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Zeitschrift für Parasitenkunde

, Volume 71, Issue 2, pp 227–240 | Cite as

Ultrastructure of the daughter sporocyst and developing cercaria ofSchistosoma japonicum in experimentally infected snails,Oncomelania hupensis hypensis

  • E. Göbel
  • J. P. Pan
Original Investigations

Abstract

Ultrastructure of daughter sporocysts and cercariae ofSchistosoma japonicum were studied 2 and 4 months after infection ofOncomelania hupensis hupensis. The body walls of daughter sporocysts are similar at all infectious stages. They consist of an external syncytial tegument on a basement membrane, and an internal cellular subtegument surrounding a body cavity containing developing cercariae. The cercariae embryos develop 2 months after infection from germinal balls in the brood chamber of the daughter sporocyst. They are at first enveloped by a primitive epithelium rising from the daughter sporocyst. Four months after infection, the cercarae were almost fully developed and the primitive epithelium had degenerated. The body wall of the cercaria consists of a thin tegument covered by a surface coat of fibrous material and connected to the subtegumental cells by cytoplasmic processes. The matrix of the tegument contains numerous dense bodies, vacuoles, and spines. Two types of sensory structures-uniciliated and multiciliated —are found at the anterior tip of the cercaria. There are five pairs of penetration gland cells of two distinct types differentiated by the morphology of secretory granules. Flame cells are found in both daughter sporocysts and in cercariae. The cilia of the flame cells are characterized by the typical 9 and 2 cilium pattern.

Keywords

Secretory Granule Body Wall Gland Cell Dense Body Fibrous Material 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Abbreviations

A

Granules of the penetration glands, type A

B

Granules of the penetration glands, type B

BB

Basal body

BC

Brood chamber

C1

Young cercaria

C2

Mature-cercaria

CA

Canaliculi

CE

Cercarial embryo

CF

Cilia of flame cell

CM

Circular muscular fibre

CP

Cytoplasmic process

CR

Cristalloid structure

CS

Cilia of sensory organelle

D

Desmosomes

DE

Dendron

DP

Duct of penetration gland

EB

Excretory bladder

EC

Excretory canals

ER

Endoplasmic reticulum

F

Folds of cercarial tegument

FL

Fibre layer

FV

Food vacuole

GC

Germinal cell

L

Lipid vacuole

LM

Longitudinal muscular fibres

M

Muscular fibre

MI

Mitochondrium

MS

Multiciliated sensory organelle

MT

Microtubules

MV

Microvilli

N1

Nucleus of subtegument cell of the daughter sporocyst

N2

Nucleus of tegument of the cercarial embryo

N3

Nucleus of the germinal cell

NS

Neurosecretion

NV

Neurosecretory vesicle

PE

Primitive epithelium of cercarial embryo

R

Rod-like body

S

Spine

SB

Spherical body

SC

Surface coat

SD

Septate desmosomes

ST

Subtegument

STC

Subtegumental cell

TC

Tegument of cercaria

TD

Tegument of the daughter sporocyst

US

Uniciliated sensory organelle

VE

Vesicles

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Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • E. Göbel
    • 1
  • J. P. Pan
    • 1
  1. 1.Institute of Comparative Tropical Medicine and ParasitologyUniversity of MunichMünchen 40Federal Republic of Germany

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