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Journals / Marine and Life Sciences / 2026 / Cilt: 8 Sayı: 1

Seasonal reproductive dynamics of the freshwater mussel Unio delicatus (Bivalvia: Unionidae) in Lake Gölbaşı, Türkiye

Hatay Gölbaşı Gölü’nde yaşayan tatlı su midyesi Unio delicatus (Bivalvia: Unionidae)’un mevsimsel üreme dinamikleri

Hülya Şereflişan(İSKENDERUN TEKNİK ÜNİVERSİTESİ)0000-0002-2510-3714
Serap Koşal Şahin(İstanbul University)0000-0001-9256-218X
Pages
54–62
Publication Date
2026-06-26
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AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

The results indicate a clear seasonal pattern in reproductive activity.

📌 3 Key Takeaways

🎯
Objective & Hypothesis:This study investigates the reproductive characteristics of the freshwater mussel Unio delicatus Lea, 1863, with a focus on its gonadosomatic index (GSI).
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Key Findings & Data:To examine seasonal variation, approximately twenty adults were randomly sampled each month from October 2023 to September 2024.
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Conclusion & Impact:The results indicate a clear seasonal pattern in reproductive activity.
🔬Design:Araştırma Makalesi
📍Scope:2023 Verileri
⚙️Variables:Tatlı su midyesi · Gölbaşı Gölü · gonadosomatik indeks

Abstract

This study investigates the reproductive characteristics of the freshwater mussel Unio delicatus Lea, 1863, with a focus on its gonadosomatic index (GSI). Samples were collected from Lake Gölbaşı (Hatay, Türkiye). To examine seasonal variation, approximately twenty adults were randomly sampled each month from October 2023 to September 2024. Shell length, soft tissue weight, and gonad weight were measured to calculate GSI values. Additionally, the relationship between water temperature and GSI was evaluated with respect to environmental conditions. The results indicate a clear seasonal pattern in reproductive activity. In females, GSI values reached their highest levels in February and March (14.65% and 15.22%) and declined during the summer months. Males showed a similar trend, peaking in March (12.38%). The sex ratio remained approximately balanced (1:1.03) and did not differ significantly (P>0.05). A positive relationship between shell length and gonad weight (R 2 =0.162) suggests that larger individuals allocate more energy to reproduction. In contrast, GSI values decreased with increasing water temperature, indicating that reproductive activity is more pronounced during colder periods. The findings show that environmental conditions, particularly temperature, play an important role in shaping the reproductive cycle of U. delicatus . Gonadal development appears to be most active from late winter to early spring. These results may help better understand the species and support future conservation efforts in freshwater ecosystems.

Özet

Bu çalışma, tatlı su midyesi Unio delicatus Lea, 1863'ün üreme özelliklerini, özellikle gonadosomatik indeks (GSI) değerlerini incelemektedir. Örnekler, Hatay (Türkiye)'daki Gölbaşı Gölü'nden toplanmıştır. Mevsimsel değişimi değerlendirmek amacıyla, Ekim 2023 ile Eylül 2024 tarihleri arasında her ay rastgele seçilen yaklaşık yirmi ergin birey örneklenmiştir. GSI değerlerini hesaplamak için kabuk uzunluğu, yumuşak doku ağırlığı ve gonad ağırlığı ölçülmüştür. Ayrıca, su sıcaklığı ile GSI arasındaki ilişki çevresel koşullar açısından değerlendirilmiştir. Elde edilen sonuçlar, üreme aktivitesinin belirgin bir mevsimsel desen gösterdiğini ortaya koymuştur. Dişilerde GSI değerleri Şubat ve Mart aylarında en yüksek düzeye ulaşmış (%14,65 ve %15,22) ve yaz aylarında azalmıştır. Erkeklerde de benzer bir eğilim gözlenmiş, en yüksek GSI değeri Mart ayında %12,38 olarak belirlenmiştir. Eşey oranı yaklaşık 1:1,03 (dişi:erkek) olup, istatistiksel olarak anlamlı bir farklılık göstermemiştir (P>0,05). Kabuk uzunluğu ile gonad ağırlığı arasında belirlenen pozitif ilişki (R² = 0,162), daha büyük bireylerin üremeye daha fazla enerji ayırdığını göstermektedir. Buna karşılık, GSI değerlerinin artan su sıcaklığı ile azaldığı belirlenmiş, bu durum üreme aktivitesinin daha çok soğuk dönemlerde yoğunlaştığını ortaya koymuştur. Sonuç olarak, özellikle su sıcaklığı olmak üzere çevresel koşulların U. delicatus'un üreme döngüsünün şekillenmesinde önemli bir rol oynadığı belirlenmiştir. Gonad gelişiminin geç kış ve erken ilkbahar döneminde en yoğun düzeye ulaştığı görülmüştür. Bu bulgular, türün üreme biyolojisinin daha iyi anlaşılmasına katkı sağlamakta ve tatlı su ekosistemlerinde yürütülecek gelecekteki koruma çalışmalarına bilimsel bir temel sunmaktadır.

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Cite This Article

Şereflişan, H., Şahin, S. K. (2026). Seasonal reproductive dynamics of the freshwater mussel Unio delicatus (Bivalvia: Unionidae) in Lake Gölbaşı, Türkiye. Marine and Life Sciences, Cilt: 8 Sayı: 1, 54–62. https://doi.org/10.51756/marlife.1941162

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