Blubber is

Options

A. subcutaneous fat of whale
B. irregular heart beats
C. artifical rubber
D. none of the above

Answer

### Step-by-Step Text Solution:

1. **Definition of Blubber**:
Blubber is a thick layer of vascularized adipose tissue found in certain marine mammals.

2. **Groups of Animals with Blubber**:
Blubber is present in several groups of marine animals, including:
- Cetaceans (e.g., dolphins and whales)
- Pinnipeds (e.g., seals)
- Spheniceiformes (e.g., penguins)
- Sirenians (e.g., sea cows)

3. **Composition of Blubber**:
Blubber is composed of lipid-rich collagen fibers and forms part of the hypodermis (the layer beneath the skin).

4. **Coverage and Attachment**:
Blubber covers most of the body except for parts of the appendages (like flippers) and is strongly attached to the musculature and skeleton through networks of tendons and ligaments.

5. **Body Mass Contribution**:
In some marine mammals, blubber can constitute up to 50% of their body mass at certain times in their life cycle.

6. **Function of Blubber**:
- **Fat Storage**: Blubber serves as the primary fat storage for these animals.
- **Thermal Insulation**: The thickness of blubber provides efficient thermal insulation, which is crucial for thermoregulation in cold aquatic environments.
- **Metabolism**: During periods of feeding and breeding in different oceanic regions, these animals metabolize the fat stored in blubber.

7. **Differences from Other Adipose Tissue**:
Blubber differs from other forms of adipose tissue in its extra thickness and vascularization, making it more effective for its functions.

8. **Conclusion**:
Blubber is essentially the subcutaneous fat found in marine mammals, playing a vital role in insulation, energy storage, and overall survival in aquatic environments.