A wet winter and spring has brought changes to the Waikoloa area… Green pastures and hills around the village, an enormous crop of weeds in the yard, uncountable cockroaches and gnats, and these guys… Giant African snails.
They are everywhere I look in the yard, in the corners and under any debris. They get caught out by the sun to roast on the driveway, or crunch beneath vehicle tires. The compost pile is snail city, with dozens visible and more underneath the detritus. They get big too, the specimen photographed below was nearly six inches long when crawling along.
I understand that folks in some parts of the world eat these guys. I jokingly brought a handful to my wife one day and let her know I had dinner planned. She did not think the idea was a good dining choice. I have to agree with her, I am not really tempted.
I had never before seen one on the reef, but I knew what it was immediately…
This thing could kill me!
It is odd to look at something so small and pretty and realize that it could be fatal to touch. There are three cone snails that feature a potentially lethal venom found on Hawaiian reefs, the textile cone (Conus textile), the banded marble cone (Conus bandanus), and the striated cone (Conus striatus oahuensis). All three feature similar markings, a sort of chevron pattern on the shell. I did not recall which one of the three I was looking at, but I knew it was one of them.
Then I see the legs.
Small red and yellow legs protrude from the shell, just barely visible underneath. No problem, the deadly snail is gone and something else has moved into the pretty shell. A hermit crab, appropriately enough a cone shell hermit crab.
With little to fear from a hermit crab I set the shell just so on the coral. I know that the crab will wait a few moments then emerge to right his shell, providing a perfect photo opportunity…
Snails move at a surprising speed underwater, much faster than their terrestrial counterparts. This shell was moving much to fast even for a marine snail. A hermit crab, of course. The shell was familiar, I had photographed a snail wearing the same shell a few mere minutes earlier. The hermit crab was using a basket snail shell.
The pimpled basket snail is quite common, finding a couple of them in the course of a night dive is no real surprise. Finding and photographing the same type of shell, with two different occupants is an odd serendipity.
In the course of identifying the hermit crab I was surprised to learn it was an anemone crab. These usually host an anemone or three on their shells. This crab had none. A new shell? No time yet to recruit the usual anemone? It was fairly small for the species, perhaps a young example.
Horned helmet snails feed on sea urchins. The snails are easy to spot once you know what to look for, a shape in the sand. The snail may appear like an abandoned shell on first examination, the top covered with algae. It is the size that is surprising, these snails are huge, the shell well over a foot long and almost as much in diameter.
If an urchin wanders by this snail comes to life, heaving itself out of the sand and moving towards its prey. The large foot appears, lifting the ponderous mass off the ground. A pair of tentacles with small black eyes on the sides appear, sweeping about to search for prey. Once the urchin is located the reaction is surprisingly swift, the snail heaves forward to engulf the hapless urchin.