Abstract:
ABSTRACT
The West African mangrove oyster, Crassostrea tulipa (Lamarck 1819) is
abundant in many coastal ecosystems and they are a rich source of protein.
Despite its abundance, ecological, and economic importance, little is known
about their diversity and evolutionary history. There are challenges associated
with the use of morphological characters only, therefore, there has been a shift
to the use of genetic markers to determine the oyster species diversity and
taxonomy. The study sought primarily to undertake genetic diversity studies on
the West African mangrove oyster, C. tulipa occurring along the coast of Ghana
by the utilization of microsatellite markers. This was an attempt to characterize
and establish if the same species of C. tulipa was occurring along the coast of
Ghana from the Volta estuary (Anyanui), Densu estuary, Narkwa lagoon,
Amisano lagoon, Benya lagoon, Whin estuary and Dominli lagoon. The
physico-chemical parameters recorded in all the seven brackish systems were
within tolerable ranges. The oysters exhibited negative allometric growth in
their morphometric relationships. Low genetic variability was observed within
the populations (He = 0.391, FIS = 0.791) and this may be attributed to
inbreeding and limited gene flow. Small to moderate genetic differentiation was
discovered between the populations where the FST range was between 0.033 and
0.100. Anyanui and Narkwa populations were more genetically differentiated
whiles Densu and Dominli populations were vice versa. There was no
relationship between genetic distance and geographical distance therefore the
genetic structure of C. tulipa occurring along the coast of Ghana did not follow
any geographical pattern of distribution.
