. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. H. AMERICAM'S EMBRYOS PROTECTED BY BACTERIA 107 \. Figure 1. Scanning electron micrographs of healthy embryos of Homarus americanus under various conditions. (A) Surface of embryo after exposure to the fungus Lagenidium callinectes. illustrating the lack of fungal attachment (1250X). (B) Surface of embryo showing the coverage by the colonial rod morphotype and the other three types occasionally found (1000.' ). (C) Surface of embryo, at near full gestation, showing extensive and thick coverage by the rod-type bacterium (5000
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. H. AMERICAM'S EMBRYOS PROTECTED BY BACTERIA 107 \. Figure 1. Scanning electron micrographs of healthy embryos of Homarus americanus under various conditions. (A) Surface of embryo after exposure to the fungus Lagenidium callinectes. illustrating the lack of fungal attachment (1250X). (B) Surface of embryo showing the coverage by the colonial rod morphotype and the other three types occasionally found (1000.' ). (C) Surface of embryo, at near full gestation, showing extensive and thick coverage by the rod-type bacterium (5000X). (D) Micrograph of the pure bacterium grown on a millipore filter (2000X). I3C NMR, 200 MHz (acetone-d6): , , , , , , (Fig. 2). All chemical and spectral data were identical to those from the commercially-avail- able 4-hydroxyphenethyl alcohol (tyrosol, Aldrich #18,825-5). Tyrosol effectively inhibited growth of L. cal- linectes in liquid culture at a concentration of 10 meg/ ml. In agar plate assays, 100 meg tyrosol per disk resulted in an 8 mm zone of fungal inhibition. Discussion All the embryos observed were covered largely by a single, rod-shaped bacterium, distinguishable from other types by its characteristic dense, mosaic-like growth pat- tern. The oldest embryos had the thickest coverage by this particular strain, thus health and successful development appear to be related to the degree of bacterial coverage. Harper and Talbot (1984), who investigated embryos of several Homarus species to determine if the presence of epibiotic bacterial flora was related to loss of embryos from the pleopods, also observed four bacterial morpho- types. Their bacteria appear to be morphologically iden- tical to those described in this article, including one that they described as a "colonial ; They found that em- bryos from wild born and wild spawned H. americanus were heavily covered by bacterial rods, and that these em- bryos were succ
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
