Aquarius Mission Journal
August 13, 1999
Caldwell

I was forced to make a late start to the morning since I was diving last evening until 11 pm. Since we must be at storage depth (47 feet) for 12 hours to start a new dive sequence, I couldn't enter the water until 11 am. The morning passed slowly spent cleaning, greasing and reloading cameras, inventorying our rapidly diminishing supply of cookies and other essential foods, and checking email that had arrived over the past two days. Finally at 10:30, it was time for Justin and I to prepare to dive. We planned to head south from the Aquarius following an established excursion line to a site named Deep S-4. This area was characterized by a sandy plain at 120 feet dotted with coral rubble and soft corals. This is very similar to the habitat where on our last mission I had found a species of mantis shrimp called Odontodactylus havanensis. Almost nothing is known about this three inch long species and studying its behavior and vision is one of my primary objectives for this mission. I have spent the past four days searching all of the places I found it on our last mission four years ago, but with no success. Deep S-4 is probably my last hope of finding it.

At 11:00, Justin and I gear up and begin to leave the wet porch. I can't find my collecting bag of ziplock bags and plastic bottles. Wearing twin 112 cubic inch steel tanks and other safety gear makes it very difficult to search through the mounds of equipment piled on the wet porch. Time is wasting. I grab a net and signal to Justin to head out. Besides, there is a voice in the back of my head telling me that if I don't take the collecting vials, fate is more likely to deliver into my hands an Odontodactylus.

It took about 10 minutes to swim down the line to Deep S-4. At over 100 feet, color was nearly extinguished and the expanse of sand took on a gloomy demeanor. I tied off my excursion reel to extend a line from the end of the rope. As I fumbled to connect the swivel hook, I realized that my brain was responding to a bit too much nitrogen making spatial tasks much more difficult than usual. Finally the reel was connected and I started a search pattern feeding out the line as I swam. This kind of diving is much like cave diving. If anything goes wrong, we must return to the Aquarius. We cannot find safety at the surface. The line will lead us quickly back to the rope which in turn will guide us back to Aquarius.

To find an Ondontodactylus, I was looking for a rocked lined burrow about an inch in diameter with two stalked eyes peering out at me. There were lots of burrows, but most contained jaw fish or gobies. No mantis shrimp! After 45 minutes of searching, not a sign of a stomatopod. With our tanks half empty, it was time to start reeling in my line and return to Aquarius. What had happened to the Odontodactylus? Was their absence one more sign of the declining health of the world's reefs or had I simply lost my search image for them. Then I heard the muffled tones of Justin calling my name. I looked up to see him pointed excitedly to a piece of coral rubble. I quickly swam to him and saw the tell-tale burrow of a mantis shrimp. Justin poked his finger in one entranced and I placed my net over the other. Soon I could see the animal's eyes as it stopped short of the entrance - then bolted for freedom and crashed into my net. I grabbed it with my gloved hand and trapped it in the net. Then it hit me. What do I do with it now? We were a long swim from home and I had no way to contain the animal.

I signaled Justin to pull off the glove on my free hand. Together, we maneuvered the animal into the glove and sealed it shut with the velcro wrist strap. As I picked up the glove containing the mantis shrimp and began to stuff it into my sleeve, it had its revenge. I felt a sharp, searing pain in my thumb followed by a tug from the glove. The animal had struck with its two raptorial appendages, penetrating the neoprene wetsuit glove and piercing my skin. I quickly pulled the spines from my thumb and watched as green fluid oozed from my hand. (At 120 feet, there is no red light penetrating from the surface and blood takes on a ghoulish green color!) Still, my prize was now safely tucked in my sleeve and being thumb-tacked to my glove was a small price to pay for success. On the way back along the excursion line we found another smaller Odontodactylus which we also caught (this one came back in the net), but now it was definitely time to return to Aquarius to replenish our air supply.

Tomorrow, I plan to start a systematic mapping of the Deep S-4 to determine the number and distribution of these animals. A few more will be captured and returned to Berkeley where we will look at their reproductive behavior, attempt to breed them, and also look at the visual pigments and filters in their eyes to try to better understand how they communicate visually in their dim - and what appears to us - rather grey world.

Roy Caldwell