Lynceus amplopedia sp. nov., A New Laevicaudatan Clam Shrimp with Asymmetrically Modified Thoracopods from Yunnan, China (Crustacea: Branchiopoda).

Abstract

Laevicaudata has a nearly global distribution, but only a few records from China. We present a new Lynceus (Crustacea: Branchiopoda: Laevicaudata) species, Lynceus amplopedia sp. nov., from Yunnan, China, which shows significant left-right differences in some non-clasper thoracopods. It can be distinguished from all congeners by asymmetrically modified thoracopods III-VI. In the 'explanate modified' side (usually the left side, occasionally the right) the following modifications are present: endites 4, 5, and endopod enlarged (explanate) (thoracopods III and IV); exopod with 14-15 digitiform processes dorsomedially (thoracopods V and VI); and broad muscular basis (thoracopods III-V). The following modifications are seen in the thoracopods of the opposing 'spinose modified' side (usually the right side, occasionally the left): endite 4 with robust, specialized spines medially (thoracopods V and VI); endite 3 elongate protruding (thoracopod VI), and broad muscular basis (thoracopod V). Other unique characters of the new species include: male and female rostrum sinuate, compound eyes protruding, male claspers with endopod constricted, and endite 3 with two scale patches. We suggest the modified thoracopods may be involved in mating and/or respiration. The diversity of Chinese Lynceus is also discussed.