. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 210 W. S. FISHER 7- 6- QC m 5 5 QC HI Q. oc LU I- o < m o O 2- DAILY ADDITION OF 2% 1/3 MB p detached / D detached / •/ attached i 8 9 10 11 12 DAYS AFTER EXTRUSION 13 i 14 FIGURE 7. Numbers of bacteria on embryos detached from two females, one after seven days of brooding and the other after eleven days of brooding, and numbers of bacteria on embryos remaining attached to those females. Detached embryos were suspended in the same compartments with the re- spective donor female and the remaining complement of attach
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 210 W. S. FISHER 7- 6- QC m 5 5 QC HI Q. oc LU I- o < m o O 2- DAILY ADDITION OF 2% 1/3 MB p detached / D detached / •/ attached i 8 9 10 11 12 DAYS AFTER EXTRUSION 13 i 14 FIGURE 7. Numbers of bacteria on embryos detached from two females, one after seven days of brooding and the other after eleven days of brooding, and numbers of bacteria on embryos remaining attached to those females. Detached embryos were suspended in the same compartments with the re- spective donor female and the remaining complement of attached embryos. Nutrient (1/3 MB) was added at a 2% concentration with the daily water change. Hatching of the older embryos was successful for those remaining attached on the female, but detached embryos had poor hatching success and poor larval survival. Another detrimental condition may result from bacteria inhabiting embryo sur- faces. Bacteria isolated from the surfaces of P. macrodactylus embryos (Fisher, 1983) produced extracellular enzymes capable of degrading (among other substrates) chitin and lipid, two structural components of decapod cuticles and egg coats (Yonge, 1937). Bell (1966) suggested that bacterial release of degrading enzymes caused damage to fish egg coats and ultimately to the embryo. Such a phenomenon might also be expected in the decapods, since it has been well established that chitinolytic bacteria (Hess, 1937: Rosen, 1967) and possibly lipolytic bacteria (Baross el ai, 1978) are capable of penetrating the tough decapod exoskeleton to create shell diseases. Eggs that were extruded without benefit of attachment (obtained by excising the first or second maternal pleopods before extrusion) lacked an outer investment coat provided by the female pleopods (Fisher and Clark, 1983). These unattached eggs rapidly deteriorated and, within 2 days, only the vitelline envelope remained ap-. Please note that these images are extracted from scanned page images that
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
