Mud Whelk

4546 Words Sep 20th, 2006 19 Pages
Introduction to the ecological niche of the mud whelk, Cominella Glandiformis

Mud whelks that are being investigated belong to the Gastropoda class and Buccinidae family. This means that they are similar to snails, having muscular foot and a spiraled shell. Cominella Glandiformis is most widely distributed among the many Cominella spp. found in New Zealand. They live exclusively on moderately sheltered beaches, principally on shores of mud. These mud whelks are ubiquitous on enclosed mudflats, creeping about actively on the surface, which is subjected greatly to fluctuating salinity and humidity.

Intensity of individuals is greatest where the beds of Austrovenus Stutchburyi and pipi are densest as these are its primary food source.
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feeding response time and hence establish the feeding activity period of the whelks by seeing if there is an optimum temperature at which they can sense and feed faster.

Hypothesis:
Higher temperatures should mean that the whelks react more rapidly and reach the food source sooner because the smell of the cockle is sensed faster by its osphradium in high temperatures. This means that whelks should probably be active at the time of the day that has the highest temperature, i.e. the noon as it will take them less time to feed.
Equipment:
1. 25 Mud whelks
2. Water bath
3. Stopwatch
4. Water and ice – to get below ambient and 20 degrees temperatures.
5. Seawater collected that same day to get the ambient temperature.
6. Electronic thermometer
7. Five 30 cm rulers
8. 10 cockles of the same species Austrovenus Stutchburyi
9. 5 salt water tanks to generate water baths.

Method:
1. The equipment was set-up in the same room, so the factors such as light intensity and so on wouldn't have any slightest effect on the investigation.
2. Five seawater tanks were utilized to generate water baths with varying temperatures (independent variable) of the following range— below ambient, ambient, 20º, 25º and 30º. This range was appropriate and ensured sufficient data for investigation and analysis.
3. Firstly, seawater was collected on that day and the ambient temperature of it was measured using an electronic thermometer and was stored in lab
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