Synonyms for tonna_galea or Related words with tonna_galea
Examples of "tonna_galea"
" has been placed on Annex II of both the Berne Convention on the Conservation of European Wildlife and Natural Habitats and the Protocol of the Barcelona Convention for Protection against Pollution in the Mediterranean Sea. In spite these designations, it continues to be "exploited".
, commonly known as the giant tun, is a species of marine gastropod mollusc in the family Tonnidae (also known as the tun shells). This very large sea snail or tun snail is found in the North Atlantic Ocean as far as the coast of West Africa, in the Mediterranean Sea and the Caribbean Sea. The species was first described by Carl Linnaeus in 1758.
"D. calidus" can grow to a length of . It uses large gastropod shells, such as those of "
" and "Charonia" species, which it often decorates with one or more sea anemones of the species "Calliactis parasitica". The relationship with the anemone is truly symbiotic, since the anemone gains scraps of food from the hermit crab, while the crab benefits from the anemone's stinging tentacles deterring predators.
Sea cucumbers are often scorned by most of the marine predators because of the toxins they contain (in particular holothurin) and because of their often spectacular defensive systems. However, they remain a prey for some highly specialized predators which are not affected by their toxins, such as the big mollusks "
" and "Tonna perdix", which paralyzes them using powerful poison before swallowing them completely.
The animal is of a clear brownish red, without spots, and its tentacles are encircled, towards the point, with a wide reddish-brown ring. The foot beneath is of a dark violet, with the edge embroidered with deep brown. "
" possess large salivary glands. The structure of these glands was first described and detailed by Heinrich Weber in 1927. Furthermore, the Giant Tun is also a luminescent species; this is an extremely rare characteristic among the prosobranch gastropods. The animal gives off light that is green-white in colour when it traverses through the water with its foot "well-extended".
Information on the biology and life history of "
" is scarce, due to the fact that the species has only rarely been studied. It is carnivorous, and utilizes its two proboscises—located on top of its head—to envelop its prey, which primarily consists of sea cucumbers. To a lesser extent it also feeds on sea urchins, starfish. fish, bivalves and crustaceans. As a defense mechanism, the snail will squirt its highly-acidic saliva when disturbed. This contains approximately 2–5% sulfuric acid, which is used to kill its prey. The presence of this acid was recorded by Franz Hermann Troschel in 1854.
The ventricose shell of adult "
" is very large, with an average height of . Specimens of this species have been quoted of the size of a man's head. The shell is thin and inflated, but still relatively solid and durable. The shell is almost diaphanous when young; at that time the transverse ribs of the surface are only indicated by lines of a slightly deeper tint. In terms of its weight however, the thin shell is very much lighter than the shell of most other large sea snails. The aperture of the shell is "distinctly round" and wide.
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