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Information on the East London intertidal and subtidal reef fauna is limited to
one documented occurrence of Pyura stolonifera, a large and common inhabitant of
the South African coast, in 1962. No other information is available on the subtidal
ascidian reef fauna, habitat diversity or species richness. This is disconcerting,
as ascidians, sponges and bryozoans are important components of intertidal rocky
shores and the most prominent and ubiquitous sessile benthic components of subtidal
reefs. The lack of past research may be ascribed to the unpredictability and unfavourable
diving conditions for which this stretch of coast is all too well known. This poor
success rate of sampling trips and limited resources hampers much needed research.
Recent collections made are incomplete. The results of two opportunistic collections
made in 1998 and 2002 from the intertidal rocky shores and subtidal reefs or structures
at East London harbour, Bonza Bay, Gonubie and Cintsa will be presented. This will
attempt to provide scientists, for the first time, with some preliminary information
on the diversity of the ascidian fauna off the East London coast.
The ascidian fauna of the South African coast is poorly understood and little in
known of the biodiversity and distribution of the species inhabiting the intertidal
and subtidal reefs of our coastline. A total of 175 species have previously been
described for the South African coast. The genus Pseudodistoma has thirty-one species
worldwide with four species; P. africanum Millar, 1954, P. delicatum Monniot, F.,
2001, P. digitum Parker-Nance, 2003 and P. flaccidum Parker-Nance, 2003, known from
the southern African coast. Species of this genus seem to be well represented and
constitute an important component of the Algoa Bay sessile subtidal reef fauna.
A comparison is made of the taxonomic important morphological characteristics of
all species within the genus. New Pseudodistoma species are described and morphological
characteristics and known distribution along the southern African coast are discussed.
The genus Pseudodistoma is a small genus with some 38 species word wide.
Two endemic species are known for the southern African coast. P. africanum
Millar, 1954 which has a wide distribution, and a recently described species by
Monniot F. (in preparation) collected north of Durban, KwaZulu-Natal. Current research
within Algoa Bay has led to the further discovery of a number of new species. These
differ markedly in morphology to the know species.
Gathering, storing and accessing information used in the process of Ascidian identification
can be simplified by the use of computer technology. The merger of computer science
and biological expertise has resulted in a project specific database that is used
for 1) identification, 2) a multi-media specimen library and 3) generating distribution
maps. By using 1 product instead of 3 different products for each of these areas,
integration problems between different systems disappear. The web based front-end
to the database will aid identification by the general biologist working on inter-tidal
and sub-tidal reef systems.
Human-Computer Interactions Research at Volkswagen S. A. T.C.
Parker-Nance 1990. Proceedings of the Fifth National Masters and Ph. D. Computer
Science Conference Students Conference.
...
Human-computer interaction has proved to be a troublesome area for both the designer
and user. Functional systems have been found to be unusable. This can be explained
by task fit - the measure of how well a system’s functions map onto the user’s task
requirements. The user’s conceptual model has to be catered for when designing a
system and should be nurtured by the interface of the system. Task fit is also a
measure of the closeness of the user’s model to the system’s model. Using various
methods to model systems we hope to derive a metric to measure the closeness of
the user and system models.
...
The Human-Computer Interface: A Strategic Issue for the 90s.
P.R. Warren and T.C. Parker-Nance 1989. Proceedings of the Conference of the South
African Institute for Management Scientists.
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