Open Access

Reproductive cycle and the occurrence of abnormal larvae inBranchiostoma lanceolatum at Helgoland

  • W. A. M. Courtney1
Helgoländer wissenschaftliche Meeresuntersuchungen27:BF01611685

https://doi.org/10.1007/BF01611685

Summary

  1. 1.

    At Helgoland (North Sea), 56% ofBranchiostoma lanceolatum develop gonads in their third year.

     
  2. 2.

    Spawning occurs annually through sexually dimorphic descrete areas of the gonadial envelope.

     
  3. 3.

    The planktonic larvae have a maximum number of 16 gill pouches and settle after 2 1/2 months.

     
  4. 4.

    Four of the 88 larvae taken at Helgoland in 1963 had a thick notochord and an ill-defined gut. These abnormal larvae differed from each other in structural detail.

     

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