Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Prymnesium parvum
(golden algae)



Prymnesium parvum (golden algae)


  • Last modified
  • 25 September 2018
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Prymnesium parvum
  • Preferred Common Name
  • golden algae
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Haptophyta
  •       Class: Prymnesiophyceae
  •         Family: Prymnesiaceae
  • Summary of Invasiveness
  • P. parvum is an algal species that forms harmful blooms in inland and coastal aquatic environments and is responsible for devastating fish kills causing ecological and economic damage. While blooms of P. pa...

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Prymnesium parvum (golden algae); a single-celled organism, often referred to as golden algae. They are microscopic (ca.10 µm), flagellated algae, and capable of producing toxins which can cause extensive fish die-offs.
TitleThe single celled organism
CaptionPrymnesium parvum (golden algae); a single-celled organism, often referred to as golden algae. They are microscopic (ca.10 µm), flagellated algae, and capable of producing toxins which can cause extensive fish die-offs.
Copyright©Greg Southard-2006/Texas Parks & Wildlife Department (TPWD)
Prymnesium parvum (golden algae); a single-celled organism, often referred to as golden algae. They are microscopic (ca.10 µm), flagellated algae, and capable of producing toxins which can cause extensive fish die-offs.
The single celled organismPrymnesium parvum (golden algae); a single-celled organism, often referred to as golden algae. They are microscopic (ca.10 µm), flagellated algae, and capable of producing toxins which can cause extensive fish die-offs.©Greg Southard-2006/Texas Parks & Wildlife Department (TPWD)


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Preferred Scientific Name

  • Prymnesium parvum N.Carter

Preferred Common Name

  • golden algae

Other Scientific Names

  • Prymnesium patelliferum J.C.Green, D.J.Hibberd & R.N.Pienaar

Summary of Invasiveness

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P. parvum is an algal species that forms harmful blooms in inland and coastal aquatic environments and is responsible for devastating fish kills causing ecological and economic damage. While blooms of P. parvum were documented in the eastern hemisphere since the early 1900s, the species has now spread widely, with blooms occurring in all southern regions of the USA and some northern regions. P. parvum is not on an alert list or listed as a regulated pest.

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Haptophyta
  •             Class: Prymnesiophyceae
  •                 Family: Prymnesiaceae
  •                     Genus: Prymnesium
  •                         Species: Prymnesium parvum

Notes on Taxonomy and Nomenclature

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In the older literature there are reports of both Prymnesium parvum and Prymnesiumpatelliferum. They were distinguishable by minor details in scale morphology seen only using transmission electron microscopy (Green et al., 1982). More recently, evidence was provided that indicated P. parvum and P. patelliferum were the same species representing different forms (Larsen and Medlin, 1997; Larsen and Edvardsen, 1998; Larsen 1999). Consequently, the names were emended to P. parvum f. parvum and P. parvum f. patelliferum.


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P. parvum is a microscopic (about 10 µm), flagellated alga believed to have four morphologically distinct forms. Two forms are bi-flagellated haploid cell types. One form is a bi-flagellated diploid cell type. Another form is non-motile with no flagella, which might be a resting stage. The flagellated forms have a haptonema, a specialized external needle-like structure that enables attachment to surfaces. The haptonema does not appear to aid in particle capture and phagocytosis in P. parvum f. patelliferum (Tillman 1998), unlike what has been observed for another haptophyte taxa (Kawachi et al. 1991). P. parvum f. parvum can be either haploid or diploid. P. parvum f. patelliferum is haploid (Larsen and Edvardsen, 1998). P. parvum cells have two saddle shaped chloroplasts that are usually yellow-green to olive in colour.Green et al. (1982) found that the flagella range from 12-15 micrometers long and the flexible, non-coiling haptonema ranges from 3-5 micrometers long. Each cell has body scales of two types found in two layers with scales of the outer layer having narrow inflexed rims and those of the inner layer having wide, strongly inflexed rims (Green et al., 1982).


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P. parvum is found worldwide (Edvardsen and Paasche, 1998; Graneli et al., 2012), including the Baltic Sea, Europe, China, Australia, the USA and Morocco. It is most often associated with estuarine or marine waters, but it can also occur in inland waters that have a relatively high mineral content. The type locality is a brackish water pond in the Isle of Wight, England, UK. 

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes


ChinaPresentPresent based on regional distribution.
-NingxiaPresentIntroduced Invasive Guo et al., 1996Inland waters
-ShandongPresentIntroduced Invasive Guo et al., 1996Inland waters
-ShanxiPresentIntroduced Invasive Guo et al., 1996Inland waters
-TianjinPresentIntroduced Invasive Guo et al., 1996Inland waters
-ZhejiangPresentIntroduced Invasive Guo et al., 1996Inland waters
IsraelPresentIntroduced Invasive Gordon and Colorni, 2008Aquaculture ponds
MongoliaPresentIntroduced Invasive Guo et al., 1996Inland waters
PalestinePresentWatson, 2001


MoroccoPresentIntroduced Invasive Sabour et al., 2000Oued Mellah Lake

North America

USAPresentPresent based on regional distribution.
-AlabamaPresentIntroduced Invasive Tomas et al., 2004; Sager et al., 2008
-ArizonaPresentIntroduced Invasive Sager et al., 2008
-ArkansasPresentIntroduced Invasive Tomas et al., 2004; Sager et al., 2008
-CaliforniaPresentIntroduced Invasive Tiffany et al., 2007; Sager et al., 2008Salton Sea
-ColoradoPresentIntroduced Invasive Roelke et al., 2016
-FloridaPresentIntroduced Invasive Sager et al., 2008
-GeorgiaPresentIntroduced Invasive Tomas et al., 2004
-HawaiiPresentIntroduced Invasive Roelke et al., 2016
-LouisianaPresentIntroduced Invasive Sager et al., 2008
-MainePresentIntroduced Invasive Sager et al., 2008
-MississippiPresentIntroduced Invasive Sager et al., 2008
-NebraskaPresentIntroduced Invasive Roelke et al., 2016
-New MexicoPresentIntroduced Invasive Sager et al., 2008
-North CarolinaPresentIntroduced Invasive Tomas et al., 2004; Barreto et al., 2011Artesian Aquaculture facility
-OklahomaPresentIntroduced2004 Invasive Hambright et al., 2010Lake Texoma
-PennsylvaniaPresentIntroduced2009 Invasive Renner, 2009; Brooks et al., 2011Dunkard Creek
-South CarolinaPresentIntroduced Invasive Lewitus et al., 2003; Tomas et al., 2004Golf course ponds
-TexasPresentIntroduced Invasive Tomas et al., 2004; Roelke et al., 2010; Dawson et al., 2015Several lakes throughout central and western regions of state
-WashingtonPresentIntroduced Invasive Sager et al., 2008
-West VirginiaPresentIntroduced2009 Invasive Renner, 2009; Brooks et al., 2011Appalachian Stream
-WyomingPresentIntroduced Invasive Sager et al., 2008


GermanyPresentIntroduced Invasive Dietrich and Hesse, 1990Coastal waters
GreecePresentIntroduced Invasive Moustaka-Gouni et al., 2004; Michaloudi et al., 2009Lake Koronia
HungaryPresentIntroduced Invasive Vasas et al., 2012Shallow lakes
ItalyPresentIntroduced Invasive Mattioli and Simoni, 1999Shallow lakes
NetherlandsPresentLiebert and Deerns, 1920; Otterstrøm and Steemann-Nielsen, 1940
NorwayPresentJohnsen and Lein, 1989; Eikrem and Throndsen, 1993Coastal waters
SpainPresentIntroduced Invasive Comin and Ferrer, 1978Ebro Delta
SwedenPresentIntroduced Invasive Johnsen et al., 2010Ryfylkefjordane fjord
UKPresentIntroduced Invasive Holdway et al., 1978; Watson, 2001Coastal waters


AustraliaPresentPresent based on regional distribution.
-Western AustraliaPresentIntroduced Invasive Hallegraeff, 1992Coastal waters

History of Introduction and Spread

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While blooms of P. parvum were documented in the eastern hemisphere since the early 1900s (Liebert and Deerns, 1920), documented blooms in the western hemisphere only started in the mid-1980’s, and then only localized in the south-central USA. The first confirmed blooms of P. parvum in North America were identified in Texas in 1985 on the Pecos River (James and Cruz, 1989), although based on physical characteristics of these blooms, Rhodes and Hubbs (1992) speculated that P. parvum blooms could have been responsible for fish kills in this river since the 1960s. A rapid proliferation of blooms in the western hemisphere occurred during the early 2000s, with Sager et al. (2008) reporting that the alga had invaded reservoirs and river systems in 15 other U.S. states, including Alabama, Arizona, Arkansas, California, Washington, Hawaii, New Mexico, Wyoming, North Carolina, South Carolina, Florida, and Georgia. Blooms now occur in all southern regions of the USA and some northern regions (Roelke et al., 2016).

Genetic analysis of P. parvum in different locations in the USA and from other locales around the world led Lutz-Carillo et al. (2010) to suggest that P. parvum in the USA originated from Europe, and that there may have been multiple invasion events.

Risk of Introduction

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Without knowledge of the origins of P. parvum in the eastern hemisphere, it is not possible to infer mechanisms that might have facilitated proliferation of blooms there. In the western hemisphere, multiple factors likely contributed to the spread of P. parvum blooms: these include changes in salinity, hydrology and nutrient concentration ratios.

In the south-central USA, where P. parvum blooms appear to have first occurred in the western hemisphere, salinity increases likely played a strong role enabling blooms. During the period of late 1990’s through early 2000s drought persisted in this region and salinity rose to a range of ~2 to ~4 psu in many lake and river systems. Of the many environmental variables measured during monitoring studies, elevated salinity related most strongly to P. parvum blooms (Roelke et al., 2012; Patiño et al., 2014; VanLandeghem et al., 2014; Hambright et al., 2015).

Lower river inflows to lakes during this period of drought might also have allowed P. parvum blooms to get established in the south-central USA. Experimentally, through deployment of in-lake mesocosm experiments, inflow events were shown to prevent bloom development (Hayden et al., 2012). In addition, field-monitoring studies showed that inflow events caused abrupt termination of blooms (Roelke et al., 2010, 2011; Jones et al., 2013). This notion was reinforced during follow-on, in-lake experiments (Hayden et al., 2012).

Long-term changes in the ratio between nutrients might have also played a role in enabling P. parvum blooms in the south-central USA. Laboratory experiments have shown that stoichiometric imbalance between nitrogen (N) and phosphorus (P) enhances toxicity to various organisms, which is probably the result of increased toxin production. When N:P was low or high, toxicity increased, with toxicity increasing more so in cultures studied when P was most limiting (Dafni et al., 1972; Johansson and Granéli, 1999; Granéli and Johansson, 2003b; Barreiro et al., 2005; Uronen et al., 2005; Valenti et al., 2010; Hambright et al., 2014).


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P. parvum occurs in brackish inland and coastal aquatic environments encompassing rivers, lakes, ponds, estuaries, lagoons and coastal oceans.

Habitat List

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Lakes Principal habitat Harmful (pest or invasive)
Lakes Principal habitat Natural
Reservoirs Principal habitat Harmful (pest or invasive)
Reservoirs Principal habitat Natural
Rivers / streams Principal habitat Harmful (pest or invasive)
Rivers / streams Principal habitat Natural
Ponds Principal habitat Harmful (pest or invasive)
Ponds Principal habitat Natural
Estuaries Principal habitat Harmful (pest or invasive)
Estuaries Principal habitat Natural
Lagoons Principal habitat Harmful (pest or invasive)
Lagoons Principal habitat Natural
Inshore marine Principal habitat Harmful (pest or invasive)
Inshore marine Principal habitat Natural

Biology and Ecology

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P. parvum is a planktonic, single-celled, ellipsoid-shaped eukaryote. Its life cycle involves bi-flagellated forms and an unflagellated form. The flagellated forms are haploid and diploid. The unflagellated form might be a resting stage.

P. parvum supports population growth through autotrophy, where energy is obtained from sunlight, but also through heterotrophy, where energy is obtained from dissolved and particulate organic matter, i.e., saprophytic and phagocytic modes of nutrition (Fistarol et al., 2003; Granéli and Johansson, 2003a; Skovgaard and Hansen, 2003; Tillmann, 2003). Some chemicals produced by P. parvum are allelopathic and toxic to many other plankton, often resulting in death of other algae and zooplankton. The remains of killed organisms are then utilized by P. parvum. The killing effect of these chemicals also leads to P. parvum blooms that are near-monospecific with waters taking on a golden colour. For this reason, colloquially P. parvum is referred to as ‘golden algae’. It has been suggested that without the ecological benefits of its allelopathic and toxic chemicals, P. parvum appears to be a poor competitor and blooms do not occur (Roelke et al., 2007; Errera et al., 2008), although the role of allelopathy is disputed by some authors (Jonsson et al., 2009).

Environmental Requirements

P. parvum is found at a wide range of salinities, being present in both coastal and inland waters. Studying one Scottish and two Israeli strains, McLaughlin (1958) found optimal NaCl concentrations of 0.3-6%, with growth possible at 0.2-10%. Larsen and Bryant (1998) reported that the Norwegian, Danish and English P. parvum strains they tested grew over a wide range of salinities each with different optimum growth concentrations, and that all three strains survived salinities from 3 to 30 psu (or 0.3%-3%). Dickson and Kirst (1987) speculated that the success of P. parvum in variable saline environments may be due to its ability to synthesize compatible solutes. Hambright et al. (2015) have found in Lake Texoma on the Oklahoma-Texas border that P. parvum presence and blooms are related positively to salinity and negatively to TN:TP ratio.

Shilo and Aschner (1953) observed that temperatures greater than 30°C were inhibitory to the growth of P. parvum, and 35°C resulted in lysis. McLaughlin (1958) reported erratic growth of Scottish and Israeli strains of P. parvum above 32°C.

Water Tolerances

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ParameterMinimum ValueMaximum ValueTypical ValueStatusLife StageNotes
Depth (m b.s.l.) Optimum Surface. Blooms occur in photo zone
Salinity (part per thousand) 0.5 35 22 Optimum Experimentally determined
Water pH (pH) 7 Optimum pH below 7 ameliorates toxicity and organism loses its competitive edge
Water temperature (ºC temperature) 10 35 27 Optimum Experimentally determined

Notes on Natural Enemies

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Experimental evidence suggests that P. parvum may be vulnerable to viruses, algicidal bacteria and some zooplankton. In virus-free waters, P. parvum growth was better during in-lake mesocosm studies, suggesting a negative association between viral presence and P. parvum (Schwierzke et al., 2010). In bacteria-free waters, P. parvum growth was better during in-estuary mesocosm studies, but only during some seasons. This suggests an intermittent negative association between the bacteria and P. parvum (Lundgren et al., 2015). Regarding zooplankton, some (few) ciliates, rotifers and copepods were able to co-exist and even feed on toxic P. parvum (Koski et al., 1999; Rosetta and McManus, 2003; Michaloudi et al., 2009; Hambright et al., 2010; Schwierzke et al., 2010; Roelke et al., 2012; Davis et al., 2015; Lundgren et al., 2015). 

Means of Movement and Dispersal

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The mechanism of P. parvum dispersal from the eastern hemisphere to the western is unknown. Within the western hemisphere, the mechanisms of dispersal are also unknown, but could involve facilitated invasions through interbasin water transfers, interbasin transportation on/in boats from recreational boaters, interbasin fish stocking activities, attachment to feathers of birds migrating across watersheds, or long distance transport during severe storms after becoming airborne (Roelke et al., 2016).

Impact Summary

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Economic/livelihood Negative
Environment (generally) Negative

Economic Impact

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Some of the chemicals produced by P. parvum disrupt the function of gill tissue (Ulitzur and Shilo, 1966; Shilo 1967) leading to wreckage of fish and shellfish populations. Blooms often result in fish kills numbering in the 100,000s of individuals and costing local economies in the tens of millions of dollars (USD) (Southard et al. 2010). Losses to local economies in Texas during 2001 winter fish kills were estimated to exceed $18 million (Texas Parks and Wildlife Department, 2002).

Watson (2001) lists mass fish mortalities from many countries, both in natural waters and in aquaculture ponds. Guo et al. (1996) report recurrent kills in carp ponds in China due to P. parvum. The alga is also a problem in Tilapia culture in Israel, and barramundi culture in Australia (Seger et al., 2015). Hallegraeff (1992) suggest that caged fish are more vulnerable than wild fish stocks to P. parvum toxins as they cannot swim away from toxic areas.

Environmental Impact

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Ecological damages to fish communities from P. parvum blooms over long periods are variable, as populations in some watersheds appear to have recovered from recurrent blooms (Zamor et al., 2014), while in other watersheds they have not (VanLandeghem et al., 2013). Differences in fish recoveries between river systems are probably due to differing watershed attributes, e.g., rock and soil types, vegetation, precipitation and land-use practices, as well as varying lake morphologies (VanLandeghem et al., 2013).

In the 1986 event in the Pecos River, about 200 blue suckers (Cycleptus elongatus) and 3600 Rio Grande darters (Etheostoma grahami) were killed: both of these fish are on the Texas list of threatened animals (Texas Parks and Wildlife Department, 2002). Several state or federally endangered or threatened fish occur in areas of previous golden algal fish kills, and future blooms may affect these protected animals (Texas Parks and Wildlife Department, 2002).

Long-term ecological damages to shellfish populations from P. parvum blooms are less studied. Die-offs of several bivalve species were documented in the south-central USA where P. parvum blooms originated in the western hemisphere (James and De La Cruz 1989). In the 1986 kill in the Pecos River, all species in the area were affected, and after the bloom no live Corbicula fluminea (Asiatic clam, previously common in the river) were observed. In addition, well-established mussel beds have been destroyed in the area of the West Virginia-Pennsylvania border, part of P. parvum’s northward expansion (Brooks et al., 2011).

Risk and Impact Factors

Top of page Invasiveness
  • Proved invasive outside its native range
  • Highly adaptable to different environments
  • Is a habitat generalist
  • Tolerant of shade
  • Highly mobile locally
  • Reproduces asexually
Impact outcomes
  • Altered trophic level
  • Damaged ecosystem services
  • Ecosystem change/ habitat alteration
  • Modification of natural benthic communities
  • Modification of nutrient regime
  • Modification of successional patterns
  • Monoculture formation
  • Negatively impacts animal health
  • Negatively impacts livelihoods
  • Negatively impacts aquaculture/fisheries
  • Negatively impacts tourism
  • Reduced amenity values
  • Reduced native biodiversity
  • Threat to/ loss of endangered species
  • Threat to/ loss of native species
Impact mechanisms
  • Allelopathic
  • Antagonistic (micro-organisms)
  • Competition
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Difficult to identify/detect as a commodity contaminant
  • Difficult/costly to control


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P. parvum is one of several microalgae species with high lipid content, making it useful, in theory, for biofuel production (Ng et al., 2015; Jayati Trivedi et al., 2015).

Detection and Inspection

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Traditional inverted microscopic techniques (bright field, phase contrast) are effective for P. parvum enumeration. To differentiate forms of P. parvum, transmission electron microscopy is required. Molecular techniques have also been developed for detection of P. parvum and activation of genes responsible for production of some toxins (La Claire, 2006; Medlin et al., 2010). Quantitative real-time PCR (qPCR) has been found to be an effective tool for detecting and monitoring P. parvum, particularly at pre-bloom densities (Zamor et al, 2012).

Similarities to Other Species/Conditions

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Within the Prymnesium genus there are seven species that are distinguishable by body scale morphology and/or DNA-sequences. All are of similar size, bi-flagellated and with haptonema. They are Prymnesium annuliferum, P. calathiferum, P. faveolatum, P. lepailleurii, P. nemametecum, P. parvum and P. zebrinum. The body scales on P. parvum cells are a diagnostic feature that can be used to distinguish it from related algal species (Green et al., 1982). The flagella-to-cell length ratio and the haptonema-to-cell length ratio are also important diagnostic features that aid in identifying this species (Chang and Ryan, 1985).

There are five additional species within the Prymnesium genus that have not been well characterized (Edvardsen and Imai, 2006) and are scarcely observed. These are P. czosnowskii, P. gladiociliatum,P. minutum, P. papillatum and the type species P. saltan.

Prevention and Control

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Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Landscape-scale reductions in nutrient loading and hydrologic manipulations would likely be required for management of P. parvum blooms at the ecosystem level (Hambright et al., 2010; Roelke et al., 2010, 2011). This has not occurred. Nor have attempts to control P. parvum blooms occurred at smaller scales, with the exception of aquaculture ponds (Barkoh and Fries, 2005; Barkoh et al., 2010; Kurten et al., 2007, 2010, 2011). From in-lake and laboratory experiments, there are promising approaches that include nutrient enrichment (Roelke et al., 2007; Errera et al., 2008), ammonium additions (Grover et al., 2013), pH lowering (Prosser et al., 2012), pulsed hydraulic flushing (Hayden et al., 2012; Lundgren et al., 2013), and herbicide application (Umphres et al., 2012, 2013). Chinese carp breeders have used suspended solids (mud), the addition of fertilizer (manure), and reduced salinity with varying degrees of success (Guo et al., 1996). Barkoh et al. (2004) point out that concentrations of ammonium sulfate required to control P. parvum may produce ammonia levels toxic to some fish.

Gaps in Knowledge/Research Needs

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While there have been great strides in developing approaches to manage P. parvum blooms, demonstration projects are still needed before significant funds will be committed to preventing blooms. In addition, information on trophic interactions between some of the organisms that appear unaffected by P. parvum’s toxins is needed. Finally, research directed at identifying toxic chemicals produced by P. parvum and under what environmental conditions is needed, as there is still much uncertainty in this area (Henrikson et al., 2010; Bertin et al., 2012a, b, 2014; Manning and La Claire, 2013; Blossom et al., 2014a, b).


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Barkoh A; Fries LT, 2005. Management of Prymnesium parvum at Texas state fish hatcheries. Austin, Texas, USA: Texas Parks and Wildlife Department.

Barkoh A; Smith DG; Schlechte JW; Paret JM, 2004. Ammonia tolerance by sunshine bass fry: implication for use of ammonium sulfate to control Prymnesium parvum. North American Journal of Aquaculture, 66(4):305-311.

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

Barreiro A; Guisande C; Maneiro I; Trinh Phuong Lien; Legrand C; Tamminen T; Lehtinen S; Uronen P; Granéli E, 2005. Relative importance of the different negative effects of the toxic haptophyte Prymnesium parvum on Rhodomonas salina and Brachionus plicatilis. Aquatic Microbial Ecology, 38(3):259-267.

Barreto FS; Tomas CR; McCartney MA, 2011. AFLP fingerprinting shows that a single Prymnesium parvum harmful algal bloom consists of multiple clones. Journal of Heredity, 102(6):747-752.

Bertin MJ; Voronca DC; Chapman RW; Moeller PDR, 2014. The effect of pH on the toxicity of fatty acids and fatty acid amides to rainbow trout gill cells. Aquatic Toxicology, 146:11.

Bertin MJ; Zimba PV; Beauchesne KR; Huncik KM; Moeller PDR, 2012. Identification of toxic fatty acid amides isolated from the harmful alga Prymnesium parvum Carter. Harmful Algae, 20:111-116.

Bertin MJ; Zimba PV; Beauchesne KR; Huncik KM; Moeller PDR, 2012. The contribution of fatty acid amides to Prymnesium parvum Carter toxicity. Harmful Algae, 20:117-125.

Blossom HE; Andersen NG; Rasmussen SA; Hansen PJ, 2014. Stability of the intra- and extracellular toxins of Prymnesium parvum using a microalgal bioassay. Harmful Algae, 32:11-21.

Blossom HE; Rasmussen SA; Andersen NG; Larsen TO; Nielsen KF; Hansen PJ, 2014. Prymnesium parvum revisited: relationship between allelopathy, ichthyotoxicity, and chemical profiles in 5 strains. Aquatic Toxicology, 157:159-166.

Brooks BW; Grover JP; Roelke DL, 2011. Prymnesium parvum, An emerging threat to inland waters. Environmental Toxicology and Chemistry, 30:1955-1964.

Chang FH; Ryan KG, 1985. Prymnesium calathiferum sp. nov. (Prymnesiophyceae), a new species isolated from Northland, New Zealand. Phycologia, 24:191-198.

Claire JWIILa, 2006. Analysis of expressed sequence tags from the harmful alga, Prymnesuim parvum (Prymesiophyceae, Haptophyta). Marine Biotechnology, 8:534-546.

Comin FA; Ferrer X, 1978. Mass Development of the Phytoflagellate Prymnesium parvum Carter (Haptophyceae) in a Coastal Lagoon in the Ebro Delta. Oecologia Aquatica, 3:207-210.

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Davis SL; Roelke DL; Brooks BW; Lundgren VM; Withrow F; Scott WC, 2015. Rotifer-Prymnesium parvum interactions: The role of lake bloom history. Aquatic Microbial Ecology, 75:55-68.

Dawson D; VanLandeghem MM; Asquith WH; Patiño R, 2015. Long-term trends in reservoir water quality and quantity in two major river basins of the southern Great Plains. Lake & Reservoir Management, 31(3):254-279.

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Errera RM; Roelke DL; Kiesling R; Brooks BW; Grover JP; Schwierzke L; Ureña-Boeck F; Baker JW; Pinckney JL, 2008. The effect of imbalanced nutrients and immigration on Prymnesium parvum community dominance and toxicity: Results from in-lake microcosm experiments, Texas, USA. Aquatic Microbial Ecology, 52:33-44.

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

Gordon N; Colorni A, 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; Edvardsen B; Roelke DL; Hagström JA, 2012. The ecophysiology and bloom dynamics of Prymnesium spp. Harmful Algae, 14:260-270.

Granéli E; Johansson N, 2003. 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.

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11/05/2016 Original text by:

Professor Dan Roelke, Texas A&M University, USA

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