Abstract
The life cycle of Echinoparyphium dunni, a new 43-spined species, is described. The first intermediate host is the freshwater snail, Lymnaea rubiginosa (Michelin). The same and other freshwater snails such as Gyraulus convexiusculus (Hutton), Indoplanorbis exustus (Deshayes), and Bellamya ingallsiana (Lea) serve as second intermediate hosts. Adult worms have been obtained under experimental conditions from pigeons; ducklings; black-headed or chestnut munias, Lonchura ferruginosa (Sparrman); spotted munias, Lonchura punctulata (Linnaeus); and Java sparrows, Padda oryzivora (Linnaeus); but not from rats, mice, and hamsters. The freshwater snail, Lymnaea rubiginosa (Michelin), collected from ponds and paddy fields in the areas surrounding Kuala Lumpur was found to serve as first intermediate host of several species of echinostomes: Hypoderaeum dingeri Lie, 1964; Echinostoma audyi Lie and Umathevy, 1965; an undescribed Echinoparyphium species with 43 collar spines; and an undescribed Echinostoma species with 47 collar spines. The complete life cycles of H. dingeri and E. audyi have been published (Lie, 1964b; Lie and Umathevy, 1965). The purpose of this paper is to report on the life cycle of the new Echinoparyphium species and to describe the larval stages and the adult worm. MATERIALS AND METHODS The adult worms were obtained by feeding mixed species of echinostome metacercariae occurring in naturally infected Lymnaea rubiginosa to ducklings and pigeons which were killed after eggs appeared in the feces. After the echinostomes were identified, eggs were collected from the worms by teasing the uterus and were the starting point for the study of the life cycle of the parasite. Methods employed in this study were the same as those described in previous papers (Lie, 1963, 1964a). All measurements are in microns unless otherwise stated. Received for publication 12 August 1964. * This work was supported by the University of California International Center for Medical Research and Training (The Hooper Foundation, San Francisco School of Medicine) with Research Grant GM-11329 from the Office of International Research, NIH, U. S. Public Health Service. t Present address: The Hooper Foundation, University of California, San Francisco Medical Center, San Francisco, California. RESULTS Egg and miracidium (Figs. 1 and 2) Eggs oval, yellow-brown, with thickening of shell at nonoperculated end, 90 to 120 by 60 to 75; passed in feces in uncleaved condition, may hatch within 8 days when kept in tap water at room temperature (average 28 C). Exposure to light by placing petri dish containing eggs under a lamp stimulates hatching. Miracidia fixed in silver nitrate measure 72 to 102 by 36 to 41. Apical papilla 7.5 to 10 by 6 to 7 with two rows of cilia and with refractile dots on anterior wall (Fig. 1). Epidermal plates in 4 rows; 6 plates in first (anterior) row, 2 ventral, 2 dorsal, and 2 lateral; 6 plates in second row, 3 ventral and 3 dorsal; 4 plates in third row, 1 dorsal, 1 ventral, and 2 lateral; 2 plates in fourth row. Position of latter difficult to determine since posterior end of fixed miracidium often somewhat rotated in relation to anterior part; position often dorsoventral, but lateral or intermediate position also seen. Miracidia within egg invariably show dorsoventral position of plates. Lateral position of plates was found in miracidium of Echinoparyphium flexum (Linton, 1892) Dietz, 1910 by Najarian (1954) and of E. recurvatum (Linstow, 1873) by Rasin (1933). Najarian's suggestion that lateral position of plates might be characteristic of the genus Echinoparyphium not confirmed by this study. Plates in first row somewhat triangular, about 16 long and 13 broad at base; second and third rows somewhat rectangular, respectively 23 by 19 and 30 by 22; fourth row, 26 long and 27 broad at anterior end. All plates covered with cilia about 10 long. Two fingerlike processes, 4 long, each situated at base of an anterior lateral plate. Short bristle immediately in front of each process. Primitive gut filled with granules and opening on tip of apical papilla. Penetration glands difficult to observe. Eyespots consisting of three pairs of crystalline lenses lodged in two pairs dark brown, pigmented bodies, similar to eyespots found in Hypoderaeum dingeri by Lie (1964b). Two flame cells; left anterior and dorsal, with duct opening situated on latero-dorsal side of body between third and fourth rows of epidermal plates; right flame cell posterior and ventral with outlet on latero-ventral side of
Published Version
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