Trophic Cascade: Effect of Hemigraspus sanguineus on Intertidal Food Chain
Abstract
Hemigraspus sanguineus (Asian crabs), an invasive species, are found in multitude on east coast and more precisely along the long island sound. The end goal of this experiment is to see what long term effect of having this invasive crab could have on other organisms in the tides, more specifically littorina littorea (periwinkle snails). This would be achieved by studying the interaction between Asian crabs, periwinkle snail, fucus and ulva.
Introduction
Hemigraspus sanguineus by large possesses the subtidal and intertidal rough shoreline, with a checked inclination for cobble shorelines. It has additionally been known to live on man-made structures, for example, seawalls and manufactured reefs, and can …show more content…
Individuals were measured based on carapace width (CW), then placed into covered plastic aquaria containing about 0.5L of seawater at a salinity of 20psu. Each crab was used only once in an experiment. Algae, Ulva spp. and fucus distichus, were used as prey in each set up, except the control group which was made up of on the algae. Two Littorina littorea or periwinkle snails were used per experimental design. Their heights were recorded for each set up and it ranged between 9-12mm. Four different treatments were set up as follow; the first treatment contained both algal species alone¬ which represents the control treatment and denoted as A. The second treatment contained both algal species and two snails. This was denoted as AS. The third treatment contained both algal species and two crabs (Algae+Crab), denoted as AC. And lastly, both algal species with two snails and two crabs (Algae+Snail+Crab) denoted as ASC. Results would be tested using IBM SPSS’s independent sample t-test and ANOVA. Results were considered significant when
Abstract
Hemigraspus sanguineus (Asian crabs), an invasive species, are found in multitude on east coast and more precisely along the long island sound. The end goal of this experiment is to see what long term effect of having this invasive crab could have on other organisms in the tides, more specifically littorina littorea (periwinkle snails). This would be achieved by studying the interaction between Asian crabs, periwinkle snail, fucus and ulva.
Introduction
Hemigraspus sanguineus by large possesses the subtidal and intertidal rough shoreline, with a checked inclination for cobble shorelines. It has additionally been known to live on man-made structures, for example, seawalls and manufactured reefs, and can …show more content…
Individuals were measured based on carapace width (CW), then placed into covered plastic aquaria containing about 0.5L of seawater at a salinity of 20psu. Each crab was used only once in an experiment. Algae, Ulva spp. and fucus distichus, were used as prey in each set up, except the control group which was made up of on the algae. Two Littorina littorea or periwinkle snails were used per experimental design. Their heights were recorded for each set up and it ranged between 9-12mm. Four different treatments were set up as follow; the first treatment contained both algal species alone¬ which represents the control treatment and denoted as A. The second treatment contained both algal species and two snails. This was denoted as AS. The third treatment contained both algal species and two crabs (Algae+Crab), denoted as AC. And lastly, both algal species with two snails and two crabs (Algae+Snail+Crab) denoted as ASC. Results would be tested using IBM SPSS’s independent sample t-test and ANOVA. Results were considered significant when