Mediterranean mussel
| Mediterranean mussel | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Mediterranean mussel ( Mytilus galloprovincialis ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Mytilus galloprovincialis | ||||||||||||
| Lamarck , 1819 |
The Mediterranean mussel ( Mytilus galloprovincialis ) is a type of mussel from the family of mussels (Mytilidae). The species can only be reliably differentiated from the other two very closely related Mytilus species ( Mytilus edulis and Mytilus trossulus ) by allozyme electrophoresis studies . It is considered an invasive species in South Africa, where the species was introduced in the 1970s.
features
The same-folding, elongated housing with a bulge at the front reaches a maximum length of 15 centimeters. The ratio of length to thickness of both flaps (L / D index) is 2.5, the L / H index = 1.8. The greatest height is reached in the rear part of the housing. However, the shape of the housing is highly variable, so that slightly different conditions arise. It is very unequal, the vertebra sits at the front end of the case. It is rounded wedge-shaped ( mytiliform ) in outline with a very long, slightly curved lock edge or ligament edge (or dorsal edge). The dorsal edge merges into the flatly rounded posterior edge at a rounded flat angle. The ventral margin is straight or very slightly concave. The front end is very tightly rounded and forms a slight hook that is bent downwards. The inner edge of the case is smooth. The ligament is external, but somewhat sunk into the dorsal field; it extends over two thirds of the dorsal margin. The castle is mostly smooth; only in the area of the front end ( hook ) are a few vertical notches and projections. Housing shape and size are very variable and also heavily dependent on ecological factors.
The whitish, mineral skin is thin but robust. It consists of a thicker outer layer of prismatic calcite . The thinner inner layer is made up of aragonitic mother-of-pearl leaves . The ornamentation consists of concentric growth lines and somewhat coarser growth interruptions. The periostracum is thin and firmly adheres to the shell. It is black-blue to dark brown.
There are two very unequal sized sphincters; the anterior sphincter is very small, the point of attachment indistinct. The posterior sphincter, together with the byssus retractor, forms a very large muscle impression directly within the surface line.
Similar species
The shell of the Mediterranean mussel is very similar to that of the common mussel ( Mytilus edulis ) and also of the Pacific mussel ( Mytilus trossulus ). It is often not possible to differentiate between individual specimens with certainty. On average or typical specimens differ in that the vertebra of the Mediterranean mussel is more pointed and forms a "hook". The case is significantly higher, i.e. H. the ratio of length to height is much smaller in the Mediterranean mussel. Due to the slightly greater height, the dorsal angle is slightly more acute or less flat than that of the common mussel. In the Mediterranean mussel, the ventral edge is straight or even very slightly concave, while in the common mussel it is slightly convex to slightly concave, usually almost straight. The species can be reliably differentiated by allozyme electrophoresis and molecular biological methods. Hybridization between the three species does occur, but the hybrids play a minor role in the populations studied and the species' gene pool remains essentially intact.
Geographical distribution and habitat
The original distribution area was the Mediterranean , the Caspian Sea and the coastal waters of the Iberian Peninsula (to the Basque Country ). As a result of mussel farming or aquaculture and through displacement, it is now also found in smaller and larger populations on the coasts of Chile and in large parts of the North Pacific (Russian Far East, Northern China, Japan, to South Korea, California). It is considered an invasive species here. There are also smaller populations in Brittany , southern England and south-western Ireland , even in Lofoten and Svalbard . Conversely, the common blue mussel is now found in smaller populations in the Mediterranean and the coastal waters of the Iberian Peninsula. The Mediterranean mussel is said to need slightly warmer water temperatures than the common mussel to grow. The occurrence on Spitsbergen contradicts this.
Mediterranean mussels occur from the tidal range to about 50 meters water depth. They can endure lying dry for hours by closing the flaps tightly.
Taxonomy
The taxon was introduced into scientific literature in 1819 by Jean-Baptiste de Lamarck . The species status has been questioned again and again. Poppe and Goto understood it as a mere form of the common mussel in 1993 . Today it is generally recognized as an independent species based on molecular biological studies. Fritz Nordsieck eliminated eleven subspecies in 1969, all of which are now reunited with the nominate subspecies; ie there are no more subspecies. The MolluscaBase lists a total of 19 Synonyms : Mytilus dilatatus Gray, 1825, Mytilus edulis diegensis Coe, 1945, Mytilus edulis zhirmunskii Scarlato & Starobogatov, 1979, Mytilus flavus Poli, 1795, Mytilus galloprovincialis angustata Philippi, 1836, Mytilus galloprovincialis eduliformis Monterosato, 1891, Mytilus galloprovincialis falcata Monterosato, 1884, Mytilus galloprovincialis herculea Monterosato, 1884, Mytilus galloprovincialis var. frequens Milaschewitsch 1906, Mytilus galloprovincialis var. latissima Monterosato, 1884, Mytilus galloprovincialis var. trepida Milaschewitsch 1906, Mytilus galloprovincialis var. uncinata Bucquoy, Dautzenberg & Dollfus , 1889, Mytilus glocinus Locard, 1889. Mytilus hesperianus Lamarck, 1819, Mytilus lamarckianus Clessin, 1887, Mytilus orbicularis Pallary, 1903, Mytilus pelecinus Locard, 1889, Mytilus sagittatus Poli, 1795, and Mytilus succineus , 1856.
Mytilus chilensis (Hupé, 1854) was regarded by some authors as a subspecies of the Mediterranean mussel (or the common mussel) until recently. According to studies of the sperm morphology, Mytilus chilensis is an independent species. Although viable hybrids could be produced in the laboratory, the survival rate of the hybrid larvae was lower than that of the purebred larvae. Hybridization has not yet been observed under natural conditions.
Economical meaning
(see also article mussels from Galicia )
The Mediterranean mussel is or was an important seafood in the Mediterranean region and on the Atlantic coast of the Iberian Peninsula . Today the Mediterranean mussel is mainly grown in aquaculture. The annual harvest is around 120,000 tons from aquaculture. In contrast, wild catches have fallen from over 50,000 tons per year (around 2000) to around a thousand tons (2014).
supporting documents
literature
- Claire Daguin, Philippe Borsa: Genetic relationships of Mytilus galloprovincialis Lmk. populations worldwide: evidence from nuclear-DNA markers. In: Crame, A., Harper, E., Taylor, J. (eds). Bivalve Systematics and Evolution. Geological Society of London Special, pp. 389-397, 2000 PDF
- S. Peter Dance, Rudo von Cosel (arrangement of the German edition): The great book of sea shells. 304 p., Verlag Eugen Ulmer, Stuttgart, 1977 ISBN 3-8001-7000-0 (p. 226)
- Rudolf Kilias: Lexicon marine mussels and snails. 2nd edition, Verlag Eugen Ulmer, Stuttgart 1997 ISBN 3-8001-7332-8 (p. 209)
- Fritz Nordsieck : The European sea shells (Bivalvia). From the Arctic Ocean to Cape Verde, the Mediterranean Sea and the Black Sea. 256 p., Gustav Fischer Verlag, Stuttgart 1969 (p. 39/40)
- Guido Poppe and Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 p., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unaltered reprint), ISBN 3925919104 (p. 52/53)
On-line
Individual evidence
- ↑ Paul C. Dalbeck: Crystallography, stable isotope and trace element analysis of Mytilus edulis shells in the context of ontogeny. PhD thesis, University of Glasgow, 2008. Abstract
- ↑ KA Lutaenko, EV Kolpakov: The extension of the distributional range of an invasive mussel, Mytilus galloprovincialis (Bivalvia: Mytilidae) in the Sea of Japan. The Bulletin of the Russia Far East Malacological Society, 20 (1): 57-76, 2016
- ↑ Han Zhiqiang, Mao Yangli, Shui Bonian, Yanagimoto Takashi, Gao Tianxiang: Genetic structure and unique origin of the introduced blue mussel Mytilus galloprovincialis in the north-western Pacific: clues from mitochondrial cytochrome c oxidase I (COI) sequences. Marine and Freshwater Research, 68: 263-269, 2016. doi : 10.1071 / MF15186
- ^ Sofie Smedegaard Mathiesen, Jakob Thyrring, Jakob Hemmer-Hansen, Jørgen Berge, Alexey Sukhotin: Genetic diversity and connectivity within Mytilus spp. in the subarctic and Arctic . In: Evolutionary Applications . tape 10 , no. 1 , January 1, 2017, ISSN 1752-4571 , p. 39–55 , doi : 10.1111 / eva.12415 , PMID 28035234 , PMC 5192891 (free full text).
- ↑ Elizabeth K. Fly, Thomas J. Hilbish, David S. Wethey, Rhiannon L. Rognstad: Physiology and biogeography: The response of European mussels (Mytilus spp.) To climate change. American Malacological Bulletin, 33 (1): 136-149, 2015. doi : 10.4003 / 006.033.0111
- ↑ Jean-Baptiste Pierre Antoine de Monet de Lamarck: Histoire naturelle des animaux sans vertèbres ... précédée d'une introduction offrant la détermination des caractères essentiels de l'animal, sa distinction du végétal et des autres corps naturels, enfin, l ' exposure of the principes fondamentaux de la zoologie. Tome 6, 232 S., Paris, Deterville, 1819. Online at www.biodiversitylibrary.org (p. 126)
- ↑ a b MolluscaBase: Mytilus galloprovincialis Lamarck, 1819
- ↑ Pablo A. Oyarzún, Jorge E. Toro, Orlando Garrido, Carolina Briones, Ricardo Guiñez: Differences in sperm ultrastructure between Mytilus chilensis and Mytilus galloprovincialis (Bivalvia, Mytilidae) : could be used as a taxonomic trait? Latin American Journal of Aquatic Research, 42 (1): 172-179, 2014
- ↑ a b Species Fact Sheets Mytilus galloprovincialis (Lamarck, 1819)
