No. 29–Questions and Answers
Q. Why do crabs turn red when you boil them?
A. Without getting too deep into the chemistry of the familiar phenomena, it has to do with pigment cells (cromatophores) within the exoskeletons of marine crustaceans that gives the familiar varied colorations of the living animals. Red, yellow and blue pigments are obtained through diet. The red cromatophores are bound with a protein giving them a blue cast while the creature is alive. Boiling destroys the protein unmasking the red pigment cells. The exoskeleton of a creature that dies in the wild will also turn red as the protein breaks down.
Q. I moved to Beaufort from the Jersey Shore about a year ago and have noticed that the fish seem to grow bigger up there, what gives?
A. It has to do with reproduction. Under normal feeding conditions, young fish grow rapidly in the race to sexual maturity after which the growth rate slows. Fish reach maturity more quickly in warm waters than their cousins in colder climes. The result is a longer period of expedited growth in cold water fish and therefore larger fish overall.
Q. My son found a large hermit crab in the grass behind the parking area at South Beach at Hunting Island, Do they usually wander that far from the water?
A. No. It was more likely a life jarring encounter with a gull than wanderlust that carried the hapless hermit so far a field. Gulls will on occasion snatch a hermit crab from the beach and drop it repeatedly on a hard surface area till the shell breaks or the crab is knocked too silly to retreat sufficiently into the shell. The gull may have been scared off before it could finish its work. Some time back I recounted a trip to the beach when clams were falling from the sky. Two resourceful herring gulls were at work that day.
Q. I found a fossil sand dollar at The Sands in Port Royal. It had a high dome in the canter and no holes. What can you tell me about it?
A. The common name of the species of sand dollar currently inhabiting local near shore waters is key hole urchin. Key hole for obvious reasons and urchin because sand dollars are in the urchin family. The fossil you found is the ancestor (30 to 50 mya) of today’s so called common sand dollar now found in the Pacific Ocean.
Q. I’m new to the area and someone told me that horseshoe crabs aren’t really crabs. Is that true and if so, what are they?
A. Horseshoe crabs are arthropods of the taxa Xiphosura and more closely related to spiders and scorpions of the sister taxa Arachnida than to crabs. They are, however, crustaceans and their empty molt shells may be found on the beach. I am currently researching a future column on this intriguing creature.
Q. What is your background and training for what you do?
A. I have no formal educational background in marine science save for a single oceanography course I took at USCB some years back. I am what is known as an amateur naturalist. I have learned over the years by doing and observing. My classroom has been the estuary and my teachers have been the creatures that inhabit it. Early on, at the old North Street Aquarium, there were a lot of “oh – I won’t do that again” moments. I must confess that my early training was at the expense of a number of hapless creatures who paid for my ignorance with their lives. In the years since I have hit the books, cultivated relationships with those more knowledgeable than me, and never pass on an opportunity to pick the brain of a real marine scientist. Any day I don’t learn something new I consider a wasted day.