Brachidontes pharaonis | |
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Museum specimens of the shell of Brachidontes pharaonis | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Bivalvia |
Order: | Mytilida |
Family: | Mytilidae |
Genus: | Brachidontes |
Species: | B. pharaonis |
Binomial name | |
Brachidontes pharaonis | |
Synonyms [1] | |
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Brachidontes pharaonis is a species of mussel from the family Mytilidae. It is native to the Indian Ocean and the Red Sea, and has colonised the Mediterranean Sea where it is regarded as an invasive species.
Brachidontes pharaonis is a small bivalve that grows its shell up to 40mm in length. The external surfaces of the shell are dark brownish black while the interior of the shell is purplish-black. The two halves of the shell are equal in size and similar in shape, being elongated and asymmetrical, with a dysodont hinge between the valves. The sculpture of the valves consists of numerous fine radial bifurcating ribs, which become coarser posteriorly and finely scalloped towards the edge. The outline is mytiliform with a terminal umbo, but the shape is very variable and specimens may be highly expanded posteriorly, occasionally curved; sometimes almost cylindrical with the beaks being sub-terminal. [3] The animal is attached to the substrate by thick byssus.
Brachidontes pharaonis is found on rocky substrates and man made structures in the intertidal zone. They appear to be able to tolerate wide temperature variations in their invasive Mediterranean range, but low winter temperatures may inhibit their physiology. [4] In the cooler waters of the western Mediterranean, B. pharaonis is restricted to habitats with higher temperatures and salinities, where it establishes dense mussel beds on hard substrates, especially where it is sheltered from waves. [3]
Brachidontes pharaonis is native only to the Red Sea and adjacent Indian Ocean (see Taxonomy). [3]
Brachidontes pharaonis was first recorded in the Mediterranean Sea in 1876 off Port Said in Egypt, reaching Lebanon and Palestine by the 1930s; Sicily by 1971; Greece by 1979; Syria and Turkey by 1985, Rhodes by 1989, Cyprus by 1996, and the northern Adriatic coast of Croatia by 1997. [5]
The populations in the Levantine Sea most likely arose from larvae that entered the Mediterranean through the Suez Canal. This is thought to be the earliest example of a Lessepsian migration. The colonisation of the central Mediterranean is probably due to transportation by ships. [4]
Brachidontes pharaonis is a filter feeder, filtering suspended food from the water, mainly phytoplankton or suspended organic detritus. [3]
There are two sexes. The sperm and eggs are released into the water column by the adults. There are two larval stages: a trochophore stage which lasts around 24 hours, and a veliger stage which lasts for some weeks before they achieve competence and settle on the substrate. [3]
In warmer, saltier regions it forms dense beds which, exclude other sessile bivalves; [3] but in colder, less saline regions, such as the Aegean Sea, it forms smaller, less densely populated beds. [3]
A species of whelk, Stramonita haemastoma , was found to preferentially prey on B. pharaonis off the coast of Israel [3] and in the south of Italy. [6] [7]
Brachidontes pharaonis is regarded as a fouling organism. It has been recorded colonising the hulls of boats in harbours, and may foul intake pipes. [3]
Brachidontes pharaonis can displace the native mussel Mytilaster minimus by interfering with the recruitment of M. minimus. The presence of B. pharaonis also has detrimental effects on the survival and growth of the native mussel. By the late 1990s Israeli surveys were showing that there had been a rapid shift in dominance, demonstrating that some populations of B. pharaonis had reached densities of up to 300 specimens per 100 cm², while M. minimus was very infrequently encountered. [4] Even higher densities have been reached in the saltpans of western Sicily, where 10,000 specimens per m² have been counted. [3]
There is some controversy about the species limits of Brachidontes pharaonis and further genetic studies are required. The current thinking is that the name B. pharaonis is best applied to the Mediterranean and Red Sea. Other species within the complex are Brachidontes exustus , Brachidontes semistriatus and Brachidontes variablis , but more study is needed to determine their distributions. [3]
Bivalvia, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. The class includes the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. Shipworms bore into wood, clay, or stone and live inside these substances.
The blue mussel, also known as the common mussel, is a medium-sized edible marine bivalve mollusc in the family Mytilidae, the mussels. Blue mussels are subject to commercial use and intensive aquaculture. A species with a large range, empty shells are commonly found on beaches around the world.
The dog whelk, dogwhelk, or Atlantic dogwinkle is a species of predatory sea snail, a carnivorous marine gastropod in the family Muricidae, the rock snails.
Intertidal ecology is the study of intertidal ecosystems, where organisms live between the low and high tide lines. At low tide, the intertidal is exposed whereas at high tide, the intertidal is underwater. Intertidal ecologists therefore study the interactions between intertidal organisms and their environment, as well as between different species of intertidal organisms within a particular intertidal community. The most important environmental and species interactions may vary based on the type of intertidal community being studied, the broadest of classifications being based on substrates—rocky shore and soft bottom communities.
Rapana venosa, common name the veined rapa whelk or Asian rapa whelk, is a species of large predatory sea snail, a marine gastropod mollusc or whelk, in the family Muricidae, the rock shells.
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Atrina fragilis, the fan mussel, is a species of large saltwater clam, a marine bivalve mollusc in the family Pinnidae, the pen shells.
The common cockle is a species of edible saltwater clam, a marine bivalve mollusc in the family Cardiidae, the cockles. It is found in waters off Europe, from Iceland in the north, south into waters off western Africa as far south as Senegal. The ribbed oval shells can reach 6 centimetres (2.4 in) across and are white, yellowish or brown in colour. The common cockle is harvested commercially and eaten in much of its range.
Perna perna, the brown mussel, is an economically important mussel, a bivalve mollusc belonging to the family Mytilidae. It is harvested as a food source but is also known to harbor toxins and cause damage to marine structures. It is native to the waters of Africa, Europe, and South America and was introduced in the waters of North America.
Ostrea lurida, common name the Olympia oyster, after Olympia, Washington in the Puget Sound area, is a species of edible oyster, a marine bivalve mollusk in the family Ostreidae. This species occurs on the northern Pacific coast of North America. Over the years the role of this edible species of oyster has been partly displaced by the cultivation of non-native edible oyster species.
Mytilopsis leucophaeata is a species of small bivalve mollusc in the false mussel family, Dreissenidae. It is commonly known as Conrad's false mussel or the dark false mussel.
Modiolus modiolus, common name northern horsemussel, is a species of marine bivalve mollusk in the family Mytilidae.
Stramonita haemastoma, common name the red-mouthed rock shell or the Florida dog winkle, is a species of predatory sea snail, a marine gastropod mollusc in the family Muricidae, the rock snails.
The Mediterranean mussel is a species of bivalve, a marine mollusc in the family Mytilidae. It is an invasive species in many parts of the world, and also an object of aquaculture.
Amphibalanus improvisus, the bay barnacle, European acorn barnacle, is a species of acorn barnacle in the family Balanidae.
Brachidontes is a genus of mussels in the family Mytilidae.
Mytella strigata is a bivalve, commonly known as the charru mussel or charrua mussel. This species was described by Sylvanus Charles Thorp Hanley based on a specimen from the Philippines. It was found in Central and South America and by Alcide d'Orbigny, a French naturalist, in 1842, where it was assigned the synonym Mytilus charruanus. They are less than an inch long (2.5 cm), and range from brown to black in color.
Mytilaster minimus, the dwarf mussel or variable mussel, is a species of mussel from sea and brackish waters of the Mediterranean Sea.
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