| 摘要 |
PROBLEM TO BE SOLVED: To make accurately measurable the fish length and number of living fishes one by one by projecting the top end of a waterway diameter adjusting means to a part of a waterway to reduce the waterway diameter and expand the waterway due to the slide action of the top end thereof on the fish body. SOLUTION: A vacuum pump 12 is actuated to form a waterway in a hollow body 1, a pump 19 generates a water flow from a hose 1A to a fish preserve A, a moving member floats up, and the fish swims to enter the hose 1A and passes through it. If the fish body outer diameter is larger than the waterway inner diameter of the waterway diameter adjusting means 3 at its top end, the waterway is expanded to allow the fish to pass through owing to the sliding action of the fish on the top end of the waterway diameter adjusting means 3. If the fish body is smaller than the waterway inner diameter, the fish passes through as it is. Thus, the front and rear spaces are ensured intermittently in the waterway for every fish, and the fish runs in a measuring chamber 4. A CCD camera 14 detects the fishes one by one. The detect signal is sent to an image processor 15 which converts the signal to a fish body length and counts it as one fish.
|
