Acanthogorgia

Preliminary remarks: Like a number of other groups, species of Acanthogorgia and the related genera Anthogorgia and Muricella are extremely difficult to identify, and many experienced researchers avoid working on them at all. To attempt to bring some order to Acanthogorgia, species have been divided into groups based on polyp morphology, but the groups overlap and taxonomist are constantly presented with frustrating problems when working on these animals. As Grasshoff (1999: 20) stated, “ Species within these groups are very similar and their differentiation is unclear. Facts are puzzling, e. g., two species on the reef may be clearly distinct by growth form and color in life, but their polyp structures and sclerites are so similar that a distinction alone by these characters would be impossible and even doubts could arize about the growth forms, as they could be taken for a mere variation within the species. Under these circumstances, it is quite unclear what the small differences between the New Caledonian species and others mean. ” The problem is magnified by the variation between polyps of different sizes, the low number of sclerite images figured in most descriptions, and the general poor quality of those images. The result is that very few descriptions approach the quality needed. There are more than 50 nominal species and adequate descriptions of the holotypes are exceedingly rare. But when taking into account Grasshoff’s comments on colonies that might look different in the wild, but “ their polyp structures and sclerites are so similar that a distinction alone by these characters would be impossible ”, there would still be huge problems even if good holotype descriptions were common. Basing identifications on the literature as it is at the moment is probably unlikely to produce a correct result unless the species possesses some highly distinctive traits. Given the current state of the taxonomy of this group it may be possible to tell if an Indian record is invalid, but not if it is valid.