Ross Jenna L, Haukeland Solveig, Hatteland Bjørn A, Ivanova Elena S
Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK.
Syst Parasitol. 2017 Jan;94(1):51-63. doi: 10.1007/s11230-016-9674-4. Epub 2017 Jan 6.
Angiostoma norvegicum n. sp. (Angiostomatidae) is described from the oesophagus, crop and the buccal mass of five species of slugs of the family Arionidae, Arion vulgaris (Moquin-Tandon), Arion ater (L.), Arion fasciatus (Nilsson), Arion fuscus (Müller) and Arion rufus/Arion ater hybrid), collected throughout Norway. Angiostoma norvegicum n. sp. was found parasitising arionids at seven of the 30 sample sites examined (23.3%), and 9.9% of all Arion spp. were infected with this nematode. The new species is characterised by its large size (4.0-8.6 mm long) and in having: lateral alae; 6 + 6 papillae at the cephalic end; a large circular mouth aperture; a spacious stoma; a pharyngeal basal bulb without valvular apparatus; an excretory pore near the base of bulb; a distal part of posterior ovary always outstretched; an anterior ovary distally nearly always outstretched; a vulva situated anterior to mid-body; long, nearly straight spicules and a small gubernaculum; three circumcloacal papillae and caudal genital papillae (GP) arranged in a pattern 1+2/3+3 with GP 5 and GP 8 opened on dorsal side of narrow bursa not reaching tail tip; short conical tails in both sexes with tips supplied by 4 short, unequal denticles. Morphologically, A. norvegicum n. sp. is similar to Angiostoma limacis Dujardin, 1845, which diagnostic characteristics are given based on examination of specimens from Norway and the UK. Conversely, the phylogenetic analyses based on D2D3 large subunit (LSU) rRNA gene sequences performed in the present study did not support the morphological affinity of these two species. Phylogenetic analyses demonstrated that although Angiostoma spp. cluster together, A. norvegicum n. sp. forms a tight monophyletic clade with the milacid nematode parasites Angiostoma margaretae Ross, Malan & Ivanova, 2011 and Angiostoma milacis Ivanova & Wilson, 2009.
挪威血管口线虫新种（血管口线虫科）是从挪威各地采集的五种阿勇蛞蝓科蛞蝓的食管、嗉囊和口腔团块中描述的，这五种蛞蝓分别是普通阿勇蛞蝓（莫坎 - 坦东）、暗黑阿勇蛞蝓（林奈）、带纹阿勇蛞蝓（尼尔森）、褐阿勇蛞蝓（米勒）以及红阿勇蛞蝓/暗黑阿勇蛞蝓杂交种。在检查的30个样本地点中的7个（23.3%）发现挪威血管口线虫新种寄生于阿勇蛞蝓科蛞蝓，所有阿勇蛞蝓属物种中有9.9%感染了这种线虫。新物种的特征在于其体型较大（体长4.0 - 8.6毫米），具有：侧翼；头部末端有6 + 6个乳突；大的圆形口孔；宽敞的口；咽基部球状体无瓣膜装置；排泄孔靠近球状体基部；后卵巢远端总是伸展；前卵巢远端几乎总是伸展；阴门位于身体中部前方；长且几乎直的交合刺和小的引带；三个围泄殖腔乳突和尾生殖乳突（GP）呈1 + 2/3 + 3模式排列，GP 5和GP 8在未到达尾尖的狭窄囊的背侧开口；两性的尾均为短圆锥形，末端有4个短且不等的小齿。在形态上，挪威血管口线虫新种与1845年杜雅尔丹描述的蛞蝓血管口线虫相似，其诊断特征是基于对来自挪威和英国的标本检查得出的。相反，本研究基于D2D3大亚基（LSU）rRNA基因序列进行的系统发育分析并不支持这两个物种的形态学亲缘关系。系统发育分析表明，尽管血管口线虫属物种聚在一起，但挪威血管口线虫新种与米莱线虫寄生虫2011年罗斯、马兰和伊万诺娃描述的玛格丽塔血管口线虫以及2009年伊万诺娃和威尔逊描述的米莱血管口线虫形成一个紧密的单系类群。
