Development of swimming behavior in sea urchin embryos. I.

✍ Scribed by Maruyama, Yoshihiko K.

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: English
• Weight: 657 KB
• Volume: 215
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402150205

✦ Synopsis

Abstract

Development of behavior in sea urchin embryos and larvae was studied with special attention to rotation on the animal‐vegetal axis. Within the fertilization membrane, each embryo rotated either clockwise or counterclockwise on the animal‐vegetal axis and the direction of rotation (= spin) sometimes reversed in the same embryo. However, the symmetric pattern of spinning motion in prehatching embryos was lost liberation of embryos from the fertilization membrane. Embryos hatching out with counterclockwise spin (as viewed from the vegetal region) maintained the same direction of spin even after hatching, whereas embryos with clockwise spin reversed the direction of spin through a characteristic transient swimming pattern. Eventually, all embryos swam with the animal pole forward and rotated counterclockwise on the animal‐vegetal axis. A developmental change of swimming behavior, first appearing at the pluteus stage, is a transient reversal of swimming direction. The direction of rotation during this backward swimming was invariably “counterclockwise” as in the case of forward swimming, if the larva was viewed from the rear with respect to the swimming direction.