Final answer:
Fish do not notice water as it is their default environment, making it undetectable as a separate entity. Their physiology is fully adapted to water, which includes gills for oxygen uptake, streamlined bodies for movement, and mechanisms like osmoregulation to manage solute concentrations in different water types. The correct option is 2) Because water is so commonplace for fish
Step-by-step explanation:
The reason fish would never notice the water is most similar to option 2 because water is such a commonplace for fish that it is essentially undetectable as a separate entity. Fish are certainly capable of noticing their surroundings, which rules out option 1. They are very much affected by water, so option 3 is incorrect.
While fish are indeed busy swimming (option 4), this isn't the reason they don't notice water. Their entire physiology and behavior are adapted for life in water, making it their default environment, similar to how humans don't constantly notice the air we breathe.
Fish have a range of adaptations for their aquatic lifestyle, such as gills that absorb oxygen from the water, a streamlined body to reduce resistance when swimming, and specialized fins for movement.
For fish, the presence of water is as constant as air is to humans, and it is the medium through which all their life processes function, from breathing to feeding to locomotion.
Options c, d, and b discuss the osmolarity of the water and its effect on fish. Fish adjust to varying osmolarities through a process called osmoregulation.
Osmoregulation is essential for maintaining the balance of water and electrolytes in a fish's body, whether they live in freshwater (hypotonic environment) or saltwater (hypertonic environment). This underscores the inaccuracy of option 3, as fish are deeply affected by the properties of the water they live in.
Moreover, fish have evolved survival strategies based on their environment. For instance, salmon have remarkable osmoregulatory mechanisms, enabling them to transition from saltwater to freshwater seamlessly.
Fish have specialized organs, like the swim bladder, for buoyancy control, while their nervous system and senses are highly developed for environmental interaction, sensing prey, and avoiding predators. The correct option is 2) Because water is so commonplace for fish