Many people dream of having an aquarium in the house. Keeping marine creatures in an aquarium may seem like an easy task, but taking care of them is not that easy. To keep your fish healthy, you have to provide them with a clean and fresh environment.
However, cleaning a fish tank is a cumbersome task, especially when you’re working and have a hectic schedule. You can spend your full day cleaning the fish tank. So, what can be done in this situation? Is there an easy way to clean the fish tank without much hassle?
Well, if you’re seeking answers to these questions, then you’re at the right place. You may know that there is a wide range of species of fish in the world. Fishes are mainly categorized into three categories based on the layer of water they pertain to themselves. It includes top-feeders or surface feeders, mid-water fishes, and bottom feeder fishes.
To get rid of the hassle of cleaning your aquarium, introducing some bottom feeder fishes to the fish tank can turn out to be the best option. Not only they help you to maintain a healthier environment for other fishes, but they will also add variety to your aquarium.
In this guide, we are going to tell you everything you need to know about bottom feeder fish. Without wasting much time, let’s get started with what is a bottom feeder fish and what are the traits of a bottom feeder.
What is a Bottom Feeder Fish?
As the name suggests, bottom feeder fishes or aquatic animals primarily live and eat at the bottom of the aquarium. Surprisingly, even they tend to go down under the water while swimming around, they consume their food long the substrate instead of the midwater or top of the water.
Since there is a wide range of bottom feeders, some of them are scavengers – who survive by eating dead fish and invertebrates, some are herbivores – who usually eat algae and other plants, and others are predators. Keeping different species of the bottom feeder is an ideal way to clean your fish tank.
What are the Traits of Bottom Feeder Fishes?
With so many species available in the market, how will you differentiate which fish is bottom feeder fish? Is there any way to recognize the bottom feeder? Well, check out the key characteristics of the bottom feeder that you can consider while finalizing your decision.
- Inferior Mouth: Bottomfeeder has an inferior mouth, which is located toward the bottom of the body and is pointed downwards. It helps the fishes to find their treats on the substrate, but they still keep their eye open for predators.
- Barbels: Many bottom feeders have fleshy whiskers on or near the mouth. These whiskers are known as Barbels and help them to trace the food. They are sensitive to touch and act as tasting buds on a tongue.
- Suckermouths: Some bottom feeders have highly specialized mouths – known as plecos and oto cats. It helps the fishes to latch onto the surface and scrape algae or biofilm. The mouth is round in shape and looks like a suction cup.
- Body Shape: Talking about the body shape, bottom feeders have a flattened ventral region, which helps them to rest and move along the bottom.
Which Bottom Feeder Fish Species is Ideal for Freshwater Aquarium?
Here comes a detailed list of the freshwater fish or the best bottom feeder fish to set up your freshwater aquarium easily. Regardless of the type of aquarium, you will be able to find out a couple of fishes that can be the best for your concern.
15 Awesome Bottom Feeder Fish for Freshwater Aquarium
Peppered Cory Catfish:
Originating from South America and Brazil, the Peppered Cory Catfish is a beauty to behold in an aquarium. This special species of catfish is often known as Blue Leopard Corydoras, Salt and Pepper Cory, and Mottled Corydoras. The scientific name of this fish is Corydoraspaleatus.
The Peppered Cory Catfishes have speckles in silver, grey, and blue colour. The female fishes of this genre are more aggressive and active than males. The females of this particular fish can grow up to 2.3 inches, whereas the males are mostly 2 inches long in size. Their barbs that contain poisonous glands help them to protect themselves from predators. They can live up to 10-15 years.
Due to their small size, you can keep a handful of cory fish in a 20-gallons of the tank. The ambient temperature of the tank should be 22.2° to 26.1° Celcius, whereas the ideal pH level should be between 6.0-8.0. The alkalinity level must be set between 3-10 degrees.
Providing food to this Pepper Cory Catfish is not difficult as they are omnivorous. So, you can feed them whatever you want to feed, but never overfeed them. Some of the food items the Peppered Cory Catfish loves to eat are pellets, flakes, worms, Zucchini, Kale, Cucumber, etc.
This fish is passive-aggressive, so it is a wise idea to keep a partner with this fish to pacify his or her anger. You can also provide your Pepper cory catfish with many aquarium mates like Otocinclus catfish, Bamboo Shrimp, Jack Dempsey, Ivory snails, Red Cherry Shrimp, Mystery snails, etc.
The Common Pleco or Suckermouth catfish is one of the most famous bottom feeder fishes for freshwater aquariums. The scientific binomial of this particular fish is Hypostomusplecostomus. The native range of this species is tropical northeastern South America and is usually found in northeastern Brazil, the Guianas and Trinidad, and Tobago.
This fish usually comes in black and brown shades. They have a protective shell that shields their body like armor. It grows up to 24 inches in size. They are blessed with a unique structure of the mouth, which is more or less like a suction cup and helps them to suck all algae. This fish has a special membrane in their eyes that acts as a shield against sun rays. This fish usually lives for 20-30 years.
Suckermouth catfishes demand large fish tanks with a min capacity of 100-200 gallons. They can inhabit in a condition where the pH ranges between 7.0 and 8.0. You must maintain a range of alkalinity of the water, ranging from 3-10°. The ideal temperature range to keep this fish species alive is 74°F to 80°F.
A well-balanced diet for your Common Plecos is comprised of nourishing items that have protein as a primary element. Suckerfishes need both plant and animal matter to survive as they are omnivorous fishes.
You can include Algae wafers, frozen bloodworms, zucchini, cucumber, carrot, etc. in their diet. Never feed them with citrus fruits, such as lemon, tomatoes, grapes, oranges, etc. Also, do not forget to provide them with driftwood to keep digestive problems at bay.
The male suckerfish helps fertilize the female. So, if you want to breed this species, don’t forget to keep male suckerfish. Apart from this, other popular species that can be best tank mates includes Snowball pleco, Dwarf Gourami, Cories, Zebra Pleco, Kuhli Loach, Yoyo Loach, etc.
The Zebra Loach is a unique aquatic creature that can be found in the Western Ghats of India. Due to stripped markings all over the body, they are named Zebra loach, stripped loach, lined loach, tiger loach, etc. The scientific name of Zebra Loach is Botiastriata. However, this fish is a part of the endangered species. So always getting hold of this rare fish may not be possible.
The fish looks so refreshing and royal with a yellowish-green body that included dark blue-green stripes mostly. These strips can vary in color and thickness. This immensely attractive bottom feeder fish is super active and can stay awake 24 hours. Their growth is relatively low, which is around 9 to 10 centimeters in size. They can live up to 10 years.
They love to live deep in cool, crystal-clear water with peaceful surroundings. This species requires at least 20 gallons of pristine water to live peacefully inside the freshwater. The pH level must be maintained around 6.5-7.5, and the temperature must be adjusted between 72°-79° Fahrenheit. These small creatures are prone to stress, which can lead to aggressive behavior.
This fish is omnivorous and mostly likes to thrive on a diet comprised of animal food and a variety of plants. The addition of flakes, pellets, small worms, Tubifex, Daphnia, etc. is good for their health. They are also fond of eating snails.
Aquarium tank mates:
Zebra Loaches are fond of meeting and playing around with new fishes, but their bossy nature can leave other fishes in a miserable condition, especially the fishes with long and feeble fins. So, it would be better if they can be kept without other loaches, such as Yoyo Loaches, Panda Garra, Kubotais, Clown Pleco, Histronicas, Giant barbs, etc.
Usually found in Orinoco and Panara rivers, As the name suggests, the twig catfish is known for its twig-like structure. While Twig Catfish is known as Whiptail Catfish in various countries, the scientific name of this fish is Farlowellaacus. However, it comes under the category of endangered species. So, it is difficult to find a twig fish.
This fish resembles a green-colored twig with a long green tail. This fish is usually found in the flooded forest are with muddy swamps. Their twig-like figure helps to save them from their enemies. This fish can grow up to 7 inches in length. The lifespan of this fish can be up to 5-10 years.
These fishes are sensitive and susceptible to allergy. So, people who are not good at devoting time to their fishes must refrain from taming them. Twig fishes demand a fish tank with a capacity of min 20 gallons of water. the level of the water must be kept in between 6.0 to7.0 & the best temperature to keep them properly is between 75°-79° Fahrenheit.
Twig Catfish likes to thrive on a vegan diet. Feeding them a combination of pellets, wafers, vegetables twice a day can prove out to be beneficial for them. They don’t forage too much and keep on slacking off in the lower part of the tank. However, it is disastrous for their appetite and digestive system. You can feed them soft meat once a while.
This fish prefers privacy and can live all alone happily ever after. However, you can include some peaceful fishes such as Gouramis, Loaches, Cories, Barbs, etc. as their aquarium mates.
This bottom-dwelling fish comes from Indonesia and southwest, Asia, and can stay in any condition under the water. This fish belongs to the Cobitidae family and is widely known as Coolie Loach, the leopard loach, the cinnamon loach. The scientific name of Khuli Loach is Pangiokhulli.
This fish has an eel-like structure. They have vertical brown strips all over the vibrant pink, yellow body. They have 4-pairs of barbels and small fins around their mouth that help them to trace their food. Their body and eyes are covered with transparent skin. They can grow up to 8-13 cm long and live up to more than 10-years.
The tiny fish requires a tank where a minimum of 30 gallons of water can be stored. The ideal pH level for the water tank must be approximately 6.5-6.8, whereas the alkalinity of water must be 2-10. The ambient temperature of the water must be 74°-79° Fahrenheit.
They are omnivores. Hence, they can eat anything from plant-based to animal-based food items. You can feed them with pellets, flakes, bloodworms, tubifex, artemia, cucumber, fruits, Shelled peas, etc. Since Kuhli loaches are nocturnal species, they are usually fed at night. Make sure to always provide them with high-quality food. Otherwise, they may end up having infections and diseases.
They can stay with any tiny sweet water fishes inside the aquarium, be it molly or Bumblebee Goby. Hence, you can include Rasboras, Corydoras, Oto catfishes, tetras, Danios, etc. in your aquarium. However, they are not compatible with Tiger barbs, Cichlids, and Chinese algae eaters.
Hails from the South-Eastern part of Asia, such as Indonesia, Vietnam, and Thailand, this fish is one of the most popular bottom feeder fishes. The scientific name of Bumblebee Goby is BrachygobiusXanthozona. These cutest fishes are shy in nature in the beginning, but after some time, they can be a little aggressive for their territory.
This dwelling fish is brightly colored like a bee with black and yellow stripes. They can grow up to 4.2 cm in length. They have a big, round-shaped head. Their ventral fins allow them to attach themselves to any surface. They often engage themselves in territorial fights. Unfortunately, they have a short life span of four years.
Bumblebee Goby stays in a tank where the water capacity must be min 10 gallons. The ideal pH level of the aquarium water should be set in between 6.5 to 7.5, and the hardness of the water should be between 143-357 ppm. The alkalinity level must be between 6-20. The ambient temperature to keep these fishes should be between 23°-26°C.
Bumblebee Gobies are omnivorous fishes. However, they are great predators, which is why their diet is similar to carnivorous fishes. Instead of preserved food items, they love to thrive on homemade foods. The best food to feed them includes brine shrimp, blood worms, flakes, fluke worms, live fish, larvae, flakes, etc.
Bumblebee Gobies are natural predators and very conscious of their territory. So, keeping an aquarium mate with them may be difficult. So be very careful with keeping this fish with other fishes. It is always recommended to keep 5-6 Bumblebee Gobies only in a single fish tank.
Born as a fighter fish, Yoyo loach is native to India and Pakistan. It is commonly known as Reticulated loach, Almorah loach, Y loach, and Pakistani loach. BotiaAlmorhae is the scientific name of this fish. Unlike other loaches, the yoyo loach is not nocturnal. It is easy to take care of yoyo loach.
Since these fish have YOYO-like dark and pale patterns all over the body, they are named YOYO loach. They can grow up to 7-13 cm in length. The black and silver beauty is highly adaptive to any situation. This fish can grow up to 7 cm to 13 cm in height. They have small barbels that help them to locate their food. They can live up to 10-15 years if taken care of properly.
Even if these fishes are shy and prefer small spaces to hide, they love to live in a group of at least 5. So, make sure your fish tank must be capable of holding 40 gallons of water. The pH Range of stable water should be between 6.5-7.5, whereas the alkalinity of water should be 2-10. The ideal temperature of the water should be between 75°-80° Fahrenheit.
This fish is a natural scavenger and omnivore. So, they can eat pretty much they can find out inside the tank. They live to thrive on small crustaceans, algae, moths, fungus, larvae, insects, dead plants, and even dead seashells and animals. You can also feed them bloodworms, shrimps, frozen food, flakes, pellets, etc.
Yoyo loaches are shy in nature in the beginning, but once they are accustomed to the surroundings, they can be compatible with the other tankmates, including Glass Catfish, Clown Loaches, Mollies, Kribensis, Goldfish, Angelfish, etc.
Originating from South America, the BrittlenosePleco fish is also known as Bushynose catfish, Common Brittlenose, and Brushmouthpleco. The scientific name of this fish is Ancistrus Cirrhosis. It can be a treasure of any water tank or aquarium.
This 5-inch fish is usually black, brown, olive, or grey in color with some white and yellow spots all over the body. It has a wider head, which is much small, fat, and flat than the common pleco. Its flattened body is covered with bony plates. And with age, they sprout tentacles from their head. They have a round mouth with an elongated mouth and a pair of pectoral and abdominal fins. The average life span of this BrittlenosePleco is approximately 5-years.
This fish needs a water tank of a minimum capacity of 25 gallons to keep this Brittle nose Pleco fish alive. The ideal level must be within the 6.5-7.5 range, whereas the ideal temperature for this fish is around 60°-80° Fahrenheit. The water hardness should fall under the range of 20-25. Make sure you clean the tank every week as it finds it difficult to breathe in the presence of ammonia and nitrate.
Bristlenose Pleco thrives on a vegetarian diet. Their primary source of food is algae and larva growing all over the surface of the aquarium. However, this is not a sufficient diet to keep them healthy. Their diet must comprise 85% plant matter and 15% protein. So, you can offer them parboiled leafy veggies, carrots, cucumber, peas, driftwood, and a very small amount of meaty foods.
Bristlenose Pleco is a peaceful species that shares a great bond with fishes like Molly, Guppy, Betta, Platy, Tetra, Torpedo, etc. Never keep two males together as they are very cautious towards their territory.
Siamese Algae Eater:
Here comes the best friend of a lazy pet master – Siamese Algae Eater, and this fish can live upon in any kind of aquarium. Originating from Southeast Asia, the Siamese Algae Eater is from the Cyprinidae family. It is scientifically known as Crossocheilus oblongus.
True Siamese algae eaters have a long, narrow body that can grow up to max of 6-inches. They usually have a pale gray or golden color body covered with back stripes. This less-demanding fish is easy to take care of and can live up to 10 years. They are quite energetic and rarely aggressive.
This hyperactive fish can live all alone, but sometimes keep jumping around inside the water tank. Hence, keeping a lid on the tank helps you to get rid of this problem. Try to find out an aquarium that can hold 20 gallons of water. The pH range must be kept between 6.5 to 7.0. The temperature of the water tank must be set in between 75-79°F. Water hardness should be 5-20 DH.
While they are great algae eaters, they would eat algae, plant matter, and veggies. However, they are herbivores. So, they also need meat or insect, or dead fish to eat. They will eat everything you will provide them to eat, including flakes, pellets, algae wafers, brine shrimp, bloodworms, frozen food, etc.
Siamese algae eaters are calm creatures, they won’t harm other tank mates. Hence, fishes like Corydoras, Guppy, Tetras, and Daniel, Cherry Shrimps, Snails, Amnao Shrimps, etc. can be the best tank mates for this fish. Don’t add notoriously aggressive fish as they might attack your algae eater.
Tiger Shovelnose Catfish:
The Tiger Shovelnose Catfish can be the attraction of your aquarium if kept nicely. Originated from South America, this fish belongs to the Pimelodidae. The scientific name of this Tiger Shovelnose Catfish is Pseudoplatystomafasciatum. It is also known as Barred Sorubium.
Tiger Shovelnose catfish has a long, slender body with silver and black coloration. The whole body is covered with black stripes and spots, which gives it a look of a tiger. The fish is blessed with wide face cutting, which helps it to tear apart the body of an enemy with the help of daggers. The size of a catfish on average is 2.5 to 3 feet long. They generally live 20 years if kept properly in a water tank.
Unfortunately, many people keep these fishes in small tanks, which leads to stress and anxiety. This way, not only you are torturing the fish, but your fish is going to expect slow death. So, if you’re planning to keep this fish, make sure the water tank must have a capacity of 180+ gallons of water.
The pH level of the water should be kept around 6-8. Please ensure to set the temperature of the water tank in between 72-82°F. You will need to change around 25% of the water every week. The alkalinity should be 6-20.
Tiger Shovelnose fish is omnivorous in nature. Since their growth rate is high, they tend to consume more food. So, make sure you provide them with enough food with a proper balance of proteins, fat, carbohydrates, nutrients, and minerals. Otherwise, they will eat the fish of your aquarium. You can offer them feeder fish, beef, chicken, turkey, pork, etc.
This fish is blessed with a large physique. So, it needs the aquarium mates of its size. Fishes like Arowana, Gourami, Common Placo, Dorado, Redtail Catfish, and Oscar fish can make a very good partner of this fish.
Natives of the Subcontinent of Southern Asia, Dwarf Gouramies are the best option to add as freshwater bottom feeder fish in your aquarium. These fishes are formerly known as ColisaLalia and belong to the Osphronemidae family. The scientific name of this fish is Trichogasterlalius.
Dwarf Gouramies come in various varieties, including blue dwarf gourami, flame dwarf gourami, honey dwarf gourami, neon blue dwarf gourami, and powder blue dwarf gourami. Their body is narrow and compressed on the sides. On the other hand, they have large fins, slightly round at the edges. Their ventral fins act as sensory organs, and the color of fishes will vary with the type. They can grow up to 5 inches in length and live up to 5 years.
Those who are going to take care of a Dwarf Gourami must buy a tank that can contain a minimum of 10 gallons of water. The ideal temperature to keep this fish ranges between 77°-78.5° Fahrenheit. The ideal pH range of a tank made for this fish ranges from 6 to 8. The water hardness can be up to 10-20 dGH. They require weekly water changes of 25-30%.
This hunter fish is omnivorous and a big-time foodie fish. From shrimps, shells, insects, moths, snails to aquatic plants, you can feed them a wide range of food items. You can also use packaged food or frozen food that is specially made for fishes. Make sure you provide them with a well-balanced diet that contains a proper amount of nutrients, minerals, proteins, fats, fiber, and carbohydrates.
Dwarf Gouramies are peacefully fishes that are compatible with a wide range of fishes, including Placo, Molly, Gouramies, Barb, and Loaches, Mystery snails, Otocinclus Catfish, etc.
One of the best freshwater bottom feeder fishes, Cory Catfish, hails from South America. The nature of this fish is not so notorious that it can be a part of a domestic water tank. This fish is known as Armored catfish, Cory fish, Cory cats, Armored catfish, Corydoras catfish, and Cory fish. The scientific name of this fish is Corydoras.
Since there is a wide range of cory catfish available, their body color may vary with species. This fish is small in size and can be up to 12 centimeters long in size. They have a short face, a flat underside, and pectoral fins, and a forked tail fin. Their dorsal fins usually point upwards. They have wide eyes and 3-pairs of barbels on their face, which makes them look adorable. They can live up to 5 years if kept nicely inside the tank.
A water tank that contains 30 gallons of water with an average pH level of 6.0-8.0 is enough to keep your Cory catfish. The ideal temperature to keep this fish properly should be set around 70-75°F. The nitrate level should be at 0ppm. You have to change 20% of the water every week.
This aquatic scavenger loves to eat worms, larvae, and small insects. No doubt that they are omnivorous. Hence, they can be fed fruits and vegetables. The fish also enjoy shrimp pellets, algae wafers. Changing their food items every few days will ensure that they are getting all types of nutrients and minerals.
Cory Catfish can easily stay with any species of Catfishes available in the market. They are peaceful and shy fishes. Hence, fishes like Platys, mollies, swordtails, and guppies are the best tank mates of this fish.
The crayfish has an uncanny resemblance to prawns, which is why it is considered as the prawn of the aquarium. It is also known as crawfish, crawdads, mudbugs. The scientific name of Crayfish is Cambarus sp. They are usually found in North America and belong to the Cambaridae family.
Crayfish usually have muted green and brown colours. The fish have a segmented body, consisting of a fused head encase by the outer shell, six-segmented abdomen, and paired jointed limbs. They have a 2-pairs of antennae and antennule, which help them during foraging and mating. Most crayfish can grow up to 7.5 cm long. They can live up to 20 years.
While a single crayfish only requires a tank of5-10 gallons. But if you want to keep more than one crayfish or with other aquarium mates, it is suggested to use an aquarium where a minimum of 20-30gallons of water can be stored. The pH range of water should be between 6.5 to7.8. The ideal temperature should be around 65-75°F to keep this fish alive. The alkalinity of water must be 3-15.
Crayfish are omnivores by nature. They eat plants, dead organisms, animals, etc. Their diet should be comprised of proteins, carbohydrates, fiber, minerals, nutrients, fats. You can feed them shrimp pellets, frozen food, and veggies like cabbage, Zucchini, peas, daphnia, blood worms, etc.
Since crayfishes are aggressive and territorial, it is best to keep them alone. If you keep crayfish with small fishes, it will attach them as it is an omnivore. On the other hand, if you keep them with large or aggressive fishes, they will eat your crayfish. So, try keeping it alone in a separate fish tank.
How many of you are fond of large bottom feeder fishes? Botia Dario fish can be the best choice for them. This fish belongs to the Cobitidae family and is usually found in South-East Asia. Botia Dario is commonly known as Bengal Loach or Queen Loach.
This tropical fish is available in black color with golden stripes on the body and the barbed fins. They are blessed with a flat body and a sharp face. They have 4-pairs of barbels, protruding from the mouth area. This fish can be up to 6 inches in length. The average life span of this fish is around 5-8 years.
This fish requires a tank where a minimum of20-30gallons of water can be stored. The ideal pH level for this fish is approximately 6.8-7.5. The ideal temperature for this fish must be kept in between 75-82°F. The water hardness should be 18-179 ppm.
They are omnivorous in nature and love to thrive on plants, worms, insects, and algae. This bottom feeder sweet water fish prefers to dive deep while searching for their food from the water. They would be happy even if you feed them frozen food or packaged food purchased from outside. In order to have a balanced diet, you can feed them with frozen bloodworms, tubifex, artemia, fruits, and veggies like cucumber, melon, blanched spinach, and peas, etc.
Bringing an aquarium mate for this Botia Dario is less difficult as they are playful and jolly in nature. They can stay with anything sweet water fishes like Guppy, Molly, Gourami inside the aquarium.
Last but not least, the Otocinclus catfish is the fish that can be included in the freshwater aquarium. They are widely known as algae eaters, dwarf otos, Oto catfish, otos, oto cats, small suckermouths, etc. This fish is from the Loricariidae family & the scientific name of this fish is Otocinclus Cocama. They are native to Latin America.
This freshwater fish comes in a wide range of varieties, including Common otocinclus, golden oto, zebra oto, dwarf otocinclus, silver otos & their body color and small lateral strops may vary from one species to another. They can rarely grow up to 2 inches and can live up to 5 years. They have a cylindrical body, which is narrow toward the head and caudal fins. They have a mouth on the head.
Since they are bottom-dwelling fishes, they require a tank size of 10 gallons. The pH level must be kept in between 6.8-7.5. The ideal temperature to keep this fish properly should be set around 70°-75° Fahrenheit. They need a freshwater tank with ammonia and nitrate levels staying up to 0ppm. They need weekly water change. The hardness of the water should not be higher than 15dH.
Otocinclus fish requires less maintenance because of their food habit. They are herbivorous by birth. Algae, moths, and dead plants all these foods can make a great natural diet for this fish. They do not need any special vegan diet to live a healthy life. You can also feed them with Zucchini, Algae wafers, smashed fruits and veggies, Pellets, etc.
Otocinclus don’t harm other fishes; they can be compatible with any herbivorous fish. Since omnivorous fishes can hunt them, try keeping them with fishes like cory catfish, mystery snails, nerite snails, bamboo shrimps, crayfish, etc.
While these are the best bottom feeder fishes you can add to your aquarium, the list doesn’t end here. There are a lot many species of fish that you are the best bottom feeders. However, there are some bottom feeders like Chinese algae eaters, channel catfish, Apple snails, etc. that should be avoided as they can really harm other aquatic animals residing in the aquarium.
I’m a 31 year-old Aquarist from San Francisco, CA. I have my Bachelor of Science degree in Marine Biology (San Francisco State University) as well as several certifications for Scuba Diving. My main responsibilities as an aquarist are to care for the animal and plant life that people see in aquarium displays.