Japanese name: Kamatsuka

Scientific name: Pseudogobio esocinus esocinus

Description: These are distinctive fish, with faces that look to me like a dog's, with big eyes and long muzzle-like mouths bearing two fleshy barbules. They are also handsome little fish too, with bands of alternately dark- and light-brown speckled pigment. They are small (not growing longer than 7 cm for males, 10 cm for females) but tough fish, with a slightly flattened belly.

Where to find them: In fast-flowing water, sometimes very fast flowing, from Hokkaido to Kyushu. Pike gudgeons like rivers and streams with gravel or sandy beds, but they can also be found in rivers and canals with muddy beds, and sometimes in lakes and ponds.

Food: The mouth is hidden under that long muzzle, and that's a clue to what they eat, or at least how they search for their food. Pike gudgeons root around in stones and sand for invertebrates, insects, insect larvae, worms and crustaceans such as freshwater shrimp. Fishermen know they bite confidently on worms on the hook.

Special features: Pike gudgeon punch above their weight. They might be small, but they are tough, aggressive and strong. Perhaps that's where the name "pike" comes from, in reference to the formidable river fish. On the other hand, they are more likely to be called pike gudgeon because anglers use them as live bait to catch pike. The fish live only for 4 or 5 years if they are not eaten by a larger fish, or speared by a bird. Depending on where they live in the country, pike gudgeon spawn from late April to early August, when the water temperature reaches 14 degrees. Females caught at this time may be observed with bellies bulging with eggs. Most spawn in May and June of their second year. Pike gudgeon often form shoals, and are highly adaptable fish, tolerating disturbances better than many others. Their eggs, too, can hatch well at a wider range of water temperatures than the eggs of most other fish. The barbels at the mouth are sensory organs, helping to detect movements in the water caused by potential prey — so leaving the eyes free to worry about predators.