On the Biology of the Caprellidae. Growth and moulting of Pseudoprotella phasma Montagu

Abstract

The process of moulting in Pseudoprotella phasma is described. Sixteen instars have been found with a discontinuity in growth at the third stage. The instar lengths differ by a common ratio of 1·169 in the male and 1·148 in the female, the animals becoming differentiated at the twelfth stage. There are no secondary sexual characteristics except the brood pouch. The growing parts display simple positive allometry. The growth rates of the chelae and antennae alter after stage XII but remain the same in the third body segment. Changes in shape in the chelae, antennae and spinous armature are described.