Sandric Leong

Biology of dinoflagellates Karlodinium, Karenia and Takayama

Photo by Sandric Leong

The family Kareniaceae was established in 2005 and it consisted of the genera Karenia, Karlodinium and Takayama.

Kareniaceae 

Kareniaceae: 30 species Genus Karenia: 12 speciesGenus Karlodinium: 11 speciesGenus Takayama: 7 species

Species of these genera are known to form harmful blooms around the global coastal areas.

Some of the species could produce ichthyotoxins such as brevetoxins and karlotoxins that could cause marine animal illness and even mortality.

http://www.sptimes.com/2004/04/02/State/Dolphin_deaths_still_.shtml

1. Karenia asterichroma2. Karenia bicuneiformis3. Karenia brevis4. Karenia brevisulcata5. Karenia concordia6. Karenia cristata Botes7. Karenia digitata8. Karenia longicanalis9. Karenia mikimotoi10.Karenia papilionacea11.Karenia selliformis12.Karenia umbella

Karenia species

12 species

• Genus Karenia is a marine unarmored/naked dinoflagellate

• Species of the genus can be found throughout the world in both oceanic and coastal waters.

• Most Karenia species could produce a variety of toxins that could kill fish and other marine organisms when they form bloom.

• Karenia brevis is known to produce brevetoxinthat could kills fish, marine mammals, and other animals, and also causes neurotoxic shellfish poisoning and respiratory distress in humans.

• Some of the Karenia dinoflagellates grow slowly.

• Karenia blooms are highly sporadic in both time and space.

Karenia mikimotoiKarenia mikimotoi is the oldest known species firstly described in Japan by Oda (1935)

K. mikimotoi is a photosynthetic species that is widely distributed species and a known fish-killer that has caused economic losses in many countries. It produces complex toxic metabolites but the fish-killing mechanisms have not been recognized.

Cells size range from 18 - 40μm in length and14 - 35μm in width

Known toxins: Gymnocin-A; Gymnocin-B; Hemolysin (lipids and proteins that destroy red blood cells); PUFA (Poly-Unsaturated Fatty Acid)

Human impacts: None known

Animal impacts: Mortality of fish and invertebrates

Distribution: Europe, America, Gulf of Mexico, Australia, New Zealand, Japan, Hong Kong, S. Korea, Singapore, the Philippines, China

Karenia mikimotoiKarenia mikimotoi is oldest known species described in Japan by Oda (1935)

Light: low to high light (Saturation around 200 µmol photon m-2 s-1)

Temperatures: 4 – 31°C

Salinity: 9 – 35 PSU

Nutrient requirement/preference: Reduced and Oxidized nitrogen (current work)

Allelochemistry and toxin production: hemolytic activity; allelopathic effects of K. mikimotoi PUFAs on diatoms

Bloom dynamics: form bloom with other species (current observation)

Karenia mikimotoi

Al‐Kandari et al. (2011)

There are two distinct sub‐groups based on geographical regions (Al‐Kandari et al. (2011)

Identification of Karenia mikimotoi

Steidinger et al. (2008)

• Identify using light microscope

• Molecular technique

Karlodinium species

11 species • Genus Karlodinium is a marine unarmored/naked dinoflagellate

• Karlodinium veneficum can be found throughout the global coastal waters.

• Some species are associated with fish mortality.

• Species are known to be mixotrophic like K. veneficum and K. australe

• Karlotoxins only found in K. veneficum

1. Karlodinium antarcticum2. Karlodinium armiger3. Karlodinium australe4. Karlodinium ballantinum5. Karlodinium conicum6. Karlodinium corrugatum7. Karlodinium corsicum8. Karlodinium decipiens9. Karlodinium gentienii10.Karlodinium veneficum11.Karlodinium vitiligo

K. australe is capable of performing photosynthesis as well as feed on other organisms (mixotrophy).

Cells size range from 19-26μm in length and16-22μm in width

Known toxins: unknown

Human impacts: None known

Animal impacts: Mortality of fish

Distribution: Australia, Malaysia, Singapore

Karlodinium australe

Light: unknown

Temperatures: 28 – 32.5°C (Singapore)

Salinity: 21 – 30 PSU (Singapore)

Nutrient requirement/preference: Reduced nitrogen and organic nitrogen (current work)

Allelochemistry and toxin production: unknown

Bloom dynamics: ?

Karlodinium australe

Karlodinium australeNutrient requirement/preference: Reduced nitrogen and organic nitrogen (current work)

Light: unknown

Temperatures: 10 – 30°C

Salinity: 5 – 30 PSU

Nutrient requirement/preference: Reduced, oxidized and organic nitrogen

Karlodinium veneficumCells size range from 9-17μm in length and 8-14μm in width

Known toxins: karlotoxins (higher toxicity when grown in ammonium, low salinity, high temperature)

Human impacts: None known

Animal impacts: Mortality of fish

Distribution: Europe, America, UK, Africa, New Zealand, Australia, Malaysia, Singapore, Korea, China (worldwide distribution)

https://microbewiki.kenyon.edu/index.php/Karlodinium_veneficum

Identification of Karlodinium australe & veneficum

Lim et al. (2014)

• Identify using light microscope

• Molecular technique

de Salas et al. (2005)

Takayama species

7 species

• Genus Takayama is a marine unarmored/naked dinoflagellate

• Some species are known to be ichthyotoxic

• Some are known as fish killers such as T.tasmanica

• Morphology well documented for many species (e.g. de Salas et al. (2008)

1. Takayama acrotrocha2. Takayama cladochroma3. Takayama helix4. Takayama pulchella5. Takayama tasmanica6. Takayama tuberculata7. Takayama xiamenensis

Takayama acrotrocha

T. acrotrocha is marine photosynthetic dinoflagellate.

Cells size range from 22-27μm in length and18-22μm in width

Known toxins: unknown (capable of producing mucus)

Human impacts: None known

Animal impacts: Mortality of fish

Distribution: Europe, Australia, New Zealand, Singapore

T. acrotrocha T. cladochromaT. pulchella

de Salas et al. (2003)

Takayama acrotrocha

Light: 80 – 700 (Singapore)

Temperatures: 28 – 32.5°C (Singapore)

Salinity: 21 – 30 PSU (Singapore)

Nutrient requirement/preference: Reduced and Oxidized nitrogen (current work)

Allelochemistry and toxin production: unknown

• Identify using light microscope

• Molecular techniquede Salas et al. (2008)

Current status of Kareniaceae species

1. Morphological descriptionsWell covered for most species

2. ToxinsMany studies were done on K. brevis & K. veneficumStudies showed a high degree of toxin variability and toxin type among strains.

Place et al. (2012)

Topics of Interests1. Killing mechanisms of Kareniaceae species

Current status: not fully documentedExisting knowledge: limitedKnowledge needed: more studies are necessary

2. Toxins

3. Distribution

4. Life cycle of Kareniaceae species

5. Ecophysiology of Kareniaceae species

6. Environmental factors that will promote fish kills

7. Warning system? Mitigation strategy?

8. Resting cysts?

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