Figure 1.
Collection localities for Diadema samples in Japan.
A, Arasaki, Sagami Bay; B, Waka, Iki Island; C, Sesoko, Okinawa Island; D, Fukai, Ishigaki Island.
Table 1.
Diadema sample collection data for mtDNA COI analyses.
Figure 2.
Neighbor-joining phylogenetic tree from COI sequence data.
Bootstrap support (>50%) after 1,000 replications is shown at each node. See Table 1 for species designations.
Figure 3.
Underwater images of Diadema setosum.
A to F correspond to DST1 to 6 (see Table 1). Note conspicuous white spots on the median naked interambulacral areas, and light colored periproctal cone with orange or red ring.
Figure 4.
Underwater images of Diadema savignyi.
A to F correspond to DSV19, 21, 23 to 26 (see Table 1). Note the central axis of the Y-shaped blue lines of iridophores along the median naked interambulacral area was approximately twice as long as the V-component, and comprised of two parallel lines.
Figure 5.
Underwater images of Diadema-sp.
A to F correspond to DSV1 to 3, and 12 to 14 (see Table 1). Note the central axis of the Y-shaped blue lines of iridophores along the median naked interambulacral area which was represented by a single line, and similar in length to the V-component. Projection of periproctal cone was observed in one individual (C), but brown in color and an orange ring was not observed. The Y-shaped blue lines of iridophore were usually accompanied by a conspicuous white streak at the fork region (A to C, F), while individuals exhibiting a Y-shaped blue broken line (E) and the absence of a white streak (D, E) were rarely observed.
Figure 6.
Primary tubercle arrangements on the interambulacral areas (bar = 5 mm).
A, Diadema-sp.; B, Diadema savignyi; C, Diadema setosum. Outer and inner series of primary tubercles in Diadema-sp. were initiated on the 3rd (rarely 2nd or 4th) and 6th (rarely 5th) coronal plates, respectively (A). Those in D. savignyi began on the 3rd (rarely 2nd or 4th) and 6th (B); and in D. setosum, on the 3rd or 4th (rarely 5th) and 7th or 8th (rarely 6th) coronal plates (C).