Verrucella diadema Grasshoff, 1999

Ramvilas, Ghosh, Alderslade, Philip & Ranjeet, Kutty, 2023, The taxonomy of Indian gorgonians: an assessment of the descriptive records of gorgonians (Anthozoa: Octocorallia: Alcyonacea) recorded as occurring in the territorial waters of India, along with neighbouring regions and the Andaman and Nicobar Islands, and the highlighting of perceived unethical practice, Zootaxa 5236 (1), pp. 1-124 : 99

Verrucella diadema Grasshoff, 1999

Verrucella diadema Grasshoff, 1999: 83 , fig. 139; pl. 11, fig. 1 ( New Caledonia).

Opinion: There is not enough evidence that this species occurs in the region, and the material is probably the same as some of the other Verrucella species described by Fernando (2011) and Fernando et al. (2017).

Justification:

These Indian records seem to be either invalid or unconfirmable: Fernando, 2011: 117, pl. 76; Kumar et al. 2014a: 36, pl. 15, fig. A–D (Andaman Is.); Fernando et al. 2017: 264, pl. 123, fig. 1–1d (SE coast).

Literature analysis: The accounts given of the Indian material by Fernando (2011) and Fernando et al. (2017) are identical but provide figures only and no description. The authors refer instead to Grasshoff’s original text and state that the “dimension of the sclerites agree”, but the scale on their figures shows the sclerites are much larger, and they are also a different shape. The double heads and double spindles are broad, densely tuberculated, and have a distinct but very short waist, whereas those of the holotype are slender, sparsely tuberculated, and any waist is just a bare region between girdles of tubercles.

On the other hand, the account given by Kumar et al. (2014a) does give a description, but this piece of text “… 3 mm in diameter, the side and end branches only 0.4– 0.3 mm. The main branch is free of polyps; on thin branches the polyps are biserially arranged and slightly elevated” and (minus the measurements) “The coenenchyme are small double heads only {0.05–0.06} mm long; elongated mostly very slender sclerites of the polyps are longer, {0.05–0.08 mm}” is taken directly from Grasshoff’s paper. The colony and sclerites figured by Kumar et al. (2014a) are quite different from those presented by Fernando (2011) and Fernando et al. (2017) and represent a different species. These sclerites include spindles that, according to the text, are only a little longer than the size of the double heads, 0.05–0.08 mm compared to 0.05–0.06 mm, but those in the figure are much larger than the double heads—up to 0.14 mm long according to the scale, which are twice as long as those reported for the holotype.

The specimen used by Fernando (2011) and Fernando et al. (2017) has a bilateral polyp distribution and from the available data, and allowing for some slight differences in sclerite dimensions (where they are reported), it appears to be the same species as the material they assigned to Verrucella dichromata Fernando, 2017 , Verrucella ixoboloides Fernando, 2011 , and Verrucella pinnata Fernando, 2011 , and they may all be the same as some of the material used for their description of Verrucella umbraculum ( Ellis & Solander, 1786) . Kumar et al. (2015) just lists the species and provide the colony image from the 2014 paper above. Verrucella diadema is probably endemic to New Caledonia.