21.04.2025 – Ocean scanners

It’s so fascinating to imagine what the world must look like for a dolphin…and it’s a lot more complicated that you’d think. While dolphins do perceive their surroundings through vision, their primary perception of the environment is auditory. Toothed whales are particularly interesting in this aspect and rely on their bio sonar, an auditory tool that allows the animals to communicate, navigate and even hunt in their vast ocean habitat.

In dolphins, such as the Striped dolphin (Stenella frontalis), Bottlenose dolphin (Tursiops truncatus) and Short-finned pilot whales (Globicephala macrorhyhnchus), the organ responsible for this is known as the melon. This globular, fatty organ is located in the head of the cetaceans and acts as a sound-focusing lens for the sonar that allows the animals to echolocate and communicate. In Sperm whales (Physeter macrocephalus) the organ is called the spermaceti and is much larger, stretching over the length of their enormous heads. While both the melon and the spermaceti share the same function, their makeup is slightly different. The spermaceti is filled with a waxy-like substance whose density is temperature dependent; it solidifies at room temperature and is liquid at the whales body temperature. The melon, is made of adipose or fatty tissue, which increases in density towards the outer layers allowing the cetacean to focus its sonar.

So if you ever wondered why Sperm whales heads are so bulky or pilot whales heads so globular, you are now aware of the remarkable reason for this.

By Paula Thake

Sightings of the day

Ribeira Brava

09:00 Bottlenose dolphins, Short-finned pilot whales, Sperm whales

13:00 Bottlenose dolphins, Short-finned pilot whales

Stenella

09:30 Bottlenose dolphins, Short-finned pilot whales, Sperm whales

13:30 Bottlenose dolphins, Short-finned pilot whales

16:00 Bottlenose dolphins, Short-finned pilot whales