Recognizing two newHippolytespecies (Decapoda, Caridea, Hippolytidae) from the South China Sea based on integrative taxonomy

Abstract

Hippolyteshrimps exhibit abundant biological diversity and display great ecological significance in seaweed bed ecosystems. Dozens ofHippolytespecimens were collected from Hainan Island and the Xisha Islands in the South China Sea. Detailed examination indicates that some of these specimens represent newHippolytespecies. Based on morphological, genetic, and ecological data,Hippolyte chaceisp. nov. andH. nanhaiensissp. nov. are described.H. chaceisp. nov. was collected from theSargassumsp. 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. nanhaiensissp. nov. was collected from the biotopes ofGalaxaurasp. orHalimedasp. 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 toH. australiensisin the phylogenetic tree. A key to identifying mature femaleHippolytespecies of the Indo-West Pacific and neighboring seas is provided.