Day 10

Today has been a mixed bag of activities. Drs. Emlet, Tyler and Young spent their morning hours spawning the Coelopleurus floridanus – a wholly successful endeavor. The existing cultures of Cidaris blakei, Stylocidaris lineata, Lytechinus euerces, and Linopneustes longispinus are progressing nicely, albeit slowly as they are living at 13 °C (55 °F). The dive this morning occurred off of New Providence Island within sight of the Atlantic casino, and we were lucky today. The dive yielded a dozen Linopneustes longispinus that will be spawned tomorrow.

Craig Brauer and I were successful today in making the first measurements of respiration (oxygen consumption) of embryos of Cidaris blakei. We incubate specimens in closed containers for 12 hours and then measure the difference in the amount of oxygen in chambers with and without embryos. We’ll start another set of measurements at midnight tonight and finish tomorrow at noon. Developmental stages of this C. blakei will accompany us back to Illinois where we can continue these measurements. We intend to take these and the existing cultures of embryos and larvae back to our respective campuses. I can’t wait for the joy of explaining why I am carrying bottles of water to the folks from the TSA at the Orlando airport on Sunday and why they should not be irradiated. Although the cruise is coming to an end, the work will follow us home.

There was a snorkel trip today in a shallow lagoon in the Egg Island area. Although I remained on board to take a nap, all reports suggest that the site was particularly rich in invertebrate and vertebrate animals. Craig B. was followed by barracuda, an eagle ray leapt out of the water, and there was an abundance of sea urchins and tropical fish. My colleagues brought me a gelatinous egg mass that contained developmental stages of a marine worm – a lovely example of direct development within an egg mass that is attached to the sea floor.

On each dive we have the ability to take still images of the animals we see. I have offered a couple of these below. Remember that what we see in the pictures is not what an animal would look like at depth, as the spectral quality of down-welling light varies as a function of depth.

This is a specimen of Araeosoma fenestratum. Unlike most sea urchins, this species has a soft “test”, but compensates for the reduced physical defense by having poisonous spines.

In the foreground is a specimen of Cidaris blakei, whose spines are covered by a type of sea anemone. Adult brittle stars (the white arms on this sea urchin) are commonly found with this species. In the far right corner of this image is a specimen of Linopneustes longispinus.