カエルウオSalarias enosimaeの産卵習性

抄録

Salarias enosimae JORDAN et SNYDER is found in the rocky tide-pool near high water mark in Southern Japan to Ryukyu Islands.
The spawing season at Nobeoka City, Miyazaki Prefecture, extended from late June to early September in 1953.
The eggs are deposited in a single layer on the under surface of flat stones, or inner wall of the crevices of the pool. The male parent fish guarded the eggs.
The behavior of the guarding male is shown in the figure III.
Usually he puts out his head from the crevice as the figure III, (8). Sometimes he goes out for feeding in the pool.
When he comes back to the crevice to guard his eggs he acts as is shown in the succeeding figures of the figure III. As he returns near the crevice he stops for a moment (1); then advances to just before the entrance of the crevice (2); turns his body (3); enters from his tail (4); sends water in the crevice by fanning his tail (5); he sends water to the mouth of the crevice by the motion of pectoral fins (6); then his body disappears in the crevice (7); soon after he puts out his head again from the crevice (8).
After the succeeding motions from (4) to (8) are repeated several times, he goes out again for feeding.
The number of the spawned eggs in one mass varies from 5, 500 to 40, 000 (table 2), containing egg groups of different developmental stages, showing that the spawning was induced several times by the same male.
The egg is colourless, somewhat flattened sphere in shape, measuring 0.79-0.88 mm. in diameter with a single large oil-globule measureing 0.25 - 0.29 mm. in diameter, accompanied by several smaller globules, and firmly attaches to the rock wall.
The hatching takes place in a week at the water temperature 24.8-31.2°C.
Newly hatching larva is 3.5-3.7mm, in total length, with large fan-like pectoral fins marginally pigmented with black blotches.