Carmet Beach Trip on April 20, 2015

     After our early morning trip to Carmet Beach on April 20, 2015 I wanted to learn more about the species I know as the black turban snail. When I visit the tidepools I seem to regularly see these snails however on this particular trip I seemed to see a lot more of them. The snails were in groups of 5-10 in the pools of water left in the high-mid intertidal after the tide lowers so since the species stuck out to me I decided to find out a little more about them.

     The black turban snail goes by the scientific name Tegula funebralis and is an intertidal species. The shell of the snail, as it says in the name, is black however they are easy to identify because the black layer on the top of the shell is often worn down to a pearly white and even further to a reddish-orange as can be seen in this picture of one from Carmet Beach.

     The snails foot is also black in color and their shell can range anywhere up to 3 cm in length. The shell of the Tegula funebralis is made out of calcium and continues to grow with the snail throughout its lifetime. Because the shell is constantly growing with the snail, the snail must maintain a adequate level of calcium in its system. When a snail dies it will leave behind its shell and theses empty shells are often found in the intertidal to be inhabited by hermit crabs.

     The black turban snails have a range that stretches from the Vancouver Islands of British Columbia, Canada down into Baja California, Mexico. They live throughout the rocky intertidal in the mid intertidal and in tide pools. Typically the snail is only found in the outer coast and not in protected coasts like the Straight of Juan de Fuca or Puget Sound. An interesting fact is that they are often found in dense populations, so 5-10 snails like I witnessed is actually not a large group for them.

     The Tegula funebralis is a herbivorous algal grazer that tends to feed on soft, fleshy algae such as Macrosystis, Nereocystis, and Rhodoglossum and Gigartina. It will eat other algae such as Ralfsia if those types are not available. On the other hand the black turban snail is food mainly to the Pisaster sea star and some carnivorous snails. When the snail is being attacked by predators, it will detach and roll if it is on the side of a rock and attach to the shell of a predator  snail to escape being eaten.

References

http://www.centralcoastbiodiversity.org/black-turban-snail-bull-tegula-funebralis.html

http://nrs.ucop.edu/host/curricula/hermitcrabs.html

http://eol.org/pages/481567/details

http://biology.fullerton.edu/biol317/murray/fall97/tegula_snails.html

http://0-dx.doi.org.iii.sonoma.edu/10.1007/BF00397079

https://scholarsbank.uoregon.edu/xmlui/bitstream/handle/1794/12738/C_funebralis.pdf?sequence=1