''Tenguella marginalba'' is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of sea snail, a marine gastropod mollusc in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Muricidae Muricidae is a large and varied taxonomic family of small to large predatory sea snails, marine gastropod mollusks, commonly known as murex snails or rock snails. With about 1,600 living species, the Muricidae represent almost 10% of the Ne ...

, the murex snails or rock snails. It is commonly known as the mulberry whelk and is found in shallow waters in the Indo-Pacific and around the north and east coasts of Australia.

Description

The mulberry whelk has a strong, robust shell and can grow to about but a more normal adult size is . Each body whorl has five rows of purple or blackish, roughly square, nodules separated by pale grey areas with fine sculptured vertical and horizontal lines. The lip is curved with four similar-sized ridges or teeth on its inner surface. The

columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the ...

, or central axis, is white and is stout with a smooth surface. The interior of the shell is purple-grey, contrasting with the cream teeth and lip.

Distribution and habitat

The mulberry whelk is found on the north and east coasts of Australia and on islands in the central Indo-Pacific Ocean. In Australia, its range extends from the north west tip to

Twofold Bay Twofold Bay is an open oceanic embayment that is located in the South Coast region of New South Wales, Australia. The bay was named by George Bass, for its shape of two bights. The northern bight is called Calle Calle Bay; while the southe ...

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

. It is common on rocks in the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species ...

where adults hide in cracks. It is also found in estuaries where it is known as the black oyster borer because it feeds on

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not a ...

s where it is regarded as a pest.

Biology

The mulberry whelk is a

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

feeding almost exclusively on molluscs and

barnacle A barnacle is a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive ...

s. It has an extensible rasping

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

with which it drills a hole through it victim's shell. The process is believed to be assisted by the sulphuric acid it produces in its salivary glands which helps to soften and dissolve the calcium carbonate in the mollusc's shell. It then uses its radula to cut the soft body of its victim in pieces before sucking the semidigested mass out. The mulberry whelk does not usually move around much when both crevices in which to hide and prey species are in the vicinity. This is in contrast to the rather similar ''

Thais orbita ''Dicathais'' is a genus of predatory sea snails, marine gastropod molluscs in the family Muricidae, the rock snails. This genus is monotypic; the only species in it is ''Dicathais orbita'', common name the white rock shell or cart-rut shell, fo ...

'' which makes foraging movements up the beach well away from the sheltered niches to which it retreats at low tide. Favoured prey includes oysters and the limpet ''

Patelloida latistrigata ''Patelloida latistrigata'' is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lottiidae Lottiidae is a family of sea snails, specifically true limpets, marine gastropod mollusks in the superfamily Lotti ...

''. The barnacle ''

Chamaesipho columna ''Chamaesipho columna'' is the type species for the barnacle genus ''Chamaesipho''. Originally, species concept, as refined by Darwin

'' was also eaten, but was avoided when more attractive prey was present.

References

External links

Photographs
of syntype specimens at Muséum National de Histoire Naturelle.
Original description
(in French) by H.-M. D. de Blainville (1832), wit
illustration
{{Commons category marginalba Gastropods described in 1832