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The dog whelk, dogwhelk, or Atlantic dogwinkle ( Nucella lapillus) is a species of predatory sea snail, a carnivorous marine gastropod in the family Muricidae, the rock snails.
Nucella lapillus was originally described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae as Buccinum lapillus (the basionym).
The shell surface can be fairly smooth interrupted only with growth lines, or when the snail is living in more sheltered areas the shell surface can be somewhat rough and lamellose. The surface is spirally corded. The outer lip is dentate and ridged within. The columella is smooth.
The external shell colour is usually a whitish grey, but can be a wide variety of orange, yellow, brown, black, or banded with any combination of these colours. They can even, occasionally, be green, blue, or pink.
The peak in dog whelk population density is approximately coincidental with the mid-tidal zone. It lives in the middle shore. In general it can be said that at high vertical heights on the shoreline the dog whelk is most threatened by Biotic component factors such as predation from birds and interspecific competition for food, but abiotic factors are the primary concern, creating a harsh environment in which it is difficult to survive. At low vertical heights it is biotic factors, such as predation from crabs and intraspecific competition, which cause problems. The upper limit of the range in which the dog whelk is generally found is approximately coincidental with the mean high water neap tide line, and the lower limit of the range is approximately coincidental with the mean low water neap tide line, so that the vast majority of dog whelks are found on the mid-tidal zone.
and comparable microhabitats extend the vertical range of such as the dog whelk as they provide a more constant environment, but they are prone to increased salinity because evaporation concentrates dissolved substances. This can create toxicity conditions for many species.
The dog whelk can only survive out of water for a limited period, as it will gradually become desiccation and die. Metabolism processes within cells take place in solution, and a decrease in water content makes it impossible for the organism to function properly. In experiments it has been shown that 50% of dog whelks die at 40 °C. The dog whelk has to excretion ammonia directly into water, as it does not have the adaptation possessed by many upper shore species which would allow it to produce uric acid for excretion without loss of water. When kept emersed for seven days at a temperature of 18 °C, 100% of dog whelks die, in contrast to many periwinkle species which can lose even more water than the dog whelk (i.e. more than 37% of their total body mass) but survive as a result of their ability to excrete toxic waste products more efficiently.
Feeding only occurs when conditions are conducive to such an activity, and during these times the dog whelk consumes large quantities of food so that the gut is always kept as full as possible. This allows shelter until more food is required, when foraging resumes. If waves are large or there is an excessive risk of water loss the dog whelk will remain inactive in sheltered locations for long periods.
Mussels have developed a defensive strategy of tethering and immobilising with byssus threads any dog whelks invading their beds, leading to the whelks' starvation.
Nucella lapillus's feeding activity is suppressed on brighter moonlight nights, in order to minimize predation risks. High-intensity ALAN levels reversed the pattern. In fact, N. lapillus would more likely forage when Artificial Light At Night (ALAN) intensities range from 10 to 50 lx, which are way higher than lunar brightness. This allows dog whelks to easily exclude predation risk.
Bede, Ecclesiastical History of the English People Book 1, Chapter 1.
In Ireland, on the island of Inishkea Islands, Co. Mayo, archaeologists found a whelk-dyeing workshop, dated to the 7th century AD, complete with a small, presumed vat, and a pile of broken-open dog-whelk shells. Unfortunately, no such workshop is known from Britain for the early medieval period. However, a double-checked trace of bromine, indicating the presence of whelk-dye, has been found on one page of an Anglo-Saxon book known as the Barberini Gospels. This manuscript dates to the late 8th or early 9th century AD, and the whelk dye occurs as a background panel to white lettering at the beginning of St John's gospel. Efforts have also been made to find whelk dye on surviving fragments of Anglo-Saxon textiles, but the chemical analyses so far carried out have proved negative for bromine.Porter, C.A., Chiari, G. and Cavallo, A., 2002. The analysis of eight manuscripts and fragments from the fifth/sixth century to the twelfth century, with particular reference to the use of and identification of "real purple" in manuscripts. In: Van Grieken, R. et al. (eds), Art 2002: Proceedings of the 7th International Conference on Non-Destructive Testing and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage, Antwerp, Belgium, 2–6 June 2002
An Anglo-Saxon account of the accession ceremony of Aldfrith of Northumbria involved whelk-dyed cloth, although this may simply be a poetic echo of Roman ceremonies. Another example involves an account of valuable textiles brought to England by Wilfrid of Ripon.
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