The following taxon apparently lies within the circumscription of Gracilaria canaliculata but has not yet been transferred or reduced to synonymy:
Gracilaria crassa Harvey ex J. Agardh forma conglomerata Børgesen, 1952: 34–35, figs. 17, 18 (type locality: Mahébourg, Mauritius).—Isaac & Chamberlain, 1958: 149–150, fig. 20.— Day, 1974: 85 (`glomerata').— Barratt et al., 1984: species list.
INDIAN OCEAN DISTRIBUTION: Mauritius, Mozambique, Oman.