International Journal of Marine Science 2016, Vol.6, No.22, 1-14
1
Research Article Open Access
Study on Abundance, Breeding and Allometric Growth of the Ocypodidae Crab
Dotilla blanfordi
in Karachi Coast, Pakistan
Rana Manzoor, Saima Haider, Meher Fatima, Rashida Qari
Institute of Marine Science, University of Karachi, Karachi 75270, Pakistan
Corresponding author email
International Journal of Marine Science
2016, Vol.6, No.22 doi
Received: 03 Jan., 2016
Accepted: 20 May, 2016
Published: 20 May, 2016
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Manzoor R., Haider S., Fatima M., and Qari R., 2016, Study on Abundance, Breeding and Allometric Growth of the Ocypodidae Crab
Dotilla blanfordi
in
Karachi Coast, Pakistan, International Journal of Marine Science, 6(22): 1-14 (
doi
Abstract
The samples of Ocypodidae crab
Dotilla blanfordi
were collected on monthly intervals for the period of March 2007 to
February 2008 from supra tidal zone of two different shores of Karachi coast i.e., Clifton and Korangi Creek. Sex ratio, population
structure and ecology of these crabs were determined. For statistically analyzing the data 100 samples were taken randomLy in each
month for each species from each site and measured their carapace length (C.L), carapace width (C.W), chela length (Ch.L),
abdominal length (Ab.L) and abdominal width (Ab.W). Significant seasonal variations were observed in the abundance of total crabs
sampled at Clifton and Korangi Creek of Karachi Coast.
Keywords
Karachi Coast; Ocypodidae;
Dotilla blanfordi
; Abundance; Breeding; Allometric Growth
1 Introduction
The Ocypodidae family possess most familiar amphibious and terrestrial crabs like fiddler crabs and ghost crabs
Dotilla fenestrate
Hilgendorf, 1869 belonging to family Dottilidae.
Dotilla
crabs are commonly called solder or
bubbler crabs.
Dotilla
crabs are an ecologically important component of the intertidal zone of tropical. Sometimes
Dotilla
form dense population and these crabs play an important role in ecology of the faunal community as a
result of their burrowing and feeding activity. They adapted sediment condition tidal fluctuation and varying
salinities found in the mangroves. The crabs have a significant role in detritus formation nutrients recycling and
dynamics of the ecosystem together with many Annelids and nematodes living in the sediments. The Ocypodidae
crab have the same role as Sesarmidae and fiddler crabs in term of retention of forest products, large amount of
algal primary production, organic matter processing and as ecosystem engineers, change particle size distribution
and enhance the soil aeration in the mangrove world (Cannicci et al., 2008; Kristensen et al., 2008). Ghost crabs
are common in the world. They are larger than fiddler crabs, which are nocturnal and move to the lower beach to
pray on clams and mole crabs or to scavenger for food (Barns, 1987).
The species of the genus inhabits sandy shores where their specialized mouth parts enabling them to sort sand
with a high efficiency in order to extract the low proportion of organic material but exceptionally, and incidentally,
Dotilla fenestrate
Hilgendorf, 1869 occurs, like
Mictyris
, among the pneumatophores of
Avicennia
in mangrove
swamps (Gherardi and Russo, 2001; Dray and Paula, 1998).
Dotilla
crabs reduced layer while digging out their
burrows, thus promoting their oxidation (Hartnoll, 1973). The substratum, water level, salinity, temperature and
floral distribution were possible factors influencing zonation and distribution of crabs in the mangrove
environment (Dissanayake and Chandrasekara, 2014).
The number of eggs produced by per female is important for determining the reproductive potential of a species
(Mantelatto and Fransozo, 1997). Fecundity and sexual maturity are commonly estimated, since they are
important tools in forecasting the turnover capacity of natural populations, providing essential information for
studies of environmental impact (Mantelatto and Fransozo 1997; Pinheiro et al., 2003).
The Ocypodid crabs (
Dotilla
Sp.) are the dominant group inhabitants of tropical sandy of Arabian Sea, Persian
Gulf and Pakistan. They remain buried whilst their habitat is submerged, emerging to feed by sorting the organic
