The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Prymnesium parvum
Prymnesium parvum
(golden algae)

Copyright Info
Prymnesium parvum N.Carter

Common name: golden algae

Taxonomy: available through www.itis.govITIS logo

Identification: Prymnesium parvum is a microscopic, single-celled algae with four morphologically distinct forms (Larsen 1998). Three of the forms are scaled, bi-flagellated, and have a flexible, non-coiling, needle-like filament called a haptonema. The fourth form is a scaled, non-motile, siliceous cyst (Manton 1966; Genitsaris et al. 2009). The scales are found in two layers: inner scales have narrow, inflexed rims, and outer scales have wide, inflexed rims (Green et al. 1982). Two of the flagellated forms are haploid, and are described as two separate forms: P. parvum f. patelliform and P. parvum f. parvum. Both have two layers of scales but ornamentation differs between forms when viewed with a transmission electron microscope (Larsen 1999, Johnsen et al. 2010). The cyst and third flagellated forms are both diploid. All forms contain two, yellow-green, saddle-shaped chloroplasts in the front of the cell near the flagella (Holdway et al. 1978). Flagella are 10 to 14.5 μm long and the haptonema is 3 to 5 μm long. Body scales are 0.3 μm long. Cysts are ovoid, 9.3 to 10.8 μm long and 6 to 6.4 μm wide and have a sub-anterior pore 2.75 to 3 μm in diameter (Green et. al 1982).

Size: Cells are 6 to 12 µm long and 3.5 to 8 µm wide

Native Range: Unknown, but P. parvum is ubiquitous worldwide in temperate zones and was first documented in the eastern hemisphere in the early 1900s (Liebert and Deerns 1920). The first confirmed P. parvum bloom in North America was in 1985 in Texas on the Pecos River (James and De La Cruz 1989). 

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Prymnesium parvum are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
TX199720198Brady; Chambers; Colorado Headwaters; Concho; Lower Prairie Dog Town Fork Red; North Fork Double Mountain Fork Brazos; Toyah; Wichita

Table last updated 6/16/2024

† Populations may not be currently present.

Ecology: Prymnesium parvum inhabits a variety of waterbodies including rivers, lakes, estuaries, fjords, coastal oceans, and ponds, including eutrophic, alkaline, and brackish waters (Granéli et al. 2012). Under optimal conditions, P. parvum can reproduce rapidly and form a nearly monocultural bloom by releasing toxins into the water that immobilize or kill zooplankton and other phytoplankton to increase available food sources. It can survive in a range of water temperatures, from 5°C to 35°C, with blooms increasing between 10°C to 27°C (Larsen et al. 1998; Baker et al. 2007; Grover et al. 2007). P. parvum can live in near-freshwater to marine conditions, from 0.5 practical salinity units (psu) to 45 psu, (Larsen et al. 1993; Larsen et al. 1998; Baker et al. 2007) with optimum growth between 7 to 22 psu (Baker et al. 2007; Weissbach and Legrand 2012; Rashel and Patino 2017). Roelke et al. (2016) hypothesized that P. parvum bloom formation is most common when cells are in intermediate salinity and under moderate environmental stress because allelopathic and toxic chemical production is too low in low salinity/high stress and vice versa. The opposite trend is seen for nutrient concentrations, where P. parvum growth and toxicity is minimal when nitrogen and phosphorus ratios are balanced, and increase as the environment becomes more deficient in one of the nutrients (Granéli and Johansson 2003a,b; Granéli et al. 2012), particularly phosphorus (Granéli and Johansson 2003b; Uronen et al. 2005; Hambright et al. 2014). Toxicity was also consistently higher in pH of 8.5 compared to 6.5 and 7.5 (Valenti et al. 2010).
Prymnesium parvum has a sexual haploid-diploid life cycle with four forms, 3 motile and one resting cyst form that may serve to reseed populations following unfavorable conditions (Garcés et al. 2001; Granéli et al. 2012). It’s growth rate ranges from 0.3 to 1.15 cell divisions per day via mitosis, increasing as environmental conditions become more favorable (Larsen et al. 1998).

It is mixotrophic, supporting its growth with autotrophy (photosynthesis) or heterotrophy if nutrients are scarce (typically during a bloom event) (Fistarol et al. 2003; Tillmann 2003; Granéli and Johansson, 2003a). During a P. parvum bloom when toxin concentrations are high enough to lyse the cells of zooplankton and other phytoplankton, P. parvum can consume them by phagotrophy and absorb the recently released dissolved organic material by saprophy, effectively resisting potential inorganic nutrient limitation from their rapid growth (Granéli et al. 2012; Roelke et al. 2016). As competition is reduced, P. parvum blooms can grow and begin to produce toxin concentrations capable of killing larger organisms, including fish and invertebrates (Ultizer and Shilo 1966; Ulitzer 1973; Granéli et al. 2012; Svendsen et al. 2018). A few grazers, including some ciliates, rotifers, and dinoflagellates, do consume P. parvum but only when it is not in bloom or producing toxins (Tillman 2003; Rosetta and McManus 2003; Schwierzke et al. 2010).

Means of Introduction: Vectors are thought to be ballast water and global trade of aquaculture (Hallegraeff and Gollasch 2006), and local dispersal is attributed to transportation by birds, wind, and anthropogenic movement (drilling equipment, water tankers, and recreational boats) (Kristiansen 1996; Renner 2009).

Impact of Introduction:
Summary of species impacts derived from literature review. Click on an icon to find out more...


Prymnesium parvum produces toxins that can destroy fish gills (Ulitzur and Shilo 1966), and can kill both fish and other aquatic organisms such as tadpoles (Shilo and Aschner 1953). Dense agregations of P. parvum lead to eutrophic conditions that produce large fish and animal kills in both freshwater in marine systems around the world (Karlson et al 2021; Renner 2009; Southard et al 2010), including aquacultural areas and fish farms (Gordon and Colorni 2008).

Remarks: A genetic analysis of U.S. P. parvum strains from northern and southern states revealed that their DNA sequences were more similar to various European strains than to each other, indicating that invasions may have been independent and relatively recent (Lutz-Carrillo et al. 2010).

References: (click for full references)

Andersen, N.G., E. Lorenzen, T.S. Boutrup, P.J. Hansen, and N. Lorenzen. 2016. Sublethal concentrations of ichthyotoxic alga Prymnesium parvum affect rainbow trout susceptibility to viral haemorrhagic septicaemia virus. Diseases of Aquatic Organisms 117(3):187-195.

Armstead, M.Y., M. Wilson, and A. Parsons-White. 2017. Demonstration of a novel control strategy for Prymnesium parvum management in fish hatcheries. North American Journal of Aquaculture 79(3):238-244.

Baker, J.W. et al. 2007. Growth and toxicity of Prymnesium parvum (Haptophyta) as a function of salinity, light, and temperature. Journal of Phycology 43(2):219-227.

Barkoh, A., D.G. Smith, and J.W. Schlechte. 2003. An effective minimum concentration of un-ionized ammonia nitrogen for controlling Prymnesium parvum. North American Journal of Aquaculture 65(3):220-225.

Barkoh, A., D.G. Smith, and G.M. Southard. 2010. Prymnesium parvum control treatments for fish hatcheries. Journal of the American Water Resources Association 46(1):161-169.

Bertin, M.J., P.V. Zimba, K.R. Beauchesne, K.M. Huncik, and P.D.R. Moeller. 2012a. The contribution of fatty acid amides to Prymnesium parvum Carter toxicity. Harmful Algae 20:117-125.

Bertin, M.J., P.V. Zimba, K.R. Beauchesne, K.M. Huncik, and P.D.R. Moeller. 2012b. Identification of toxic fatty acid amides isolated from the harmful alga Prymnesium parvum Carter. Harmful Algae 20:111-116.

Binford, J.S., D.F. Martin, and G.M. Padilla. 1973. Hemolysis induced by Prymnesium parvum toxin calorimetric studies. Biochimica et Btophysica Acta 291:156-164.

Brooks, B.W. et al. 2010. Comparative toxicity of Prymnesium parvum in inland waters. Journal of the American Water Resources Association 46(1):45-62.

Chen, J., and G. Pan. 2012. Harmful algal blooms mitigation using clay/soil/sand modified with xanthan and calcium hydroxide. Journal of Applied Phycology 24:1183-1189.

Dabney, B.L., and R. Patiño. 2018. Low-dose stimulation of growth of the harmful alga, Prymnesium parvum, by glyphosate and glyphosate-based herbicides. Harmful Algae 80:130-139.

Doig, M.T., and D.F. Martin. 1973. Anticoagulant properties of a red tide toxin. Toxicon 11(4):351-355.

Dugan, H.A. et al. 2017. Salting our freshwater lakes. Proceedings of the National Academy of Sciences 114(17):4453.

Errera, R.M. et al. 2008. Effect of imbalanced nutrients and immigration on Prymnesium parvum community dominance and toxicity: results from in-lake microcosm experiments. Aquatic Microbial Ecology 52(1):33-44.

Fistarol, G.O., C. Legrand, and E. Granéli. 2003. Allelopathic effect of Prymnesium parvum on a natural plankton community. Marine Ecology Progress Series 255:115-125.

Fistarol, G.O., C. Legrand, and E. Granéli. 2005. Allelopathic effect on nutrient-limited phytoplankton species. Aquatic Microbial Ecology 41:153-161.

Flood, S.L., and J.M. Burkholder. 2018. Imbalanced nutrient regimes increase Prymnesium parvum resilience to herbicide exposure. Harmful Algae 75:57-74.

Garcés, E., A. Zingone, M. Montresor, B. Reguera, and B. Dale. 2001. LIFEHAB: Life histories of microalgal species causing harmful blooms. https://www.researchgate.net/publication/282322754_LIFEHAB_Life_history_of_microalgal_species_causing_harmful_blooms.

Genitsaris, S., K.A. Kormas, and M. Moustaja-Gouni. 2009. Microscopic eukaryotes living in a dying lake (Lake Koronia, Greece). FEMS Microbiology Ecology 69:75-83.

Glass, J. 2003. Historical Review of Golden Alga (Prymnesium parvum) in Texas in Singhurst, L., and D. Sager, eds. Golden Alga (Prymnesium parvum) Workshop. Fort Worth, Texas.

Gordon, N., and A. Colorni. 2008. Prymnesium parvum, an ichthyotoxic alga in an ornamental fish farm in southern Israel. Israeli Journal of Aquaculture (Bamidgeh) 60(1):5-8.

Granéli, E., and N. Johansson. 2003a. Effects of the toxic haptophyte Prymnesium parvum on the survival and feeding of a ciliate: the influence of different nutrient conditions. Marine Ecology Progress Series 254:49-56.

Granéli, E., and N. Johansson. 2003b. Increase in the production of allelopathic substances by Prymnesium parvum cells grown under N- or P-deficient conditions. Harmful Algae 2(2):135-145.

Granéli, E., and P.S. Salomon. 2010. Factors influencing allelopathy and toxicity Prymnesium parvum. Journal of the American Water Resources Association 46(1):108-120.

Granéli, E., B. Edvardsen, D.L. Roelke, and J.A. Hagström. 2012. The ecophysiology and bloom dynamics of Prymnesium spp. Harmful Algae 14:260-270.

Green, J.C., D.J. Hibberd, and R.N. Pienaar. 1982. The taxonomy of Prymnesium (Prymnesiophyceae) including a description of a new cosmopolitan species, Prymnesium-Patellifer sp-nov, and further observations on Prymnesium parvum Carter N. British Phycological Journal 17(4):363-382.

Grover, J.P. et al. 2007. Laboratory tests of ammonium and barley straw extract as agents to suppress abundance of the harmful alga Prymnesium parvum and its toxicity to fish. Water Research 41:2503-2512.

Grover, J.P. et al. 2013. Ammonium treatments to suppress toxic blooms of Prymnesium parvum in a subtropical lake of semi-arid climate: Results from in situ mesocosm experiments. Water Research 47(13):4274-4285.

Hallegraeff, G., and S. Gollasch. 2006. Anthropogenic introductions of microalgae. Pages 379-388 in Granéli, E., and J.T. Turner, eds. Ecology of Harmful Algae. Springer.

Hambright, K.D., J.D. Easton, R.M. Zamor, J. Beyer, A.C. Easton, and B. Allison. 2014. Regulation of growth and toxicity of a mixotrophic microbe: implications for understanding range expansion in Prymnesium parvum. Freshwater Science 33(3):745-754.

Hambright, K.D., R.M. Zamor, J.D. Easton, K.L. Glenn, E.J. Remmel, and A.C. Easton. 2010. Temporal and spatial variability of an invasive toxigenic protist in a North American subtropical reservoir. Harmful Algae 9(6):568-577.

Henrikson, J.C. et al. 2010. Reassessing the ichthyotoxin profile of cultured Prymnesium parvum (golden algae) and comparing it to samples collected from recent freshwater bloom and fish kill events in North America. Toxicon 55(7):1396-1404.

Herdendorf, C.E., D.M. Klarer, and R.C. Herdendorf. 2006. The ecology of Old Woman Creek, Ohio: an estuarine and watershed profile.

Holdway, P.A., R.A. Watson, and B. Moss. 1978. Aspects of ecology of Prymnesium parvum (Haptophyta) and water chemistry in Norfolk Broads, England. Freshwater Biology 8(4):295-311.

Igarashi, T., M. Satake, and T. Yasumoto. 1996. Prymnesin-2: A potent ichthyotoxic and hemolytic glycoside isolated from the red tide alga Prymnesium parvum. Journal of the American Chemical Society 118(2):479-480.

Igarashi, T., M. Satake, and T. Yasumoto. 1999. Structures and partial stereochemical assignments for prymnesin-1 and prymnesin-2: Potent hemolytic and ichthyotoxic glycosides isolated from the red tide alga Prymnesium parvum. Journal of the American Chemical Society 121(37):8499-8511.

Jackson, P.R., C.M. García, K.A. Oberg, K.K. Johnson, and M.H. García. 2008. Density currents in the Chicago River: Characterization, effects on water quality, and potential sources. Science of The Total Environment 401(1):130-143.

James, T.L., and A. De La Cruz. 1989. Prymnesium parvum Carter (Chrysophyceae) as a suspect of mass mortalities of fish and shellfish communities in western Texas. The Texas Journal of Science 41:429-430.

James, S.V. et al. 2011. Sunlight amelioration of Prymnesium parvum acute toxicity to fish. Journal of Plankton Research 33(2):265-272.

Karlson, B., P. Andersen, L. Arneborg, A. Cembella, W. Eikrem, U. John, J.J. West, K. Klemm, J. Kobos, S. Lehtinen, and N. Lundholm. 2021. Harmful algal blooms and their effects in coastal seas of Northern Europe. Harmful Algae, p.101989. Harmful Algae 102(101989):22 pp. https://doi.org/10.1016/j.hal.2021.101989.

Kristiansen, J. 1996. Dispersal of freshwater algae - a review. Hydrobiologia 336:151-157.

Kurten, G.L., A. Barkoh, D.C. Begley, and L.T. Fries. 2010. Refining nitrogen and phosphorus fertilization strategies for controlling the toxigenic alga Prymnesium parvum. Journal of the American Water Resources Association 46(1):170-186.

Kurten, G.L., A. Barkoh, D.C. Begley, and L.T. Fries. 2011. Nutrient manipulation to control the toxic alga Prymnesium parvum: verification of treatments and resolution of the issue of elevated pH. North American Journal of Aquaculture 73(2):141-152.

Kurten, G.L., A. Barkoh, L.T. Fries, and D.C. Begley. 2007. Combined nitrogen and phosphorus fertilization for controlling the toxigenic alga Prymnesium parvum. North American Journal of Aquaculture 69(3):214-222.

Larsen, A. 1999. Prymnesium parvum and P-patelliferum (Haptophyta) - one species. Phycologia 38(6):541-543.

Larsen, A., S. Byrant; and U. Båmstedt. 1998. Growth rate and toxicity of Prymnesium parvum and Prymnesium patelliferum (Haptophyta) in response to changes in salinity, light and temperature. Sarsia 83(5):409-418.

Lauren, A. 1998. Autecology, toxicity and life history of Prymnesium parvum and Prymnesium patelliferum (Haptophyta): is a species separation warranted? Unpublished Ph.D. dissertation. University of Bergen, Bergen, Norway.

Liebert, F., and W.M. Deerns. 1920. Onderzoek nach oorzaak van een vischsterfte in den polder Workumer-Niewland, nabij Workum. Rijksinstituut voor Visscherijonderzoek 1(2):81-93.

Legrand, C., K. Rengefors, G. Fistarol, and E. Granéli. 2003. Allelopathy in phytoplankton - Biochemical, ecological and evolutionary aspects. Phycologia 42:406-419.

Lutz-Carrillo, D.J., G.M. Southard, and L.T. Fries. 2010. Global genetic relationships among isolates of golden alga (Prymnesium parvum). Journal of the American Water Resources Association 46(1):24-32.

Manton, I. 1966. Observations on scale production in Prymnesium parvum. Journal of Cell Science 1(3):375.

Ng, D.H.P., Y.K. Ng, H. Shen, and Y.K. Lee. 2015. Microbial technology: the way forward. Pages 69-80 in Kim, S, ed. Handbook of Marine Microalgae.

Padilla, L.V., M.L San Diego-McGlone, and R.V. Azanza. 2010. Exploring the potential of clay in mitigating Pyrodinium bahamense var. compressum and other harmful algal species in the Philippines. Journal of Applied Phycology 22:761-768.

Patiño, R., R.H. Rashel, A. Rubio, and S. Longing. 2018. Growth-suppressing and algicidal properties of an extract from Arundo donax, an invasive riparian plant, against Prymnesium parvum, an invasive harmful alga. Harmful Algae 71:1-9.

Pienaar, R.N. 1980. Observations on the structure and composition of the cyst of Prymnesium (Prymnesiophyceae). Pages 73-74 in Annual Conference Proceedings of Electron Microscopy Society of South Africa.

Pflugmacher, S. 2002. Possible allelopathic effects of cyanotoxins, with reference to microcystin-LR, in aquatic ecosystems. Environmental Toxicology 17(4):407-413.

Prochazka, E., D. Hawker, G.S. Hwang, G. Shaw, L. Stewart, and W. Wickramasinghe. 2010. The removal of microcystins in drinking water by clay minerals. Pages 230-232 in Pagou, P. and Hallegraeff, G, eds. International Society for the Study of Harmful Algae and Intergovernmental Oceanographic Commission of UNESCO 2013. Proceedings of the 14th International Conference on Harmful Algae.

Rashel, R.H., and R. Patiño. 2017. Influence of genetic background, salinity, and inoculum size on growth of the ichthyotoxic golden alga (Prymnesium parvum). Harmful Algae 66:97-104.

Rasmussen, S.A. et al. 2016. Chemodiversity of ladder-frame pymnesin polyethers in Prymnesium parvum. Journal of Natural Products 79(9):2250-2256.

Remmel, E.J., and D.K. Hambright. 2012. Toxin-assisted micropredation: experimental evidence shows that contact micropredation rather than exotoxicity is the role of Prymnesium toxins. Ecology Letters 15(2):126-132.

Renner, R. 2009. Salt-loving algae wipe out fish in Appalachian stream. Environmental Science & Technology 43(24):9046-9047.

Rodgers, R.H., B.M. Johnson, and W.M. Bishop. 2010. Comparison of three algaecides for controlling the density Prymnesium parvum. Journal of the American Water Resources Association 46(1):153-160.

Roelke, D.L. et al. 2007. Effects of nutrient enrichment on Prymnesium parvum population dynamics and toxicity: results from field experiments, Lake Possum Kingdom, USA. Aquatic Microbial Ecology 46(2):125-140.

Roelke, D.L. et al. 2010. Factors influencing Prymnesium parvum populations dynamics during bloom initiation: results from in-lake mesocosm experiments. Journal of the American Water Resources Association 46(1):76-91.

Roelke, D.L. et al. 2010. Hydraulic flushing as a Prymnesium parvum bloom-terminating mechanism in a subtropical lake. Harmful Algae 9:323-332.

Roelke, D.L. et al. 2016. A chronicle of a killer alga in the west: ecology, assessment, and management of Prymnesium parvum blooms. Hydrobiologia 764(1):29-50.

Roelke, D.L., B.W. Brooks, J.P. Grover, G.M. Gable, L. Schwierzke-Wade, and N.C. Hewitt. 2012. Anticipated human population and climate change effects on algal blooms of a toxic haptophyte in the south-central USA. Canadian Journal of Fisheries and Aquatic Sciences 69:1389-1404.

Rosetta, C.H., and G.B. McManus. 2003. Feeding by ciliates on two harmful algal bloom species, Prymnesium parvum and Prorocentrum minimum. Harmful Algae 2(2):109-126.

Schug, K.A. et al. 2010. Hemolysis, fish mortality, and LC-ESI-MS of cultured crude and fractionated golden alga (Prymnesium parvum). Journal of the American Water Resources Association 46(1):33-44.

Schwierzke, L. et al. 2010. Prymnesium parvum population dynamics during bloom development: a role assessment of grazers and virus. Journal of the American Water Resources Association 46(1):63-75.

Schwierzke-Wade, L., D.L. Roelke, B.W. Brooks, J.P Grover, and T.W. Valenti. 2011. Prymnesium parvum bloom termination: role of hydraulic dilution. Journal of Plankton Research 33(2):309-317.

Seger, A. et al. 2015. Mitigating fish-killing Prymnesium parvum algal blooms in aquaculture ponds with clay: the importance of pH and clay type. Journal of Marine Science and Engineering 3(2):154-174.

Sengco, M.R., and D.M. Anderson. 2004. Controlling harmful algal blooms through clay flocculation. Journal of Eukaryotic Microbiology 51(2):169-172.

Sengco, M.R., J.A. Hagstrom, E. Granéli, and D.M. Anderson. 2005. Removal of Prymnesium parvum (Haptophyceae) and its toxins using clay minerals. Harmful Algae 4(2):261-274.

Shilo, M. and Aschner, M.,. 1953. Factors governing the toxicity of cultures containing the phytoflagellate Prymnesium parvum Carter. Microbiology 8(3):333-343.

Skingel, T.R. et al. 2010. Hemolytic toxicity and nutritional status of Prymnesium parvum during population growth. Aquatic Microbial Ecology 61(2):141-148.

Southard, G.M., L.T. Fries, and A. Barkoh. 2010. Prymnesium parvum: The Texas Experience. Journal of the American Water Resources Association 46(1):14-23. https://doi.org/10.1111/j.1752-1688.2009.00387.x.

Svendsen, M., N. Andersen, P. Hansen, and J. Steffensen. 2018. Effects of harmful algal blooms on fish: insights from Prymnesium parvum. Fishes 3:11.

Tillmann, U. 2003. Kill and eat your predator: a winning strategy of the planktonic flagellate Prymnesium parvum. Aquatic Microbial Ecology 32:73-84.

Ulitzer, S. 1973. The amphiphatic nature of Prymnesium parvum hemolysin. Biochimica et Biophysica Acta 298:673-679.

Ulitzur, S., and M. Shilo. 1966. Mode of action of Prymnesium parvum ichthyotoxin. Journal of Protozoology 13(2):332.

Umphres IV, G.D., D.L. Roelke, and M.D. Netherland. 2012. A chemical approach for the mitigation of Prymnesium parvum blooms. Toxicon 60:1235-1244.

Umphres IV, G.D., D.L. Roelke, and M.D. Netherland. 2013. The potential algaecide flumioxazin has little effect on growth, survival and feed conversion of the bluegill sunfish Lepomis macrochirus. Aquaculture 380:80-83.

Uronen, P., P. Kuuppo, C. Legrand, and T. Tamminen. 2007. Allelopathic effects of toxic haptophyte Prymnesium parvum lead to release of dissolved organic carbon and increase in bacterial biomass. Microbial Ecology 54(1):183-193.

Uronen, P., S. Lehtinen, C. Legrand, P. Kuuppo, and T. Tamminen. 2005. Haemolytic activity and allelopathy of the haptophyte Prymnesium parvum in nutrient-limited and balanced growth conditions. Marine Ecology Progress Series 299:137-148.

Valenti, T.W. et al. 2010. A mechanistic explanation for pH-dependent ambient aquatic toxicity of Prymnesium parvum Carter. Toxicon 55(5):990-998.

VanLandeghem, M.M., M. Farooqi, B. Farquhar, and R. Patiño. 2013. Impacts of golden alga Prymnesium parvum on fish populations in reservoirs of the Upper Colorado River and Brazos River Basins, Texas. Transactions of the American Fisheries Society 142(3):581-595.

Weissbach, A., and C. Legrand. 2012. Effect of different salinities on growth and intra- and extracellular toxicity of four strains of the haptophyte Prymnesium parvum. Aquatic Microbial Ecology 67(2):139-149.

Witt, B.A., J.E. Beyer, T.C. Hallidayschult, and K.D. Hambright. 2019. Short-term toxicity effects of Prymnesium parvum on zooplankton community composition. Aquatic Sciences 81(4):55.

Yates, B.S., and W.J. Rogers. 2011. Atrazine selects for ichthyotoxic Prymnesium parvum, a possible explanation for golden algae blooms in lakes of Texas, USA. Ecotoxicology 20(8):2003-2010.

Author: Bartos, A., and C.R. Morningstar

Revision Date: 1/27/2022

Citation Information:
Bartos, A., and C.R. Morningstar, 2024, Prymnesium parvum N.Carter: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=3234, Revision Date: 1/27/2022, Access Date: 6/16/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


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