Rodríguez, A., Hernández, J. C., Clemente, S. & Coppard, S. E. 2013. A new species of Diadema (Echinodermata: Echinoidea: Diadematidae) from the eastern Atlantic Ocean and a neotype designation of Diadema antillarum (Philippi, 1845). Zootaxa 3636, 144-170.
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Rodríguez, A.; Hernández, J. C.; Clemente, S.; Coppard, S. E.
2013
A new species of Diadema (Echinodermata: Echinoidea: Diadematidae) from the eastern Atlantic Ocean and a neotype designation of Diadema antillarum (Philippi, 1845)
Zootaxa
3636: 144-170
Publication
Available for editors
Diadema africanum sp. nov. Rodríguez et al. 2013 occurs in the eastern Atlantic Ocean at depths of 1–80 meters off Madeira
Islands, Salvage Islands, Canary Islands, Cape Verde Islands, Sâo Tome Islands and at the continental coast off Senegal
and Ghana. This species was previously considered an eastern Atlantic population of D. antillarum. Genetic distances
between the holotype of D. africanum and the neotype of D. antillarum herein designated, measured 3.34% in Cytochrome
oxidase I, 3.80% in ATPase-8 and 2.31% in ATPase-6. Such divergence is similar to that already highlighted between other
accepted species of Diadema. Morphometric analysis of test, spine and pedicellarial characters also separated D. africanum
from D. antillarum and reveals that this new species is morphologically similar to D. antillarum ascensionis from the
mid Atlantic. The tridentate pedicellariae, which have been shown to have diagnostic characters which discriminate
among species of Diadema, occur as both broad and narrow valved forms in D. antillarum from the western Atlantic. In
D. africanum the tridentate pedicellariae occur only as a single form which is characterized by moderately broad and
curved valves, with an expanded distal gripping region. This form of tridentate pedicellaria is very similar to that of D.
antillarum ascensionis from the central Atlantic, with only slight variations in valve serration and valve curvature differentiating
the two forms.