International Journal of Marine Science, 2016, Vol.6, No.11, 1-10
7
of
Ocypode ceratophthalma
. Chan et al. (2006) have studied the burrow architecture of
Ocypode ceratophthalmus
on the sandy shores of Hong Kong and have reported presence of five different shapes of burrow which includes J
shape burrow, J shape with branch at the base burrow, Y shape burrow, spiral burrow and single tube burrow. In
the present study, more complexity is recorded in the structure of
O. ceratophthalmus
burrows as compared to
previous studies (Chakrabarti, 1981; Chan et al., 2006). In the present study, differences in the burrow architecture
were reported with the age and size of crab. Juvenile crab had made J shape, Y shape and single tube burrows,
adult crabs had created JBB shape, bulb shape, MB shape while older and large crab have made YDO and U shape
burrows.
Figure 4 Vertical temperature profiles with the burrow depth for different shapes of the burrows. Single tube burrow (a), J shape with
branch at the base (b), J shape (c), Bulb shape (d), Y shape burrow (e), Multi branched burrow (f), Y shape with double opening (g),
U shape burrow (h).
The burrow types like J shape, Y shape and single tube burrows made by juvenile crabs were shallow in depth
with narrower opening diameter and lesser volume. Chakrabarti (1981) and Chan et al. (2006) have also observed
similar pattern in juveniles of the species, as noted by us. They stated that the juveniles of the species have smaller
gill area and because of that they cannot tolerate prolonged air or sunlight exposure without renewing their
respiratory water. In this situation, the juveniles have to leave their burrow frequently to go to sea water to renew
their respiratory water.
The single tube burrows and bulb shaped burrows were created by adult and juvenile of the species. Similar kinds
of burrows were also reported in other brachyuran crab species like
Uca pugilator, Cradisoma carnifex
and
Macrophthalmus parvimanus.
These kinds of burrows are believed to be temporary and made by the species to get
refuge during the high tide time or get protection from the predator (Braithwaite and Talbot, 1972; Christy, 1982).
In the present study, the juveniles of the species have created J shape burrows with mean depth of (14 cm to 19 cm)
which are little shallower than J shape burrows reported for juveniles of
O. ceratophthalmus
and
O. quadrata
in
different countries like India, Taiwan, America and Hong Kong. (Chakrabarti, 1981; Takahashi, 1932; Hill and
Hunter, 1973; Chan et al., 2006). In Hong Kong, the juveniles of
O. ceratophthalmus
make J shape burrow with
