. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 202 J. D. SHIELDS with a stereo microscope. After three days the samples were observed again and streaked with sterile pipettes onto a sterile modified Vishniac medium (M V): g glucose. g gelatin hydrolysate, g bacto-peptone, g yeast extract, 1 seawater, g agar (modified from Fuller ct 1964), containing antibiotics (500 mg each ofpen- icillin-G and streptomycin sulfate per liter). Seawater controls were also cultured. After an additional 3-5 days the plates were examined lor the presence or abse
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 202 J. D. SHIELDS with a stereo microscope. After three days the samples were observed again and streaked with sterile pipettes onto a sterile modified Vishniac medium (M V): g glucose. g gelatin hydrolysate, g bacto-peptone, g yeast extract, 1 seawater, g agar (modified from Fuller ct 1964), containing antibiotics (500 mg each ofpen- icillin-G and streptomycin sulfate per liter). Seawater controls were also cultured. After an additional 3-5 days the plates were examined lor the presence or absence of chytrid thalli. Other substrates from the habitat of C. an- thonyi were not examined for chytrids. Pure cultures of R. littoreum were isolated from the eggs of different crabs on numerous occasions. Isolated cultures of R. littoreum were grown in sterile liquid MV medium (MV as above with g agar instead of g agar). Cultures were maintained both with, and without, antibiotics (500 mg/1 each of penicillin-G and strepto- mycin sulfate, Sigma Co.) at 15° and 20°C. To establish the host-symbiont relationship, live and dead crab eggs (see below) were exposed to the chytrid separately and in combination. Before exposure, egg- bearing setae were removed from the pleopod and placed in UV-filtered seawater. Samples consisting of 80-300 eggs that were attached to individual and intertwined setae were counted, and the number of dead eggs and their apparent cause of death (, mechanical disruption, in- fertility, etc.) were noted. After they had been counted, the samples were washed in UV-filtered seawater con- taining bleach for 3-5 min to kill or remove micro- organisms. They were then placed in 35 X 10 mm plastic petri dishes with ml of UV-filtered seawater containing antibiotics (500 mg/1 each of penicillin-G and strepto- mycin sulfate). Combinations of live and dead eggs (80- 300 of each per replicate) were then exposed to approxi- mately 1000 zoospores of
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
