Factors influencing the small-scale spatial patterns of motile invertebrates on the surface of Monastrea annularis /

Small, motile invertebrates associated with coral reefs are

Bibliographic Details
Main Author: Runnels, Randy James, 1960-
Format: Thesis Book
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1994.
Subjects:
Online Access:http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=741965811&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD
Description
Summary:Small, motile invertebrates associated with coral reefs are
an important component of the reef community. Previous
studies of these organisms have largely neglected any
questions involving those organisms epizoic on living coral
surfaces. methodological limitations have probably been one
of the reasons for this neglect. In this research, I
developed and tested a method to study spatial patterns in
small epizoites on relatively simple surfaces. I used this
sampler to study epizoite spatial patterns on areas of
Montastrea amularis colonies in various physical regimes. I
did preliminary samples to estimate the variability that
might be associated with subsequent tests. In the water
column, as in terrestrial systems, light is a major physical
influence on the spatial patterns of organisms. Epizoite
spatial patterns were studied in relation to coral surface
light regimes. Two common epizoic species, the
siphonostomatoid copepod Asteropontius proximus and a
halacarid mite with parasitic mouthparts, were distributed
significantly toward the sun in the morning and evening. A
variety of small harpacticoid species also showed this
pattern, but no species occurred consistently enough for
statistical analyses. In all the phototactic species, mid-
day abundances on top of the corals were too low to confirm
that organisms were tracking the sun across the coral
surfaces-Dye streamlines were used to determine high- and
low-flow surfaces on the sides of M. amularis colonies. I
sampled epizoites in these high and low-flow zones on coral
heads along a forereef transect. Both absolute abundances
and relative abundances between types of organisms differed
significantly between the high and low-flow surfaces of the
corals. Copepod abundances were very low on high-flow days,
but I detected a fairly strong trend of increasing
abundances with depth. This study demonstrates that
informative studies of epizoic organisms can be done on
coral reefs if measures are taken to minimize experimental
error. Overall, the results appear to fit a model of a
community structured by a combination of behavioral
interactions and physical extremes. Greater knowledge
concerning these organisms may lead to a better
understanding of factors influencing the health of reef
corals. The ability to quantify and model the abundances of
organisms on consistent substrates like some corals may
eventually be applied to monitoring the health of coral reef
systems.
Item Description:Vita.
"Major Subject: Oceanography".
Physical Description:xiii, 138 leaves : illustrations, maps ; 28 cm.
Issued also on microfiche from University Microfilms Inc.
Bibliography:Includes bibliographical references.