Extant fishes with internal nostrils are

Options

A. coelacanths
B. Chondrichthyes
C. lung fishes
D. teleosts

Answer

To answer the question "Extant fishes with internal nostrils are," we will follow a step-by-step approach:

### Step 1: Understand the Definition
- **Extant Fishes**: These are fish species that are currently living, as opposed to extinct species.
- **Internal Nostrils**: These are nostrils that are located inside the mouth, which can be associated with the ability to breathe air.

### Step 2: Identify Types of Fishes
- We need to consider different groups of extant fishes, such as:
- **Lungfish**
- **Cartilaginous fishes** (like sharks and rays)
- **Teleosts** (the largest group of bony fishes)

### Step 3: Analyze Each Group
- **Lungfish**:
- Known for having internal nostrils. They can breathe air and have adaptations that allow them to survive in low-oxygen environments.

- **Cartilaginous Fishes** (e.g., sharks):
- They do not possess internal nostrils. Their nostrils are external and primarily used for smelling.

- **Teleosts**:
- Generally do not have internal nostrils. Their respiratory system is adapted for aquatic life, relying on gills.

### Step 4: Conclusion
- Based on the analysis, the only extant fishes that have internal nostrils are **Lungfish**. Therefore, the correct answer to the question is **Lungfish**.

### Final Answer:
Extant fishes with internal nostrils are **Lungfish**.

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