Thorny Oyster – Spondylus senegalensis
The Thorny Oyster is a species in the class of the Bivalvia and thus belongs to the phylum of the Mollusca. Spondylus senegalensis was first described in 1793 by Schreiber.
The Thorny Oyster has a round shape and is only flattened at the foot end. In addition, it laterally compressed.
The spiked shell has a pink to red colour, but is often covered with algae, moss animals, Cnidaria or sponges. The mantle edge is yellowish on the outside and white on the inside. On it are found many brown and white spots, which almost give a striped pattern.
Between the mantle edge and shell protrude several small tentacles. There are also numerous small eyes.
The maximum size I do not know, but individuals that I have seen were about 10cm in diameter. According to some sellers of shells they can be larger than 15cm.
Habitat and Distribution
Spondylus senegalensis lives on rocky ground or on wrecks. They tend to prefer shady reef areas with water movement or current.
When diving in the Canaries you can find them from time to time. However, you have to look quiet close, because it is often overgrown.
Their distribution area ranges from the Azores, via Madeira and Cape Verde to Gabon. According to its name, it is also found in Senegal.
There is not much known about the biology of the Thorny Oyster. Representatives of the same genus are, however, permanently fixed to the ground.
Its diet consists of small particles, such as plankton and detritus, that it filters out of the water.
It can be up to 80 years old.