This study describes two new species of freshwater crab of the genus Heterochelamon Türkay & Dai, 1997 from southern China, H. huidongense from Guangdong Province and H. jinxiuense from Guangxi Zhuang Autonomous Region. The two new species can be differentiated from congeners by characters derived from the shape of the epibranchial tooth, external orbital angle, cheliped proportions and structure of the male first gonopod. The present study brings the number of Heterochelamon species to seven. We used the mitochondrial 16S rRNA gene for a molecular analysis and the results are consistent with the morphological features that support the recognition of two new taxa.

The small-sized genus Haroldius Boucomont, 1914 consists of 38 known species widely distributed in the Old World including South Asia, Southeast Asia and West Africa (Pereira 1954; Krikken & Huijbregts 2006; Král & Hájek 2012). Members of this genus are probably saprophagous or mycophagous (Scheuern 1995) and so far were collected by light traps, sifted from leaf litter or soil and captured by flight interception traps (Paulian 1939; Paulian & Scheuern 1994; Krikken & Huijbregts 2006). Some researches suggested that they could have precise ecological relationship with ants. Their myrmecophily habit was indicated mainly by the special morphological characters including smooth body and the characteristically broad­ened and flattened tibiae (Pereira 1954; Krell & Philips 2010). However, their bi­ology are still rarely reported, and the larvae are still unknown (Pereira 1954; Krikken & Huijbregts 2006).