First description of karyotypes and localization of ribosomal genes in two sand lances (Uranoscopiformes: Ammodytidae); small sand-eel (Ammodytes tobianus Linnaeus, 1758) and great sand-eel (Hyperoplus lanceolatus Le Sauvage, 1824)

摘要

The sand lances (also known as sand-eels) are small fish belonging to family Ammodytidae that consists of 31 species belonging to 7 genera. Despite world-wide distribution, key role in the ecosystems and significant commercial importance, sand lances have rarely been objects of the cytogenetic studies. The chromosomes of small sand-eel (Ammodytes tobianus) and great sand-eel (Hyperoplus lanceolatus) were analysed for this study. Karyotypes of both species were composed of 48 acrocentric chromosomes (FN = 48). Chromosomes of the great sand-eel were stained equally with DAPI. However, small sand-eels exhibited one pair of chromosomes with DAPI-negative blocks of chromatin located on the q-arm in the vicinity of the centromeric regions. Major and minor rDNA sites were observed on the separate single chromosome pairs in both species. These results provide new data regarding the genetics of Ammodytidae, showing an ancestral teleostean type of karyotype, based on the number of chromosomes (48), their morphology (FN = 48) and the distribution of rDNA sequences.