Keratoisis Wright 1869

Keratoisis Wright, 1869

Diagnosis (modified from Dueñas et al., 2014: 6). Colonies may be unbranched or more commonly branch from the internodes. The internodes are white, and can be smooth to regularly grooved externally, and hollow or solid in the older parts of the colony. The polyp body generally has eight longitudinal rows of spindles or needles that follow the alignment of the mesenteries; the distalmost needles usually project beyond the bases of the tentacles. Smaller sclerites, non-aligned, can be arranged longitudinally or obliquely on the polyp body. Coenenchyme sclerites can be present or absent.

Type species. Keratoisis grayi Wright, 1869

Remarks. The spelling of Keratoisis was changed to Ceratoisis by Verrill (1883) based on his transliteration from Greek. Ceratoisis was then used until Bayer (1956) reverted to the original. The genus currently includes 26 species (Cordeiro et al. 2022), with a wide range of morphologies. Consequently, determining consistent and robust diagnostic morphological characters for this genus is problematic and suggests revision is needed. Species attributed to the genus Keratoisis are spread throughout the cladogram of Watling et al. (2022), but the type species for the genus, K. grayi, is nested within clade D2. Based on morphological analyses and supported by genetic evidence, two new species of Keratoisis were discovered in the Tasmanian material examined in this study (Fig. 2). A previously known species, K. magnifica, is not genetically related to the type species of Keratoisis, therefore a new genus is erected below to encompass that species and a mis-identified species of Lepidisis by Grant (1976).