Once upon a time there was a scientist. The scientist could communicate with crabs, specifically Hemigrapsus oregonensis, because he himself was secretly a cool crab. The scientist invited all the crabs to a year-end party where each crab was allowed to eat unlimited mussels! On one condition, the crabs had to be willing to get the size of your claw measured. The crabs all shouted, “Yes!” They all wanted to escape the dangerous environment of fish, birds, and other hungry creatures.
The scientist asked around and found that one of their favourite foods was a mussel with the exotic name Mytilus edulis. The scientist prepared for a party with enough of these mussels for every crab. The scientist knew the feeling of going to a party where there was not enough food and didn’t want these brave crabs to experience that. The scientist journeyed out to Kitsilano Beach in Vancouver in the middle of the night when the tide was low to collect these yummy dark blue mussels.
The scientist placed half of the crabs in seawater at 12°C and the other half at 18°C. The laidback crabs did not mind one bit as they were still able to mingle with the other crabs.
After 4 days, the crabs began to complain about not being fed. They were about to revolt and attempted to execute an elaborate escape. The scientist, having the ability to understand crab, decided to hurry up with the preparations for the party in order to satisfy half the guests on this day.
In preparation for the big party, the scientist, sorted the crabs into 3 groups based on size (Small 1-2cm, Medium 2-4cm, Large >4cm). The scientist predicted that the smaller crabs with their smaller crab claws would want to eat smaller mussels as they’ll have a weaker claw that won’t be able to open large mussel shells. The scientist also predicted that the crabs in the cooler temperature will have stiffer muscles and so they will have lower locomotor activity and a weaker claw resulting in a longer mussel selection time and a smaller mussel selection size.
The scientist then crushed up the mussels and placed 1 of each size in a prestigious white bucket previously owned by Queen Vanilla Ice Cream. The lucky crabs from the 12°C seawater were allowed to one at a time, pick 1 of the crushed crabs from the bucket to devour!
The scientist then recorded how long it took each crab to select a mussel and the size of mussel that they selected. The scientist also measured each crab’s claw length.
The scientist apologized to the crabs in the 18°C seawater that didn’t make it into the packed party and notified them that preparation for the next buffet was already underway.
Three days later, the scientist delivered on his promise and these crabs were provided with the same fancy party held in the prestigious white bucket.
After the parties were over, the scientist analyzed the data and found that the temperature of the water the crabs were in and their claw size had no effect on the mussel selection time or mussel selection size.
After the experiment was finished, the scientist placed all the VICs (Very Important Crabs) into the same area as the crushed mussels. The crabs bustled about, gorged themselves and lived happily ever after in the seawater room in our UBC biology lab! The end.