Abundance and SpatioTemporal Distributional Patte

Authors: Shahnawaz Ali S K Chakraborty Pawan Kumar

Publish Date: 2014/08/14

Volume: 85, Issue: 4, Pages: 943-949

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Abstract

The abundance and distributional pattern of Ocypodid crab Dotilla myctiroides MilneEdwards was studied on a sandy beach of Mumbai from January 2005 to December 2006 The area experiences semidiurnal tides The beach is intermediate dissipative type and consists of medium to fine grade sand The data were collected after fixing a transect line from high to low shore zone based on tidal heights A mean abundance of 40 ± 455 indm−2 was found during 2005 while it was 3782 ± 731 indm−2 during 2006 Although no significant difference p  005 in abundance was observed on seasonal scale there was a marked variation p  005 in the vertical distribution with an obvious increasing trend in abundance from high to low shore zone The zonal variation in the abundance was distinct in different seasons and it increased from pre to postmonsoon with decreasing tidal heights during both the years A significant difference p  005 in the abundance was recorded between high and mid shore zone during all the seasons while mid shore zone showed significantly higher p  005 abundance during postmonsoon season Data on distributional pattern of different maturity stages juvenile immature young adult and adult based on carapace width were also collected The juveniles were mostly observed in mid and low shore zone while adults dominated mostly the high shore areas The factors like morphodynamic state of beach and behavioural ecology of this species seemed to play important role in its high abundance and vertical distribution on the sandy beach of Aksa Mumbai

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