Two new nematode species of the family Sphaerolaimidae (Nematoda, Monhysterida) from the Yellow Sea, China

Two new species of free-living marine nematodes from the subtidal zone of the Yellow Sea were found and are described. Sphaerolaimus articulatus sp. nov. is characterized by circular amphidial fovea located at the level of the gymnostoma, the longest subcephalic setae 15–20 µm long, spicules arcuate, divided into two parts by a fine suture anterior to the middle, handle-shaped proximally and blunt distally and gubernaculum with two dorsally hook-shaped apophyses.

The second new species, Parasphaerolaimus sinensis sp. nov. is characterized by amphidial fovea located at the level of the gymnostoma base, length of longest subcephalic setae 19–22 µm in males, 6–7 µm in females, cuticle with lateral longitudinal alae, 15 µm in males, 8 µm in females, slender and slightly curved spicules 1.3–1.8 cloacal body diameter, gubernaculum with dorsally straight apophyses, 9–11 µm long, position of the vulva very close to the anus, 84–87% of body length from anterior end and ovoviviparity.