Incendiamoeba cascadensis

• New species: Incendiamoeba cascadensis is a new species of amoeba.
• Discovery: Found in the geothermal streams of Lassen Volcanic National Park, California, USA.
• Name: Means “fire amoeba from the Cascade mountain range.”
• Heat tolerance:
  • Can reproduce at 145°F (63°C).
  • Can remain mobile at around 147°F (64°C).
  • Can recover after brief exposure to about 158°F (70°C), but does not normally reproduce at this temperature.
• Record: Described as the most heat-tolerant eukaryote.
• Comparison: Some thermophilic bacteria and archaea can grow at temperatures exceeding 100°C.
• Eukaryote: Amoebae are eukaryotic organisms with a nucleus and specialised cellular structures.
• Cell division: I. cascadensis divides through mitosis.
• Forms: Has an elongated, worm-like form and a compact amoeboid shape with pseudopodia.
• Heat adaptation:
  • Protects proteins and cell membranes from extreme heat.
  • Changes shape and movement patterns with rising temperatures.
  • Forms a protective structure at higher temperatures.
• Important: The precise mechanisms responsible for its heat tolerance have not yet been identified.

Prelims Question

Q. Consider the following statements regarding Incendiamoeba cascadensis:

1. It is a newly identified species of amoeba.
2. It was discovered in geothermal streams of Lassen Volcanic National Park, California.
3. It is a prokaryotic organism lacking a nucleus.
4. It can reproduce at temperatures reaching about 63°C.

Which of the statements given above are correct?

A. 1 and 2 only
B. 1, 2 and 4 only
C. 2, 3 and 4 only
D. 1, 2, 3 and 4

Answer: B. 1, 2 and 4 only

Explanation:

• Statement 1 – Correct: I. cascadensis is a new species of amoeba.
• Statement 2 – Correct: It was discovered in geothermal streams of Lassen Volcanic National Park, California, USA.
• Statement 3 – Incorrect: Amoebae are eukaryotes, which contain a nucleus and other specialised cellular structures.
• Statement 4 – Correct: It can reproduce at temperatures up to about 63°C (145°F), making it the most heat-tolerant eukaryote described in the given information.