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IMIS Photogallery » Echinodermata (echinoderms) » Echinoidea (sea urchins)
Antrechinus mortenseni (ontogeny)
Antrechinus mortenseni (ontogeny)
Description Diagrammatic longitudinal section showing fertilization, growth and "birth" of juveniles: a. The sperm of the male fertilizes the egg (1,8 mm long), which has left the gonads to be deposited in one brood pouch. b.The egg grows to a short-spined juvenile (3 mm) in the expanding brood pouch. c. The original juvenile has reached the long-spined stage (4,5 mm) as new eggs are fertilized in the other pouches. d. The apical plates hinge downwards to enlarge the aperture when the juvenile leaves the pouch. It is "born". e. The young sea urchin starts his independent life, while the other eggs continue to develop. Author Schultz, Heinke JPG file - 217.13 kB - 1 980 x 988 pixels added on 2005-02-23285 viewsFrom reference Schultz, H. (2006). Sea urchins: A guide to worldwide sha... © 2005 Schultz, Heinke
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