Question

Porpoises use _____ to navigate and to locate prey. a. echolocation b. statocysts c. infrasound d. thermoreceptors

Short answer

The answer is (a) echolocation.

Step-by-step solution

Understand the Question

The question is asking how porpoises navigate and find their prey. It gives four options: echolocation, statocysts, infrasound, and thermoreceptors.

Define Echolocation

Echolocation is a biological sonar used by some animals like bats and porpoises to navigate and hunt by emitting calls and listening to the echoes that return from objects in the environment.

Define Statocysts

Statocysts are sensory organs used by some aquatic animals to detect gravity, helping them maintain balance and orientation in water, but not directly for navigation or hunting prey.

Define Infrasound

Infrasound refers to sound waves with frequencies below the lower limit of human audibility, typically below 20 Hz. It is not a method of navigation or prey detection for porpoises.

Define Thermoreceptors

Thermoreceptors are sensory receptors that respond to temperature changes; they are not used by porpoises to navigate or locate prey.

Choose the Correct Option

Based on the definitions, echolocation is the method that porpoises use for navigation and prey detection by emitting sounds and listening for echoes.

Key concepts

Porpoises Navigation

Porpoises are remarkable marine animals known for their impressive navigation skills in the ocean. These skills are primarily due to their ability to use echolocation, a sophisticated biological sonar system. When porpoises navigate, they emit a series of clicks underwater. Once these sound waves bounce off an object, they return echoes. Porpoises interpret these echoes to gauge their surroundings, much like how humans use sight.

This unique navigation system allows them to detect:

• Distance: By timing how long it takes for the echoes to return, they can estimate how far away an object is.
• Size: The nature of the echoes helps determine the size of the object.
• Shape: Variations in the echoes give insights into the shape of the detected object.
• Movement: Change in echo positioning over time indicates movement.

Porpoises' echolocation is not only essential for navigation but also for hunting, as it helps them locate prey in the murky depths of the ocean where visibility is minimal.

Biological Sonar

The concept of echolocation, often termed as biological sonar, is an extraordinary natural phenomenon. It demonstrates how some animals, including porpoises, bats, and dolphins, have evolved to "see" using sound instead of sight. This ability is crucial for survival, especially in complex and dark environments like the ocean.

Here's how biological sonar works:

• Sound Emission: The animal emits sound pulses or clicks.
• Echo Reception: These sounds travel through the environment, hitting objects and reflecting back to the animal.
• Signal Processing: The animal's brain processes the time delay and other characteristics of the returned echoes to form an understanding of its surroundings.

The use of biological sonar allows animals to:

• Navigate: Find their way around obstacles.
• Hunt: Locate prey even in total darkness or turbid waters.
• Communicate: Interact with other members of their species using variations in sound emissions.

This intricate system turns sound into a powerful tool, functioning as the animals' guiding "eyes" in the deep, dark waters where vision could be severely limited.

Marine Animal Sensory Systems

The sensory systems of marine animals like porpoises are fine-tuned for underwater life, offering them the edge they need to survive and thrive in the aquatic environment. A vital component of a marine animal's sensory system is its ability to process various stimuli that aid in navigation, hunting, and communication.

A few noteworthy sensory systems include:

• Echolocation: As previously described, it's a sophisticated system that allows location and identification of objects underwater.
• Electroreception: Some marine animals, like sharks, can detect the electric fields produced by other organisms, helping in prey detection.
• Pressure Sensitivity: Allowing them to sense changes in water pressure, which is crucial for deep-sea navigation.
• Temperature Sensitivity: By utilizing thermoreceptors, they can detect slight changes in water temperature, aiding in habitat selection and migration.
• Vision and Smell: Despite the challenges of underwater light diffusion, many marine species have adapted sharp vision and keen olfactory senses.

These sensory systems work in harmony, enabling marine animals to acclimate to their vast and often unpredictable surroundings, ensuring they remain effective predators and communicators in the ocean's depths.