Two New Species of Free-Living Marine Nematodes of the Desmodoridae from Mangrove Wetlands of Xiamen Bay, China

Abstract

Mangroves are unique in their biodiversity, but studies on their meiobenthic biodiversity in China are scarce. Despite the importance of mangroves, little work has been done on the classification of nematodes in mangrove wetlands. Fujian Province is the most northern point of China’s natural mangrove distribution, and it is also one of the provinces with the earliest constructed mangrove forest. In this paper, two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described. Metachromadora xiamenensis sp. nov. is characterized by a cylindrical body, and smooth head capsule set off from the rest of the body. The cuticle is finely annulated and thickened at the midbody. Lateral ridges run from the posterior end of the pharynx to the middle of the tail. The amphid foveae is loop shaped and opens at the top with a double contour amphidial, pharynx with bipartite cuticularized internal cavity. There are 18 tubular precloacal supplements and tail with three small protuberances. Molgolaimus euryformis sp. nov. is characterized by a relatively short and plump body with finely annulated cuticle, which is particularly obvious in the tail. The head is small and wide with intensive striates. The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis, a gubernaculum with a block-shaped hook, a swollen conical-cylindrical tail and an absence of precloacal supplements.