Genetic homogeneity detectable in the sedentary moray eel Gymnothorax minor based on mitochondrial DNA analysis

Abstract

On the basis of traditional morphological classification, Gymnothorax minor has been misidentified as Gymnothorax reticularis in China. Because of the special ecological habits and aggressiveness of this species, little research has been performed on its population genetics. Given the general decline in offshore fishery resources, it is necessary to study the genetic characteristics of G. minor in order to protect this resource. In the present study, six different geographical populations of G. minor were collected from their distribution areas in China, and their genetic signatures were investigated for the first time based on the control region fragments. The results showed that G. minor had a very high degree of genetic diversity, and there was no genetic differentiation between these populations. However, the genetic analysis failed to reject panmixia among geographic populations of this species. The life-history characteristics of G. minor and the heterogeneity of its habitat promote the rapid growth of its populations, resulting in gene mutation accumulation and rich genetic diversity. G. minor experienced a population expansion event during the late Pleistocene, which shaped its various genetic signatures. The prolonged pelagic larval duration (PLD) of this species ensures that its leptocephali effectively avoid various physical obstacles and have the opportunity to follow ocean currents to various coastal areas of China. Finally, this moray eel exchanges genetic material with recruitment populations from other locations. All the current genetic signature results for G. minor will serve as a reference for genetic research on moray eels with similar life-history characteristics.