Aging fish is similar to aging a tree by counting the number of growth rings. However, the age of the fish is determined by counting the number of wide growth rings called annuli. In our example, the bluegill is 4 years old.
What are the two ways that allow us to determine the age of the fish?
The two primary ways to age fish is to either examine scales from the fish or to examine one of the otolith’s (inner ear bones). During times of slow growth, such as in winter for warm water fish, the layers of growth in these structures are closer together and form a dark line (annuli, for annual rings).
How old is the fish species?
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish.
What is the most dangerous fish?
10 of the World’s Most Dangerous Fish
- Puffer. puffer fish Jupiterimages/Photos.com/Getty Images Plus. …
- Red Lionfish. red lionfish. …
- Candiru. candiru © Morphart Creation/COMEO—Shutterstock. …
- Great White Shark. great white shark. …
- Moray Eel. mosaic moray eel. …
- Tigerfish. Tigerfish. …
- Piranha. …
How can you tell a fish’s gender?
This is the fin that sits under the fish, just behind their anus. Male’s have long, pointed anal fins, whereas the females will have a shorter, triangular-shaped anal fin. Do not count on color to tell you the difference!
Are fish older than dinosaurs?
Since the extinction event that wiped out the dinosaurs 66 million years ago, fish have evolved and diversified, leading to the wide variety of fish species we see today. According to a new study, many of today’s fish lineages emerged right around this time. …
Can a fish feel pain?
Fish do not feel pain the way humans do, according to a team of neurobiologists, behavioral ecologists and fishery scientists. The researchers conclude that fish do not have the neuro-physiological capacity for a conscious awareness of pain. Fish do not feel pain the way humans do.
What’s the best fish to eat?
12 Best Types of Fish to Eat
- Alaskan salmon.
- Rainbow trout.
Which fish kills most humans?
They sure are! Of the estimated 1,200 venomous fish species on Earth, the stonefish is the most lethal – with enough toxin to kill an adult human in under an hour.
Do fish attack humans?
Yes, fish attack humans. These attacks are rare, but they occur nonetheless. Fish that attack are a predatory marine life. It often attacks humans out of desperation or confusion (attacking people that are wearing something shiny, which is seen as prey).
What is the most beautiful fish in the world?
- Clownfish. …
- Picasso Triggerfish. …
- Lionfish. …
- French Angelfish. …
- Regal Tang. …
- Clown Triggerfish. The striking clown triggerfish is instantly recognizable. …
- Juvenile Emperor Angelfish. Emperor Angelfish are some of the most beautiful fish in the world. …
- Mandarinfish. These spectacular looking fish are the most beautiful in the ocean.
What is a female fish called?
What is a female fish called? A female fish does not have a specific name, male and female fish are both just called fish. However, around 500 species of fish are able to change their gender during their later life after birth. A species of fish that can change its gender is called a hermaphrodite.
Are my fish fighting or mating?
If the fish are fighting, they will tend to leave each other alone, but if they’re mating, you will typically see them together or with their eggs. Fertilized eggs are clear and unfertilized eggs are white in color.
Do fishes sleep?
While fish do not sleep in the same way that land mammals sleep, most fish do rest. Research shows that fish may reduce their activity and metabolism while remaining alert to danger. … These periods of “suspended animation” may perform the same restorative functions as sleep does in people.