3 the Blue Mussel – Irreplaceable Filter-Feeder and Geneticist's Favourite

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The Blue mussel – irreplaceable filter-feeder and geneticist’s favourite | Kamila Sfugier | EDUKACJA BIOLOGICZNA I ŚRODOWISKOWA 1/2015 3

The Blue mussel Biological and ecological characteristics between 0 ppm and 31 ppm. Their growth rate, however, significantly decreases in salinity below 12.8 ppm. – irreplaceable filter-feeder The Mytilus edulis spp. complex includes the three This bivalve attains an average length of 3 to 5 cm, but in and geneticist’s favourite taxa: Mytilus edulis, Linnaeus, 1758; Mytilus gallopro- deeper water forms larger shells of about 9 cm. vincialis, Lamarck, 1819; Mytilus trossulus, Gould, 1850. The outer part of the blue mussel shell is often dark Kamila Sfugier All these species are widely distributed and hybridise blue, blackish or brown. The inner part is silvery and within areas where their habitats overlap (McDonald et slightly pearly. Blue mussels grow a shell consisting of al., 1991). two valves that are opened by two dorsal muscles and coherence with the Curriculum – see. p. 10 Size, shape and colour Scientific classification closed by sphincters (Jura, 2004). Summary: of blue mussels depend Blue mussels are gonochoric, but it is only possible Mussels from Mytilus spp. complex are important in on their habitat. Growth Kingdom: Animalia to identify their gender during the breeding season. In aquatic ecosystems as well as their worldwide economic rate is influenced largely Phylum: Mollusca the Atlantic Ocean breeding takes place from mid-May importance. Annual world production of marine mussels by water temperature, sa- Class: Bivalvia to the end of September. Duration is dependent on nu- for consumption is around one million tons and in Eu- linity, quality and avail-

Subclass: Pteriomorphia merous factors, such as food, water temperature and SCIENCE rope exceeds 600.000 tons. These bivalves contain nutri- ability of food. The ideal Order: Mytiloida physical processes in the water column. In stagnant wa- tious proteins, carbohydrates, mineral salts and a small temperature for growth Family: Mytilidae ter it is also possible to find hermaphroditic blue mus- amount of fat, but apart from cooks they fascinate sci- varies between 10 and sels (Saavedra, 1997). entists. The sensitivity of mussels to environmental pol- Subfamily: Mytilinae 200C, while temperatures The breeding strategy of blue mussels is a combina- lution allows their exploitation as bioindicators. Addi- Genus: Mytilus above 270C are consid- tion of three features, i.e., relative fecundity (Bayne et tionally their inheritance of mitochondrial DNA is quite Species: extraordinary. This article aims to present the blue mussel ered lethal. Blue mus- Mytilus edulis (Linnaeus, 1758) al., 1983; Sprung, 1983), comparatively high mortality in the light of its ecology and genetics. sels have a cosmopolitan Mytilus trossulus (Gould, 1850) of larvae (Yap, 1977) and plankton dispersal (Crisp, distribution, inhabiting Mytilus galloprovincialis 1975). Gametes are discharged once or several times SCHOOL Key words: blue mussel, doubly uniparental inheritance, hy- (Lamarck, 1819) bridisation, masculinization water bodies of salinity directly into the water, where fertilisation occurs. In-

received: 16.01.2015; accepted: 12.02.2015; published: 27.03.2015

mgr Kamila Sfugier: Institute of Oceanology of the Polish Academy of Sciences, Genetics and Marine Biotechnology Department, [email protected] IN SHORT

The Author – Kamila Sfugier – is a participant of the project „Stypendia dla doktorantów województwa podlaskiego”, co-financed within the Operational Programme Human Capital, measure 8.2 Transfer of knowledge, sub-measure 8.2.2 Regional Innovation Strategies, from the European Social Fund, state budget and Podlaskie Voivodship budget. Figure 1. Shape of the shell: Mytilus galloprovincialis, Lamarck, 1819; Mytilus trossulus, Gould, 1850; Mytilus edulis, Linnaeus, 1758 Source: http://naturalhistory.museumwales.ac.uk/britishbivalves

Fig. 2. Blue mussel anatomy Due to the low salinity of the Baltic Sea, blue mus- Source: http://www.design-site.net sels have developed a dwarf form (up to 5 cm long), but they constitute about 75% of the epifauna (Jura, 2004). The total population of blue mussels inhabiting the Bal- tic proper to a maximum depth of 25 m (with shell) is estimated at 8 million tons dry weight (Kautsky, 1991).

Aquaculture and use in food industry

In many countries blue mussels are harvested for consumption. In Poland, however, blue mussels are not commercial owing to their small size. The first men- tion of human blue mussel cultivation in Europe is de-

scribed on wooden stakes in 1235 AD, in France. From SCIENCE that time, blue mussel breeding started in Europe over the full area of their distribution. Subsequently breed- dividual development stages of Mytilus have been de- The bivalve lives in shoals in coastal zones. The belt ing techniques emerged in the late 19th century when scribed by Field (1922) and Bayne (1976) and have been of blue mussels starts at a depth of several-metres and aquaculture began to be regarded as a cheap protein divided into three separate phases (Sprung, 1984). The spreads to a depth of 30 m. Blue mussels are highly im- source. Blue mussels then became a very popular dish first larval stage ofMytilus a trochophore is formed – portant filter feeders. They transform the sea water sus- in Western Europe. characterized by the presence of cilia. A larva reaches pension into high-quality proteins which can be used Aquaculture is always in phytoplankton rich zones. a length of up to 120 µm and has a D-shaped shell. Dur- by animals and humans. Individual shoals filter hun- There are several methods used depending on type of SCHOOL ing the growth phase the larva feeds and increases in dreds of cubic metres of water daily. Within an area of size. It loses its D-shape with a velum in its prostomium, 160 km2 near Asko (Sweden) in the northern part of the functioning as a swim organ. In the setting phase, the Baltic proper, all bivalves are capable of filtering the to- planktonic larva is distinguished by the germ of the tal water mass in two and a half months. Shoals of blue foot, head, mantle and mantle cavity. In the pediveliger mussels also provide a good food source for flounder, stage it has a shell, 360 µm in length. Throughout the cod, ray and sturgeon. In the upper water zone, blue various larval stages, the veliger struggles to settle on mussels are eaten mainly by common eiders which can IN SHORT a firm foundation in order to transform into the ulti- dive to a depth of 10 m. The blue mussel’s main preda- mate juvenile form (Flyachinskaya and Kulakowski, tors in Kattegat, the Asterias rubens starfish and Carci- 1991; Sprung, 1984). nus meanas littoral crab, were not able to adapt to the Larvae, capable of floating in the water column, may low salinity of the Baltic. This explains why the blue travel with ocean currents and long distance passive mussel has found such favourable conditions to develop migration is also possible in ballast water (Carlton and in the Baltic Sea, despite its weakened shell structure Fig. 3. Mussel on a rocky shore Geller, 1993). Adult forms may travel attached to hard in lower salinity waters (Reimer and Harms-Ringdahl, Source: http://en.academic.ru/pictures/enwiki/66/Blue_mus- surfaces, like the hulls of ships. 2001). sel_Mytilus_edulis.jpg

(Breber and Sirocco, 1998; Bishop, 2001; Bürgin et al., SCIENCE 2001). Primarily, a bioindicator cannot have inherent prob- Bivalves contain high-quality proteins which pro- lems with identification and at the same time it must vide essential building blocks for nutrition. They are be accurately identified, morphologically, anatomically also a perfect source of calcium, fluorine as well as sele- and physiologically. Bioindicators are characteristi- nium that can protect against cancer. They also contain cally species which respond to specific changes in the B and D vitamins which are important for healthy skin, environment in a manner, appropriate to the degree of the central nervous system and structural and function- contamination. Their reaction is permanent and repeat- al maintenance of bone. able. A long life cycle is required to watch their reactions SCHOOL The blue mussel is usually boiled before eating and throughout the seasons. should be cooked quickly for about 1-2 minutes until Bivalves are sensitive to water pollution and their re- the shell opens. If the shell does not open after this short sponse to contamination with heavy metals (mercury, time, it suggests that the bivalve was probably not fresh. Fig. 4. EU mussel aquaculture production (2009) copper and cadmium), formaldehyde or pesticides (e.g., Blue mussels are usually sold live or processed in tins Source: Eurostat. lindane) is immediate. Blue mussels immediately re- or marinated. Cultivated bivalves are fleshier and have spond to increased amounts of chlorine, ammonia or thinner shells. Depending on the feed they are given, iron. When a toxic substance first appears, the shell im- IN SHORT the bivalves can also vary from those in the natural en- mediately closes and eventually the bivalve’s vital func- vironment in flavour and shell colour. The blue mussel’s Calories: 103 kcal Tab.1. Nutrition per 100 g tions cease. At first, the bivalve restricts its activities by filtration of water, however, poses a certain threat to hu- Protein: 17 g (average values for cooked slowing down its metabolism and switching to anaero- man health. In highly polluted regions, the bivalves can Selenium: 50 µg mussels, M. edulis) bic respiration. However, this is a disadvantage in terms accumulate large amounts of toxic substances which Vitamin D: < 0,5 µg EPA – Eicosapentaenoic acid, of energy intake, therefore the shell still opens from can lead to poisoning (Bürgin et al., 2001; Sikorski, EPA: 340 mg DHA – Docosahexaenoic acid time to time. An increase in concentration of aqueous DHA: 214 mg 2004; Rajski, 1997; Kwoczek, 2006). Source: Eurostat. toxic substances shortens the interval at which the shell

while Mytilus galloprovincialis inhabits the Mediter- SCIENCE ranean, southern coasts of the Atlantic and North Af- rica. Introduction of Mytilus galloprovincialis to the Japanese Sea, southern California and Puget Bay has been recently discovered. In the southern hemisphere it is found along the South American Atlantic coast, the Kerguelen Islands, the Republic of South Africa, Aus- tralia, Tasmania and New Zealand (Hilbish et al,. 2000). Mytilus californianus occurs along the coasts of Pacific SCHOOL Ocean between San Diego and Humboldt Bay. This bivalve is distinct genetically and in terms of morphology and is therefore not a member of the Mytilus edulis spp. complex (Sarver and Foltz, 1993). The blue mussel population along the coasts of Chile and the Falkland Islands is Mytilus chilensis (Hupe, 1854). Morphological analysis of M. edulis, M. trossulus and M. chilensis allow IN SHORT distinction between the three taxa. However, the mitochondrial and other molecular markers (e.g. ITS; inter- nal transcribed spacer) do not reveal significant differ- ences between these forms, which leads many scientists to believe the Chilean blue mussel to be a subspecies, Mytilus edulis chilensis (Toro, 1998). Numerous studies indicate that Mytilus trossulus Fig. 5. Mussel distribution in the World’s Oceans evolved in the Pacific Ocean and colonized the north Source: own work.

Atlantic through the Bering Strait about 3.5 million genes of both previously separated pools from two dif- • Eastern Canada: between the boreal and Arctic zo- years ago (Riginos and Cunningham, 2002). M. edu- ferent species. The newly created hybrid is characterized nes (Mytilus trossulus × Mytilus edulis), (Gardner, lis emerged in the Atlantic through allopatric specia- by increased variability. The heterosis effect is com- 1994); tion (Vermeij, 1991). M. galloprovincialis evolved in the monly observed among hybrids. Such hybridisation is • The Japanese Sea: Mytilus( galloprovincialis × My- Mediterranean when it had limited connection with a frequent phenomenon in marine organisms. A few tilus trossulus), (Inoue et al., 1996) the Atlantic. The second, recent migration from the Pa- hybridisation zones have been described for the Mytilus There are two ideas used to explain the existence of cific into the Atlantic took place in the Pleistocene or species. All forms are able to reproduce fertile crosses the hybrid zones. The first assumes that zones are inde- the Holocene and as a result, M. trossulus colonized the and create hybridisation zones at diverse latitudes. pendent of the environment and constitute a by-prod- Baltic and Canadian coastal waters (Riginos and Cun- Four principal zones of hybridisation are known: uct of relations between the two populations. Accord- ningham, 2002). • Northern Europe: where the Baltic Sea and the ing to this model, hybrids are worse adapted, compared North Sea meet (Mytilus trossulus × Mytilus edulis); with their parental populations and the hybridised zone Hybridisation • Western Europe: (Mytilus edulis × Mytilus gallo- is maintained by a balance between proliferation of pa- provincialis); rental genotypes and selection against hybrids, which

Hybridisation can induce exchange of genes be- • The Pacific Ocean: along the northern coast of -Ca leads to emergence of buffer zones (Barton and Hewitt, SCIENCE tween species, with consequent mixing of the gene pool lifornia and Oregon (Mytilus galloprovincialis × 1985). The hybridisation zone betweenMytilus edulis × for both taxa. The process creates a form that possesses Mytilus trossulus); Mytilus galloprovincialis, where, despite the high possi- bility of contact, hybridisation occurs only in a separate buffer zone and in addition, the life-span of the hybrids at the larval stage is greatly reduced in comparison with parental forms (Bierne et al., 2002). The hybridisation zones can also be present within areas in which hybrids demonstrate better adaptation SCHOOL than non-hybrids. If hybrids are favoured in terms of specific features, the parental forms and hybrids will be arranged according to the environmental conditions which they favour (Moore, 1977).

Doubly uniparental inheritance (DUI) IN SHORT Uniparental inheritance and lack of recombination allow mtDNA to be used as a molecular marker in much animal research into populations. Until a mutation occurs, the whole progeny line of a female share the same haplotype. Such inheritance prevents the distribution of defective mitochondrial genomes beyond the progeny Fig. 6. Polar maps with the migration pathways of Mytilus of an individual female. Source: http://www.superstock.com

In the animal world, mitochondria and their own mtDNA are inherited almost exclusively by the ma- Fig. 7. Distribution ternal (female) line, because all, or almost all originate of Mytilus edulis spp. from the oocyte. Few are transferred with the sperma- complex mussels tozoon. What is more, those arriving with the male in Europe gamete (along with their mtDNA) are destroyed during Source: own work. the early phases of zygote development. Hence, the mitochondrial genes are passed from the mother to male and female progeny. Bivalves from the Mytilus family are characterized by unusual inheritance of mtDNA – doubly uniparental inheritance (DUI). Apart from genomes inherited along the maternal line, males of these bivalves have another

mitochondrial haplotype which is inherited exclusively SCIENCE along the paternal line, being a typical example of heteroplasmy. In these molluscs recombination between mtDNA genomes has also been documented (Zbawicka et al., 2007). This peculiarity of bivalves from the Myti- lus family stimulates particular interest.

Scandinavian zone of hybridisation SCHOOL The Scandinavian zone of hybridisation includes the Baltic Sea – a region that bivalves have recently colonized. During the last North-Poland glaciation, the Baltic Sea was entirely ice-covered. As the result of accumulation of snowmelt waters, the sea trans- formed into a lake. Contact with the North Sea took place about 7500 years ago (Donner, 1995) and enabled Baltic Sea are smaller and characterized by thin shells. may be the consequence of frequent changes in salinity. IN SHORT bivalves and other marine organisms to colonize. Cur- The low salinity explains their smaller size. Based on While examinations of allozymes show diversification rent salinity of the Baltic is estimated at 5–10‰. In the morphological examination and analysis of allozymes along the Scandinavian hybridisation zone, blue mus- Bothnian Sea the salinity is about 4‰ and the Bay of it was established that populations in the North Sea sel DNA sequence analysis reveals extensive movement Bothnia can be considered a body of freshwater. Signifi- and Skagerrak belong to Mytilus edulis, while popula- of genes. Asymmetrical introgression of female Mytilus cant fluctuations in salinity are present in the Kattegat, tions in the Baltic Sea are Mytilus trossulus (McDonald edulis mtDNA into Baltic Sea populations has caused between 10–20‰ and 20–30‰ in the Skagerrak Strait. et al., 1991; Väinölä and Hvilsom, 1991). In the Katte- the F-mtDNA (female mtDNA) of M. trossulus to disap- The bivalves of the Baltic differ from the North Sea and gat population, the number of alleles is somewhere be- pear (Rawson and Hilbish, 1998; Quesada et al., 1999). Skaggerak population. Mature forms of bivalves in the tween the count for the Baltic and the North Sea, which Moreover, the standard male mtDNA was not observed

EDUKACJA BIOLOGICZNA I ŚRODOWISKOWA | ebis.ibe.edu.pl | [email protected] | © for the article by the Authors 2015 © for the edition by Instytut Badań Edukacyjnych 2015 The Blue mussel – irreplaceable filter-feeder and geneticist’s favourite | Kamila Sfugier | EDUKACJA BIOLOGICZNA I ŚRODOWISKOWA 1/2015 9 either. In heteroplasmic individuals, mtDNA originates ful bioindicators. Owing to their important roles, blue Flyachinskaya LP, Kulakowski EY (1991). Larval development of from M.edulis females which suggests that F-mtDNA in mussels are a popular subject for ecological and biologi- Mytilus edulis (Mytilida, Mytilidae). Russian Journal of Zoology, 70(11): 23-29. M.edulis has acquired M-mtDNA (male mtDNA) func- cal research. Modern methods in genetics have allowed Gardner JPA (1994). The structure and dynamics of naturally occur- tion (Wenne and Skibiński, 1995; Quesada et al., 1999). discovery and investigation of processes such as hybrid- ring hybrid Mytilus edulis Linnaeus, 1758 and Mytilus gallopro- This phenomenon is often referred to as virilization and isation or doubly uniparental inheritance. Hybridisa- vincialis Lamarck, 1819 (Bivalvia: Mollusca) populations: Review and interpretation. Arch. Hydrobiol. Supp., 99: 37-71. is most common within the hybridisation zones (Raw- tion zones offer miraculous systems for analysis using Hilbish TJ, Mullinax A, Dolven SI, Meyer A, Koehn RK, Rawson PD son et al., 1996). molecular markers. The main stimulus for the intense (2000). Origin of the antitropical distribution pattern in marine There are two hypotheses to explain the above phe- study of blue mussels is that they provide an unusually mussels (Mytilus spp.): routes and timing of transequatorial migration. Mar. Biol., 136: 69-77. nomenon. According to Vainola and Hvilsom (1991), rich population for progress in the understanding of Inoue K, Odo S, Noda T, Nakao S, Takeyama S, Yamaha E, Yamaza- this situation is a result of introgression of genes through evolution and speciation. ki F, Harayama S (1996). A possible hybrid zone in the Mytilus hybridisation between Mytilus edulis of Skagerrak and edulis complex in Japan revealed by PCR markers. Marine Biol- the Mytilus trossulus of the Baltic Sea. However, Bul- ogy, 128(1), 91-95, DOI:10.1007/ s002270050072. References Jenner HA, Noppert F, Sikking T (1989). A new system for the de- nheim and Gosling (1988) claim that Mytilus trossulus tection of valve-movement response of bivalves. Kema Scientific & Technical Reports, 7(2): 91-98.

evolved in the Baltic Sea from Mytilus edulis. This hy- SCIENCE Barton NH, Hewitt GM (1985). Analysis of hybrid zones. Annual Jura Cz (2004). Bezkręgowce. Podstawy morfologii funkcjonalnej, sy- pothesis, however, does not explain the resemblance of Review of Ecology and Systematics 16:113-148, DOI: 10.1146/an- stematyki i filogenezy. Warszawa, PWN, pp. 203. nurev.es.16.110185. 000553. the Baltic population to the Pacific and west-Atlantic Kautsky L (1991). Życie w Bałtyku. http://www.wgsr.uw.edu.pl/tmp/ Bayne BL (1976). The biology of mussel larvae.In: Bayne B. L., (ed.) populations. Taxonomy and distribution of the Myti- BSE-02.pdf (23.03.2011). Marine mussels: their ecology and physiology. IBP 10, Cambridge Kramer KJM, Jenner HA, de Zwart D (1989). The valve movements lus edulis spp. complex was first based on morphology University Press, London, 81-120. response of mussels: a tool in biological monitoring. Hydrobiolo- Bayne BL, Salkeld PN, Worrall CM (1983). Reproductive effort and and allozymes (McDonald et al., 1991), but later studies gia, 188/189: 433-443. value in different populations of the marine mussel,Mytilus edu- identified many markers based on DNA. Selected nu- Kwoczek M (2006). Ocena bromatologiczna i chemometryczna owo- lis L. Oecologia, 59: 18-26, DOI: 10.1007/BF00388067. ców morza na podstawie ich składu pierwiastkowego. http://pbc. clear DNA markers now permit more detailed compari- Bierne N, David P, Boudry P, Bonhomme F (2002). Assortative fertil-

gda.pl/Content/5725/kwoczek_magdalena.pdf 18.01.2015 SCHOOL son of species that belonging to the Mytilus edulis spp. ization and selection at larval stage in the mussels Mytilus edulis Lindberg DR (1991). Marine biotic interchange between the northern and M. galloprovincialis. Evolution, 56(2): 292-298. complex. and southern hemispheres. Paleobiology, 17(3): 308-324. Bishop D (2001). Innovative in bivalves – a personal view. Eurofish McDonald JH, Seed R, Koehn RK (1991). Allozymes and morpho- Magazine, 4: 84-86. metric characters of 3 species of Mytilus in the northern and Breber P, Scirocco T (1998). Open-sea mussel farming in Southern It Conclusions southern hemispheres. Mar. Biol., 111:323-333 Sanjuan, DOI: aly. Eurofish Magazine, 3: 36-38. 10.1007/BF01319403. Bulnheim HP, Gosling EM (1988). Population genetic structure of Blue mussels occupy many diverse habitats, from Moore WS (1977). An evaluation of narrow hybrid zones in verte- mussels from the Baltic Sea. Helgoländer Meeresunters, 42: 113– brates. Quarterly Review of Biology, 52(3): 263-277. tidal areas to entirely submerged zones with wide tem- 129, DOI: 10.1007/BF02364207. Quesada H, Wenne R, Skibinski DOF (1999). Interspecies transfer of perature and salinity ranges. Bivalves of the Mytilus Bürgin R, Hofmann H, Lillelund K, Mosiman A, Terofal F, Teubner female mitochondrial DNA is coupled with role-reversals and de- IN SHORT Ch. (2001). Owoce Morza i Ryby. Muza SA, Warszawa. spp. complex play a major role in aquatic ecosystems parture from neutrality in the mussel Mytilus trossulus. Molecular Carlton JT, Geller JB (1993). Ecological roulette: The global trans- Biology and Evolution, 16(5), 655-665. and belong to the most economically significant group port of nonindigenous marine organisms. Science, 261: 78-82, Rajski A (1997). Zoologia. Tom 2. Część Systematyczna. Wydawni- of invertebrates. They are effective cleaners of large DOI:10.1126/science. 261.5117.78. ctwo Naukowe PWN, Warszawa. Crisp DJ (1975). The role of the pelagic larva. In: Spencer Davies P bodies of water, removing of excess organic matter by Rawson PD, Secor CL, Hilbish TJ (1996). The effects of natural -hy (ed.) Perspectives in experimental biology. Pergamon Press, Ox- filtration. The mussels are a quality food source for bridization of the regulation of doubly uniparental mtDNA in- ford, 145-155. heritance in blue mussels (Mytilus spp.). Genetics, 144(1): 241–248. other organisms, including humans. Edible species are Donner J (1995). The Quaternary History of Scandinavia. Cambridge Rawson PD, Hilbish TJ (1998). Asymmetric introgression of mito- University Press, Cambridge, pp. 212. cultivated and eaten worldwide and their sensitivity to chondrial DNA among European populations of blue mussels Field IA (1922). Biology and economic value of the sea mussel Myti- environmental pollution also recommends them as use- (Mytilus spp.). Evolution, 52(1), 100–108. lus edulis. Bull. U. S. Bur. Fish., 38: 127-259.

Reimer O, Harms-Ringdahl S (2001). Predator-inducible changes in blue mussels from the predator-free Baltic Sea. Marine Biology, Compatability with 139(5): 959-965, DOI: 10.1007/s002270100606. the Polish core curriculum: Riginos C, Sukhedeo K, Cunningham CW (2002). Evidence for selection at multiple allozyme loci across a mussel hybrid zone. Mol Biology – 4th educational stage – basic scope: Biol Evol, 19: 347–351. Educational goals: Saavedra C (1997). Male-Dependent Doubly Uniparental Inheritance I. Searching, utilization and creation of information. of Mitochondrial DNA and Female-Dependent Sex-Ratio in the Mussel Mytilus galloprovincialis. Genetics, 145(4): 1073-1082. A student receives, analyses and judges information coming from Sikorski ZE (2004). Ryby i Bezkręgowce Morskie – Pozyskiwanie, various sources, taking into account particularly the press, the Właściwości i Przetwarzanie. Wydawnictwa Naukowo-Technicz- media, the Internet. ne, Warszawa. Contents: Sprung M (1983). Reproduction and fecundity of the mussel (Mytilus 1. Biotechnology and genetic engineering. A student: edulis) at Helgoland (North Sea). Helgolander Meeresunters, 36: 6) provides examples of utilization of research DNA (judicial system, 243-255, DOI: 10.1007/BF01983629. medicine, science); Sprung M (1984). Physiological energetics of mussel larvae (Mytilus edulis). I. Shell growth and biomass. Marine Ecology – Progress 2. Biological diversity and threats for it. A student: Series, 17: 283-293. 1) describes biological diversity on a genetic, species and ecosystem SCIENCE Väinölä R, Hvilsom MM (1991). Genetic divergence and a hybrid level; indicates causes of a de-crease in genetic diversity, extin- zone between Baltic and North Sea Mytilus populations (Mytili- ction of species, deterioration of habitats and ecosystems; dae: Mollusca). Biology Journal of the Linnean Society, 43: 127-148, Biology – 4th educational stage – extended scope: DOI: 10.1111/j.1095-8312.1991.tb00589.x Toro JE. (1998). PCR-based nuclear and mtDNA markers and shell Educational goals: morphology as an approach to study the taxonomic status of the IV. Searching, utilization and creation of information. Chilean blue mussel, Mytilus chilensis (Bivalvia). Aquatic Living A student reads, selects, compares and processes information Resources, 11(5): 347-353, DOI:10.1016/S0990-7440(98)80006-5. obtained from various sources, including this obtained by means Vermeij GJ (1991). Anatomy of an invasion: the trans-Arctic inter- of information-communication technologies.

change. Paleobiology, 17(3): 281-307. SCHOOL VI. Attitude towards nature and environment. Wenne R, Skibinski DOF (1995). Mitochondrial DNA heteroplasmy in European populations of mussel Mytilus trossulus. Marine Bi- A student understands the importance of nature and environ- ology, 122: 619-625, DOI: 10.1007/BF00350683. ment protection, and knows and understands principles of Werner B (1940). Uber die Entwicklung und Artunterscheidung von sustained development; presents an attitude of respect towards themselves and all living creatures, the environment; describes an Muschellarven des Nordseeplanktons, unter gesonderter Beriick- attitude and behaviour of a human who utilizing goods of nature sichtigung der Schalenentwicklung. Zool. Jb. (Anatomie), 66: 1-54. and environment in a responsible way, knows rights of animals Yap WG (1977). Population biology of the Japanese littleneck clam, and analyzes their relation towards living creatures and the envi- Tapes philippinarum, in Kaneohe Bay, Oahu, Hawaiian Islands. ronment. Pacif. Sci., 31(3): 223-244. Contents of education:

Zbawicka M, Burzyński A, Wenne R (2007). Complete sequences of IN SHORT mitochondrial genomes from the Baltic mussel Mytilus trossulus. 11. Invertebrate animals. A student: Gene, 406: 191-198, DOI: 10.1016/j.gene.2007.10.003. 13) presents the importance of molluscs in nature and for humans; 6. Genetic variability. A student: 1) defines sources of genetic variability (mutations, recombination); 8. Molecular biotechnology, genetic engineering and molecular medicine. A student: 7) presents various applications of genetic methods, i.a. (...) evolu- tionary research;

EDUKACJA BIOLOGICZNA I ŚRODOWISKOWA | ebis.ibe.edu.pl | [email protected] | © for the article by the Authors 2015 © for the edition by Instytut Badań Edukacyjnych 2015