The First Chromosomal Characteristics of Nucleolar Organizer Regions and Karyological Analysis of Pink Anemonefish, Amphiprion perideraion (Perciformes, Amphiprioninae)

Abstract

This study examined for the first time the chromosomal characteristics of nucleolar organizer regions (NORs) and karyological analysis of the pink anemonefish, Amphiprion perideraion (Bleeker 1955) from the Andaman Sea, Phuket Province, Thailand. Kidney cell samples were taken from five male and five female fish. Mitotic chromosome preparations were conducted using a standard squash technique as well as taken directly from kidney cells. Metaphase spreads were performed on microscopic slides and then air-dried. Conventional and Ag-NOR banding techniques were applied to stain the chromosomes. The results showed that the diploid chromosome number of A. perideraion was 2n=48, and the fundamental number (NF) was 94 in both males and females. Karyotpes were present as 2 large metacentric, 18 large submetacentric, 8 large acrocentric, 10 medium metacentric, 6 medium submetacentric, 2 medium acrocentric and 2 medium telocentric chromosomes. No irregularly sized chromosomes related to sex were observed. The results indicated that the short arm of the large acrocentric chromosome pair No. 19 showed clearly observable NORs. The karyotype formula for A. perideraion is as follows:
2n(diploid)48=L₂^m+L₁₈^sm+L₈^a+M₁₀^m+M₆^sm+M₂^a+M₂^t