144      Accepted by M. Eleaume: 23 Jan. 2013; published: 3 Apr. 2013
ZOOTAXA
ISSN 1175-5326  (print edition)
ISSN 1175-5334 (online edition)Copyright ? 2013 Magnolia Press
Zootaxa 3636 (1): 144?170  
www.mapress.com/zootaxa/ Article
http://dx.doi.org/10.11646/zootaxa.3636.1.6
http://zoobank.org/urn:lsid:zoobank.org:pub:FF3A24CC-6545-4B77-83C5-2503143E7F16
A new species of Diadema (Echinodermata: Echinoidea: Diadematidae) 
from the eastern Atlantic Ocean and a neotype designation of 
Diadema antillarum (Philippi, 1845) 
ADRIANA RODR?GUEZ1,3, JOS? CARLOS HERN?NDEZ1, SABRINA CLEMENTE1 
& SIMON EDWARD COPPARD2
1Biodiversidad, Ecolog?a Marina y Conservaci?n (BIOECOMAC). Departamento de Biolog?a Animal. Facultad de Biolog?a, 
Universidad de La Laguna, Avenida Astrof?sico Francisco S?nchez sn, La Laguna 38206. Spain 
2Smithsonian Tropical Research Institute, Post Box 0843-03092, Balboa, Ancon, Republic of Panama 
3Corresponding author. E-mail:adrianar@ull.es
Abstract
Diadema africanum sp. nov. Rodr?guez et al. 2013 occurs in the eastern Atlantic Ocean at depths of 1?80 meters off Ma-
deira Islands, Salvage Islands, Canary Islands, Cape Verde Islands, S?o Tome Islands and at the continental coast off Sen-
egal 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. africa-
num 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 differ-
entiating the two forms. 
Key words: Diadematidae, Diadema antillarum, Diadema africanum sp. nov. eastern Atlantic Ocean, test, spines, pedi-
cellariae, taxonomy
Resumen
Di. africanum sp. nov. Rodr?guez et al. 2013 se encuentra en el noreste del Oc?ano Atl?ntico a 1?80 metros de 
profundidad en las islas de Madeira, Salvajes, Canarias, Cabo Verde y S?o Tome y en la plataforma continental de Senegal 
y Ghana. Esta especie fue previamente considerada como una poblaci?n del Atl?ntico oriental de Diadema antillarum. La 
distancia gen?tica entre el holotipo de Diadema africanum y el neotipo de Diadema aff. antillarum aqu? designadas, 
midieron 3.34% en Citocromo oxidasa I, 3.80% en ATPasa-8 y un 2.31% en ATPasa-6. Estas divergencias son similares 
a las ya encontradas entre otras especies  aceptadas de Diadema. El an?lisis de los caracteres morfom?tricos del caparaz?n, 
p?as y pedicelarios separa D. africanum de D. antillarum e indica que esta nueva especie se encuentra muy pr?xima a D. 
antillarum ascensionis del Alt?ntico medio. Los pedicelarios tridentados, usados normalmente como car?cter diagn?stico 
discriminante entre especies de Diadema se encuentran s?lo en una forma en D. africanum los cuales se caracterizan por 
tener unas valvas moderadamente anchas y valvas curvadas, con una amplia regi?n distal de agarre. Esta forma de 
pedicelario tridentado es muy similar al de Diadema antillarum ascensionis del Atl?ntico central, con solo ligeras 
variaciones en el aserramiento de las valvas y la curvatura de las mismas que diferencian las dos formas.