【摘要】 <正> 寄生于家鸭台湾鸟龙线虫(Avioserpens taiwana(sugimoto,1919),隶于龙线科(Dracunculidae),首先是杉本正笃(sugimoto,1914)在我国台湾从家鸭和番鸭(Cairina moschata)下颔的柔软组织中发现,检得雌虫作简短的记载,至1919年定名为台湾丝状线更多还原

【Abstract】 Avioserpens taiwana (Sugimoto, 1919) is a common parasite of duckling in South Chi-na. Despite its wide distribution and common occurence, the male was not described until recently and information about the life cycle was lacking. This paper presents the following descriptions.First-stage larvae develop within the uterus of the female, the firststage larvae fully formed hatch from the eggs membrances and actively move around in the female uterus. They escape to exterior through the lacerated head which protrudes through the host’s skin. The free-living first-stage larvae are slender and 0.416-0.450 mm ×14-15 μ wide, the anterior end is rounded, the esophagus 92-102 μ long, nerve ring 50-56 μ and ex-.cretory pore 56-60 μ from anterior end. The intestine is filled with granular material. The tail is 0.140-0.144 mm long, attenuated. The genital primordium 0.194-0.198 mm from the posterior end.Through experimental infection of copepods, the Eucydops serrulatus, Mesocydops leu-ckarti, Thermocydops hyalinus and Cyclops sternuus are found to be its intermediate hosts. When eaten by coppods, the larvae penetrate through the gut wall into haemocoele, the first molt occurs on the 3rd to 4th day after infection at 28-30*, and the second molt on the 7th day after infection.The second-stage larvae 0.420-0.460 mm×16-18 μ , the esophagus 0.156-0.160 mm in length, nerve ring 68-72 μ and excretory pore 86-88 μ from the anterior end. The intestine is filled with a pigmented rough granular material. The tail 74-76 μ long, attenuated. The third-stage larvae 0.420-0.450 mm×15-61 μ . The entric esopgagus 0.218-0.240 mm long is distinctly divided into parts: the anterior muscular part is 92-108 μ long and posterior glandular part is 126-132 μ long. The nerve ring is 70-72μ and excretory pore 86-90 μ from the anterior end. The intestine filled with dense yellowish-green glandular material. The tail 52-54 μ in length, and terminates with a two-cuspidated tip.Experimental infection of duckling, the male found in the mesentery of duckling on the 18th day and female in the subcutaneous tissue of duckling on the 20th day after infection. The male 6.0×0.128 mm. Cuticle finely striated transversely, the head is rounded and provided with two large median (dorsal and ventral) and four double submedian papillae, and a pair of amphids; mouth small without circumoral cuticular ring. Esophagus consists of short anterior muscular portion and long posterior glandular portion, and with three uninu-cleate esophagus glands one dorsal and two subventral; the anterior muscular portion 0.144 mm and posterior glandular portion 0.598 mm in length. The nerve ring 0.140 mm from the anterior end. The tail attenuated, curved ventrally 0.27 mm long. Spicule slender, dissimilar, subequal, left spicule long, relatively large 0.192×0.018 mm and right one short, small 0.140×0.014 mm in size. Gubernaculum triangular in shape, 35×8 μ in size.The worms occur seasonally in Fujian Province. In surveying of the naturally infected duckling, we found that in the first season (May to June) 120 duckling showed an infected rate of 8.5%; in the second season in August, 80% of 160 duckling; and in the third season (September) 40% of 50 duckling.更多还原