Investigation of metric and meristic characteristics of Mastacembelus mastacembelus (Banks & Solander, 1794) species distributed in Atatürk dam lake

In this study, morphometric and meristic features of Spiny Eel, Mastacembelus mastacembelus (Banks & Solander, 1794) in Atatürk Dam Lake has been investigated. 2020-2022, field studies of the spiny eel, M. mastacembelus, were carried out at 14 different stations determined in Atatürk Dam Lake, the largest dam of our Türkiye, which ranks sixth in the world in terms of body volume located in the Southeastern Anatolia Region of Türkiye. A total of 47 individuals (37 ♀♀, 10 ♂♂) of M. mastacembelus, which is categorized as Least Concern (LC) according to IUCN's red list criteria, were captured during field studies in all seasons. The specimens were examined metrically and meristically by taking their gonads, sex determination and measurements of some taxonomic characters. As a result of the examinations, gonad weight was found to be minimum 0.3g and maximum 0.13g; dorsal length was found to be minimum 28 cm and maximum 37 cm. In addition, the maximum total length was 63.2 cm in a female individual, while the highest standard length was 60 cm in a female individual. Significant weight differences were observed between males and females of the spiny eels collected in the study area. Almost half of the females (43.75%) weighed 300-400 g, while more than half of the males (65%) weighed 200-400 g. However, no significant correlation could be established between the metric-meristic values of the samples in terms of other characters. These data will contribute to the existing knowledge about M. mastacembelus and will contribute to the development of more active and comprehensive conservation programs and to increase alternative crop cultivation in Atatürk Dam Lake, where food production from aquatic ecosystems is considered one of the most important resources.