Breeding behaviour, egg surface morphology and embryonic development in four Australian species of the genus Pseudomugil (Pisces : Melanotaeniidae)

Abstract

Spawning behaviour in P. tenellus, P. gertrudae, P, signifer and P. mellis was similar under controlled laboratory conditions. Spawning occurred mainly in the summer months, except in P. gertrudae.

The rate of embryonic development varied from 10-12 days in P. tenellus to 14-19 days in P. signifer. The four Pseudomugil species in this study fall into two groups based on their geographic distribution, the place chosen for spawning, the size of the eggs and their surface morphology. P. tenellus and P. gertrudae had tufted, long chorionic filaments (15-20 mm) while P. signifer and P. mellis had dispersed short chorionic filaments (5.5-13.0 mm).

The genus Pseudomugil differs from Melanotaenia in number and size of eggs spawned and their incubation time. These differences support recent work suggesting that the genus Pseudomugil be placed outside the family Melanotaeniidae.