A biological reconnaissance of the photoreceptors of invertebrates and fish from the Ross Sea, identifying the micro fauna and flora of Dry Valley lakes and other organism from the Ross Sea region

A variety of research activities on the organisms in the Ross Dependency was undertaken to determine the biological research potential of the organisms. Most work focused on photoreceptors of different invertebrates and fishes. The studies included work on:

a) Glyptonotus antarcticus: The dorsal and ventral eyes of this big isopod were prefixed, postfixed, dehydrated and embedded for transmission electron microscopy (TEM). Additional eyes were prepared for TEM of the inner and outer surfaces. Groups of 4 animals were adapted to 0°C, 5°C and 10°C and their eyes were also prepared for TEM. Another experiment involved painted one eye black and exposing the other to 200 lux for 1 week. Both eyes were analysed with TEM.

b) Orchomenella plebs: Freshly caught amphipods were exposed to bright sunlight for 1, 2 and 3 hours. Their eyes, as well as those of fully dark adapted ones were prepared for TEM. This species can also recover when placed in 10°C for 7h and then returned to 0°C water. Eyes of animals adapted to 5°C and 10°C and those that had recovered afterwards in 0°C were prepared for TEM.

c) The compound eyes of approx 100 facets belonging to a tiny (1-2mm) parasitic isopod from fish and invertebrate hosts were prepared for TEM.

d) Retinae of 3 species of fishes (Trematomus bernacchii, Trematomus brochgrevinkii and Dissostichus mawsoni) were fixed for TEM. The eyes of the Trematomus species were prepared for gas-chromatographical analyses of the fatty acid composition. Observations were carried out on the antifreeze behaviour of D. mawsoni aqueous and vitreous humor.

e) The microfauna and flora of Deep Lake and Skua Lake were studied in culture. Numerous drawings of the microorganisms were prepared.

f) A number of organisms were collected for identification including benthic marine organism from under the 3-5m thick sea ice, marine mite species, skua egg shells, moss samples (from the top of Mt Erebus) and bacteria which were attempted to be cultured from snow samples.