Hydrophilidae
Hydrophilidae, the water scavenger beetles, are a family of aquatic beetles in the order Coleoptera, superfamily Hydrophiloidea. They include about 2,000 described species in many genera and are found worldwide, especially in warm temperate to tropical regions. Adults are typically oval or elongated; the dorsum is smooth and often dark. The head is often tucked under the thorax. Antennae are short and clubbed; maxillary palps are long and conspicuous, sometimes extending beyond the head. Hind legs are flattened for swimming.
They inhabit still or slow-moving freshwater, including ponds, marshes, and ditches. Diet is variable: detritus, decaying
Hydrophilidae belong to Hydrophiloidea and include several subfamilies, such as Hydrophilinae and Sphaeridiinae. They are cosmopolitan