The moment of chum salmon spawning exhibited at Shibetsu Salmon Science Museum

Male and female chum salmon open their mouths and shake their bodies as they spawn

A ‘spawning behavior exhibition’ has begun in an aquarium fish tank at the Shibetsu Salmon Science Museum in the Nemuro region of eastern Hokkaido. Two pairs of fish are exhibited in the tank, and an in-house broadcast informs visitors with a ‘one-hour forecast’ when spawning approaches.

A natural spawning environment has been reproduced in the aquarium tank, into which the staff have put two pairs to exhibit. One pair spawned on the afternoon of November 4. The female salmon digs a hole called a ‘spawning bed’ in the pebbles and sand with its tail fin and when it is ready, it rests it’s belly in the hole and signals to the male by opening its mouth before laying the eggs. The male salmon locates itself beside the female, opens its mouth and shakes its body as it releases its sperm over the eggs. After the spawning has finished, the female covers the fertilized eggs with sand.

As Nishio Tomotaka, the deputy head of the museum, explains, “Females lay eggs 3 to 5 times, with approximately two hours between each time. We want visitors to see this and inform them when it is about to happen.”

The spawning behavior exhibition will continue until the museum closes at the end of November. Open time is 9:30 a.m. to 5 p.m. Closed on Wednesdays.


Shibetsu Salmon Science Museum