中国绦虫三新种记述(绦虫纲:原头目,圆叶目)

报道绦虫纲3新种,即原头科的中华蛇带绦虫Ophiotaenia sinensis sp.nov、戴维科的林氏瑞列绦虫Raillietina(Paroniella)linisp.nov和囊宫科的苦恶鸟异带绦虫Anomotaenia amaurornisus sp.nov。     

Spermiogenesis in the cestode Corallobothrium solidum Fritsch, 1886 (Proteocephalidea: Corallobothriinae)

Spermiogenesis of Corallobothrium solidum Fritsch 1886, has been investigated by transmission electron microscopy. The zone of differentiation contains the two centrioles, each with one thin root, being orientated in the same plane only when a single intercentriolar body (ICB) appears between them. A median cytoplasmic process (MCP) develops distally to the two flagella, which are of unequal length, get longer and rotate towards the MCP. The nucleus penetrates into the spermatid body after the fusion of both flagella with the MCP has started. Flagellar roots occur occasionally in some spermatids. New for the Eucestoda are the following findings: 1. cortical microtubules (CMs) are arranged in two short parallel rows in one‐axoneme region of some spermatids; 2. the crested body of spermatid consists either of electron‐dense tubular elements and interposes itself between CMs, or it is rather homogeneous and situated more peripherally above one continuous semicircle of CMs. The present results support previous data that the type of spermiogenesis in proteocephalideans resembles mostly that observed in tetraphyllideans (Onchobothriidae and Phyllobothriidae), thus supporting the view of a close phylogenetic relationship of tetraphyllidean and proteocephalidean cestodes.     

Ultrastructural study of spermiogenesis and the spermatozoon of the proteocephalidean cestode Barsonella lafoni de Chambrier et al., 2009, a parasite of the catfish Clarias gariepinus (Burchell, 1822) (Siluriformes, Clariidae)

Spermiogenesis in the proteocephalidean cestode Barsonella lafoni de Chambrier et al., 2009 shows typical characteristics of the type I spermiogenesis. These include the formation of distal cytoplasmic protrusions forming the differentiation zones, lined by cortical microtubules and containing two centrioles. An electron-dense material is present in the apical region of the differentiation zone during the early stages of spermiogenesis. Each centriole is associated to a striated rootlet, being separated by an intercentriolar body. Two free and unequal flagella originate from the centrioles and develop on the lateral sides of the differentiation zone. A median cytoplasmic process is formed between the flagella. Later these flagella rotate, become parallel to the median cytoplasmic process and finally fuse proximodistally with the latter. It is interesting to note that both flagellar growth and rotation are asynchronous. Later, the nucleus enlarges and penetrates into the spermatid body. Finally, the ring of arching membranes is strangled and the young spermatozoon is detached from the residual cytoplasm.The mature spermatozoon presents two axonemes of the 9 + ‘1’ trepaxonematan pattern, crested body, parallel nucleus and cortical microtubules, and glycogen granules. Thus, it corresponds to the type II spermatozoon, described in almost all Proteocephalidea. The anterior extremity of the gamete is characterized by the presence of an apical cone surrounded by the lateral projections of the crested body. An arc formed by some thick and parallel cortical microtubules appears at the level of the centriole. They surround the centriole and later the first axoneme. This arc of electron-dense microtubules disorganizes when the second axoneme appears, and then two parallel rows of thin cortical microtubules are observed. The posterior extremity of the male gamete exhibits some cortical microtubules. This type of posterior extremity has never been described in proteocephalidean cestodes. The ultrastructural features of the spermatozoon/spermiogenesis of the Proteocephalidea species are analyzed and compared.     

The fine structure of frontal glands in adult cestodes

Kuperman B. I. & Davydov V. G. 1982. The fine structure of frontal glands in adult cestodes. International Journal for Parasitology12: 285–293. The localization and structure of frontal glands of adult cestodes of 20 species from 4 orders: Caryophyllidea, Pseudophyllidea, Proteocephalidea and Cyclophyllidea were studied by light and electron microscopy. In cestodes of various orders there was evidence of differences in the ultrastructure of secretory cells, in the character of the secretion, and in the method of its discharge. The localization of glands in most adult cestodes is in the scolex. In Cyatocephalus, Ligulidae, Bothriocephalus claviceps, they are distributed also in the anterior and middle part of the body. In the species Caryophylleus (C. laticeps) and Khawia sinensis a major gland complex previously not described was discovered. The glands of the cestodes investigated may be divided into three main groups by their structure, localization and functional role in ontogenesis: (1) penetration glands in oncospheres which develop into procercoids and plerocercoids; (2) glands of plerocercoids and adult cestodes which develop in the gut; (3) gland complexes in the representatives of the order Caryophyllidea. The secretion is usually discharged at the scolex region and less frequently on the lateral surface. Three different ways of discharging secretory material from the cestodes body are described.