ULTRASTRUCTURE OF THE PROTONEPHRIDIAL SYSTEM,OF ~~~P~U~rSCU~ C~~~U~SP~~~~~~ (MONO~ENEA MONOPISTHO~OTYLEA) K. ROHDE,*~ N. A. WATSON* and F. R. ROUBAL$ *Department of Zoology, University of New England, Armidale, New South Wales 2351, Australia $Department of Parasitology, Unive~ity of Queensland, St. Lucia, ~~nsland 4072, Australia (Received 31 Jury 1991; accepted IO January 1992)
Abstract-Ronon
K., WATSON N. A. and ROUBAL F. R. 1992. Ultrastructure of the protonephridial system of
Anoplodiscus cirrusspiralis (Monogenea Monopisthocotylea). International Journal for Parasitology 22: 443-457. The flame bulb is formed by a terminal cell and a proximal canal cell. The weir consists of
in~rdi~tating ribs all of which form one circle, i.e. alternating ribs do not have distinctly ‘internal’ or ‘external’ positions. Cytoplasmic cords are absent and all ribs, i.e. those continuous with the proximal canal cell and those continuous with the terminal cell, form external leptotriches. At least some external leptotriches have interconnected branches extending along the flame bulb. Internal leptotriches are not branched and arise from the basal perikaryon of the terminal cell. In the cytoplasmic cylinder at the tip of the flame bulb, structures resembling incomplete septate junctions were seen. However, neither the cytoplasmic cylinder nor the small protonephridial capillaries contain complete septate junctions as found in all other Monogenea Polyopisth~tylea, Monogenea Monopisth~tylea, Trematoda Aspidogastrea and Trematoda Digenea examined to date. In the lack of a septate junction, Anop~odjsc~ resembles Udone~~u, Amphilinidea, Gyrocotylidea and Eucestoda. However, the presence in this species of rudimentary septate junctions in the small capillaries and of complete junctions in larger ones indicates that complete junctions have been secondarily lost. Anoplodixus resembles the Monogenea and Trematoda in the presence of lamellae in the larger protonephridial ducts. For the first time in a monogenean, the ultrastructure of the excretory bladder is described. A nucleated convoluted duct opens through a narrow connecting duct into the bladder, which in turn opens through a narrow connecting duct into the excretory pore lined by tegument. Convoluted duct, connecting ducts and bladder are lined by a lamellated epithelium. A thick layer of fibrous tissue containing many muscle fibres, some nuclei, flame bulbs and protonephridial capillaries underlies the epithelium. INDEX KEY WORDS: Anoplodiscus cirrusspirah; bulbs; excretory bladder; phylogeny.
Monogenea; ultrastructure; protonephridia;
flame
pair of cytoplasmic cords arising from the proximal canal cell and connected by a septate junction, whereas Udonella, the Gyrocotylidea, Amphilinidea and Eucestoda examined lack such cords. In this paper, we examine the flame bulb, capillaries, and, for the first time in the Monogenea, the excretory bladder of Anoplodiscus cirrusspiralis from the fins of the snapper, Chrysophrys aurntus (see Roubal, Armitage & Rohde, 1983). Adults of the species, like other species of the genus, lack hooks, although Ogawa & Egusa (1981) have demonstrated the presence of 16 hooks in the oncomiracidium and immature worms of A. spari which are gradually ‘absorbed into the tissue’. Number and shape of the hooks as well as presence of two pairs of eyes clearly indicate that the genus belongs indeed to the Monogenea.
INTRODUCTION STUDIES of the ultrastructure of the protonephridial
system have significantly contributed to our understanding of the phylogeny of the Platyheiminthes (Rohde, 1988, 1990, 1991). For example, all the major groups of parasitic Platyhehninthes (Neodermata) have in common a flame bulb formed by a terminal cell and a proximal canal cell: the internal ribs of the filtration apparatus (weir) are continuous with the terminal cell, the external ones with the proximal canal cell. Among the Neodermata, all Monogenea, Digenea and Aspidogastrea examined to date have, in addition to external and internal ribs, a
t To whom all correspondence should be addressed. 443
K. ROHDE,N. A. WATZZ~N and F. R. ROUBAL
FIGS.I-4. Cross-sections through one flame bulb, at level of ciliary rootlets (Fig. 1), at level of basal bodies (Figs. 2,3), at level of basal parts of cilia (Fig. 4). B, Basal body; EL, external leptotrich; G, Golgi complex; IL, internal leptotrich; M, microtubule; MI, mitochondrion; R, rootlet of cilium; small arrowheads, attachment of external ribs to cytoplasm of terminal cell; large arrowheads, electron-dense material in periphery of terminal cell proximal to ribs. Note branching external leptotriches from both rows of ribs. Scale bars, 1 pm.
MATERIALS AND METHODS Infected snapper, Chrysophrys aurafus, were aquacultured in a cage at the Fisheries Research Institute, Cronulla, Sydney. Worms removed from the fins or still attached to the fins were sent alive in cooled sea-water by air from Sydney to Armidale, and fixed for 1.5-2 h at 4°C in 3% glutaraldehyde in 0.1 M-sodiumcacodylate buffer, pH 7.3, made with filtered sea-water, washed for 30 min in the same buffer at 4’C, postfixed for 30 min at room temperature in 1% 0~0, in the same buffer, dehydrated in an ethanol series and embedded in
Spurr’s resin. Sections of 60-70 nm were stained with alcoholic uranyl acetate and lead citrate and examined under a Jeol 1200 EX electron microscope at 60 kV. RESULTS A series of cross-sections shows that the cytoplasm
through the flame bulb of the terminal cell is
strongly reticulated (Figs. l-3) forming many interconnected cell processes. It contains mitochondria,
Ultrastructure of the protonephridial system of A. cirmsspiralis
445
Frcs,. 5-8. Cross-sections through the same flame bulb as in Figs. 1 4, at midlevel of weir (Fig. 5), at tip of weir (Fig. 6), a,t level of continuous cytoplasmic cylinder (Fig. 7). Cross-section through protonephridial capillary (Fig. 8). C, CapilIary of protonepb~dium; RR, external ribs; IR, internal rib, M, mi~rotubule; ME, ‘membrane’ between ribs of weir; N, nucleus. Note: all ribs arranged in one circle, i.e. no clear internal or external location of alternating ribs, ‘external’ ribs fuse to form continuous cytoplasmic cylinder (Fig. 6). Scale bars, 1 pm.
microtubules (Fig. l), and Golgi apparatus (Fig. 2). Ciliary rootlets are compact (Fig. 1) and short (Figs. 9, 10). The weir apparatus is formed by two aite~ating rows of ribs arranged in a complete circle and connected by a ‘membrane’ of intercellular matrix (Figs. 4, .5), i.e. the ribs arising from the terminal cell (‘internal’ ribs in analogy with other species) and canal cell (‘external’ ribs) do not he internal and external to each other as in most parasitic Piatyhelminthes. All
ribs have microfilaments. Ribs from the terminal cell appear to originate in a continuous layer of electrondense cytoplasm which s~ounds the basal bodies of the flame (Fig. 3). For some distance along the weir, these ribs remain connected by external leptotriches to a cytoplasmic network of the terminal cell (Pigs. 4,5). Unbranched internal leptotriches arise from the terminal cell at the base of the weir (Figs, 4, 5, 9-12). Ribs from the proximal canal extend beyond the IeveI
446
K.
ROHDE, N. A.
WATSONand F. R. ROUBAL
FIGS.9-13. Some of a series of longitudinal sections through one flame bulb. C, Capillary of protonephridium; ER, external rib; IL, internal kptotrich; IR, internal rib; N, nucleus; R, rootlet of cilium; arrowhead, septate junction. Note: multilobed nucleus, numerous branching and interconnected cytoplasmic processes of terminal cell, unbranched internal leptotriches arising from basal cytoplasm of terminal cell, and protonephridial capillary without lamellae or microvilli. Scale bars, 1pm.
Ultrastructure of the protonephridial system of A. cirrusspiralis
447
FIG. 14. Diagrams of flame bulb. A. Longitudinal section. B. Cross-section at level ofcytoplasmic cylinder. C. Cross-section at level of weir. C, Capillary; CI, cilium; DR, dense cytoplasmic ring; EL, external leptotrich; ER, external rib; G, Golgi complex; IL, internal leptotrich, IR, internal rib; M, microtubule; ME, ‘membrane’ between ribs ofweir; MI, mitochondrion; N, nucleus of terminal cell; PC, proximal canal cell; TC, terminal cell; arrow, rudimentary septate junction (?). Note: lack of complete septate junction in the cytoplasmic cylinder and of cytoplasmic cords in the weir; external leptotriches arising from ‘external and ‘internal’ ribs, at least some forming an interconnected cytoplasmic network. Scale bar, 1 pm.
of origin of ribs arising from the terminal cell and are in contact with the cytoplasm of the terminal cell by desmosome-like structures (i.e. the ends of the weir ‘membrane’) (Fig. 3, small arrowheads). Ribs from the canal cell also have external leptotriches which form an extensive cytoplasmic network along the flame bulb (Figs. 4, 5). Distally these ribs and processes fuse to form a continuous cylinder (Figs. 6, 7) which narrows significantly at the tip of the flame (Figs, 9, 10). Ribs from the terminal cell do not fuse with this cylinder (Figs. 11, 12) but are separated from it throughout by the weir membrane. The internal surface of the cylinder
is smooth, i.e. there are neither lamellae nor microvilli (Figs. 7, 9-13). Similarly protonephridial capillaries some distance from the weir are smooth walled (Fig. 8). Longitudinal sections show that the nucleus of the terminal cell is strongly indented and is located basally to the weir (Fig. 9). In the cytoplasm of the cylinder near the top of the flame, adjoined membranes with dense septa crossing the space between them were observed, closely resembling septate junctions (Figs. 9-12). However, such junctions were never seen to completely cross the wall of the flame bulb or the
448
K. ROHDE,N. A. WATSONand F. R. ROUBAL
FIGS. 11-16. Cross-sections through large protonephridial ducts. Note one septate junction (arrowhead) in Fig. 15 and sevcxal SC:ptate junctions (arrowheads) in Fig. 16. Also note numerous lamellae (L) and mitochondria (MI). Scale bars, 1 pm. capillaries. The entire flame bulb is surrounded by a dense fibrous intercellular matrix. Diagrams of the flame bulb are given in Fig. 14. Large protonephridial duct and bladder The walls of large protonephridial ducts have one (Fig. 15) or several septate junctions (Fig. 16), and their surface is increased by numerous lamellae (Figs. 15, 16). Also common are mitochondria (Figs. 15, 16). The paired excretory bladders, located in the anterior part of the body, are each supplied by a convoluted excretory duct (Fig. 17) that is lined by a strongly vacuolated epithelium with many surface
lamellae (Figs. 21,22) and opens into the bladder by a narrow connective duct also containing numerous lamellae (Fig. 22). The nucleus of the epithelium near the bladder has a large nucleolus and a thick layer of compartmentalized peripheral electron-dense material, probably heterochromatin (Figs. 20, 21); many mitochondria were observed in the cytoplasm near it (Fig. 20). A thick layer of tissue around the convoluted duct and bladder consists of muscle fibres embedded in much fibrous material, some nuclei, cisternae of agranular endoplasmic reticulum (?), and some flame bulbs and protonephridial capillaries (Figs. 17-19,21). Different parts of the tissue around
Ultrastructure of the protonephridial system of A. cirrusspiralis
449
FIGS.$7~20. Sections through one excretory bladder (EB). Fig. 17: section through bladder, convoiuted duct(X) with nucieus
(N) on left and excretory pore (EP) on right. Figs. 18 and 19: sections through wall of bladder with lamellae (L) on surface, many muscle fibres (ML), nucleus (N), protonephridial capillaries (C), many cisternae of agranular endoplasmic reticulum (?) (small arrows in Fig. 19), and much fibrous matrix. Fig. 20: part of Fig. 21 at higher magnification. Note nucleus of convoluted duct with large nucleolus and peripheral dense layer, and numerous mitochondria (MI) in cytoplasm. Scale bars, IO pm (Fig. 17), I pm (Figs. 18-20).
K. ROHDE. N.
A. WATSON and F. R. ROUBAL
FIGS. 21-22. Sections through convoluted duct. Fig. 21: nucleus (N) of convoluted duct (X) and adjacent part of excretory bladder (EB). Note lamellae (L) at surface of bladder wall and convoluted duct, and flame bulb (F). Fig. 22: connection between convoluted duct on left and excretory bladder (EB) on right. Note numerous lamellae. Scale bars, 1 pm.
the bladder vary considerably in their composition: some parts are particularly rich in mitochondria (Fig. 26) others are particularly rich in cistemae of agranular endoplasmic reticulum (Fig. 19), and others again contain a conspicuously large number of muscle fibres, arranged in a predominantly circular fashion near the excretory pore (Fig. 25). The surface area of the wall lining the bladder is enlarged by numerous lamellae (Figs. 18, 19,21,22,25,26). The narrow part of the bladder, close to the excretory pore, contains densely packed lamellae that are arranged more or less parallel with the duct connecting the bladder to the pore (Figs. 17, 23-25). The excretory pore is lined by tegument (Figs. 23,24). Many outfoldings of the basal lamina protrude into the tegument around the excretory pore (Fig. 23) and into the wall of the bladder near the pore (Fig. 25). DISCUSSION
Studies of many species of free-living and parasitic Platyhelminthes have shown that the ultrastructure of
the protonephridia is useful for phylogenetic considerations in the phylum (see recent review by Rohde, in press). Uniformity of the flame bulbs and protonephridial capillaries within certain parasitic taxa shows this particularly well. Thus, all nine genera of Trematoda Digenea, three genera of Trematoda Aspidogastrea and nine genera of Monogenea examined prior to this study have flame bulbs containing two cytoplasmic cords continuous with the proximal canal cell (Table 1); a junction in the wall of the proximal protonephridial capillary is a continuation of the septate junction between the cords. Udonella, two amphilinid genera, Gyrocotyle and seven genera of Eucestoda lack the cytoplasmic cords and junction (Table 1) (see also Xylander, 1987b). Anoplodiscus is the only species of Monogenea examined to date that has a flame bulb resembling not only the Monogenea but the Cestoda. In the lack of hooks, the adult stage of Anoplodiscus also differs from most monogeneans. However, the presence of 16
Ulttastructure of the protonephridial system of A. cirrusspiralis
FIGS.23-26. Sections through part of excretory bladder near excretory pore. Fig. 23: excretory pore (EP) lined by te~ument (T), narro w connection between excretory pore and bladder (EB) filled with iamellae (L). Arrow indicates protrusion of basal lamina into 1tegument. Figs. 24 and 25: distal and proximal parts of connection between excretory pore and bladder at higher magnification. Note numerous IameHae (L). evaginations of basal lamina into wall of bladder (arrows), and muscle fibres (ML) a short distance below basal lamina. Fig. 26: wall of excretory bladder witb ‘Lamellaeand many mitochondria (MI). Scale bars, I pm.
Philophthalmus cercaria Parorchis cercaria Cryptocotyfe cercaria Cyathocotyle Paucivitellosus cercaria Neophosis Trematoda Aspidogastrea ~batostoma Multicotyk larva and adult Rugogaster Monogenea Polyopisthocotylea Gotocotyla
Cionorchis Paragonimus metacercaria and juvenile Schistosoma miracidium, cercaria and adult Austrobilharzia cercaria ~~aehy~aimus
Trematoda Digenea Fasciola miracidium and adult
Taxon
+
+ + +
+
f + +
f
Rugogastridae
Gastrocotylidae
4.
Aspidogastridae
Cyathocotylidae Bivesiculidae
Heterophyidae
+
+
7
+
+ +
+ +
f
+
+
Ksie, 1973
?
Rohde, I980
Unpublished observations
Rohde. 1989a Rohde, 1970,1971,1972,1982
Erasmus, 1967 Unpublished observations
?
Rees, 1977
Rees. 1967
?
Philophthalmidae
Unpublished observations
Senft, Philpott & Pelofsky, 1961; Ebrahimzadeh & Kraft, 1971; Pan, 1980
Kiimmel, 1958,1959; Kiimmei 8r Brandenburg, 1961; Pante.louris & Threadgold, 1963; Wilson, 1969; Bennett & Threadgold, 1973; Wilson &Webster, 1974; Brandenburg, 1974; Bennett, 1977 Jeong, Rim, Kim, Kim 8r Yang, 1980 Orido. 1987
Author
_
Microvilli in proximal capillaries
Philophthalmidae
+ +
+
? +
+ + +
+
Septate junction(s) in capillaries
+
Lameilae in small capillaries
Soboleva, Zdarska, St.%ba & Valkounova, 1988 Unpublished observations
+
+
+
+ +
Brachylaemidae
+
+
Schistosomatidae
+ f
?
+
+ f
? +
Opisthorchiidae Paragonimidae
f
Ciliary rootlets
Schistosomatidae
+
+
Fasciolidae
Family
Internal leptotriches
OF FLAME BULBS AND PROTONEPHRIDIAL CAPILLARIES OF THE NEODERMATA
External leptotriches
~--CHARACTERISTICS
Cytoplasmic cords
TABLE
Diagramma
plerocercoid and adult
Diphyllobothrium
procercoid and plerocercoid
Triaenophorus
Lacistorhynchus
plerocercoid
NybeI~ia
Caryophyllaeus
larva and adult Eucestoda
Gyrocotyle
Gyrocotylidea
Amphilina
larva and adult
Awtramphilina
Amphilinidea
(idon&
Udonellidea
Anoplodiscus
Diplectanidae gen.
Lamellodiscus
ElUetWila
Ancyroeephaiinae gen.
D~iy~ogy~s
Gyrodactyhu
Calceostoma
Loimosinn
Monogenea Monopisthocotylea
Polystomoides
HexosIoma
Taxon
TABLE 1 Conrinued
Diphyllobothriidae
Caryophyllidea Caryophyllaeidae Trypanorhyncha Tentaculariidae Lacistorhynchidae Pseudophyllidea Triaenophoridae
Gyrocotylidae
Amphilinidae
Austramphilinidae
Udonellidae
Diplectanidae Diplectanidae Anoplodiscidae
?
?
?
? ?
?
? ? ?
+
_
(+)
(+I
(+I
+ ? (+I +
?
? + +
_
(+)
+
+
+
+
+
+
+ + + +
He~ostomatidae Polystomatidae
+ + + + +
1 +
? +
? +
Family
Loimoidae Calceostomatidae Gyrodactylidae Dactylogyridae Dactylogyridae
Internal leptotriches
External leptotriches
Cytoplasmic cords
?
+
+
+
+
+
+ +
+ + +
? ? +
+
? ? +
?
? ? ?
+ + + + +
? +
+ +
? +
Septate junction(s) in capillaries
Lamellae in small capillaries
Ciliary rootlets
1.
+
+
+
?
?
Microvilli in proximal capillaries
Justine & Watson, Justine & Watson, 1989b Watson & Roubal, Watson & Roubal,
1989b 1989b
1989 1989
Continued
van Bonsdorff & Teikka, 1966 Yamane, 1968; Kuperman, 1988 Kuperman, 1988
Lumsden & Hildreth. 1983 Kuperman. 1988
Kuperman, 1988
Kuperman, 1988
Xylander, thesiscited above, 1987a
Rohde & Georgi. 1983: Rohde & Watson, 1987. 1988; unpublished observations Xylander, W.E.R., unpublished Ph.D thesis, University of Gottingen, 1986
Rohde, Watson & Roubal, 1989a
Clement & Foumier, 1981 Unpublished observations Unpublished observations This paper
Rohde, Rohde, Rohde, Rohde, Rohde,
Rohde. 1980 Rohde, 1973.1975, 1982
Author
1
Continued
Taeniidae
Taerziarhynchus
Hymenolepididae
Catenotaeniidae
Hymenolepis
Carenotaeniu
-
-
-
?
7
? ? ? -
Cytoplasmic cords
(-t)
(+)
(+)
(+)
?
(+)
? ? ?
External leptotriches
+
+
f +
I-
?
+
? f ‘? +
Internal leptotriches
+
+
f +
+
?
+
? ? ? +
Ciliary rootlets
?
?
?
?
?
? ? ? ?
? ? 7 _
7
Septate junction(s) in capillaries
Lamellae in small capillaries
+
+
+ ?
+
+
+
+ + + +
Microvilli in proximal capillaries
Kuperman, 1988 Kuperman, 1988 Kuperman, 1988 McCulIough & Fairweather, 1991 Morseth, 1967; Sakamoto & Sugimura, 1969 Nieland & Weinbach, 1968; CardenasRamirez, Zaragoza & Gonzalez-de1 Phego, 1982 Slais, Serbus & Schramlova, 1971; Slais, 1973 Howells, 1969 Swiderski, Euzet & SchGnenberger, 1975 Swiderski, Euzet & SchBnenberger, 1975; Lumsden & Specian, 1980 Swiderski, Euzet & Schonenberger, 1975
Author
?-Not examined. (+) weakly developed. Adult stages if not otherwise indicated. Classification according to Yamaguti (1958a,b), classification of Anoplodixus according to Ogawa & Egusa (1981).
Anoplocephalidae Anoplocephalidae
Inermicapsijer
Moniezia
cysticercus
Taeniidae
Diphyllobothriidae Bothriocephalidae Amphi~otyiidae Cyclophyllidea Triloculariidae Taeniidae
Family
protoscolex Taenia cysticercus
Echinococcus
juvenile
Trikmdaria
Eu~ff~hrj~~
Bothriocephalus
Schistocephalus
Taxon
TABLE
F g f”
7:
455
Ul~astm~ture of the proto~~h~di~ system of A. cirr~sp~u~js marginal hooks in the larva, which are gradually lost in the developing juvenile (Ogawa & Egusa, 1981), indicates that the genus is a monogenean. In Anoplodiscus, adjoined membranes resembling septate junctions were observed in the wall of the capillary near the tip of the flame, although they never extend completely through the wall. Such membranes indicate that lack of cytoplasmic cords and junctions in Anoplodiscus is secondary, due to fusion of the ends of the capillary wall once in contact with each other. Studies of the development of the protonephridia in this species are necessary to confirm this. Arrangement of ‘external’ and ‘internal’ ribs in a single circle in which alternating ribs are not distinctly external or internal to each other has previously been shown to occur in the two monogeneans Gotocotylu (see Rohde, 1982) and Gyrodactylus (see Rohde, 1989b), and does not seem to have any phylogenetic significance in view of occurrence of the normal (external plus internal) and abnormal pattern (in one row) in obviously related taxa and the fact that it is a very slight modification of the same basic structural ‘plan’. The aberrant structure of the flame bulbs of Anoplodiscus may indicate that the genus simply is an aberrant monogenean; alternatively, it may indicate that the genus is phylogenetically close to the cestodes (including the gyrocotylids and amphilinids), i.e. that the sister group of the cestodes is to be found among the monopisthocotylean Monogenea. However, in the only ultrastruct~~ study of the development of the flame bulbs, i.e. those in Austramphilina elonguta, Rohde & Watson (1988) did not see a septate junction at any stage of development, whereas according to unpublished observations on the development of the flame bulbs of three species of cercariae, a junction is present at a very early stage of development in the trematodes (and probably also in the monogeneans). Thus, it seems that lack of cytoplasmic cords and junction in Anoplodiscus on the one hand and in the cestodes on the other has convergently evolved in different ways. This conclusion is further supported by different protonephridial capillaries: lamellae in Anop~od~s~~, other Monogenea and Trematoda, short microvilli in the cestodes. The epithelium lining the excretory bladder and connecting duct of Anoplodiscus has many surface lamellae, as also shown to occur in the bladder of trematodes, e.g. Lobatostoma manteri (see Rohde, 1989a). Particularly well-develops and densely packed lamellae in the ducts leading into and out of the bladder may indicate that they contribute to blocking the entry into and exit from the bladder of urine, which is then discharged by pressure from the surrounding tissue including its muscle fibres. They may also
contribute to re-absorption of molecules from the urine. However, experimental evidence for these suggestions is not available. study was supported by grants from the Australian Research Council and the University of New England. We wish to thank Peter Garlick for making facilities at the Electron Microscope Unit, UNE, available to us, Rick Porter for developing and Zoltan Enoch for printing the EM graphs, and Sandy Higgins, Barbara Rochester and Steph West for typing the manuscript. Angela Nesic helped with the ink drawing. Acknow~edgement~~is
REFERENCES BENNE~ C. E. & THREAD~OLDC. T. 1973. Electron microscope studies of Fasciola hepatica XIII. Fine structure of newly excysted juvenile. Experimental Parasitology34 85-99. BENNE~ C. E. 1977. Fasciula hepatica: development of excretory and parenchymal systems during migration in the mouse. Experimental Parasitology 41: 42644 1. BONSDORFF C.-N. VON & TELKK~~ A. 1966. The flagellar structure of the flame cells in fish tapeworm (Diphyllobothrium 169-179.
latum). Zeitschrift fir Zelijorschung
70:
BRANDENBURGJ. 1974. The morphology of the protonephridia. Fortsc~~tte der Zoologie 23: l-15. CARDENAS-RAMIREZ L., ZARAGOZA A. M. & GONZALEZ-DEL PLIEG~ M. 1982. Neural and excretory structures of Cysticercus cellulosae. In: Cysticercosis; Present State of Knowledge and Perspectives (Edited by FLISSER A., WILLMS K., LACLEI?EJ. P., LARRALDE C., RIDAWAC. & BELTRAN F.), pp. 281-305. Academic Press, New York. CLEM~~NT P. & FOURNIERA. 1981. Un appareil excr&eur prim&if: ies proton6phridies (Plathelminthes et N&nathehninthes). Bulletin de la SociM Zoologique de France 106:55-67. EBRAHIMZADEH A. & KRAFT M. 1971. Ultrastrukturelle Untersuchungen zur Anatomic der Cercarien von Schistosoma mansoni. II. Das Exkretionssystem. Zeitschr~t~r
Paras~tenkun~
36: 265-290.
ERASMUSD. A. 1967. Ultrastructural observations on the reserve bladder system of Cyathocotyle bushiensis Khan, 1962 (Trematoda: Strigeoidea) with special reference to lipid excretion. Journal of Parasitology 53: 525-536. HOWELLS R. E. 1969. Observations on the nephridial system of the cestode Moniezia expansa (Rud. 1805). Parasitology 59: 449450. JEONG K.-H., RIM J.-J., KIM W.-K., KIM C.-W. &YANG H.Y. 1980. A study of the fine structure of Cionorchis sinensis,
a liver fluke. II. The alimentary tract and the excretory system. Korean Journal of Parasitology18:8 l-9 1. K~IE M. 1973. The host-parasite interface and associated structures of the cercaria and adult Neophasis lageniformis (Lebour, 1910). aphelia 12:205-219. KOMMELG. 1958. Das Terminalorgan der Protonephridien, Feinstruktur und Deutung der Funktion. Zeitschrijt ftir Naturforschung 13b:627629. KOMMELG. 19.59. Feinstruktur der Wimperflamme in den Protonephridien. Protoplasma Sl: 371-376.
456
K. ROHDE. N. A. WATSON and F. R. ROUBAL
KOMMELG. & BRANDENBURG J. 1961. Die Reusengeisselzellen (Cyrtocyten). Zeitschriftfir Naturforschung 16b: 692-697. KUPERMAN B. I. 1988. [Functional Morphology of Lower Cestodes. Ontogenetic and Evolutionary Aspects.] ‘Nauka’, Leningrad (in Russian). LUMSDEN R. D. & SPECIAN R. 1980. The morphology, histology, and fine structure of the adult stage of the cyclophyllidean tapeworm Hymenolepis diminuta. In: Biology ofthe Tapeworm Hymenolepis diminuta (Edited by ARAI H. P.), pp. 157-280. Academic Press, New York. LUMSDENR. D. & HILDRE~H M. B. 1983. The fine structure of adult tapeworms. In: Biology of the Eucestoda (Edited by ARME C. & PAPPAS P. W.), pp. 177-233. Academic Press, London. MCCULLOUGHJ. S. & FAIRWEATHERI. 1991. Ultrastructure of the excretory system of Trilocularia acanthiaevulgaris (Cestoda, Tetraphyllidea). Parasitology Research 17: 157160. MORSETH D. J. 1967. Fine structure of the hydatid cyst and protoscolex of Echinococcus granulosus. Journal of Parasitology 53: 3 12-325. NIELAND M. L. & WEINBACH E. C. 1968. The bladder of Cysticercus fasciolaris: electron microscopy and carbohydrate content. Parasitology 58: 489-496. OGAWA K. & EGUSA S. 1981. The systematic position of the genus Anoplodiscus (Monogenea: Anoplodiscidae). Systematic Parasitology 2: 253-260. ORIDO Y. 1987. Metamorphosis of the excretory system of Purugonimus ohirai (Trematoda), with special reference to its functional significance. Journalof Morphology 194: 303310. PAN S. C.-T. 1980. The fine structure of the miracidium of Schistosoma mansoni. Journal of Invertebrate Pathology 36: 307-372. PANTELOURISE. M. & THREADGOLDL. T. 1963. The excretory system of the adult Fasciola hepatica L. Cellule 64: 61-67. REES F. G. 1977. The development of the tail and the excretory system in the cercaria of Cryptocotyle lingua (Creplin)(Digenea: Heterophyidae) from Littorina littoreu (L.). Proceedings of the Royal Society of London Series B 195: 425452. REES G. 1967. The histochemistry of the cystogenous gland cells and cyst wall of Parorchis acanthus Nicoll, and some details of the morphology and fine structure of the cercaria. Parasitology 57: 87-l 10. ROHDE K. 1970. Ultrastructure of the flame cells of Multicotylepurvisi Dawes. Naturwissenschaften 57: 398. ROHDE K. 1971. Untersuchungen an Multicotyle purvisi Dawes, 1941 (Trematoda, Aspidogastrea). VIII. Elektronenmikroskopischer Bau des Exkretionssystems. International Journalfor Parasitology 1: 275-286. ROHDE K. 1972. The Aspidogastrea, especially Multicotyle purvisi Dawes, 1941. Advances in Parasitology 10: 77-15 1. ROHDE K. 1973. Ultrastructure of the protonephridial system of Polystomoides malayi Rohde and P. renschi Rohde (Monogenea, Polystomatidae). International Journal for Parasitology 3: 329-333. ROHDE K. 1975. Fine structure of the Monogenea, especially Polystomoides. Advances in Parasitology 13: 1-33. ROHDE K. 1980. Some aspects of the ultrastructure of
Gotocotyla secunda (Tripathi, 1954) (Monogenea: Gotocotylidae) and Hexostoma euthynni Meserve, 1938 (Monogenea: Hexostomatidae). Angewandte Purasitologie 21: 32-48. ROHDE K. 1982. The flame cells of a monogenean and an aspidogastrean, not composed of two interdigitating cells. Zoologischer Anzeiger 209: 3 1 l-3 14. ROHDE K. & GEORGI M. 1983. Structure and development of Austramphilina elongata Johnston, 1931 (Cestodaria, Amphilinidea). International Journal for Parasitology 13: 273-287. ROHDE K. & WATSON N. 1987. Ultrastructure of the protonephridial system of larval Austramphilina elongata (Platyhelminthes, Amphilinidea). Journal of Submicroscopic Cytology 19: 113-l 18. ROHDE K. 1988. Phylogenetic relationship of free-living and parasitic Platyhelminthes on the basis of ultrastructural evidence. Fortschritte der Zoologie (Progress in Zoology) 36: 353-357. ROHDE K. & WATSON N. 1988. Development of the protonephridia of Austramphilina elongata. Parasitology Research 74: 255-261. ROHDE K. 1989a. Ultrastructure of the protonephridial system of Lobatostoma manteri (Trematoda, Aspidogastrea). Journal of Submicroscopic Cytology and Pathology 21: 599-610. ROHDE K. 1989b. Ultrastructure of the protonephridial system of Gvrodactylus (Monogenea, Gyrodactylidae). Zoologischer Anzeiger 233: 3 1 l-322. ROHDE K.. JUSTINEJ.-L. &WATSON N. 1989. Ultrastructure of the flame bulbs of the monopisthocotylean Monogenea Loimosina wilsoni (Loimoidae) and Calceostoma herculanea (Calceostomatidae). Annales de Parasitologie Humaine et Comparee 64: 433442. ROHDE K., WATSONN. & ROUBALF. 1989a. Ultrastructure of flame bulbs, sense receptors, tegument and sperm of Udonella (Platyhelminthes) and the phylogenetic position of the genus. Zoologischer Anzeiger 222: 143-157. ROHDE K., WATSONN. & ROUBALF. 1989b. Ultrastructure of the protonephridial system of Dactylogyrus sp. and an unidentified ancyrocephaline (Monogenea: Dactylogyridae). International Journal for Parasitology 19: 859864. ROHDE K. 1990. Phylogeny of Platyhelminthes, with special reference to parasitic groups. International Journal for Parasitology 20: 979-1007. ROHDE K. 1991. The evolution of protonephridia of the Platyhelminthes. Hydrobiologia 227: 3 15-32 I ROUBALF. R., ARMI~AGEJ. & ROHDE K. 1983. Taxonomy of metazoan ectoparasites of snapper, Chrysophrys nuratus (family Sparidae), from southern Australia, eastern Australia and New Zealand. Australian Journal of Zoology Supplement 94: 1-68. SAKAMO~OT. & SUCIMURAM. 1969. Studies on Echinococcus XXI. Electron microscopical observations on genera1 structure of larval tissue of multilocular Echinococcus. Japanese Journal of Veterinary Research 17: 67-80. SENFT A. W., PHILPOTT D. E. & PELOFSKY A. H. 1961. Electron microscope observations of the integument, flame cells and gut of Schistosoma mansoni. Journal of Parasitology 47: 2 17-22 1.
Ultrastructure
of the protonephridial
J., SERBUSC. & SCHRAMLOVA J. 1971. The microscopical anatomy of the bladder wall of Cysticercus bovis at the electron microscope level. Zeitschrifi fir Parasitenkunde 36: 304-320. SLAB J. 1973. Functional morphology of cestode larvae. Advances in Parasitology 11: 395480. SOBOLEVA T. N., ZDARSKA Z., STERBAJ. & VALKOUNOVAJ. 1988. Ultrastructure of the excretory system of Brachylaimus aequans (Trematoda: Brachylaimoidea). Folia Parasitologica 35: 335-339. SWIDERSKIZ., EUZET L. & SCH~NENBERGERN. 1975. Ultrastructure du systkme nephridien des cestodes cyclophyllides Catenotaenia pusilla (Goeze, 1782), Hymenolepis diminuta (Rudolphi, 1989) et Intermicapsifer madagascariensis (Davaine, 1870) Baer, 1956. Le Cellule 71: 7-18. WILSON R. A. 1969. The fine structure of the protonephridial of the miracidium of Fasciola hepatica. system Parasitology 59: 461467. SLAB
system of A. cirrusspiralis
457
WILSON R. A. & WEBSTER L. A. 1974. Protonephridia. Biological Reviews 49: 127-160. XYLANDERW. E. R. 1987a. Ultrastructure of the lycophora larva of Gyrocofyle urna (Cestoda, Gyrocotylidea). III. The protonephridial system. Zoomorphology 107: 88-95. XYLANDERW. E. R. 1987b. Das Protonephridialsystem der Cestoda: Evolutive Verlnderungen und ihre mBgliche funktionelle Bedeutung. Verhandlungen der Deutschen Zoologischen Gesellschaft 80: 257-258. YAMACUTI S. 1958a. Sysfema Helminihum. I. The Digeneric Trematodes of Vertebrates, Parts I and 2. Interscience Publications, New York. YAMAGUTI S. 1958b. Systema Helminthum. II. The Cestodes of Vertebrates. Interscience Publications, New York. YAMANEY. 1968. On the fine structure of Diphyllobothrium erinacei with special reference to the tegument. Yonago Acta Medica 12: 169-181.