Saprolegnia - The iLumina Digital Library

It would appear on the surface that Saprolegnia uliginosa is a relatively rare
species. One of the Norwegian isolates in our collections is latent in the development of
its sporangia and the sexual apparatus, and grows very slowly in water culture. This
suggests that the species may be overgrown quickly by more rapidly developing
species, and thus not appear at all in gross cultures.
The description and illustrations of a Saprolegnia sp. recovered by Shibuya (1959)
suggest that he may have collected Johannes’ species, but we cannot be certain; we
include the Japanese record as an unconfirmed one.
CONFIRMED RECORDS: -- GERMANY: Johannes (loc. cit.). ICELAND: Howard
et al. (1970:77, fig.37). INDIA: J. N. Rai and Misra (1977b:76, fig. 3c). UNITED STATES:
Seymour (1970:47, figs. 78-84).
RECORDED COLLECTION: -- JAPAN: Shibuya (1959:149, fig. 4)().
SPECIMENS EXAMINED: -- ICELAND (1), NORWAY (2), TWJ. UNITED
STATES (5), RLS.
Saprolegnia furcata Maurizio
Z. Fischerei und deren Hilfswiss. Mitt. Deutsch. Fischerei-Vereins 7:48 et seq., figs. 13-15.
1899
(Figure 97 E-I)
Saprolegnia retorta Horn, Ann. Mycol. 2:233, fig. 21. 1904.
Monoecious. Mycelium moderately delicate, sparingly branched. Sporangia
clavate, cylindrical, or fusiform, straight, curved, or irregular; renewed internally or by
cymose branching; 60-420 x 16-40 µm. Spores dimorphic; discharge and behavior
saprolegnoid; primary spore cysts 10-13 µm in diameter. Gemmae sparse; clavate,
spherical, subspherical, pyriform, or irregular; terminal, single. Oogonia lateral,
occasionally terminal, very rarely intercalary; obpyriform or napiform, infrequently
spherical, very rarely dolioform; (33-) 43-48 (-81) µm in diameter. Oogonial wall
unpitted or sparsely pitted; smooth. Oogonial stalks ( 1 / 2 -) 1-6 (-8) times the diameter of
the oogonium, in length; slender, branched or unbranched; usually coiled, strongly
bent, or irregular and twisted. Oospores centric, rarely subcentric; spherical; (1-) 4-10
(-28) per oogonium, and usually nearly filling it; (16-) 20-24 (-45) µm in diameter;
germination not observed. Antheridial branches predominantly androgynous, rarely
monoclinous or diclinous; slender, occasionally branched, usually twisted or irregular;
infrequently bearing oogonia; persisting. Antheridial cells simple; tubular, clavate, or
irregular, rarely once-branched; persisting; laterally or apically appressed; fertilization
tubes present, not persisting.
The strongly bent (Fig. 97 F) or conspicuously coiled (Fig. 97 E), relatively long
oogonial stalks constitute the chief feature by which this species can be recognized.
Maurizio (loc. cit.) emphasized that the antheridial branches in Saprolegnia furcata could
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