浙江洞头岛自由生活线虫两个优势种的形态描述及其系统发育分析OA北大核心CSTPCD

Two dominant species,Sabatieria foetida Gagarin&Nguyen Vu Thanh,2008 and Metachromadora xiamenensis Zhou,Zeng,Cai,Fu,&Tan,2020,were redescribed during the classification and diversity studies of free-living marine nematodes in Dongtou Island,Zhejiang Province.S.foetida was first described as a recorded species and characterized by a cuticle with small punctuations and lateral differentiation with large dots,four short cephalic setae(3-4 μm in length),spiral-shaped amphidial fovea(2.5-3.0 turns),curved spicules with proximal ends that are cephalate and slender from the middle part,gubernaculum with straight apophysis(20-25 μm in length),and 13-15 papilliform precloacal supplements.Furthermore,M.xiamenensis is characterized by a coarsely striated cuticle with lateral alae starting from the middle pharynx to the tail,four short and stout cephalic setae,amphids with a double contour at the anterior end,spicules with a cephalated proximal end(58-65 μm in length),15 tubular precloacal supplements,and a short and conical tail.The D2-D3 fragments of the LSU rDNA of S.foetida and M.xiamenensis were amplified and sequenced.Moreover,phylogenetic trees based on Bayesian infer-ence and maximum likelihood revealed polyphyletic evolution in the genera Sabatieria and Metachromadora.