Pennella balaenoptera Koren & Danielssen, 1877 (Crustacea, Siphonostomatoida, Pennellidae) is so far known as the largest copepod species and has only been found as a parasite on marine mammals. Previous studies on parasitic copepods in China only focused on those found on economic fishes, no records of P. balaenoptera having ever been reported before.
A Bryde's whale (Balaenoptera edeni Anderson, 1879) and a pygmy sperm whale [Kogia breviceps (Blainville, 1838)] were respectively stranded on the eastern and southern coast of China in 2021 and 2022. A total of eight parasitic copepods found on their body surface were sampled and examined. The parasites were identified as Pennella balaenoptera, based on morphological characteristics and measurements. Descriptions and photomicrographs of this newly-recorded species from China are given in the present study.