Quasipaa spinosa is a species of frog in the family Dicroglossidae. It is known under many common names, including Chinese spiny frog, giant spiny frog, Chinese edible frog, and spiny paa frog. Its names refer to the distinctive characteristics of the species, relatively large size and the spiny chest of male frogs. Giant in frog terms only, it can nevertheless grow to lengths above ; this makes it the largest frog in Hong Kong. Taxonomy Recent molecular phylogenetic analyses have suggested that Quasipaa spinosa is split in three distinct lineages; the nominal Quasipaa spinosa may thus represent a cryptic species complex. The lineages are geographically distinct; one lineage is found in Yunnan, another one in southeastern China (Anhui, Zhejiang, northern Fujian, and Jiangxi), and the third one in south-central China (southern Fujian, Jiangxi, Hunan, Guangdong, and Guangxi). In this analysis, Quasipaa exilispinosa is nested within Quasipaa spinosa. It's sibling species is Quasipaa acanthophora from Vietnam. The complete mitochondrial genome (18,012 base pairs in length) of Quasipaa spinosa has been sequenced, helping to shed light into the phylogeny of Quasipaa and related frogs. Distribution and habitat It is found in China south of the Yangtze River, including Hong Kong. It is expected to be found in Vietnam, Laos, and Myanmar. No certain records exist from Vietnam, earlier records may refer to Quasipaa acanthophora described in 2009 as a new species from that country. It may also have been mixed with Quasipaa verrucospinosa and Nanorana yunnanensis. Quasipaa spinosa is associated with rocky streams in evergreen forests and open countryside on hills and mountains. Its altitude range is about above sea level. Description and life cycle The most distinctive characteristic of Quasipaa spinosa are the keratinized skin spines in the chest of males. It is dark brown in colour, interspersed with dense, yellowish mottling. Quasipaa spinosa are moderately large frogs: males grow to a snout–vent length of about and females to or more, up to in snout–vent length. It is the largest frog in Hong Kong. Later studies has shown that usually males are larger than females, but with considerable overlap between sexes. Body size is positively correlated with maximum temperature and rainfall. Mean body weight among males may reach at least . Quasipaa spinosa breeds in streams, laying the eggs in water under stones. Reproduction takes place in April–October. Male frogs call near slow-flowing sections of streams or around pools adjacent to