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Twenty Cittarium pica shells were observed in an isolated  tide pool to determine whether shells of various sizes had different behavioral traits that allowed for species survival.

Introduction:

Spittal Pond Nature Reserve was the site of my Bermuda study. The decision was easily made once I seen the extremely isolated tide pool located east of Spittal pond with an abundance visible activity.  This separate mini-ocean habitat was the perfect location to track the avoidance behavior of Cittarium pica, also known as the west Indian top shell.  (Background)

Material and Methods:

·         20 Live C. pica

·         1 meter stick

·         20 Bee tags

·         Vernier caliper

Twenty live C. Pica shells were removed from the rocky intertidal in total. On  October 15, 2008 ten shell were removed directly from the splash zone. The shells were labeled with bee tags for identification purposes. The shells were measured with Vernier caliper. (second sample only) Then shells were then placed in the designated isolated tide pool with their  operculum facing the ocean. The samples were of varying size. This process was repeated the following day.

Results:

Of the fourteen shells that were recovered, the distance traveled was recorded by using the meter stick.The data analysis done with the  details collected were considered in t-Test (Two sample Assuming Equal Variances /Microsoft excel 2003) proved to be significant (P(T<=t) one-tail7.49E-12 & P(T<=t) two-tail1.5E-11) These details  gave statistical confirmation that the larger C. pica shells did try to return to the ocean. The Chart below shows a clear distinction of this fact.

The clear dispersion of the C. pica gives us some insight to how this relatively defenseless organism is able to avoid predation. The Larger shells were observed to be very illusive. The larger shells were only observed  once the  incoming tide began to refill this isolated tide pool. The pool was not filled at every tide influx was especially high when the waves crashing   on the rocks below  allowed  residual water to enter the pool. The finding inherently call to mind some biological  motifs, such as Natural selection.  The larger shells were able to avoid being seen in this isolated environment. Even  when conditions were favorable the were found under secure substrates further exemplifying their elusive nature. The smaller shells where all found in the open waters of the tide pool and used relatively no protective cover. It was observed that these larger shells in fact did have some  stronger attributes for survival along the rocky intertidal. These defensive traits can be the reason that they were able to grow the larger size.