PLATE 1
Figs. 1-5. Chytriomyces hyalinus Karling (Karling, 1945).
Fig. 1. Young thallus.
Fig. 2. Mature operculate, non-apophysate zoosporangium with coarse, thick-walled rhizoidal axis.
Fig. 3. Emerging zoospores in an exogenous discharge vesicle.
Fig. 4. Mature apophysate resting spore.
Fig. 5. Ovoid, 3-3.5 × 5-5.5 µm zoospore with a hyaline refractive globule.
Figs. 6-11. Chytriomyces aureus Karling. Figs. 6, 8-11 after Karling, 1945; fig. 7 after Karling, 1977.
Fig. 6. Young apophysate thallus.
Fig. 7. Apophysate zoosporangium with the large primary nucleus.
Fig. 8. Mature operculate, apophysate zoosporangium.
Fig. 9. Discharged zoosporangium.
Fig. 10. Mature resting spore.
Fig. 11. Ovoid, 3-3.5 × 5 µm zoospore with a golden-red globule.
Figs. 12-15. Chytriomyces hyalinus v. granulatus Karling (Karling, 1967).
Fig. 12. Young operculate, apophysate thallus.
Fig. 13. Spherical, 5-6 µm diam. zoospore with numerous granules.
Fig. 14. Zoospores swarming in an exogenous discharge vesicle.
Fig. 15. Mature resting spore.
Figs. 16-21. Chytriomyces nodulatus Haskins (Haskins, 1946).
Fig. 16. Mature, operculate apophysate thallus.
Figs. 17, 18. Stages of dehiscence of the zoosporangium showing operculum and vesicle.
Fig. 19. Empty zoosporangium with two nodules
Fig. 20. Ovoid, 3-4.5 µm zoospore with a single refractive oil globule near point of attachment of flagellum.
Fig. 21. Resting sporangium.
Figs. 22-28. Chytriomyces elegans (Ingold) Dogma. Fig. 22 after Ingold, 1944; figs. 23, 27 after Canter, 1961; figs. 24-26, 28 after Paterson, 1958.
Fig. 22. Young, immature thallus.
Fig. 23. Mature thallus.
Figs. 24-26. Stages in the vesicular discharge of the operculate zoosporangium.
Fig. 27. Mature resting spore; associating bodies with apophyses.
Fig. 28. Spherical, 3.5-4.5 µm zoospores with eccentric oil globule.
Figs. 29-35. Chytriomyces closterii Karling (Karling, 1949)
Figs. 29, 30. Two stages of development and maturation of zoosporangium with sparsely branched rhizoidal axis.
Fig. 31. Vesicle discharge of zoospores.
Fig. 32. Zoospores swarming in vesicle prior to release.
Figs. 33. Mature resting spores.
Fig. 34. Germinating resting spore.
Fig. 35. Spherical, 2-2.5 µm diam. zoospores.
PLATE 2
Figs. 36-40. Chytriomyces cosmaridis Karling (Karling, 1967).
Figs. 36, 37. Developing sporangia, each surrounded by a halo.
Fig. 38. Zoospores swarming in and escaping from an exogenous discharge vesicle.
Fig. 39. Resting spore.
Fig. 40. Spherical, 2-2.6 µm diam. zoospores with a brilliantly refractive yellow-orange globule.
Figs. 41-44. Chytriomyces nagatoroensis Konno (Konno, 1972).
Fig. 41. Developing sporangium.
Fig. 42. Empty sporangium with non-persistent operculum.
Fig. 43. Spherical resting spore with rough wall.
Fig. 44. Ovoid, 3.5 µm diam. zoospores.
Figs. 45-50. Chytriomyces tabellariae Canter (Canter, 1949).
Fig. 45. Three stages in early development of thallus on Tabellaria flocculosa.
Fig. 46. Spherical, 3 µm diam. zoospore with single refractive globule.
Fig. 47. Mature sporangium.
Fig. 48. Empty sporangia.
Fig. 49. Mature resting spore.
Fig. 50. Resting spore formed by rounding off of protoplasm of the sporangium.
Figs. 51-56. Chytriomyces gilgaiensisWilloughby (Willoughby, 1965).
Fig. 51. Encysted zoospore with beak-
like protrusion.
Fig. 52. Young thallus.
Fig. 53. Mature thallus with delineated zoospores and lobed haustorium.
Fig. 54. Dehisced sporangium with detached operculum.
Fig. 55. Dehisced sporangium with a single residual zoospore.
Fig. 56. Pyriform, tuberculate resting spores.
Figs. 57-61. Chytriomyces heliozoicola Canter (Canter, 1966).
Fig. 57. Immature sporangium.
Fig. 58. Mature sporangium.
Fig. 59. Empty sporangia.
Fig. 60. Resting spores with 1-2 large refractive globules.
Fig. 61. Spherical, 2.5-3 µm diam. zoospores, with an anterior spherical highly refractive globule and a posterior less refractive oval body.
Fig. 62-65. Chytriomyces rhizidiomycis Dogma (Dogma, 1983).
Fig. 62. Germling, and immature, mature, and discharged sporangia on Rhizidiomyces bivellatus.
Fig. 63. Young zoosporangium with single (a) and two (b) discharge tubes; zoospores escaping through discharge tube (c); two zoospores encysted in situ in empty zoosporangium (d).
Fig. 64. Mature resting spores.
Fig. 65. Spherical, 2-2.5 µm diam. zoospores with a central cluster of colorless globules.
PLATE 3
Figs. 66-69. Chytriomyces stellatus Karling, 1947. All figures after Karling, 1977.
Fig. 66. Sparsely spiny apophysate zoosporangium with two exit canals which are filled with hyaline matrix.
Fig. 67. Zoosporangium with two exit papillae.
Fig. 68. Mature, stellate resting spores.
Fig. 69. Ovoid 3.5-4 × 4.5-5 µm zoospore with a single hyaline refractive globule.
Figs. 70-74. Chytriomyces appendiculatus Karling (Karling, 1947).
Fig. 70. Maturing zoosporangium with thickened wall and primary nucleus within.
Fig. 71. Mature, thick-wall zoosporangium with coarse, thick-walled rhizoidal axis; sac-shaped area of hyaline matrix underneath the operculum.
Fig. 72. Exogenous discharge vesicle containing quiescent zoospores.
Fig. 73. Mature resting spore.
Fig. 74. Ovoid, 4-5 × 6-6.5 µm zoospore with single refractive hyaline globule.
Figs. 75-78. Chytriomyces lucidus Karling (Karling, 1949).
Fig. 75. Mature zoosporangia filled with large brilliant refractive globules; rhizoidal axis thick-walled.
Fig. 76. Zoospores in an exogenous discharge vesicle.
Fig. 77. Mature resting spores filled with polyhedral refractive bodies.
Fig. 78. Ovoid, 5.8-6.2 µm zoospores with large refractive globule.
Figs. 79-83. Chytriomyces fructicosus Karling (Karling, 1949).
Fig. 79. Bi-apophysate, fully formed sporangium with large primary nucleus.
Fig. 80. Portion of mature thallus.
Fig. 81. Discharge of zoospores into an exogenous vesicle, from a sporangium with two discharge tubes.
Fig. 82. Spiny hyaline resting spore.
Fig. 83. Ovoid, 3.8-4.2 × 5.5-6 µm zoospore with hyaline, spherical refractive globule.
Figs. 84-88. Chytriomyces spinosus Fay (Fay, 1947).
Fig. 84. Spiny zoosporangium; hyaline matrix filling upper ⅓ of zoosporangium.
Fig. 85. Two stages in formation of the vesicle and emergence of the zoospores.
Fig. 86. Mature ovoid resting spore with large refractive globule.
Fig. 87. Germination of secondary sporangium from resting spore.
Fig. 88. Ovoid and spherical, 3-4.5 µm diam. zoospores with a hyaline refractive globule.
Figs. 89-95. Chytriomyces confervae (Wille) Batko, 1975. Figs 89-91 after Canter, 1962; figs. 92-95 drawn from living material by Letcher.
Fig. 89. Encysted zoospore and germling.
Fig. 90. Immature sporangium and halves of the split zoospore cyst.
Fig. 91. Immature sporangium with vacuoles and two horns.
Fig. 92. Mature sporangium with hyaline matrix below operculum.
Fig. 93. Zoospores in an exogenous discharge vesicle.
Fig. 94. Spherical to subspherical, hyaline resting spores, both epibiotic and endobiotic.
Fig. 95. Spherical, 5 µm diam. zoospores with eccentric hyaline refractive globule.
PLATE 4
Figs. 96-100. Chytriomyces verrucosus Karling (Karling, 1960).
Fig. 96. Sporangium of Karlingiarosea parasitized by five thalli of Chytriomyces verrucosus.
Fig. 97. Zoospore discharge in a thin, slimy layer.
Fig. 98. Empty sporangium.
Fig. 99. Resting spores with verrucose wall.
Fig. 100. Spherical, 2.2.8 µm zoospores with small refractive globule.
Figs. 101-105. Chytriomyces reticulatus Persiel. Figs. 101, 102A, 103-105 after Persiel, 1960; fig. 102B after Willoughby, 1965.
Fig. 101. Immature sporangium with small apophysis.
Fig. 102. Two empty sporangia with collapsed opercula.
Fig. 103. Resting spore with thick, reticulated, ridged wall.
Fig. 104. Germinated resting spore.
Fig. 105. Spherical, 2-5-3.5 µm diam. hyaline zoospore.
Figs. 106-110. Chytriomyces mammilifer Persiel (Persiel, 1960).
Fig. 106. Maturing zoosporangium.
Fig. 107. Partly dehisced sporangium with large operculum.
Fig. 108. Mature resting spore with mammiliform ornamentation.
Fig. 109. Germinating resting spore.
Fig. 110. Spherical, 3.5-4.5 µm diam. zoospores with single refractive globule.
Figs. 111-114. Chytriomyces vallesiacus Persiel (Persiel, 1960).
Fig. 111. Immature and mature sporangia on pollen grain.
Fig. 112. Empty, cupule-shaped
zoosporangium with large collapsed operculum.
Fig. 113. Mature resting spore, with characteristic vacuole, on pine pollen.
Fig. 114. Subspherical, 3-3.5 µm diam. zoospore with single, refractive, eccentric globule.
Figs. 115-119. Chytriomyces suburceolatus (Willoughby) Willoughby Figs. 115-117, 119 after Willoughby, 1956; fig. 118 after Willoughby,1965.
Fig. 115. Developmental stages of sporangia.
Fig. 116. Two suburceolate sporangia.
Fig. 117. Empty sporangia with both persistent and detached opercula.
Fig. 118. Resting spores with thick, brown wall and a single large refractive globule.
Fig. 119. Spherical, 2-2.5 µm diam. zoospores with single oil globule.
Figs. 120-124. Chytriomyces macro-operculatus Karling (Karling, 1981).
Fig. 120. Immature multioperculate sporangium.
Fig. 121. Emergence of zoospores surrounded by an exogenous vesicle.
Fig. 122. Spherical, 4-5.5 µm diam. zoospores with grayish granular content and a minute refractive globule.
Fig. 123. Empty multioperculate sporangium.
Fig. 124. Resting spore with smooth reddish-brown wall and coarsely granular content.
Fig. 125. Chytriomyces macro-operculatus v. hirsutus Karling (Karling, 1981). Sporangium, covered by a weft of hairs, with two rhizoidal axes arising at the base.
PLATE 5
Figs. 126-130. Chytriomyces reticulosporus Dogma (Dogma, 1983).
Fig. 126. Germling and immature sporangium on Spizellomyces punctatus.
Fig. 127. Initial, passive discharge of zoospores.
Fig. 128. Partially collapsed, empty sporangium with detached operculum.
Fig. 129. Mature resting spores: surface view (left) showing reticulum, and optical section (right) showing complex wall layers with granular content and small eccentric vacuole.
Fig. 130. Spherical, 2.5-3.5 µm diam. zoospores with large, sub-basal globule.
Figs. 131-136. Chytriomyces laevis Karling (Karling, 1987).
Fig. 131. Slightly stalked sporangium and apophysis, causing hypertrophy of Pythium mycelium.
Fig. 132. Sporangial dehiscence, with operculum being pushed up by mass of zoospores.
Fig. 133. Release of zoospores, with operculum remaining attached to edge of sporangium.
Fig. 134. Empty sporangium with detached, wrinkled operculum.
Fig. 135. Spherical resting spore with large central globule surrounded by smaller ones.
Fig. 136. Spherical, 2.5-3 µm diam. zoospores with conspicuous hyaline refractive globule.
Figs. 137-140. Chytriomyces mortierellae Persiel (Persiel, 1960).
Fig. 137. Multioperculate, non-apophysate zoosporangium on Mortierella hygrophila.
Fig. 138. Empty sporangium.
Fig. 139. Spherical granular mature resting spores with limited rhizoidal system.
Fig. 140. Ovoid, 2.5 × 3.5 µm
zoospores with eccentric globule.
Figs. 141-144. Chytriomyces multioperculatus Sparrow and Dogma (Sparrow and Dogma, 1973).
Fig. 141. Mature sporangium with true opercula surrounded by dehiscence zone surmounting discharge pores.
Fig. 142. Stipitate mature sporangium.
Fig. 143. Discharged sporangium, showing both persistent and detached opercula.
Fig. 144. Spherical, 3.5-4 µm diam. zoospores with single oil globule and lunate body.
Figs. 145-150. Chytriomyces parasiticus Karling (Karling, 1947).
Fig. 145. Apophysate young thallus, parasitic on mycelium of Aphanomyces laevis.
Fig. 146. Developing sporangium with large primary nucleus.
Fig. 147. Non-apophysate, maturing sporangium.
Fig. 148. Zoospores emerging in an exogenous discharge vesicle.
Fig. 149. Zoospores swarming in exogenous vesicle and escaping after rupture of vesicle.
Fig. 150. Ovoid, 2.5-3 µm diam. zoospores with a minute, hyaline refractive globule.
Figs. 151-156. Chytriomyces rotoruaensis Karling (Karling, 1970).
Fig. 151. Fully grown sporangium with large primary nucleus, and vacuoles at the base and apex.
Fig. 152. Maturing, oblong sporangium.
Fig. 153. Discharge vesicle elongate, narrow and cylindrical in the exit orifice end enveloping a group of zoospores in center of zoosporangium.
Fig. 154. Ovoid, 2.8-3.2 × 3-3.6 µm zoospores with small hyaline refractive globule.
Fig. 155. Mature resting spore.
Fig. 156. Germination of resting spore.
PLATE 6
Figs. 157-162. Chytriomyces willoughbyi (Willoughby) Karling (Karling, 1968).
Fig. 157. Stages in the development of a thallus in which the incipient sporangium is budding out of the apex of the zoospore cyst.
Fig. 158. Stages in the development of a thallus in which the zoospore cyst is enlarging to form the sporangium.
Fig. 159. Spherical (2.2-3 µm diam.) and amoeboid zoospores with single, anterior globule.
Fig. 160. Empty sporangia.
Fig. 161. Mature resting spore with fairly extensive branched rhizoids.
Fig. 162. Germination of resting spore.
Figs. 163-168. Chytriomyces annulatus Dogma. Figs. 163-167, Dogma, 1969; fig. 168, drawn from living material by Letcher.
Fig. 163. Early and mature sporangia.
Fig. 164. Dehiscing sporangium with hinged operculum.
Fig. 165. Empty sporangium.
Fig. 166. Spherical, 4.7-6.5 µm diam. zoospores with single globule.
Fig. 167. Dehisced sporangium in
which young thalli have developed from
trapped zoospores.
Fig. 168. Resting spore.
Figs. 169-174. Chytriomyces poculatusWilloughby and Townley. Figs. 169-171, 173 after Willoughby and Townley, 1961; figs. 172, 174 drawn from living material by Letcher.
Fig. 169. Young thalli at various stages of development.
Fig. 170. Large, mature sporangium.
Fig. 171. Dehisced sporangium with detached operculum.
Fig. 172. Spherical (3.5 µm diam.) and ellipsoid zoospores with single refractive globule.
Fig. 173. Dehisced sporangium with young thallus developing inside.
Fig. 174. Mature resting spores.
Figs. 175-179. Chytriomyces angularis Longcore (Longcore, 1992).
Fig. 175. Germling and two gibbose, young sporangia.
Fig. 176. Cluster of mature sporangia.
Fig. 177. Slightly ovoid, 4-5 µm diam. zoospores with single, large lipid globule.
Fig. 178. Dehisced sporangium with young thallus developing from trapped zoospore.
Fig. 179. Resistant sporangium.