Green-lipped mussel
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Green-lipped mussel ( Perna canaliculus ) |
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| ( Gmelin , 1791) |
The green-lipped mussel ( Perna canaliculus ), also known as green-lipped mussel is known, a shell -Art from the family of mussels (Mytilidae). The mussels are endemic to the waters around New Zealand. The green-lipped mussels are grown in large aquacultures in New Zealand and are for the most part exported as "New Zealand green-lipped mussels".
features
The housings are comparatively very large, around 10 to 17 cm. They are elongated-egg-shaped with a curved dorsal edge and a slightly convex curved ventral edge. The front end is almost pointed, the rear edge is broadly rounded.
The shell is relatively thin but firm. The anterior sphincter or the sphincter impression is missing. The posterior sphincter is divided into two bundles and forms a rounded anterior impression and a larger, flat U-shaped posterior impression. 10 to 18 primary teeth are formed during early ontogenesis, later they are reduced again. Usually two dysodontic teeth are preserved, rarely just one. There is only one tooth in the left valve, a pit in the right valve and a weaker tooth on either side of the pit. The surface or outside of the housing is essentially smooth, only provided with growth strips. The periostracum is thick and shiny green. The shell is named after the green shell.
Geographical distribution and way of life
The range of the green-lipped mussel was originally limited to New Zealand and some surrounding islands. The species has since been introduced to Tasmania and South Australia by humans.
Like other mussels, the green-lipped mussels form mussel banks where a density of up to 100 individuals per square meter can be achieved. They live in the tidal range up to the flat subtidal, where they settle on stones, harbor pillars and in the soft bottom. The limits of temperature tolerance are 5.3 ° C in the south and up to 27 ° C in the north. The salinity tolerance is between 30 and 35 Practical Salinity Units (PSU).
development
The green-lipped mussel is sexually separated. Sexual maturity is reached after a year. Eggs and sperm are released into the open water in cooler areas of New Zealand from June to December. In the warm north, the mussels can reproduce all year round. The eggs have a diameter of 56 to 62 µm. Trochophora larvae hatch from the egg just 6 hours after fertilization, after 16 hours the plankton-eating Veliger larva is formed, which forms a first organic housing, the so-called Prodissoconch I, 20 hours after fertilization. The Prodissoconch I is formed by the shell gland, but also continues to grow on the edge of the mantle. The Prodissoconch I is D-shaped with a straight dorsal edge and without a vertebra. It initially measures 75 µm in length and 53 µm in height, with a thickness of 42 µm. While maintaining the general shape, it continues to grow up to 135 µm in length, 112 µm in height and 94 µm in thickness. The Prodissoconch I is then mineralized, the surface shows a pattern of shallow, small pits. Then the formation of the Prodissoconch II begins, which grows on the edge of the mantle and already mineralizes during growth. The formation of the Prodissoconch II is also correlated with the food intake of the larva. It gradually takes on a distinctly different shape and the vortex is formed. The Prodissoconch II shows clear growth lines. During the formation of the prodissoconch, the ligament and the lock teeth form.
The Veliger larva remains free-swimming in the water for about 15 to 20 days. The (limited) movement in the water column takes place through the velum. At the end of the larval phase, the very mobile foot develops. This stage is also called pediveliger. The larva now looks for a suitable place to attach. It is attached by byssus threads that are excreted by the byssus gland. Then the metamorphosis and the excretion of the adult housing (dissoconch) begins. The Prodissoconch II (or the larval case) is 190 to 300 µm in size at this point in time. However, the development time is also strongly dependent on the temperature. Other authors give the development time from fertilization to transition to soil life as 26 days or up to 28 days.
Taxonomy
The taxon was first described in 1791 by Johann Friedrich Gmelin as Mytilus canaliculus . The species name canaliculus is a noun in apposition; the ending is therefore not adapted to the gender of the genus.
The green-lipped mussel as a seafood
The wild stocks of green-lipped mussels are under protection in New Zealand. Due to the high national and international demand, the mussel is grown in large aquacultures ( hanging line culture ), mainly in the Marlborough Sounds and in the Hauraki Gulf . The value of exports of green-lipped mussel products was around NZ $ 220 million in 2012 (2012: around EUR 134 million), about 74% of all aquaculture products. In New Zealand aquacultures, up to 60,000 tons of the 10 to a maximum of 25 centimeters long and approximately two year old mussels are harvested once a year. This harvest is exported as delicatessen and is also available in Germany under the name “New Zealand green-lipped mussel”. The major weakness of these aquacultures is that the mussel fry mainly comes from wild stocks. Intensive research is currently being carried out with the aim of breeding the mussel fry in tanks.
The green-lipped mussel is also known as the "New Zealand mussel". Shape, consistency and taste are definitely comparable.
supporting documents
literature
- Scott E. Siddall: A clarification of the genus Perna (Mytilidae) . In: Rosenstiel School of Marine & Atmospheric Science of the University of Miami (Ed.): Bulletin of Marine Science . tape 30 (4) . AllenPress, Inc, 1980, ISSN 1553-6955 , pp. 858–870 ( siddall.info [PDF; accessed December 15, 2015]).
- Jan M. Vakily: The Biology and Culture of Mussels of the Genus Perna . Ed .: International Center for Living Aquatic Resources Management, Manila & German Society for Technical Cooperation [GTZ]. Eschborn 1989, ISBN 971-10-2270-2 ( books.google.de [accessed December 15, 2015]).
- S. Peter Dance, Rudo von Cosel (arrangement of the German edition): Mytilus canaliculus . In: The great book of sea shells . Eugen Ulmer, Stuttgart 1977, ISBN 3-8001-7000-0 , pp. 226 .
Individual evidence
- ^ Robert B. Allen, William G. Lee: Biological Invasions in New Zealand. XXIV, Springer, Berlin / Heidelberg / New York 2006, ISBN 3-540-30022-8 , limited preview on Google Books .
- ↑ P. Redfearn, P. Chanley, M. Chanley: Larval shell development of four species of New Zealand mussels: (Bivalvia, Mytilacea) . In: New Zealand Journal of Marine and Freshwater Research . tape 20 , no. 2 , 1985, ISSN 1175-8805 , pp. 157-172 , doi : 10.1080 / 00288330.1986.9516140 .
- ^ A b c Adam B. Rusk: Larval development of the New Zealand mussel Perna canaliculus and effects of cryopreservation . Thesis. Ed .: Auckland University of Technology. Auckland 2012 ( aut.researchgateway.ac.nz [PDF; accessed December 15, 2015]).
- ^ Johann Friedrich Gmelin: Caroli a Linné, systema naturae. Tom. I. Pars VI. [Editio decima tertia, aucta, reformata]. Pp. 3021-3910, Beer, Leipzig 1791 biodiversitylibrary.org (p. 3363).
annotation
- ↑ The correct common name in English is actually green-lipped mussel , i.e. green- lipped mussel. However, it is marketed under the name Greenshell mussel , i.e. green-lipped mussel .
