Migration exhibited by marine lampreys is

Options

A. ocanodromous
B. potamodromous
C. catadromous
D. anadromous

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks about the type of migration exhibited by marine lampreys. We need to identify the correct term that describes their migratory behavior.

2. **Identifying the Organism:**
The marine lamprey, specifically the sea lamprey (scientific name: Petromyzon marinus), is an ectoparasitic fish found in the northeast Atlantic coast.

3. **Understanding Lamprey's Migration:**
Sea lampreys migrate from their habitat in lakes or seas up rivers. This migration is primarily for spawning purposes.

4. **Defining Migration Types:**
- **Anadromous:** Fish that migrate from the sea to freshwater rivers to spawn.
- **Catadromous:** Fish that are born in freshwater and migrate to the sea to spawn.
- **Potamodromous:** Fish that migrate within freshwater systems.
- **Oceanodromous:** Fish that migrate within the ocean.

5. **Analyzing the Options:**
- **Oceanodromous:** Incorrect, as this term does not apply to lampreys.
- **Potamodromous:** Incorrect, as lampreys do not spend their entire life in freshwater.
- **Catadromous:** Incorrect, as lampreys do not migrate from freshwater to saltwater for spawning.
- **Anadromous:** Correct, as lampreys migrate from the sea to freshwater rivers for spawning.

6. **Conclusion:**
The correct type of migration exhibited by marine lampreys is **anadromous**.

**Final Answer:**
The migration exhibited by marine lampreys is **anadromous**.

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