Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Formation of the Multiple-Layered Fertilization Envelope in the Embryo of Calanus sinicus Brodsky (Copepoda: Calanoida)

Euichi Hirose, Hideshige Toda, Yasunori Saito and Hiroshi Watanabe
Journal of Crustacean Biology
Vol. 12, No. 2 (May, 1992), pp. 186-192
Published by: Brill on behalf of The Crustacean Society
DOI: 10.2307/1549073
Stable URL: http://www.jstor.org/stable/1549073
Page Count: 7
  • Read Online (Free)
  • Download ($34.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Formation of the Multiple-Layered Fertilization Envelope in the Embryo of Calanus sinicus Brodsky (Copepoda: Calanoida)
Preview not available

Abstract

In Calanus sinicus, a multiple-layered fertilization envelope is formed from materials sequentially released from the embryo after spawning and fertilization. The mature oocyte in the ovary does not have any envelopes, and contains spherical granules and yolk bodies in the cytoplasm. Just after spawning, a thin dense layer (L1) separates from the cell membrane of the fertilized egg. Then dense materials are released into the perivitelline space and form a flocculent matrix (L2). Before the first cleavage, spherical granules begin to be released, and form a dense layer (L3) and a thick striated layer (L4). Furthermore, an embryonic envelope (L5) appears during early cleavage stages. The layer 5 is composed of electron-dense and pale layers arranged alternately. Eventually, the fully developed envelope complex is made up of 5 layers. These 5 layers are in contact with each other. The cell surface of the embryo is extremely electron dense. Layers 1 and 2 together form foldlike processes (blisters) on the surface of the envelope.

Page Thumbnails

  • Thumbnail: Page 
186
    186
  • Thumbnail: Page 
187
    187
  • Thumbnail: Page 
188
    188
  • Thumbnail: Page 
189
    189
  • Thumbnail: Page 
190
    190
  • Thumbnail: Page 
191
    191
  • Thumbnail: Page 
192
    192