More than 27,000 types and counting

The relationship with humans     show

For all their differences, fishes and land animals share remarkable similarities. We each use two sets of paired appendages to move around, whether its pairs of fins, wings, legs or arms. We both have skulls, brains, jaws usually and complex sensors concentrated on our heads. When Nemo looks at us, we recognize a face.

Fishes and humans resemble each other because they are related. The lungfishes are our closest living fish relatives. Modern lungfishes and all land vertebrates are descendants of a common ancestor that lived 365 million years ago (ref.).

Descendants of that ancestral species separated and evolved along two branches of a family tree. One branch gave rise to the modern lungfishes and the other one which started with the first tetrapod would sprout all the branches that gave rise to every four-limbed land animal that exists today, including cows, pigeons, armadillos, opposums, toads, gila monsters and us. The earliest fishes lived in a world with no vertebrate land animals.

Evidence of our common ancestry is both hidden and obvious. It appears in the body parts we share, such as our vertebrae and lungs, and in the commonality of the genetic code stored in each cell of our bodies.

Something special we share with the very first fish that lived over 530 million years ago is absolutely essential - our brains.

The value of knowing more about fishes     show

   Icefish larva  Family Channichthyidae. This icefish larvae is clear because it has no red blood cells. Cold water absorbs and contains so much more oxygen than warm water that this polar fish doesn't need hemoglobin to absorb enough oxygen across its gills. But this adapation to dealing with extremely cold water may prove to be a fatal disadvantage if water warms. Photographer - Uwe Kils, Creative Commons Attribution ShareAlike 3.0.

We've begun to see what's in the deep, aquatic realms where numbers of fish species comparable to the animals on land, live.

Having lost the ability to live in water, we have been kept out of the dark until recently. While manned expeditions to the depths are still rare, remote expeditions with either camera or net are increasingly common. Communication, submersible and observational technologies have finally made it possible for humans to venture where their anatomy can not go.

When we peek, we see the mysterious - We see a tiny Desert Pupfish that withstands waters nearly 100°F in a limestone cavern near Death Valley, and a bloodless icefish that lives in near-freezing seawater around the Antarctic. A miniscule male anglerfish exists by permanently attaching itself to the underside of a much larger female, conserving energy and ensuring a mate where food and mates are very hard to find in the dark.

We see a complexly interconnected world - Salmon return from the sea to the streams where where they hatched, completing a reproductive cycle that ends in death. In that process, nutrients in the fish are carried from the sea onto land, supporting part of the life in a forest. When bears feed on salmon and then do what they do, they fertilize surrounding land. For some eels, the life cycle goes in reverse, beginning in the sea rather than land. Because multiple habitats support their life cycles, conservation of these species requires the coordinated efforts for which humans are so well-equipped.

For the duration of their existence, the lifestyles of these species accommodated environmental variations like El Niño events. But today, rates of extinction are unsually fast because of the accelerating pace of overfishing and habitat loss that fishes cannot accommodate.

When a species goes extinct - it is a loss of food, not just for humans but for other living things that depend on that species, and it is also the loss of a supporting role in the complex web of life on Earth. When fishing takes out too many fishes from a coral reef, algae overtake the reef, kill the coral and essentially evict its diverse tenants.

Extinction is the loss of biological hints and clues that might inspire future technologies. Waterproof brains usually smaller than a walnut allow salmon and eels to navigate thousands of miles without the need for batteries or cell towers. The body of each living thing holds secrets we are just beginning to understand and utilize.

The more we know about fishes and how they live, the better our chances of sustaining the fishes that sustain us. So join us to learn more.