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Are Lobsters Really Bottom Feeders?

When you mention lobster, the word bottom feeder naturally comes up. The association being that lobsters feed on dead things on the ocean floor. This type of thinking is only somewhat true. So are lobsters bottom feeders?

Most Lobsters are considered bottom feeders because they mainly dwell and feed on the bottom of the ocean or bodies of water. However, depending on species, they do not feed exclusively on the dead flesh of other ocean-dwelling organisms. Lobsters are classed as bottom feeders because they generally prey on other bottom dwellers.

The word bottom feeder has many negative and misconstrued connotations—one which is alluded to above. To rectify this misunderstanding, we will discuss what is meant by the word bottom feeder, its relation to other aquatic species that fall within the defining parameters, and how lobsters fit into this classification.

What are bottom feeders?

The word “bottom feeder” relates to the marine biology term benthos, which means “depth of the sea” in Greek. Bottom feeders are any aquatic animal that feeds near or on the bottom of a body of water. This means that many organisms are considered bottom feeders. As mentioned before, people mistakenly assume that all bottom feeders are detrivores or organisms that feed on dead, decaying, decomposing plant and animal matter and feces. Below we will list some examples of bottom feeders that are detrivores and some that are not.

Bottom feeders that are detrivores

Detrivores are looked down upon because of their diet. However, they play a vital role in maintaining and stabilizing ecosystems, both below and above the water. Bottom feeder detrivores can be found in fresh and saltwater environments. Examples of detrivores that also share the term bottom feeders are:

  • Sea cucumbers are members of the echinoderm family and are found on the ocean floor worldwide. There are 1717 different sea cucumbers species, of which many are harvested and used in international cuisines. They feed primarily on plankton and decaying organic matter through filter-feeding or catching detritus with their tentacles.
  • Sea stars or starfish are also members of the echinoderm family and number 1500 in different species. They are found on the bottom of rock pools in the ocean across the world. Some starfish, believe it or not, are considered opportunistic predators and may prey on sea snails and sponges. However, others like the African Red Knob Starfish will eat almost any decaying or decomposing aquatic animal matter. These starfish are also sought after for fish-only aquariums as they keep these environments clean and healthy.
  • Fiddler crabs or calling crabs are those crabs you see on television with one larger pincher and one smaller claw. These are typically the males of this species. They can be found in lagoons, salt flats, beaches, and even mangroves. These crabs use their pinchers to bring sediment to their mouths, filtering it for algae, microbes, or decaying detritus. 

Bottom Feeders that are not detrivores

As mentioned before, many bottom feeders are not detrivores. They are equally crucial for ecosystems and can also be found in both salt and freshwater environments. There are quite a few, and some of them might surprise you as they are consumed by coastal inhabitants regularly. Below a few are listed:

  • Flatfish or Halibut is well known as a sport fish. The Atlantic Halibut is the largest flatfish species in the world. They can grow up to 7-8 foot or 2.62 meters and weigh more than 500 pounds or 230 kilograms. They feed on anything that can fit in their mouths, which means anything that moves on the ocean floor is fair game. Raw Halibut meat is 80 percent water, 19 percent protein, and contains no carbohydrates. The protein increases along with magnesium and selenium content when cooked freshly, making it a popular fish to grill, boil, or deep fry.
  • Catfish are a well-known species of bottom feeder that are found in running freshwater environments. They are famous for eating almost anything as they are opportunistic feeders. This means they will eat what is available, from plant materials to snakes, in extreme cases. They are distinguishable by their barbels, fleshy whisker-like protrusions that hang from around their mouths. These barbels are used for communication and smell. Catfish species range in size from 12 centimeters or 4 inches to 2.5 meters or 8.2 feet. The largest catfish ever caught weighed 293 kilograms or 646 pounds and was caught in Northern Thailand.
Eels are also bottom feeders
  • Eels are well-known snakelike fish that can be found in both fresh- and saltwater environments. There are about 800 different species of eel, and they can be found all over the world. They can range in size from 5 centimeters or 2 inches up to 4 meters or 13 feet. They are amongst the few animal species in nature that can generate electricity with their bodies. Most species of eel are nocturnal prey animals and will eat worms, small fish, octopi, crustaceans, clams, and other mollusks. Eel blood is toxic to humans and mammals, but the proteins that make up the toxin can be eliminated through cooking and the digestive tract.
  • Sand sharks or Sand Tiger Sharks are mackerel sharks that feed on lobsters, crabs, squid, and smaller sharks. In other words, they are bottom feeders that feed on other bottom feeders. They are only found in tropical and temperate saltwater environments and generally spend most of their time at the bottom. They generally range in size from 2.3 meters or 7.54 feet to 3.2 meters or 10.5 feet and can weigh up to 150 kilograms or 330 pounds. They are mostly harmless and are not known to attack people unless threatened. They may look scary and toothy, but divers are known to swim amongst them without issues.

Different kinds of lobsters and their diet

There are many different types of lobsters in the world. We will discuss the most well-known variants, along with some interesting lesser-known species, along with what they generally eat on a day-to-day basis.

  1. Clawed lobsters are the most common and well-known of their kind. They are considered a delicacy to eat and are found in both European and American oceans. They have two large pincher claws, two smaller pairs of claws, and two regular legs or subchelate with which they move around. Both of the species found around America and Europe thrive in cold waters. The American varieties are often brown, while the European lobsters are blue. American lobsters feed on mollusks, fish, algae, other crustaceans, and other lobsters in extreme circumstances. European lobsters feed on worms, crabs, starfish, algae, and zooplankton. 
  2. Reef lobsters look similar to Clawed lobsters but are much smaller and only have one set of pincher claws. They are beautifully colored in ranges from bright reds, purples, spotted, orange to even white. They are primarily scavengers and feed on shrimps, smaller fish, clams, and carrion, making them also detrivores.
  3. Spiny lobsters or rock lobsters cover most lobster species that do not have pincher claws in front of their bodies. Their large and very thick antennae can easily identify them. They are a sign of a healthy and diverse ecology and can be found in warm waters. They are also referred to as crayfish in Australasia and South Africa. Although they are called spiny lobsters, they are actually from a different crustacean family. They are nocturnal bottom feeders whose diet includes snails, clams, sea hares, and sea urchins. They use smell and taste to move around, and it has been discovered that they migrate using the Earth’s magnetic field to navigate.
  4. Slipper lobsters are found in warm oceans and seas. They are more closely related to spiny lobsters than American or European lobsters. They have enlarged antennae that project from their head as wide plates and no claws or pinchers. They typically feed on mollusks, mussels, oysters, crabs, sea cucumbers, and limpets. Although edible, they are not intense commercially fished. There is a significant deviation in size, depending on species and where they are found. In the Meditteranean, the Scyllarus Pygmaeus reach 55 millimeters or 2.2 inches. Whereas the Scyllarides Haani, located in the Pacific ocean, can reach up to 50 centimeters or 20 inches.

Conclusion

All species of lobster are considered bottom feeders. However, as we discussed, not all of them are detrivores that feed on carrion or dead organic material. Lobsters, depending on the species, are highly prized for their culinary value and their influence on fishing-dependent economies. Regardless of the species, they play a vital role on the bottom feeders ecology.

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