| Novocrania anomala | |
|---|---|
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| Three specimens of Novocrania anomala on a stone | |
Scientific classification  | |
| Kingdom: | Animalia |
| Clade: | Lophophorata |
| Phylum: | Brachiopoda |
| Class: | Craniata |
| Order: | Craniida |
| Family: | Craniidae |
| Genus: | Novocrania |
| Species: | N. anomala |
| Binomial name | |
| Novocrania anomala (Müller, 1776) | |
| Synonyms [1] | |
| |
Novocrania anomala is a species of brachiopod found offshore in the eastern Atlantic Ocean. [1]
Novocrania anomala is found from the Canary Isles, Ireland, Scotland, the Faeroe Isles, Norway, Iceland and Svalbard. [2] It is found attached to the bedrock and boulders at a depth of up to 1500 metres in sheltered environments where the water movement is low. [2]
In appearance, N. anomala resembles a cockle or limpet with a low conical, oval shell up to fifteen millimetres long. The upper valve is the only part visible as the lower valve is cemented to the rock beneath. The shell surface is smooth, white, buff or pale grey and has fine concentric lines. The outer surface is covered by a thin brown periostracum. [2]
Novocrania anomala is a filter feeder, using the lophophore between the two valves to selectively catch particles that drift past. It lives for up to ten years but growth is slow after the first year. It is free-spawning with external fertilisation in the water. The eggs sink to the bottom and hatch into free-swimming juveniles. These larvae are fully developed within three days and settle out a few days later, attaching themselves to the substrate. Because N. anomala favours waters with tidal flows of less than one knot, dispersal may be limited. [2]
Novocrania anomala is often the dominant species in its environment. It is eaten by starfish, crustacea, gastropods and fish. Compared to molluscs, the shell is easily drilled into and the shells are often heavily bored. However predation seems to be limited, perhaps because the brachiopod is unpalatable. [2]
This species is often found in association with the sea anemone Protanthea simplex in very sheltered deep water, usually on littoral bedrock, silty boulders and rock slopes in fiords and other areas with calm waters. They are often accompanied by the parchment worm Chaetopterus variopedatus , encrusting red algae and the polychaete worm Pomatoceros triqueter . Other members of the community may be the saddle oyster Pododesmus patelliformis and the fan worm Sabella pavonina . Scattered colonies of Alcyonium digitatum are occasionally present along with the hydroid Bougainvillia muscus . The barnacle Balanus balanus and the hermit crab Pagurus bernhardus can often be seen in the vicinity and the squat lobster Munida rugosa may be hiding in crevices nearby. [3]
A range of solitary sea squirts are often present including Ciona intestinalis , Corella parallelogramma , Polycarpa pomaria , Ascidia mentula and Ascidia virginea . Echinoderms such as the brittle star Ophiothrix fragilis are frequently seen with their arms protruding from rock cracks, whilst the starfish Asterias rubens and the sea urchins Echinus esculentus and Psammechinus miliaris occasionally form part of the community, as does the whelk Buccinum undatum . [3]
A survey was undertaken of the marine ecology in deep water off County Kerry in Ireland, The rock and boulders were covered with a fine silt and there were coralline crusts over most surfaces. N. anomala was found on the steep sides and lower parts of boulders while the tube worm Pomatoceros triqueter and the stony coral Caryophyllia smithii predominated on the upper parts. [4]
The periostracum is a thin organic coating or "skin" which is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs it is primarily seen in snails and clams, i.e. in gastropods and bivalves, but it is also found in cephalopods such as Allonautilus scrobiculatus. Periostracum is an integral part of the shell, and it forms as the shell forms, along with the other shell layers.
Lingula is a genus of brachiopods within the class Lingulata. Lingula or forms very close in appearance have existed possibly since the Cambrian. Like its relatives, it has two unadorned organo-phosphatic valves and a long fleshy stalk. Lingula lives in burrows in barren sandy coastal seafloor and feeds by filtering detritus from the water. It can be detected by a short row of three openings through which it takes in water (sides) and expels it again (middle).
The common starfish, common sea star or sugar starfish is the most common and familiar starfish in the north-east Atlantic. Belonging to the family Asteriidae, it has five arms and usually grows to between 10–30 cm across, although larger specimens are known. The common starfish is usually orange or brownish in color, and sometimes violet; specimens found in deeper waters are pale. The common starfish is found on rocky and gravelly substrates where it feeds on mollusks and other benthic invertebrates.
Brachiopods, phylum Brachiopoda, are a group of lophotrochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major groups are recognized, articulate and inarticulate. The word "articulate" is used to describe the tooth-and-groove features of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic feature (fossilizable), by which the two main groups can be readily distinguished. Articulate brachiopods have toothed hinges and simple opening and closing muscles, while inarticulate brachiopods have untoothed hinges and a more complex system of muscles used to keep the two valves aligned. In a typical brachiopod a stalk-like pedicle projects from an opening in one of the valves near the hinges, known as the pedicle valve, keeping the animal anchored to the seabed but clear of silt that would obstruct the opening.
The origin of the brachiopods is uncertain; they either arose from reduction of a multi-plated tubular organism, or from the folding of a slug-like organism with a protective shell on either end. Since their Cambrian origin, the phylum rose to a Palaeozoic dominance, but dwindled during the Mesozoic.
Anomia is a genus of saltwater clams, marine bivalve mollusks in the family Anomiidae. They are commonly known as jingle shells because when a handful of them are shaken they make a jingling sound, though some are also known as saddle oysters.
Amphibalanus improvisus, the bay barnacle, is a species of acorn barnacle in the family Balanidae.
Chlamys hastata, the spear scallop, spiny scallop or swimming scallop, is a species of bivalve mollusc in the family Pectinidae found on the west coast of North America from the Gulf of Alaska to San Diego, California. A limited number of these scallops are harvested by divers or by narrow trawls off the west coast of Canada.
Balanus balanus is a species of acorn barnacle in the Balanidae family. It is native to the colder seas of the northern hemisphere.
Balanus crenatus is a species of acorn barnacle in the Balanidae family. It is found in the North Pacific and the North Atlantic Ocean.
Pododesmus patelliformis, the ribbed saddle-oyster, is a species of bivalve mollusc in the family Anomiidae. It is found in the north east Atlantic Ocean.
Serpula vermicularis, known by common names including the calcareous tubeworm, fan worm, plume worm or red tube worm, is a species of segmented marine polychaete worm in the family Serpulidae. It is the type species of the genus Serpula and was first described by Carl Linnaeus in his 1767 12th edition of Systema Naturae. It lives in a tube into which it can retract.
Crassadoma is a genus of rock scallops, marine bivalve molluscs in the family Pectinidae. It is monotypic, the only species being Crassadoma gigantea, the rock scallop, giant rock scallop or purple-hinge rock scallop. Although the small juveniles are free-swimming, they soon become sessile, and are cemented to the substrate. These scallops occur in the eastern Pacific Ocean.
Evasterias troschelii is a species of starfish in the family Asteriidae. Its common names include the mottled star, false ochre sea star and Troschel's true star. It is found in Kamchatka and the north western coast of North America.
Pomatoceros lamarckii is a species of tube-building annelid worms which is widespread in intertidal and sub-littoral zones around the United Kingdom and northern Europe. They are found attached to firm substrates, from rocks to animal shells to man made structures, and often are noted for their detrimental effect on shipping. It is closely related to, and often confused with, Pomatoceros triqueter.
Ficopomatus enigmaticus, commonly known as the Australian tubeworm, is a species of serpulid tubeworms. Their true native range is unknown, but they probably originated in the Southern Hemisphere, perhaps from the Indian Ocean and the coastal waters of Australia. Today they have a cosmopolitan distribution, having been introduced to shallow waters worldwide. The Australian tubeworm is an invasive species that dominates and alters habitats, reduces water quality, depletes resources, and causes biofouling.
Argyrotheca is a genus of very small to minute lampshells. All species share a large pedicel opening, one ridge on the inside of the pedunculate valve, pits in a diamond pattern on the inside of both valves, and without radial ridges that end in tubercles. It occurs in depths between 6 and 1300 m. It is known since the latest Cretaceous.
Valdiviathyris quenstedti is a small species of brachiopods with a maximum size of about 0.3 inches or 7.6 millimetres wide.
Novocrania is a genus of brachiopods found off shore.
Chorizopora brongniartii is a species of bryozoan in the family Chorizoporidae. It is an encrusting bryozoan, the colonies forming spreading patches. It has a widespread distribution in tropical and temperate seas.