Octactis

Octactis refers to a genus of sea anemones within the family Antipatharia, commonly known as black corals. This classification, however, is considered outdated and no longer widely accepted within modern scientific taxonomy. Historically, Octactis was used to categorize certain black coral species based on specific skeletal and polyp characteristics.

The distinction that once defined Octactis primarily revolved around the arrangement and structure of the polyps and the sclerites (calcium carbonate skeletal elements) compared to other black coral genera. Particular emphasis was placed on the number and arrangement of mesenteries (internal partitions within the polyp) and the overall morphology of the coral skeleton.

The current understanding of black coral phylogeny, informed by molecular and morphological data, has largely superseded the Octactis designation. Many species formerly classified under Octactis have been reclassified into other genera within the Antipatharia order, reflecting a more accurate evolutionary understanding of these marine organisms. Modern classifications rely on a broader range of characteristics and phylogenetic analysis to determine relationships between species. Therefore, while the term Octactis may still appear in older literature, its use is generally discouraged in contemporary scientific publications.