Sediment, Particle Size and Population Distribution of Uca tangeri (fiddler crab) from Two Brackish Water Ecosystems in Rivers State, Nigeria

Abstract

The influence of sediment particle size on the population distribution of Uca tangeri was studied at
Bonny Rivers and the New Calabar River in Rivers State. A quadrant of 20 X 20m were made at
the stations. The study stations were visited once a week for 12 weeks. A total of 24 (One)
sediment samples was collected from the burrow upon each visit and analyzed for % particle size
composition. A total of 720 (360) from each station. Uca tangeri samples were collected, age with
sediment particle size. Spearman’s correlation was used to check for the relationship between
sediment particle size and population distribution of Uca tangeri. The result from Bonny samples
showed that, there is strong correlation between adult male samples and silt-clayey sediment (silt
0.15 and clay 0.22) rich in organic matters (0.77). Samples collected from New Calabar Rives
showed that, adult female and juvenile male samples show preference to sandy sediments (0.28
and 0.057). Juvenile female samples prefer silt sediment (o.076) It was concluded that resource
sharing, strength of the setae and burrowing capacity influence habitat and sediment utilization.