The mangrove swamps of Sri Lanka provide “vital nurseries for young fish. One mangrove specialist, the archer fish, has developed an extraordinary way of getting a bite to eat.”
Watch this video, from the Nat Geo WILD series “Destination Wild,” to see Sri Lanka’s amazing archers in action. Check out the other tabs to learn more about them and the mangrove ecosystems in which they’re found.
  1. Why are the root systems of Sri Lanka’s mangrove forest an ideal underwater nursery for archer fish and other aquatic organisms?

    • Answer

      Mangrove roots are natural nurseries for three major reasons: food, shelter, and protection from predators.

      • Food: The hard roots of the mangrove tree provide an ideal substrate for organisms at the base of the ecosystem’s food web: algae, sponges, barnacles, oysters. (A substrate is a hard material on which a non-moving organism grows. Learn more about substrates here.) First-order consumers, such as shrimp and crabs, feed on these organisms. Predators, such as fish, turtles, or even crocodiles, are at the top of the food web of the underwater mangrove forest.
      • Shelter: The wiry structure of mangrove roots reduces the impact of powerful waves from the open ocean. In this way, mangrove roots provide a calmer aquatic ecosystem for fish and other species that may be swept to sea or stranded on shore during high tides, storm surges, or tsunamis.
      • Protection: The dense network of mangrove roots provides a sort of camouflaged habitat for fish and other aquatic animals. The shifting shadows of the dark and dappled environment make it difficult for predators to see and keep track of quickly moving prey. Additionally, large predators, including many sharks, are simply too big to navigate the “fenced-in” fortress of mangrove roots.


  2. The “Destination Wild” video shows how aquatic creatures thrive in mangrove swamps. What terrestrial creatures—animals that live primarily on land—inhabit this ecosystem?

    • Answer

      Mangrove forests are some of the most biodiverse ecosystems on the planet, home to a dazzling array of birds, reptiles, insects, and mammals. For example:

      • Saltwater crocodiles, monitor lizards, and tigers prowl the mangrove swamps of the Sundarbans, in India and Bangladesh. 
      • The mangroves of the U.S. state of Florida are home to dozens of species of butterflies.
      • West Africa’s coastal mangrove forests provide crucial habitat for endangered species of monkeys and hippopotamuses.

  3. How do you think the shape and coloring of an archer fish allows it to “sneak up” on prey?

    • Answer

      • Archer fish are very, very flat when viewed from above, what biologists call “laterally compressed.” Their razor-thin profiles can go undetected in shallow water.
      • The dark-and-light markings of the archer fish provide excellent camouflage in the sun-dappled water of the mangrove root system.

  4. Some biologists think that the archer fish uses water as a tool to target prey. What other animals use tools for hunting?

    • Answer

      • Primates, such as humans, chimpanzees, bonobos, and orangutans, use sharp sticks for hunting insects, fish, and other mammals. 
      • Other mammals, such as sea otters and mongooses, use rocks to crack the shells of sea urchins, beetles, and eggs. 
      • Birds, such as crows and woodpecker finches, use sharpened tools to access insects trapped in tree bark. 
      • Fish, such as wrasses, use rocks to crack clam shells.

  • There are only seven species of archer fish in the world.
  • All archer fish are native to coastal waters of Southeast Asia, Australia, and Oceania.
  • Archer fish can live in freshwater, saltwater, and brackish water.
  • During archer fish “shooting parties,” several fish shoot at a single prey—and then scramble to recover it when an archer in their party knocks it over.
  • An archer fish is just as likely to leap out of the water to grab an insect in its mouth as it is to “take aim” from below the surface.

having to do with water.


large group.


all the different kinds of living organisms within a given area.

brackish water

salty water, usually a mixture of seawater and freshwater.


to hide or disguise by blending in to surroundings. Also called cryptic coloration.


edge of land along the sea or other large body of water.


spotted, or having areas of differently colored shades or tones.


having parts or molecules that are packed closely together.


community and interactions of living and nonliving things in an area.


organism threatened with extinction.

first-order consumer

in a food chain or food web, an organism that eats (consumes) a producer. First-order consumers are usually herbivores.


all related food chains in an ecosystem. Also called a food cycle.


ecosystem filled with trees and underbrush.


having to do with a habitat or ecosystem of a lake, river, or spring.


environment where an organism lives throughout the year or for shorter periods of time.

high tide

water level that has risen as a result of the moon's gravitational pull on the Earth.

laterally compressed

flattened from side-to-side, or appearing normally from the side but unusually thin and narrow from above or below.


type of tree or shrub with long, thick roots that grows in salty water.


place where young animals are cared for.


animal that hunts other animals for food.


animal that is hunted and eaten by other animals.


type of mammal, including humans, apes, and monkeys.

root system

all of a plant's roots.

saltwater swamp

wooded area near a tidal basin or a protected ocean shore that is partially flooded with seawater for most of the year.


abnormal rise in sea level accompanying a hurricane or other intense storm. Also called a storm tide.


land permanently saturated with water and sometimes covered with it.


having to do with the Earth or dry land.


instrument used to help in the performance of a task.


ocean waves triggered by an earthquake, volcano, or other movement of the ocean floor.