Is it them?
Hemiramphidae ? Hemiramphus ? Fish
The picture below shows ? Kyushu Hemiramphus Hemiramphus kurumeus, distributed in the middle and lower reaches of the Yangtze River and its subsidiary lakes.
The body is silver-white, with a gray-black stripe on the back from the back of the head to the caudal fin, and small, neatly arranged black spots on both sides. There is a silver-white band of spots in the middle of the side of the body, wider between the dorsal and anal fins; the dorsal and caudal fins are gray-black, all other fins are yellow-white, and the upper and lower jaws and gill covers are gray-black.
The head is large, laterally compressed, broad and flat on the dorsal surface, and narrow on the ventral surface. The mouth is large, with a flat slit. The upper jaw forms a triangular mouth cover from the intermaxillary bones; the lower jaw extends forward exceptionally long and needle-like; the upper and lower jaws have multiple rows of sharp denticles on opposite parts. Nostrils large, near eyes; eyes large. Gill-membranes separate, not connected with the isthmus. Body scales thin, very easily removed; head and upper jaw scaly. Lateral line complete, curving sharply downward at the pectoral fins and along the ventral margin to the base of the caudal peduncle. Dorsal fin located in the posterior half of the body, about opposite the anal fin; caudal fin forked, with the lower lobe larger than the upper; all fins without hard spines.
The Kyushu Hemiptera lives in the upper layer of rivers and lakes, often swimming in groups on the surface of the water to feed, taking zooplankton as its main food, and also eating insects and so on. Reproductive period in May-June individual is not large, but the number is quite large, is a common small edible fish.