THIRD PUBLICATION, JANUARY 2015. The Bioscientist. Vol. 3
The Bioscientist: Vol. 3(1): 14- 30, January 2015.
Available online at http://www.bioscientistjournal.com
Onadeko et al., 2015 Page 14
HABITAT DIVERSITY AND SPECIES RICHNESS OF BRACHYURAN CRABS OFF
UNIVERSITY OF LAGOS LAGOON COAST, AKOKA.
Onadeko, A. B., Lawal-Are, A. O. and Igborgbor, O. S.
1 Department of Zoology, Faculty of Science, University of Lagos, Akoka, Nigeria.
2 Department of Marine Sciences, Faculty of Science, University of Lagos, Akoka, Nigeria..
.*Corresponding author email: firstname.lastname@example.org or email@example.com
ABSTRACT (Download PDF )
The habitat diversity and species richness of brachyuran crabs of the University of Lagos Lagoon
Coast were investigated from seven study sites. Six crabs species were collected and identified
namely; Callinectes amnicola (Lagoon crab), Uca tangeri (Fiddler crab), Ocypoda africana
(Ghost crab), Sesarma huzardi (Hairy mangrove crab), Goniopsis pelii (Purple mangrove crab)
and Cardiosoma armatum (Land crab). The land crab Cardiosoma armatum showed the highest
occurrence of all six species and was observed in all the study sites. Uca tangeri and Ocypoda
africana showed low occurrence and low abundance where they occurred while Callinectes
amnicola was the least occurring species. Site A had the highest species richness (0.7239)
followed by Site B (0.7072), both having the lowest elevations of 13.72m and 11.58m
respectively. The highest number of species was recorded at site A and B that had five species
each. One crab species was each observed at Sites D and E which was the lowest, however these
sites were located on higher elevations which were 21.03m and 18.29m respectively. The
number of crab holes per site also followed similar pattern with sites A and B having the highest
numbers recorded, 18.7x101 and 17.2x101 respectively and sites D and E having the lowest,
0.8x101 and 0.2x101 respectively. C. armatum had the greatest carapace length and heaviest
weight, while C. amnicola the longest carapace width. The difference in mean length between
left and right chelae of U. tangeri was pronounced when compared to other crab species. It was
observed that high amount of oxygen, neutral or near neutral pH, relatively high salinity (6-80/00)
and lower temperatures were preferred by these species of crabs. These physiochemical
characteristics were present at most sites hence the relative high abundance of crabs within the
University of Lagos campus.
Keywords: habitat diversity, species richness, brachyuran crabs, physicochemical and
© 2013. Journal of Faculty of Biosciences, Nnamdi Azikiwe University,
P. M. B. 5025 Awka, Nigeria.