturity was determined to be 39 mm.