Species diversity of freshwater shrimp in Henan Province, China, based on morphological characters and COI mitochondrial gene.

Freshwater shrimp are a rich species group, with a long and problematic taxonomic history attributed to their wide distribution and similar morphological characteristics. Shrimp diversity and species identification are important cornerstones for fisheries management. However, identification based on morphological characteristics is a difficult task for a nonspecialist. Abundant freshwater shrimp species are distributed in the waters of Henan Province, but investigations of freshwater shrimp are limited in this region, especially concerning molecular features. Here, we combined morphology and DNA barcodes to reveal the species diversity of freshwater shrimp in Henan province. A total of 1,200 freshwater shrimp samples were collected from 46 sampling sites, and 222 samples were chosen for further microscopic examination and molecular delimitation. We used tree-based methods (NJ, ML, and bPTP) and distance-based methods (estimation of the paired genetic distances and ABGD) to delimit species. The results showed that there were nine morphospecies based on morphological characteristics; all could effectively be defined by molecular methods, among which bPTP and ABGD defined 13 and 8 MOTUs, respectively. The estimation of the paired genetic distances of K2P and the p-distances had similar results. Mean K2P distances and p-distances within species were both equal to 1.2%. The maximum intraspecific genetic distances of all species were less than 2%, with the exception of Palaemon modestus and M. maculatum. Various analyses have shown that P. modestus and M. maculatum have a large genetic differentiation, which may indicate the existence of cryptic species. By contrast, DNA barcoding could unambiguously discriminate 13 species and detect cryptic diversity. Our results demonstrate the high efficiency of DNA barcoding to delimit freshwater shrimp diversity and detect the presence of cryptic species.

Taxonomy of the Hirtodrosophila melanderi species group (Diptera: Drosophilidae), with descriptions of four new species from southwestern China.

The Hirtodrosophila melanderi species group contains nine known species recorded from either the Old or the New World. All these species were thought to be strict fungivorous drosophilids. In the present study, we give supplementary descriptions for three of these known species, all recorded from Yunnan, southwestern China, H. furcapenis, H. furcapenisoides, and H. longifurcapenis, by examining respective type specimen(s). We then describe four new species of the same group, H. seticlasper Katoh Gao, sp. nov., H. spinicerca Katoh Gao, sp. nov., H. serratifurcapenis Katoh Gao, sp. nov., and H. truncifurca Katoh Gao, sp. nov., all discovered recently from high altitudes (ca. 3,500 to 3,800 m a.s.l.) in Tibet (Xizang), southwestern China. The delimitation of these new species is firstly performed in light of morphology and further with the aid of DNA sequences of the mitochondrial COI (cytochrome c oxydase, subunits I) gene. In addition, a key to all the species of the species group is provided.