Overview

Brief Summary

Species Overview

Alexandrium ostenfeldii is an armoured, marine, planktonic dinoflagellate. Generally, it is a cold-water coastal species found in low numbers mainly along the west coast of Europe.

Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Comprehensive Description

A. ostenfeldii has a rounded epitheca and hypotheca. The anterior and posterior sulcal plates are broad and the 1? plate has a large oval ventral pore located at the point of inflection of the angular right margin of the 1?.
  • Tomas C ed. (1996) Identifying marine diatoms and dinoflagellates. pp 598. Academic Press Ltd. London
  • Balech E and Tangen K (1985) Morphology and taxonomy pof toxic species in the tamarensis group (Dinophceae) Alexandrium excavatum (Braarud) comb. nov. and Alexandrium ostenfeldii (Paulsen) comb. nov. Sarsia, 70: 333-343
  • Balech E (1995) The genus Alexandrium Halim (Dinoflagellata). Sherkin Island Marine Station
  • K.E. Gribble, B.A. Keafer, N.A. Quilliam, A.D. Cembella, D.M. Kulis, A. Manahan & D.M. Anderson (2005). Distribution and toxicity of Alexandrium ostenfeldii (Dinophyceae) in the Gulf of Maine, USA. Deep Sea Research II 52: 2745-2763
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© University of Liverpool

Source: Harmful Phytoplankton Project

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Morphology

Morphology and Structure

A. ostenfeldii is a photosynthetic species with radiating chloroplasts. The nucleus is U-shaped and equatorial (Fig. 5).

  • Balech, E. & K. Tangen 1985. Morphology and taxonomy of toxic species in the tamarensis group (Dinophyceae): Alexandrium excavatum (Braarud) comb. nov. and Alexandrium ostenfeldii comb. nov. Sarsia 70: 333-343.
Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Thecal Plate Description

The plate formula for A. ostenfeldii is: Po, 4', 6'', 6c, 10s, 5''', 2''''. The apical pore complex (APC) is triangular or rectangular in shape. The apical pore plate (Po) is relatively large with a large comma-shaped foramen (Figs. 2, 4). It can be either in direct contact with the first apical plate (1') (Fig. 4a) or indirectly connected via a thin suture (thread-like process) (Fig. 4b). The most distinctive plate of this species is the 1' plate: a) it bears a large characteristic ventral pore; and b) a 90 degree angle is formed at the point where the ventral pore and the 4' plate come in contact (Figs. 2, 3). The distinctive sixth precingular plate (6'') is wider than high (Figs. 2,3).

The broad epitheca is convex-conical, while the hypotheca is hemispherical with an obliquely flattened antapex (Figs. 1, 5). The slightly excavated cingulum is equatorial and displaced in a descending fashion less than one time its width; it has narrow lists (Figs. 1,3). The sulcus is slightly depressed and inconspicuous.

  • Balech, E. & K. Tangen 1985. Morphology and taxonomy of toxic species in the tamarensis group (Dinophyceae): Alexandrium excavatum (Braarud) comb. nov. and Alexandrium ostenfeldii comb. nov. Sarsia 70: 333-343.
  • Balech, E. 1995. The Genus Alexandrium Halim (Dinoflagellata), Sherkin Island Marine Station, Ireland. 151 pp.
  • Konovalova, G.V. 1993. Toxic and potentially toxic dinoflagellates from the far east coastal waters of Russia. In: Smayda, T.J. & Y. Shimizu (eds.), Toxic Phytoplankton Blooms in the Sea, Elsevier, Amsterdam: 275-279.
  • Larsen, J. & O. Moestrup 1989. Guide to Toxic and Potentially Toxic Marine Algae. The Fish Inspection Service, Ministry of Fisheries, Copenhagen. 61 pp.
  • Taylor, F.J.R., Y. Fukuyo & J. Larsen 1995. Taxonomy of harmful dinoflagellates. In: G.M. Hallegraeff, D.M. Anderson & A.D. Cembella (eds.), Manual on Harmful Marine Microalgae, IOC Manuals and Guides No. 33. UNESCO, France: 283-317.
Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Taxonomical Description

A distinctive species, cells of A. ostenfeldii are large and nearly spherical (Fig. 1). Cells are single, but are often found in two-celled colonies. Epitheca and hypotheca equal in height (Figs. 1). This species has thin thecal plates and a characteristic large ventral pore on the first apical plate (1') (Fig. 2). Faint surface pores are numerous and unevenly distributed. Cells range in size between 40-56 µm in length and 40-50 µm in transdiameter width.

  • Balech, E. & K. Tangen 1985. Morphology and taxonomy of toxic species in the tamarensis group (Dinophyceae): Alexandrium excavatum (Braarud) comb. nov. and Alexandrium ostenfeldii comb. nov. Sarsia 70: 333-343.
  • Balech, E. 1995. The Genus Alexandrium Halim (Dinoflagellata), Sherkin Island Marine Station, Ireland. 151 pp.
  • Konovalova, G.V. 1993. Toxic and potentially toxic dinoflagellates from the far east coastal waters of Russia. In: Smayda, T.J. & Y. Shimizu (eds.), Toxic Phytoplankton Blooms in the Sea, Elsevier, Amsterdam: 275-279.
  • Larsen, J. & O. Moestrup 1989. Guide to Toxic and Potentially Toxic Marine Algae. The Fish Inspection Service, Ministry of Fisheries, Copenhagen. 61 pp.
  • Steidinger, K.A. & K. Tangen 1996. Dinoflagellates. In: C.R. Tomas (ed.), Identifying Marine Diatoms and Dinoflagellates, Academic Press, New York: 387-598.
  • Taylor, F.J.R., Y. Fukuyo & J. Larsen 1995. Taxonomy of harmful dinoflagellates. In: G.M. Hallegraeff, D.M. Anderson & A.D. Cembella (eds.), Manual on Harmful Marine Microalgae, IOC Manuals and Guides No. 33. UNESCO, France: 283-317.
Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Look Alikes

Species Comparison

A. ostenfeldii is easily misidentified as other Alexandrium species; detailed thecal plate observation is often necessary for proper identification.

A. ostenfeldii and A. tamarense are often confused for each other since they overlap in size and often co-occur; however, A. ostenfeldii is slightly larger and is more widely distributed (has a wider salinity range) than the latter species. Other differences between these two species include: A. ostenfeldii has a much larger ventral pore on the first apical plate 1'; and the 6'' plate is wider than high, whereas the width and height of the 6'' plate in A. tamarense are equal.

This species also closely resembles another Alexandrium species, A. peruvianum. Both species are large cells with distinctive large ventral pores on the 1' plate; however, morphological differences are evident in the 1' plate and the APC. Moreover, A. ostenfeldii is a larger cell and produces PSP toxins.

  • Balech, E. 1995. The Genus Alexandrium Halim (Dinoflagellata), Sherkin Island Marine Station, Ireland. 151 pp.
  • Hansen, P.J., A.D. Cembella & O. Moestrup 1992. The marine dinoflagellate Alexandrium ostenfeldii: Paralytic shellfish toxin concentration, composition, and toxicity to a tintinnid ciliate. J. Phycol. 28: 597-603.
  • Larsen, J. & O. Moestrup 1989. Guide to Toxic and Potentially Toxic Marine Algae. The Fish Inspection Service, Ministry of Fisheries, Copenhagen. 61 pp.
  • Moestrup, O. & P.J. Hansen 1988. On the occurrence of the potentially toxic dinoflagellates Alexandrium tamarense (= Gonyaulax excavata) and A. ostenfeldii in Danish and Faroese waters. Ophelia 28: 195-213.
  • Steidinger, K.A. & K. Tangen 1996. Dinoflagellates. In: C.R. Tomas (ed.), Identifying Marine Diatoms and Dinoflagellates, Academic Press, New York: 387-598.
  • Taylor, F.J.R., Y. Fukuyo & J. Larsen 1995. Taxonomy of harmful dinoflagellates. In: G.M. Hallegraeff, D.M. Anderson & A.D. Cembella (eds.), Manual on Harmful Marine Microalgae, IOC Manuals and Guides No. 33. UNESCO, France: 283-317.
Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

Habitat and Locality

A cold-water estuarine species, A. ostenfeldii was, until recently, believed to be confined to the western European coast: Iceland and Norway, Denmark, Belgium (as Pyrodinium phoneus), and Spain. Recently, Balech (1995) collected cells of A. ostenfeldii from Alexandria Harbor, Egypt, and also from the NW Pacific Ocean, off of Washington State, U.S.A. Populations have also been observed from British Columbia and the Kamchatka Peninsula in the Pacific Ocean. In the northwest Atlantic Ocean, cells have been reported from Canada: in the Gulf of St. Lawrence, and southeastern Nova Scotia.

  • Balech, E. & K. Tangen 1985. Morphology and taxonomy of toxic species in the tamarensis group (Dinophyceae): Alexandrium excavatum (Braarud) comb. nov. and Alexandrium ostenfeldii comb. nov. Sarsia 70: 333-343.
  • Balech, E. 1995. The Genus Alexandrium Halim (Dinoflagellata), Sherkin Island Marine Station, Ireland. 151 pp.
  • Braarud, T. 1945. Morphological observations on marine dinoflagellate cultures (Porella perforata, Goniaulax tamarensis, Protoceratium reticulatum). Avh. Utgitt. Nor. Vidensk. Akad. Oslo Mat.-Naturvidensk. Kl. 11: 1-18.
  • Cembella, A.D., N.I. Lewis & M.A. Quilliam 2000. The marine dinoflagellate Alexandrium ostenfeldii (Dinophyceae) as the causative organism of spirolide shellfish toxins. Phycologia 39: 67-74.
  • Fraga, S. & F.J. Sanchez 1985. Toxic and potentially toxic dinoflagellates in Galician Rias (NW Spain). In: D. Anderson, A.W. White & D.G. Baden (eds.), Toxic Dinoflagellates, Elsevier, New York: 51-55.
  • Konovalova, G.V. 1993. Toxic and potentially toxic dinoflagellates from the far east coastal waters of Russia. In: Smayda, T.J. & Y. Shimizu (eds.), Toxic Phytoplankton Blooms in the Sea, Elsevier, Amsterdam: 275-279.
  • Levasseur, M., L. Berard-Therriault, E. Bonneau & S. Roy 1998. Distribution of the toxic dinoflagellate Alexandrium ostenfeldii in the Gulf of St. Lawrence, Canada. In: Reguera, B., J. Blanco, M.L. Fernandez & T. Wyatt (eds.), Harmful Algae, Xunta de Galicia and Intergovernmental Oceanographic Commission of UNESCO, Spain: 54-57.
  • Moestrup, O. & P.J. Hansen 1988. On the occurrence of the potentially toxic dinoflagellates Alexandrium tamarense (= Gonyaulax excavata) and A. ostenfeldii in Danish and Faroese waters. Ophelia 28: 195-213.
  • Prakash, A. & F.J.R. 1966. A 'red water' bloom of Gonyaulax acatenella in the Strait of Georgia and its relation to paralytic shellfish toxicity. J. Fish. Res. Bd. Can. 23: 1265-1270.
  • Steidinger, K.A. & K. Tangen 1996. Dinoflagellates. In: C.R. Tomas (ed.), Identifying Marine Diatoms and Dinoflagellates, Academic Press, New York: 387-598.
  • Taylor, F.J.R., Y. Fukuyo & J. Larsen 1995. Taxonomy of harmful dinoflagellates. In: G.M. Hallegraeff, D.M. Anderson & A.D. Cembella (eds.), Manual on Harmful Marine Microalgae, IOC Manuals and Guides No. 33. UNESCO, France: 283-317.
  • Woloszynska, J. & W. Conrad 1939. Pyrodinium phoneus n. sp., agent de la toxicite des moules du canal maritime de Bruges a Zeebruge. Bull. Mus. Hist. Nat. Belg. 15: 1-5.
Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Depth range based on 124 specimens in 1 taxon.
Water temperature and chemistry ranges based on 50 samples.

Environmental ranges
  Depth range (m): 0 - 100
  Temperature range (°C): -1.743 - 12.224
  Nitrate (umol/L): 1.134 - 6.894
  Salinity (PPS): 24.378 - 34.778
  Oxygen (ml/l): 6.447 - 9.192
  Phosphate (umol/l): 0.119 - 0.630
  Silicate (umol/l): 1.782 - 39.813

Graphical representation

Depth range (m): 0 - 100

Temperature range (°C): -1.743 - 12.224

Nitrate (umol/L): 1.134 - 6.894

Salinity (PPS): 24.378 - 34.778

Oxygen (ml/l): 6.447 - 9.192

Phosphate (umol/l): 0.119 - 0.630

Silicate (umol/l): 1.782 - 39.813
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

General Ecology

Ecology

A. ostenfeldii is a planktonic estuarine dinoflagellate species found in low numbers, mainly along the west coast of Europe, and recently along the southeast coast of Nova Scotia, Canada. To date, no blooms have been reported (except in Belgium as Pyrodinium phoneus).

This species produces temporary resting cysts (Fig. 6). Cysts are large and spherical, ranging in size from 35 to 40 µm in diameter. Cysts are pale in color with a reddish-brown granule, and a well-defined cingular groove. The smooth and clear cell wall is covered with mucilage.

  • Cembella, A.D., N.I. Lewis & M.A. Quilliam 2000. The marine dinoflagellate Alexandrium ostenfeldii (Dinophyceae) as the causative organism of spirolide shellfish toxins. Phycologia 39: 67-74.
  • Hansen, P.J., A.D. Cembella & O. Moestrup 1992. The marine dinoflagellate Alexandrium ostenfeldii: Paralytic shellfish toxin concentration, composition, and toxicity to a tintinnid ciliate. J. Phycol. 28: 597-603.
  • Jensen, M. & O. Moestrup 1997. Autecology of the toxic dinoflagellate Alexandrium ostenfeldii: life history and growth at different temperatures and salinities. Eur. J. Phycol. 32: 9-18.
  • Mackenzie, L., D. White, Y. Ohima & J. Kapa 1996. The resting cyst and toxicity of Alexandrium ostenfeldii (Dinophyceae) in New Zealand. Phycologia: 35: 148-155.
  • Woloszynska, J. & W. Conrad 1939. Pyrodinium phoneus n. sp., agent de la toxicite des moules du canal maritime de Bruges a Zeebruge. Bull. Mus. Hist. Nat. Belg. 15: 1-5.
Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Reproduction

A. ostenfeldii reproduces asexually by binary fission. This species also has a sexual cycle with isogamous mating types; a planozygote is formed.

  • Jensen, M. & O. Moestrup 1997. Autecology of the toxic dinoflagellate Alexandrium ostenfeldii: life history and growth at different temperatures and salinities. Eur. J. Phycol. 32: 9-18.
Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physiology and Cell Biology

Physiology

Toxicity

There has long been some doubt as to the toxic potential of this species. Because A. ostenfeldii does not form monospecific blooms, it has been difficult to determine this species' toxin producing potential. A. ostenfeldii, however, is capable of producing paralytic shellfish poison (PSP) toxins; albeit, it is the least toxic of all the Alexandrium species tested for PSP toxins. This species has been associated with shellfish poisoning in Scandinavia, and one report of mussel Toxicity (as Pyrodinium phoneus) has been reported from Belgium.

Recently, a study of aquaculture shellfish from Nova Scotia, Canada, revealed the presence of spirilides, fast-acting neurotoxins, primarily produced by western Atlantic strains of A. ostenfeldii.

Hansen et al. (1992) conducted studies with a tintinnid ciliate exposed to high concentrations of A. ostenfeldii: results were erratic swimming behavior (backwards) followed by swelling and lysis of the ciliates.

  • Balech, E. 1995. The Genus Alexandrium Halim (Dinoflagellata), Sherkin Island Marine Station, Ireland. 151 pp.
  • Cembella, A.D., J.-C. Therriault & P. Beland 1988. Toxicity of cultured isolates and natural populations of Protogonyaulax tamarensis from the St. Lawrence estuary. J. Shellfish Res. 7: 611-621.
  • Cembella, A.D., J.J. Sullivan, G.L. Boyer, F.J.R. Taylor & R.J. Anderson 1987. Variation in paralytic shellfish toxin composition within the Protogonyaulax tamarensis/catenella species complex; red tide dinoflagellates. Biochem. Syst. Ecol. 15: 171-186.
  • Cembella, A.D., N.I. Lewis & M.A. Quilliam 2000. The marine dinoflagellate Alexandrium ostenfeldii (Dinophyceae) as the causative organism of spirolide shellfish toxins. Phycologia 39: 67-74.
  • Hansen, P.J., A.D. Cembella & O. Moestrup 1992. The marine dinoflagellate Alexandrium ostenfeldii: Paralytic shellfish toxin concentration, composition, and toxicity to a tintinnid ciliate. J. Phycol. 28: 597-603.
  • Jensen, M. & O. Moestrup 1997. Autecology of the toxic dinoflagellate Alexandrium ostenfeldii: life history and growth at different temperatures and salinities. Eur. J. Phycol. 32: 9-18.
  • Woloszynska, J. & W. Conrad 1939. Pyrodinium phoneus n. sp., agent de la toxicite des moules du canal maritime de Bruges a Zeebruge. Bull. Mus. Hist. Nat. Belg. 15: 1-5.
Public Domain

National Museum of Natural History, Department of Botany

Source: Smithsonian National Museum of Natural History Department of Botany

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Management

Toxicity

A. ostenfeldii is a producer of PSP toxins and also produces spirolides (macrocyclic imine, a neurotoxin).
  • Tomas C ed. (1996) Identifying marine diatoms and dinoflagellates. pp 598. Academic Press Ltd. London
  • Balech E and Tangen K (1985) Morphology and taxonomy pof toxic species in the tamarensis group (Dinophceae) Alexandrium excavatum (Braarud) comb. nov. and Alexandrium ostenfeldii (Paulsen) comb. nov. Sarsia, 70: 333-343
  • Balech E (1995) The genus Alexandrium Halim (Dinoflagellata). Sherkin Island Marine Station
  • K.E. Gribble, B.A. Keafer, N.A. Quilliam, A.D. Cembella, D.M. Kulis, A. Manahan & D.M. Anderson (2005). Distribution and toxicity of Alexandrium ostenfeldii (Dinophyceae) in the Gulf of Maine, USA. Deep Sea Research II 52: 2745-2763
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© University of Liverpool

Source: Harmful Phytoplankton Project

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!