These micrographs illustrate interesting features of cleavage stages in the local sand dollar, Dendraster excentricus. Please note: images on this page belong to George von Dassow. You are welcome to use them in your own presentations/lectures as long as you provide an appropriate credit, but please do not use them otherwise without consulting him. All were taken using a 20x multi-immersion lens, mild DIC shading, and QImaging's MicroPublisher camera.
If you prefer, you may download a montage of the entire set, ordered by developmental age, in the following sizes:
The thumbnail images below link to expanded images that will open in a new window, 600 x 700 pixels [approx. 40 KB].
01-oocyte
(George von Dassow)
02-unfertilized
(George von Dassow)
03-fertmembrane1
(George von Dassow)
04-fertmembrane2
(George von Dassow)
05-fertmembrane3
(George von Dassow)
06-zygote
(George von Dassow)
07-spermaster
(George von Dassow)
08-pronuclei
(George von Dassow)
09-streak
(George von Dassow)
10-1stmetaphase
(George von Dassow)
11-1stanaphase1
(George von Dassow)
12-1stanaphase2
(George von Dassow)
13-1stcleavage1
(George von Dassow)
14-1stcleavage2
(George von Dassow)
15-1stcleavage3
(George von Dassow)
16-2cell1
(George von Dassow)
17-2cell2
(George von Dassow)
18-2ndanaphase
(George von Dassow)
19-2ndcleavage
(George von Dassow)
20-4cell1
(George von Dassow)
21-4cell2
(George von Dassow)
22-3rdcleavage
(George von Dassow)
23-8cell
(George von Dassow)
24-4thcleavage1
(George von Dassow)
25-4thcleavage2
(George von Dassow)
26-16cell
(George von Dassow)
27-micromeres
(George von Dassow)
28-32cell1
(George von Dassow)
29-32cell2
(George von Dassow)
30-morula1
(George von Dassow)
31-morula2
(George von Dassow)
32-earlyblastula1
(George von Dassow)
33-earlyblastula2
(George von Dassow)
34-blastula1
(George von Dassow)
35-blastula2
(George von Dassow)