VOUCHER SPECIMEN: LE 221993.; COLLECTION SITES: Stream 5 (both samples), dwarf forest soil, megaherbfield soil.

DESCRIPTION: Thallus polycentric, bearing numerous zoosporangia, these connected by long or short isthmuses, occasionally septate, with rhizoids arising along their length and from the periphery of the zoosporangia. Zoosporangia sac-like, ovoid, irregular, thin-walled, colourless, inoperculate, ranging from 10 to 60 µm in diam. Dehiscence by means of one or more long, straight or curved exit tubes or prominent papillae, the tip of the tube or papilla deliquescing and the initial emerging zoospores forming a globular mass at the exit orifice. As these disperse, the planospores within the zoosporangium swarm and emerge in a stream from the exit tube. Dormant sporangia yellowish amber, light and dark brown, thick-walled, terminal or subterminal, usually spherical, about 40 µm in diam. Zoospores ovoid to elongated, 3 x 5 µm, with numerous small refractive granules present.

Campbell Island

COMMENTS: Catenophlyctis variabilis is a ubiquitous species that has been recorded from all continents. It is a typical soil saprotroph that develops on chitin and keratin substrates and is easily recovered from soil and water samples on baits such as snake skin.
Colonies of C. variabilis species appear on these substrates before other fungi and bacteria. It is probably distributed by wind along with small particles of soil. Resting sporangia are formed very quickly and easily and remain in a living state for a long time.
The species has been isolated by the first author from soils of the Kola and Taimyr Peninsulas in the Russian Arctic (Pystina & Golubeva 1995).

Campbell Island: VOUCHER SPECIMEN: LE 221997. COLLECTION SITE: Stream 5.

DESCRIPTION: Thallus monocentric. Zoosporangia spherical, colourless, smooth-walled, 10-60 µm in diam., operculate, developing on the substrate in groups of 3-6. Operculum saucer-shaped, 5-8 µm in diam., apical or subapical. Rhizoids long, straight, richly branched, arising from the base of the zoosporangium. Zoospores oval, 3 x 5 µm, with a small colourless globule and flagellum, 18-20 µm long, discharging after the opening of the operculum and swarming in a vesicle. Resting spores spherical, 10-20 µm in diam, with a smooth colourless or light yellow wall and a large oil globule.

COMMENTS: This is a saprotroph that occurs only on chitin substrates in freshwater habitats. It has been reported from Europe, North and South America, and Africa.

Campbell Island: VOUCHER SPECIMEN: LE 221995. COLLECTION SITE: Stream 5.

DESCRIPTION: Thallus polycentric, intramatrical. Zoosporangia terminal or intercalary, without an apophysis, formed from the swellings of the rhizomycelium, spherical or citriform, 8-30 µm in diam., with small papillae or a rather thick discharge tube. Rhizomycelium consisting of intensive, branched, tenuous filaments that bear intercalary spindle organs 10-17 µm in diam. and with one or two septae. Zoospores spherical, 4.5-5.5 µm in diam. with colourless oil globule and flagellum 25- 28 µm long, emerging to form a globular mass at the exit orifice and after remaining quiescent for a while, then separating and swimming away. Resting spores spherical, 8-16 µm in diam., oval, broadly spindleshaped with a colourless smooth wall and one largecolourless oil globule.

COMMENTS: This species is a saprotroph of various types of dead plant material in water. It is widely distributed and has been recorded from freshwater habitats in Europe, North America, South America, and Africa.

Campbell Island: VOUCHER SPECIMEN: LE 221994. COLLECTION SITES: Streams 3, 4, 5, and 6.

DESCRIPTION: Thallus monocentric. Zoosporangia spherical, oval, ovoid, pyriform or oblong, 20- 250 µm in diam., with a smooth orange-brown wall and several exit papillae 2-12 µm high and 5-18 µm in diam., filled by a gelatinous plug of hyaline material and separated from the inner part of sporangium by a septum (endo-operculum). Rhizoid axes arising from the periphery or base of the sporangium and spreading and branching in the substrate and also extending extramatrically in the surrounding water for a distance of up to 600 µm. Resting spores spherical, oval, irregular with a smooth thick wall, containing several orange-brown globules.

COMMENTS: This species, which is considered to be a very common soil saprotroph, occurs mostly on cellulose substrates (i.e., plant debris). It is easily isolated, using pieces of onion epidermis, from samples of water and soil. Karlingia rosea has been recorded from Europe, the Americas, and Africa. Like C. variabilis, it is one of the first species to colonise cellulose substrates in water.

Campbell Island: VOUCHER SPECIMEN: LE 222000. COLLECTION SITE: Stream 4.

DESCRIPTION: Hyphae 1.5-7 µm in diam. Sporangia elongated, often branched, 80-170 µm in diam., germinate producing zoospores. Cysts 5-8 µm in diam. Oogonia terminal, intercalary, lateral, spherical, 14-24 µm in diam., smooth-walled. Antheridia monoclinal or diclinal, 1-2 per oogonium, antheridial cell club-shaped, attached to the oogonium by its apex. Oospore pleurotic with a smooth wall, 1-2 µm thick.

COMMENTS: This species commonly occurs as a saprotroph on plant and animal debris in freshwater habitats and also can be found in soil. It has been recorded as a parasite of fish, reptiles and their eggs, aquatic insects, and other invertebrates. Pythium monospermum has been recorded from Europe, Asia, North America, and Australia.

Campbell Island: VOUCHER SPECIMEN: LE 221996. COLLECTION SITE: Stream 6 (both samples).

DESCRIPTION: Thallus monocentric. Zoosporangia inoperculate, spherical or ellipsoidal, thin-walled, colourless, about 40 µm in diam., each with a short apical exit tube. Rhizoids sometimes absent or 1-2, arising from the base of the zoosporangium. Zoospores 5 x 8 µm, ovoid, with a large oil globule, emerging through the pore on the top of the papilla or exit tube and forming a globular mass enveloped in the hyaline matrix. Resting spores were not observed.

COMMENTS: This species occurs as a saprotroph on various types of plant debris in water and also has been isolated from soil on cellulose substrates. It has been recorded from Europe, Asia, and South America.

Campbell Island: VOUCHER SPECIMEN: LE 221999. COLLECTION SITE: Stream 6.

DESCRIPTION: Hyphae branched, 15-60 µm in diam. Gemmae not numerous, pyriform, varying in size, terminal or intercalary. Zoosporangia numerous, thread-like, club-shaped, straight, 100-250 x 20- 60 µm, internally proliferated, sympodial. Cysts 10- 14 µm in diam. Oogonia numerous, lateral on the stalk, spherical, club-shaped, 50-60 µm in diam., smooth-walled, pores developing only at the place of antheridial attachment. Antheridia diclinal, 3 per oogonium, antheridial cell tubular or club-shaped. Oospores centric, 4-18 per oogonium, 20-25 µm in diam.

COMMENTS: Saprolegnia diclina is a common saprotroph on animal and plant debris in freshwater habitats and soil. The species also occurs as a parasite of fish, reptiles and their eggs, aquatic insects, and other invertebrates. It is widely distributed in Europe, Asia, North and South America, and Africa.

Campbell Island: VOUCHER SPECIMEN: LE 221998. COLLECTION SITE: Stream 6.

DESCRIPTION: Hyphae branched, 20-70 µm in diam. Gemmae numerous, irregular in form, intercalary or terminal. Zoosporangia numerous, thread-like, straight or curved, 500 x 20-70 µm, internally proliferated. Cysts 9-14 µm in diam. Oogonia numerous, spherical, ovoid, club-shaped, 50- 100 µm in diam., terminal or intercalary, wall with numerous pores. Antheridia monoclinal, 1-3 per oogonium, antheridial cell tubular, sometimes branched. Oospores centric or subcentric, 10-20 per oogonium, 20-30 µm in diam.

COMMENTS: This species is a saprotroph found on animal and plant debris in freshwater habitats and soil, but it also occurs as a parasite on fish, reptiles, aquatic insects, and other invertebrates. Saprolegnia ferax is a very common and widely distributed species and has been recorded from all continents.