International Journal of Marine Science 2016, Vol.6, No.22, 1-14
2
detritus from the surface layer of the substrate only after the tides have receded. Hashmi (1963) reported
ninety-four species of brachyurans in list of marine crabs occurring on the coast of Karachi, Pakistan. Tirmizi and
Kazmi (1986) and Tirmizi and Ghani (1986) reported 105 species of crabs. Siddiqui (1989) studied feeding season
and fecundity of many species of marine crabs.
Pakistan coast is rich in the anomuran and brachyuran crab. The brachyuran (or true crabs) are prized for
food to some extent. Several species of the genus
Charybdis
and
Thalamita
belonging to the family
Portunidae were reported by Khan (1975) and Mustaquim and Rabbani (1976). Sandy beaches particularly
Clifton and Korangi Creek are getting a lot of pollutant (Abbas and Qari, 2010). In Pakistan, the coastal
areas of Karachi accommodate well over 60% of the country’s industries. The unregulated industrial and
municipal waste inputs into the sea through the Indus, Layari, Malir, Hub and Winder Rivers have increased
sharply due to industrialization. Accumulation of heavy metals in the marine soil, sediments, fauna and flora
particularly Fe, Mn, Cu, Ni, Zn, Cr, Pb, Co and Cd in the regions of Karachi coast due to pollution from
different areas as well as mixing of polluted waters and the effluents discharge from industries and runoff,
residential wastes, soil erosion and other factors could also contribute towards the overall metal
contamination (Abbas and Qari, 2010; Qari and Siddiqui, 2004; Qari et al., 2005; Qari and Siddiqui, 2008).
Pakistan is a developing country and as compared to its population (192 million) food is not much. Therefore
as a part of monitoring and conserving species diversity at the community, it is a great need to investigate the
population structure, ecology and reproduction of
Dotilla blanfordi
crab.
2 Materials and Method
2.1 Study area
2.1.1 Clifton
Clifton is one of the long (20 KM) sandy beach of Pakistan, located in between longitude 67
o
00´E and at latitude
24
o
46´N (Plate 1). It is most approachable picnic beach of Karachi near Keamari oil terminal. The largest numbers
of animals were present in the intertidal zone at Clifton especially during the winter season (Ahmed and Hameed,
1999). It received the sewerage and industrial waste from Layari through harbor (Firdous, F., 2001). Hard texture
mica inflamed the sand particles of the shore make it difficult for organism. It was that coastal area surrounding
the port of Karachi which had a big environmental disaster last few years (27
th
July 2003) (Abbas and Qari, 2010).
Plate 1. Burrowing activity of Ocypodid crabs at Clifton beach.
