Scallops for the holidays

Sarah's scallop scrub station

In the Meyer-Kaiser lab, we do things our own way. We travel frequently, multi-task constantly, and work however the science requires. So when my technician, Sarah, asked if it was ok to take scallop shells to her parents' home over the holiday break, I did not hesitate for a second. Sure, why not!

The photos speak for themselves. Sarah's assignment is to measure growth rings in the shells of scallops that I collected the last two summers. The scallops were already shucked, but scraps of tissue clung to a few of the shells. There was biofouling on the exterior of many shells, and for others, the growth rings were not very visible. Sarah's solution was to start by cleaning the shells before she measured any rings. She used dish soap and water to clean off the scraps of tissue. Each shell had to go through two wash-rinse cycles and scrubbing with a wire brush to make sure the growth rings were unimpeded and clearly visible. Then she soaked the specimens in water to soften the hinge ligament. The end result was a series of bins and old yogurt jars full of shells. Thank goodness Sarah is so organized!

Scallop shells ready for measurement. Photo by Sarah Zuidema.

There are a lot of rings on scallop shells, so learning which ones to measure has been a challenge. The data we need are based on annual growth, so Sarah has to figure out which of the many color variations in a scallop shell correspond to one year worth of growth. She read scientific papers and reports to see what others had done, then devised her own methodology. The hinge ligament, a protein structure that connects the two shells of a scallop, also has growth rings. In some specimens, the annual growth rings in the hinge ligament are more starkly visible than on the shell. Sarah starts by examining each hinge ligament first to count how many annual rings there should be and get an idea of their general spacing. Then she examines the shell and marks the corresponding annual rings with a marker. Once she's content that every ring is properly identified, she can make her measurements. 

We were warned going into this project that measuring scallop growth rings is more art than science. Our experience has certainly reinforced that claim, but I'm proud to say that Sarah has gotten really good at it! I'm so grateful to have her supporting my lab's research!