. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 128 M. ENZIEN ET Figure 17. Amoeba from embedded microbial mat with large food vacuoles (v), taken directly from a microbial mat sample at North Pond, Laguna Figueroa, Baja California, Mexico. TEM. Bar scale = ion. ter inundation. Electron microscopy of fresh mat from North Pond (Laguna Figueroa. Baja California Norte, taken October 1987) reveals an amoeba similar in form to P. jugosits (Fig. 17). The trophic amoeba appears to have uroid and large digestive vacuoles containing bacte- ria. The only other amoeba regul
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 128 M. ENZIEN ET Figure 17. Amoeba from embedded microbial mat with large food vacuoles (v), taken directly from a microbial mat sample at North Pond, Laguna Figueroa, Baja California, Mexico. TEM. Bar scale = ion. ter inundation. Electron microscopy of fresh mat from North Pond (Laguna Figueroa. Baja California Norte, taken October 1987) reveals an amoeba similar in form to P. jugosits (Fig. 17). The trophic amoeba appears to have uroid and large digestive vacuoles containing bacte- ria. The only other amoeba regularly seen in these field samples are larger acanthamoebae with acanthopodia. The organism greatly resembles in size and cell structure the limax amoebae in our cultures (Fig. 17); it is not an acanthamoeba. Thus, we interpret it to be a free-living P. jugosus photographed under natural conditions in as- sociation with purple phototrophic and other mat bac- teria. An encysted amoeba, with at least five areas of active- looking chromatin, can be seen in embedded material from the Thiocupsa layer at North Pond, Laguna Figue- roa (Fig. 18). Bacterial digestion is evident, emphasizing the rapidity with which temporary encystment can oc- cur. Photographed by John F. Stolz during his study of phototrophic bacteria, we interpret Figure 18 to be a sec- ond example of P. jugosits in situ in a stratified microbial community. The electron micrograph corresponds to the Figure 18. Organism from the Thioi-apsa .tp. layer of the microbial mat from North Pond interpreted to be an ectoplasmic cyst of P. jugo- sits. Although enclosed in a cyst wall (W), the ribosome-studded cyto- plasm (R), active digestion of bacteria (B) in vacuoles (V) and the well- developed chromatin (C) indicate metabolic activity in this amoebo- mastigote. TEM courtesy of John F. Stolz. Bar scale = ^m. PJBC Cuba ATCC 30703 II 1 "& 0 ^ TJ n rr •-• M 11 1 1 Figure 19. Diagram of isoenzyme analysis of three d
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
