Hydrovatus picipennis, is a species of predaceous diving beetle found in India, Sri Lanka, Indonesia, Philippines, China and Thailand.

[1][2][3][4] Body elongated with a typical length of about 3.0 and 4.2 mm and the apex of elytra is distinct.

Penis apex is broad, which narrows abruptly to a slender tip.

In male, the ridges of stridulatory file is larger, and clearly discernible.

Male protarsal claws are not distinctly thickened.