Marine hatchetfish facts for kids
Quick facts for kids Marine hatchetfishes |
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| Half-naked hatchetfish, Argyropelecus hemigymnus eating a shrimp | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Stomiiformes |
| Family: | Sternoptychidae |
| Subfamily: | Sternoptychinae |
| Diversity | |
| 3 genera, some 40 species | |
Marine hatchetfishes are small fish that live deep in the ocean. They are also called deep-sea hatchetfishes. You can find them in the Atlantic, Pacific, and Indian Oceans.
These fish are usually quite small. The smallest, Polyipnus danae, is about 2.8 cm (1.1 in) long. The largest, the giant hatchetfish (Argyropelecus gigas), can grow to about 12 cm (4.7 in). They typically live a few hundred meters below the surface, but some can go as deep as 1,500 meters!
Contents
What Do Hatchetfishes Look Like?
Hatchetfishes have a unique look. Their bodies are usually shiny silver and very flat, almost like a hatchet. This is how they got their name! Their mouth is at the very tip of their snout and points downwards.
One of their most special features is their eyes. They have large, tube-shaped eyes that point straight upwards. This helps them spot food or dangers swimming above them in the dark ocean.
What Do Hatchetfishes Eat?
Deep-sea hatchetfishes are always on the lookout for food. They mainly eat tiny ocean creatures like plankton, small crustaceans (like tiny shrimp), and other little fish.
They often swim closer to the surface of the water to find their meals. They usually feed at night, using their super light-sensitive eyes to easily find prey in the dim light.
Amazing Hatchetfish Facts
Hatchetfishes have some really cool abilities that help them survive in the deep sea.
How They Glow
- Deep-sea hatchetfishes can actually make their own light! This amazing trick is called bioluminescence.
- They have special cells called photophores along their bodies. These cells create light through a chemical reaction.
- Hatchetfishes can control how bright their light is. They can make it just as bright as the faint sunlight coming from the surface. This helps them hide from predators below. By matching the light from above, they become almost invisible!
Jumping Fish
- Believe it or not, hatchetfishes can jump out of the water!
- When they jump, they can sometimes catch small insects flying near the surface.
Short Lives
- Most hatchetfishes have a very short lifespan. They usually live for less than a year.
Types of Hatchetfishes
There are three main groups, or genera, of marine hatchetfishes. Together, they include about 40 different species.
- Argyropelecus – These are known as silver hatchetfishes and include 7 species.
- Polyipnus – This group has the most species, with 32 different kinds.
- Sternoptyx – This group contains 4 species.
