Abstract:

Although the Zoarcidae family is one of the families with the largest number of fish species in the Southern Ocean, there is currently a lack of research on this family. This study analyzed Zoarcidae samples collected from the waters near South Shetland Island during China’s 38th Antarctic Expedition. A combination of morphological examination and molecular methods were used to identify the species of the obtained samples, and the morphological characteristics of the sagittal otoliths were compared through Fourier analysis. The results showed that: (1) fish captured in the waters surrounding the Antarctic Peninsula belonged to four species from four genera, namely Ophthalmolycus amberensis, Pachycara brachycephalum, Lycenchelys nigripalatum, and Lycodichthys antarcticus. (2) The shape of the sagittal otolith in the Zoarcidae fish was mainly elliptical, with a narrow and elongated auditory sulcus extending from the anterior main sulcus to the posterior end of the otolith core. Interspecific differences were mainly reflected in the length of the main sulcus, basal lobe, and pterygoid lobe. The body length was positively correlated with the weight of the otoliths. (3) There were relatively small differences between O. amberensis and L. antarcticus. The greatest differences were between L. nigripalatum and the other three species, which was consistent with the phylogenetic tree results.

Key words: Zoarcidae, Sagittal otolith, Fourier analysis, principal component analysis, cluster analysis, Antarctic Peninsula waters