Showing papers by "Peter A. Jumars published in 1976"

Deep-Sea species diversity : does it have a characteristic scale?

Abstract: Dispersion patterns and species diversities of deep-sea macrobenthos were examined for evi- dence that diversity-controlling processes operate predominantly on any one of several spatial scales . Identification of such scales, if any, would aid in the identification of the diversity-regu- lating processes themselves . The specific hypothesis that species diversity is independent of scale and location within the deep sea was tested with replicated, partitioned box cores taken at one station in the Santa Catalina Basin (1130 m) and one station in the San Diego Trough (1230 m) of the Southern California continental borderland . Attention was focused on within- community scales . Bathyal rather than abyssal sampling areas were selected to provide ade- quate animal densities for quantitative treatment . The hypothesis was discredited for some taxa at all sampling scales

In situ morphologies of deep-sea and sediment bacteria.

Abstract: Deep-sea and sediment bacteria at the bottom of an approximately 1200-m water column were sampled by means of pressure vessels attached to a remote underwater manipulator. Cells were immediately fixed in situ with glutaraldehyde, and after processing in the laboratory their morphologies were observed with the scanning electron microscope. Most bacteria were coccoid or rod-lide and less than 0.4 mum in diameter or width. Few filamentous bacteria were observed. Bacteria were in aggregates or free-living. It is concluded that morphologies of deep-sea bacteria collected and fixed at the hydrostatic pressure of their environment are, in general, similar to the observed morphologies of deep-sea bacteria determined at 1 atm pressure after collection and decompression during ascent through the water column.