This is a guest post by my friend Isaac, who loves fishing:
Fish have many survival techniques to thrive in their varied habitats. Some techniques are more important than others but all of them matter. Searching for food and avoiding predators consumes most of their time where as reproduction is usually just an annual event.
Feeding is one of the most important parts of a fish’s life. Bigger fish like to eat zooplankton and tiny microscopic animals. Most fish hunt for their prey but a few fish called scavengers feed on the bodies of the dead or wounded. Some fish, for example, a lamprey, are jawless so they suck blood out of other creatures. Swordfish stab their prey with their long mouth and rip them apart.
Another critical aspect for the survival of fish is reproduction. After mating the female salmon will lay many eggs in her rock nest. The male mate will later release sperm to fertilize the eggs after which they can grow. The reason the female lays so many eggs is because only a handful of them survive predators and natural hazards. Some types of fish guard their young to protect them from assailants. Baby fish are called fry.
Fish have many common senses like sight, smell, and hearing. Obviously without them they wouldn’t be able to catch their prey or perform other vital functions. There is one sense that is particularly essential to a fish. On the side of every fish there is a lateral line of holes, which allows water to flow in and out. When another fish moves in the water it sends a vibration to the fish because it moves water into the lateral line, letting the fish know he’s there. This mechanism is important for hunting and navigating especially if the fish is in dark or murky waters.
Out of many survival abilities I have only pointed out three of the most significant features: feeding, reproduction, and senses. Most interestingly, is how they detect their prey and predators with their lateral line. So next time you catch a fish, hopefully you will have more appreciation for these amazing fishy creatures.