Significant interspecies differences were established in activities of aminotransferases, alanine aminotransferase (ALT, EC 2.6.1.2) and aspartate aminotransferase (AST, EC 2.6.1.1), and alkaline phosphatase (ALP, EC 3.1.3.1) in the gonads of seven Black Sea fish species during spawning and non-spawning seasons. In most species, ALT and AST activities were higher in the non-spawning phase compared to the spawning one, while ALP activity demonstrated an opposite trend. The peak enzymatic activities were found in the gonads of the whiting, probably due to its spawning in the winter season. No significant differences were revealed between the test parameters in animals of different ecological groups. ALT, AST and ALP activities in fish gonads can be used as convenient and efficient markers to explore both the peculiarities of the gonadogenesis at different stages of the reproductive cycle and the ability of different fish species to adapt to unfavorable environments, including those caused by anthropogenic pollution.

中文翻译：

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黑海鱼性腺中某些酶活性的种间特性

七个黑海性腺中转氨酶、丙氨酸转氨酶（ALT，EC 2.6.1.2）和天冬氨酸转氨酶（AST，EC 2.6.1.1）和碱性磷酸酶（ALP，EC 3.1.3.1）的活性存在显着的种间差异产卵和非产卵季节的鱼类。在大多数物种中，与产卵阶段相比，非产卵阶段的 ALT 和 AST 活性更高，而 ALP 活性则表现出相反的趋势。在鳕鱼的性腺中发现了最高的酶活性，这可能是由于它在冬季产卵。不同生态组动物的试验参数无显着差异。ALT,