egg mass in the mouth cavity. During the next several months spawning
occurred at regular intervals. A record for several of these is shown in
Table 2. The same individual, 35.6 mm standard length, orally incubated the
eggs in every case. Subsequent preservation of this fish and examination
of the gonads revealed it to be a male. The egg mass which it was incubating
contained 216 spherical eggs approximately one mm in diameter.
In spite of intensive observation, the actual spawning was never seen.
Perhaps it occurs during the night. When they first appear in the male's oral
cavity, the eggs are semi-transparent, slightly milky in colour. Several days
later they become more transparent as the eyes of the embryo begin to
develop.
During incubation the male swims out in the open and behaves more or
less normally except it does not appear to feed. No obvious behavioural
interactions were observed between the male parent and the other fishes in
the tank, including the two Assessor. The incubation period generally lasts
for 15-16 days. Several days prior to hatching the male's mouth is continually
held open and the eggs are shifted back and forth at intervals
ranging between two to eight minutes.
Hatching was not witnessed. Evidently it takes place at night as the fry
were usually discovered in the early morning. The larvae, which swim close
to the surface, are mostly transparent and four to five mm in total length.
Unfortunately they did not live more than a few hours.