Pourtalesia miranda (ontogeny of apical system)
Description Development of the apical system during ontogeny. a. The apical plates are continous. There is a single anterior genital plate with a single hydropore. b. The posterior part of the apical system, G1 and G4, plus ocular plates OI and OV, shifted to the posterior and become separated from the anterior part, containing OIII, G2/G3 and OII + OIV. c. The posterior ocular plates become disrupted from the posterior genital plates and from each other. d. The ocular plates OII and OIV turn out to bear the third and fourth gonopore. The triply disjunct apical system distinguishes Pourtalesia from Echinosigra, in which it is only once interrupted. Ocular plates bluish, genital plates reddish, interambulacra grey. The borders of the growth zones are indicated by solid blcak lines, pp = periproct.
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added on 2009-02-23120 viewsWoRMS taxaScan of drawing Pourtalesia miranda A. Agassiz, 1869checked Kroh, Andreas 2021-02-24From reference Schultz, H. (2009). Sea urchins II: Worldwide irregular d...
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© 2009 Schultz, Heinke