. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTIVE BEHAVIOR OF LEPTASTERIAS POLARIS. Figure 9. Lcplastcrias polaris. Photographic sequence showing the principal steps of development from fertilization to young starfish (4X); see Table I for corresponding age and size of the embryos. (A) Fertilized eggs with fertilization membrane completely elevated (arrows). (B) 4-cell stage. (C) 8-cell stage. (D) Wrinkled- blastula stage on which it is possible to observe the furrows (arrows). (E) Early brachiolaria stage (newly hatched) showing early shaping of brachiolar arm
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTIVE BEHAVIOR OF LEPTASTERIAS POLARIS. Figure 9. Lcplastcrias polaris. Photographic sequence showing the principal steps of development from fertilization to young starfish (4X); see Table I for corresponding age and size of the embryos. (A) Fertilized eggs with fertilization membrane completely elevated (arrows). (B) 4-cell stage. (C) 8-cell stage. (D) Wrinkled- blastula stage on which it is possible to observe the furrows (arrows). (E) Early brachiolaria stage (newly hatched) showing early shaping of brachiolar arms (ba) and the persistent blastopore (arrow). (F) Growth of the three brachiolar arms (ba). (G) Fully developed brachiolarian embryo with the larval body (Ib) and the slightly ramified brachiolar arms (ba). (H) Metamorphosing embryo with brachiolar arms (ba), showing the development of the first five hydrocoelic lobes (hi). (I) Further metamorphosed embryo with two pairs of ambulacral podia (p) and a terminal tentacle (t) on each of the five arms. The six hydrocoelic lobes are transforming into the radial canals (re). A distinct oral disk (od) and the residual brachiolar arms (ba) with central fixing disk (f) are visible. (J) Aboral view of a free-moving, six-rayed young starfish showing clearly visible dorsal spines (ds), madreporite (m), and regressing preoral lobe (pi). (K) Aboral view of a small starfish showing the well-developed terminal spines (ts). (L) Oral view of a small starfish ready to leave the brood. The buccal cavity (be) has opened and the stomach (s) is visible surrounded by the ring canal (ri). We can also see the amhulacral podia (p). the well-developed radial canals (re), and the ocelli (o).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass.
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
