Recognizing two new Hippolyte species (Decapoda, Caridea, Hippolytidae) from the South China Sea based on integrative taxonomy.

Hippolyte shrimps exhibit abundant biological diversity and display great ecological significance in seaweed bed ecosystems. Dozens of Hippolyte specimens were collected from Hainan Island and the Xisha Islands in the South China Sea. Detailed examination indicates that some of these specimens represent new Hippolyte species. Based on morphological, genetic, and ecological data, Hippolyte chacei sp. nov. and H. nanhaiensis sp. nov. are described. H. chacei sp. nov. was collected from the Sargassum sp. biotope in Hainan Island and is distinguished from congeners by its unique mandible and the dactylus of the third to fifth pereiopods; this species has a basal position in the Indo-West Pacific species clade in the phylogenetic tree which is reconstructed based on 16S rRNA gene. H. nanhaiensis sp. nov. was collected from the biotopes of Galaxaura sp. or Halimeda sp. in the Xisha Islands, and it differs from congeners in a series of characters associated with rostrum, scaphocerite, antennular peduncle, and spines on the dactylus of the third to fifth pereiopods. Additionally, it is sister to H. australiensis in the phylogenetic tree. A key to identifying mature female Hippolyte species of the Indo-West Pacific and neighboring seas is provided.

[Ecological characteristics and seasonal variation of macrobenthos near the Ningjin coastal water of Shandong, East China].

The coastal water off Ningjin is located at the eastern end of the Shandong Peninsula, the boundary of the Northern and Southern Yellow Sea. In this paper, the ecological characteristics and seasonal variation of macrobenthic community in this region were studied, based on the investigation data collected from the four cruises in January (winter), April (spring), July (summer), and October (autumn), 2007. A total of 243 macrobenthic species were identified, of which, 96 species were of Polychaeta, 77 were of Crustacea, 43 were of Mollusca, 13 were of Echinodermata, and the rest 14 species were of other benthic groups. The dominant species varied with seasons, but Paralacydonia paradoxa (Polychaeta) and Amphioplus japonicus (Echinodermata) were dominant throughout the four seasons. The average biomass of the macrobenthos estimated from the four cruises was 9.5 g x m(-2), with the highest biomass during the spring cruise and the lowest one during the winter cruise. The average abundance estimated from the four cruises was 219.6 ind x m(-2), with the highest abundance during the winter cruise and the lowest one during the autumn cruise. The Shannon index (H) of the macrobenthos community varied from 2.82 to 3.23, the species richness index (D) varied from 2.28 to 2.75, and the species evenness index (J) varied from 0.82 to 0.86. The Bray-Curtis similarity cluster analysis and MDS ordination analyses indicated that there was a distinct distribution of macrobenthic communities from seashore to offshore, which was closely correlated with the spatial structure of bathymetry and the sediment type in the study region.