鲫寄生车轮虫一新种的描述

TRICHODINID ECTOPARASITES FROM GOLDEN CARP, WITH A DESCRIPTION OF TRICHODINA PARANIGRA SP.NOV.

本文记述了寄生在鲫鱼鳃上的车轮虫属一新种———Trichodinaparanigrasp .nov .。文中采用Lom(196 0 )所倡导的统一特定方法及由VanAs&Basson(1989)提出的齿体各鉴定特征的定位描述 ,对本新种的各形态学特征 (包括虫体外形、附着盘、齿体、辐线、中央颗粒、核器、口围绕体等 )进行了较为详尽的描述 ,并对本种与相似种进行了比较研究。文中还为齿体定位描述模式图新增了两个参数。

This article is an account of a new species of trichodinids Trichodina paranigra sp.nov.,a kind of parasites that live on the gills of Carassius auratus. It gives a detailed description and diagrams illustration of the morphological characteristics including the shape,the size,and all other basic biological features following the widespread acceptance of the uniform specific characteristics proposed by Lom(1960) and the description of denticle elements follows the format recommended by Van As & Basson (1989).It also gives the interspecific comparison with the closely ralated populations.Two new parameters are also added for the diagram of Van et al in this article. Trichodina paranigra sp.nov. (Figure 1-3;Table 1) Syn: Trichodina nigra Lom,1961 Sensu Chen, 1963 Host and site of infection: Carassius auratus ,gills,2002. Locality:Chongqing,China. Type specimens:Syntypes on slide(No:2002-1210-01)are deposited in The Key Laboratory of Animal Biology,Chongqing,Chongqing Normal University,China. The morphology of Trichodina paranigra sp.nov.(Measured specimens number:12):Large,freshwater Trichodina Ehrenberg,1838.Body diameter 60.3±3.4(56—65μm).Diameter of adhesive disc 50.3±3.2(46—53μm).Border membrane 5.6±0.5(5—6μm)in width.Diameter of denticulated ring 30.6±2.9(27—33μm).Number of denticles 29±3.6(25—32).Number of radial pins(mode)per7—8.Span of denticle 16.0±1.4(14—17μm).Length of denticle 6.7±1.7(4—8μm).Blade broad,almost obliquely rectangular,tapering gradually downwards,length 7.6±0.2(4—8μm).Distal blade surface straight,lower than tangent point.Blade connection slender.Central part thicker with rounded point fitting tightly into preceding denticle,extending more than half way to Y-1 axis.Width of central part 1.9±0.5(1—2μm).Length of ray 8.4±0.2(8—9μm).Based on methly green pyronin stained specimens,macronucleus horseshoe shaped,external diameter 48μm(mode).Distance between terminations of macronucleus 10μm(mode)Micronucleus ellipsoid,situated in +Y position.Adoral ciliary spiral turns 360°-400°around peristomial disc.