Aquatic fungi: their occurrenceon Ross Island and in the dry valleys

R. A. PATERSON and JOHN S. KNOX

Department of BiologyVirginia Polytechnic Institute and State University

All our attempts at axenic culture of algal "para-sites" have been unsuccessful. However, we havesucceeded in growing clonal isolates of five antarcticfreshwater algae. We are trying to establish unifungalcultures of the algal parasites by infecting our algalclones with single fungal propagules. In this way,we hope to determine the life cycles of the algalparasites, thus permitting their accurate identification.

Towards the end of the austral summer of 1970-1971, we made a month's visit to McMurdo Stationto investigate the occurrence of aquatic phycomyceteson Ross Island and in the dry valleys of VictoriaLand.

Between January 22 and February 2, 171 samplesof soil and fresh water were collected and returnedto the McMurdo biolab for preliminary study. Eachsample was divided into four subsamples, which weremaintained at 8°C. and constant light, 5°C. and nolight, 20°C. and no light, and room temperaturewith constant light. According to standard myco-logical practice, sterile "baits" were added to eachculture to encourage the growth of saprophyticaquatic phycomycetes. Preliminary microscopic ob-servations of the samples were made to determinethe presence and morphological features of phyco-mycetes that grew on attendant protistans and theadded "baits."

After 20 days of preliminary observations at thebiolab, several general remarks could be made.Aquatic phycomycetes ate indeed abundant in thearea studied, appearing in 131 of the 171 collections.Algal parasites occurred Iti 57 collections, chytridsaprophytes in 118 collections, and oomycetes in 57collections. Moreover, the oOmycetes were observedonly in subsamples that were maintained at 5°C.or 8°C.

Collections that yielded aquatic phycomycetes wereshipped to our labs at Virginia Polytechnic Instituteand State University for further study.

Proper identification of aquatic phycomycetes re-quires knowledge of the entire life cycles. So thatinterspecific variation is not confused with intra-specific variation and ontogeny, pure or unifungalcultures must be obtained before life-cycle studiescan be made.

So far, 12 unifungal clonal isolates of saprophyticChytridiales have been made. Taxonomic studies ofthese isolates and subsequent comparison with thepreliminary McMurdo observations have shown thatthe species diversity of saprophytic chytrids in thestudy area is remarkably low. Only four species havebeen distinguished (specific determination is pend-ing), and these occurred in 118 of the 171 collections.

Pure cultures of three Phythium species have beenobtained and are being studied taxonomically.

Waterfowl ecosystem studieson the Falkland Islands

MILTON W. WELLER

Department of Zoology and EntomologyIowa State University

Only a few orders of birds have adapted to thesevere cold and harsh winds of high latitudes. Bestknown in the southern hemisphere are the penguins(Sphenisciformes), the albatross-petrel group (Procel-lariiformes), and the gulls (Charadriiformes).

Waterfowl (Anseriformes) are widely scattered onisolated austral islands but are restricted in numberof species and range. They are unique because oftheir isolation, their nonmigratory behavior, their ori-gins from different stocks, their patterns of sexualdimorphism in color, and their adaptations to themarine habitat including flightiessness. They have notbeen intensively studied because of their isolation, lowdensity, and inconspicuous behavior.

This study, being made to investigate the ecologicalrelationships and behavior of waterfowl on severalislands, began in the austral spring of 1970 on thecool-temperate Falkland Islands. These islands havea relatively large waterfowl fauna of 11 commonspecies, whereas most southern islands have only oneor two species. (At least 34 species occur in Argen -tina.)

Field work extended from October 1970 throughmid-January 1971. Two study areas were establishedon East Falkland Island—one at Port Fitzroy and onenear Port Stanley. Observations were made also atfour other sites to ascertain possible geographic dif-ferences in habitat selection and food utilization.Study areas included seashore with various habitatsand freshwater ponds of various depths, shorelinephysiography, soil type, and acidity. Five study specieswere selected because they are widespread andabundant, can be collected, and are representative ofbirds well-adapted to island conditions. One is flight-

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less. Also, these five appeared to frequent differenthabitats. Studies included food utilization, food avail-ability, habitat preferences, brood behavior, territorialdefense, brood mobility, and behavior of adults inrelation to sexual dimorphism. Birds were collectedduring feeding, and analyses were made of the birds'digestive contents and of benthos samples collected atthe feeding site. Each site was classified as to watertype, plant occurrence, topography, and related habi-tat features.

Upland geese (Chloephaga picta) fed exclusivelyin the uplands on fine grasses such as Poa spp., oftenin direct competition with sheep. Although C. picta isa highly terrestrial species, freshwater ponds and pro-tected bays of the ocean were used for escape areasfor pairs with broods or for adults flightless during thepostbreeding simultaneous wing molt.

Kelp geese (Chloephaga hybrida) (fig. 1) fed al-most entirely on several species of marine algae andgenerally utilized rocky outcrops along rugged oceanshores for both feeding and nesting. Fine grasses wereconsumed in small quantities in areas near freshwaterponds where they occasionally nested. No animal foodswere recorded even in young birds.

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--Figure 1. Kelp goose, Chloephaga hybrda.

Kerguelen Islandsbotanical expedition, 1971

HENRY A. IMSHAUG

Department of Botany and Plant PathologyMichigan State University

The Kerguelen Islands archipelago consists ofabout 400 islands and islets covering a land area ofabout 5,000 sq km with elevations ranging to 1,960 m

Crested ducks (Lophonetta speculariodes) utilizedboth marine and freshwater ponds but showed thegreatest affinity for marine gravel beds where inverte-brates were abundant.

Falkland flightless steamer ducks (Tachyeresbrachypterus) (fig. 2) were restricted to marine areasbut occasionally walked across sand barriers to drinkand loaf in freshwater pools and ponds. Their foodwas exclusively marine invertebrates, often of sizable.proportions. Apparently, this species does not breeduntil 2 or 3 years of age, as several groups of non-'breeding immatures were observed.

Yellow-billed or speckled teal (Anas flavirostris)used freshwater streams and ponds during the broodrearing but also utilized brackish areas followingbreeding. Their food included seeds as well as inverte-brates, but a dominance of animal food was noted.

These anatids differ from northern species in sev-eral ways. Breeding seasons are longer, and some nest-ing occurs all year because of the mild winters. Growthrate of young birds is relatively slow, and protectionby both male and female is regular in all but theyellow-billed teal. Marine foods are usual for fourof the five species at some season of the year.

hFigure 2. Falkland flightless steamer ducks, Tachyeres brachypterus.

above sea level. One of the largest of the wind-sweptland areas in the southern oceans, it is also one of themost isolated areas, lying about midway betweenAfrica and Australia. Nevertheless, about three dozenspecies of ferns and flowering plants and at least 200species of lichens and bryophytes have somehow man-aged to establish themselves in this remote environ-ment.

Five botanists comprised a 1971 expedition to searchout as many of these species as possible. Vascularplants were the specialty of Dr. Steven Young (OhioState University), bryophytes the specialty of Mr.John Engel (Michigan State University), and lichensthe specialty of Dr. Henry Imshaug, Dr. Geoffrey

108 ANTARCTIC JOURNAL