. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 338 A. SCARBOROUGH AND E. WEIDNER Experiment 1. Laboratory-reared and collected fish were exposed to a suspension of G. hcrtiviyi spores. Four weeks after exposure, 40% of the smelt exhibited one or two Glugca cysts in the posterior region of the intestine. These cysts were uniformly dense and protruded from the submucosa distending the peritoneal cavity. The fish fed continually throughout the experimental period. Several fish died during the period, were examined and one was found infected with a single Glugea cyst. Experi
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 338 A. SCARBOROUGH AND E. WEIDNER Experiment 1. Laboratory-reared and collected fish were exposed to a suspension of G. hcrtiviyi spores. Four weeks after exposure, 40% of the smelt exhibited one or two Glugca cysts in the posterior region of the intestine. These cysts were uniformly dense and protruded from the submucosa distending the peritoneal cavity. The fish fed continually throughout the experimental period. Several fish died during the period, were examined and one was found infected with a single Glugea cyst. Experiment 2. Laboratory-reared fish were exposed to spore-carrying plankton. One week after exposure all fish exhibited numerous small xenomas beginning just behind the stomach and continuing along the entire length of the intestine to the vent (Fig. 2). Gradually the fish stopped feeding, had difficulty swimming and all died by 16 days after exposure to the spores. Experiment 3. Collected smelt were exposed to spore-carrying plankton. The results were similar to those in Experiment 2; however, these fish stopped feeding and died at about 25 days after exposure to the parasite. Experiment 4. Smelt from Experiment 1, 4 weeks after being exposed to a spore suspension, were fed spore-carrying plankton. One week after feeding, all fish exhibited numerous small xenomas along the intestine as well as the large posterior xenomas (Fig. 3). All fish died within 2 weeks after exposure to the spore-carrying vectors. Controls were examined periodically and found free of infection. Parasite development Parasite growth was rapid at 20° C. Examination of the intestine from a heavy infection (Experiments 2, 3, and 4) showed the extensive tissue involvement. In- fections protruded to the serosa and were easily dissected away intact (Fig. 4). Extensive host cell hypertrophy was the obvious feature of sectioned material (Fig. 5). Xenomas ranged from 20 to 50 /AUI in diameter. Smaller xenomas containe
Size: 2322px × 1076px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
