spawning Behavior of Cottid — MORRIS 
during daylight hours, at about 8:00 A.M., 
2:00 P.M., and 5:00 p.m. The time at which the 
other spawnings occurred is not known. 
Copulation was observed on two occasions. 
A different female was involved each time. 
The behavior pattern was almost identical in 
both cases. 
One of the females deposited a cluster of 
eggs at about 2:00 p.m. on March 23. These 
eggs were spawned in a groove at one end of 
the tank, against the glass of the side and 
about 6 inches above the bottom. Immediate- 
ly after spawning, the female dropped down 
to the bottom of the tank. At this time, the 
male came alongside the female and seized 
the female by the left pectoral fin as shown in 
Figure lb. It appeared that the male was trying 
to induce the female to return to the site of 
the egg cluster. The male persisted in drag- 
ging the female across the aquarium by the 
pectoral fin. After this struggle had gone on 
for perhaps 5 minutes, the female did return 
to a position over the egg cluster, clinging to 
the side and end of the tank, with head upper- 
most. The male then moved up against the 
left side of the female and held this position 
for only a moment and then turned and 
passed over the back of the female, as in 
Figure Ic. This was repeated several times, 
the female being rolled slightly to the right 
side on each occasion. On about the sixth 
such attempt, copulation was achieved while 
the male was across the female at right angles 
(Fig. id). The vigor of the male’s thrust, 
which lasted for perhaps 3 seconds, carried the 
two away from their position and into mid- 
water. Immediately thereafter, the male 
dropped to the bottom of the tank and the 
female returned to the previous position over 
the egg cluster. The female clung there for 
about 5 minutes, during which time a large 
quantity of milt poured from the region of 
the genital opening and created a dense cloud 
in the immediate vicinity. After that, the 
female too dropped down to the bottom of 
the aquarium. 
Copulation with the second female oc- 
257 
Fig. 1. Clinocottus recalvus. a. Female with ab- 
dominal protrusion, indicating readiness to spawn; 
h, position at the start of mating activities (the male in 
this and subsequent figures is represented by the darkly 
stippled individual) ; c, the male moving over the body 
of the female; d, position at copulation; e, position of 
the male after copulation. 
curred shortly after deposition of an egg 
cluster at about 8:00 A.M. on March 27. The 
behavior of the male and female was almost 
identical with that previously observed. This 
cluster of eggs was deposited in a vertical 
crack between the two stones. These stones 
gave a much better substrate to which the fish 
could cling. In consequence, they were not 
swept from the site during the copulatory 
thrust, but remained in a fixed position. After 
