A new genus and three new species of free‐living marine nematodes from the Yellow Sea,China

One new genus, Paramphimonhystrella gen. nov., and three new species of free‐living marine nematodes in this genus, P. elegans sp. nov., P. minor sp. nov., and P. sinica sp. nov., are described and illustrated from the Yellow Sea, China. Paramphimonhystrella gen. nov. differs from the similar genus Amphimonhystrella by the elongated buccal cavity, cervical setae and large caudal glands. Paramphimonhystrella elegans sp. nov. is characterized by ovoid amphids and spicules with a small hook at distal end and cylindrical part of tail shorter than conical part. Paramphimonhystrella sinica sp. nov. is characterized by circular amphids, wide buccal cavity, spicules with blunt tip, and cylindrical part of tail longer than conical part. Paramphimonhystrella minor sp. nov. differs from the other two species by its smaller body (shorter than 800 µm), circular amphids, and spicules with sharp tip. The type species of this new genus is P. elegans gen. nov. and sp. nov. Types are deposited in the College of Marine Life Sciences, Ocean University of China.     

Cienfuegia gen. nov. (Xyalidae) and Pseudoterschellingia gen. nov. (Linhomoeidae), two new genera of free‐living marine nematodes from the Caribbean Sea

Two new genera of nematodes are described from the Caribbean Sea. Cienfuegia gen. nov. belongs to the Xyalidae based on the position of the anterior gonad constantly left of the intestine, cuticle clearly striated, second and third circle of anterior sensilla inserted at the same level and buccal cavity surrounded by pharynx. The new genus is differentiated from other genera by the buccal cavity divided in two chambers and by the four cephalic setae being longer than the six outer labial setae. Within the Xyalidae, Cienfuegia shows most affinities with the genera Daptonema and Theristus. Pseudoterschellingia gen. nov. is placed within the Linhomoeidae on the basis of the presence of anterior rounded amphidial fovea, unarmed narrow buccal cavity, distinctive cardia and presence of apophysis of gubernaculum. Pseudoterschellingia is closely related to the genera Terschellingia and Terschellingioides, but is differentiated by the crypto‐spiral amphidial fovea, and conical buccal cavity surrounded by pharyngeal tissue.     

Three new species of the brackish‐water copepod Halicyclops (Crustacea,Cyclopoida) from Ariake Bay,Japan

Three new species of the cyclopoid copepod Halicyclops are described from river estuaries of Ariake Bay, Japan. Halicyclops continentalis sp. nov. is most similar to H. laminifer, but differs by the shape of an angular protuberance on the genital double‐somite and a serrate hyaline frill of the fourth urosomite. Halicyclops sinensis described by Tai and Chen is widely distributed in China and is identifiable to H. continentalis, indicating that the population in Ariake Bay is probably a continental relict. Halicyclops uncus sp. nov., belonging to the thermophilus group, is distinguishable by the shape of the lateral process on the genital double‐somite, a frill of the fourth urosomite and caudal rami; it is probably endemic to Japan. Halicyclops ariakensis sp. nov. differs from the other congeners by a combination of the shape of the prosome, urosomal hyaline frills and caudal ramus length; it is considered endemic to Ariake Bay.