Diadema G RAY 1825
Creators: name: Coppard, Simon Edward
name: Campbell, Andrew C.
Publisher: name: Zenodo
Year: 2006
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Echinoidea
Diadematoida
Diadematidae
Diadema

description: KEY TO THE SPECIES OF THE GENERA DIADEMA G RAY, 1825 AND ECHINOTHRIX P ETERS, 1853 BASED ON TEST MORPHOLOGY
1. Apical system monocyclic ........................................................................................... 2
— Apical system hemicyclic ............................................................................................ 5
2. Swollen periproctal cone with white platelets present in the membrane. Large naked median areas present down the mid-lines of the interambulacra ...................................... 3
— Small periproctal cone with no white platelets present in the membrane. Many tubercles on genital plates .......................................................................................... E. diadema
3. Triangular-shaped naked median areas on the interambulacra. Arch-shaped depressions on genital plates. Black anal ring present ..................................................... D. palmeri
— No triangular-shaped naked median on the interambulacra, no arch-shaped depressions on genital plates. No black anal ring. Green bands of iridophores present down the midlines of the interambulacra ......................................................................................... 4
4. Ambulacra prominently raised aborally. Genital plates significantly longer than wide .... .............................................................................. E. calamaris (brown colour morph)
— Ambulacra only slightly raised aborally. Genital plates not significantly longer than wide ................................................................................ E. calamaris (white colour morph)
5. Orange anal ring. Blue/green “spot” markings on genital plates ................... D. setosum
— No distinct orange anal ring. No “spot” markings on genital plates ............................ 6
6. Distinct arch-shaped depressions on the genital plates of adults (spines not banded) .... 7
— No arch-shaped depressions on the genital plates of adults (spines not banded) .......... 8
7. Test distinctly rounded pentagonal when viewed aborally. Test (in living echinoids) black with a brown tinge and only a faint pattern of blue iridophores down the mid-lines of the interambulacra ...................................................................................... D. mexicanum
— Test distinctly circular not rounded pentagonal when viewed aborally. Test (in living echinoids) distinctly black, with a bold pattern of iridophores down the mid-lines of the interambulacra ............................................................................................ D. savignyi
8. Interambulacral plates number 12-14, corresponding to fewer spines ... D. paucispinum
— Interambulacral plates number 15-16 ......................................................................... 9
9. Six series of primary tubercles on the interambulacra .............................. D. antillarum
— Four or five series of primary tubercles on the interambulacra ................. D. ascensioins
description: Published as part of Coppard, Simon Edward & Campbell, Andrew C., 2006, Taxonomic significance of test morphology in the echinoid genera Diadema Gray, 1825 and Echinothrix Peters, 1853 (Echinodermata), pp. 93-112 in Zoosystema 28 (1) on page 96, DOI: 10.5281/zenodo.5401706