中国小无环咽属线虫一新纪录种(线虫纲,矛线目,无环咽科)

描述了采自山东省沂水县烟草Nicotiana tabacum Linn.根围土的中国线虫1新纪录种,钝尾小无环咽线虫Aporcelaimellus obtusicaudatus(Bastian,1865)Altherr,1968。该种主要的鉴别特征是雌虫虫体中等到大型,角质层由明显的2层组成;唇区角状,明显缢缩,唇瓣彼此分离;齿针强壮,长22.1(19.9～27.1)μm,其开口占齿针长的一半;食道矛线型,贲门圆锥形;雌虫双生殖腺,阴门通常位于体中部,内阴唇骨化明显,呈心形;内阴唇和阴道总长约占阴门处体宽的2/5;尾长31.9(23.2～37.3)μm,是肛门处体宽的0.7(0.6～0.8)倍,尾呈钝圆锥形到半球形,末端圆,有厚的肌肉层,肛门后有粗糙的放射状条纹。它与A.faridpuriensis的主要区别在于:齿针较短(19.9～27.1μm vs.35～39μm),前直肠较短(96.2μm vs.145μm)。它与A.krygeri的主要区别在于:齿针较短(22.1μm vs.25μm),尾较长(23.2～37.3μm vs.20～25μm),c’值大(0.6～0.8vs.0.2～0.3),尾呈钝圆锥形到半球形,A.krygeri尾非常短,半球形且背凹,具钉状末端(Singh,Sharma&Khatoon,2002;T horne,1974)。讨论了钝尾小无环咽线虫的已有报道和国内分布,对Aporcelaimellus属及相关属科的中文译名进行了厘订。

A NEW RECORD SPECIES OF THE GENUS APORCELAIMELLUS HEYNS FROM CHINA(NEMATODA,DORYLAIMIDA,APORCELAIMIDAE)

A new record species,collected from rhizosphere of tobacco(Nicotiana tabacum Linn.) in Yishui County,Shandong Province,was redescribed and illustrated.Aporcelaimellus obtusicaudatus(Bastian,1865) Altherr,1968 New record to ChinaThe new record species is characterized by female body robust,large and middle sized with the body length of 2 095.2(1591.0-2934.0) μm;cuticle consisting of double layers;labial region set off by deep constriction,lips angular and separated from each other;odontostyle strong and 22.1(19.9-27.1) μm long,with aperture occupying half of its length;esophagus dorylaimoid;cardia conoid;prerectum 2.0-3.1 anal body diameters long;vulva located at middle body with the Ⅴ value of 52.0(47.8-55.2) ,inner lips heavily sclerotized and heart-shaped;tail 31.9(23.2-37.3) μm long with c’ value of 0.7(0.6-0.8) ,bluntly conoid to hemispheroid,with rounded terminus,very thick somatic muscle layer and coarse postanal radial striae.The new record species is similar to A.faridpuriensis Singh,Sharma & Khatoon,2002 and A.krygeri(Ditlevsen,1928) Heyns,1965.The new record species differs from A.faridpuriensis in shorter odontostyle(19.9-27.1 μm vs.35-39 μm in A.faridpuriensis) ,and shorter prerectum(85 μm vs.145 μm in A.faridpuriensis) .The new record species differs from A.krygeri in shorter odontostyle(22.1 μm vs.25 μm in A.krygeri) ,longer tail(23.2-37.3 μm vs.20-25 μm in A.krygeri) ,larger c’value(0.6-0.8 vs.0.2-0.3 in A.krygeri) ,and the different tail shape(hemispheroid to bluntly conoid,with rounded terminus vs.tail very short,hemispheroid and dorsally concave,with prominent peg-like terminal projection in A.krygeri) .