The peacock flounder is a fascinating saltwater fish with a beautiful, eye-like pattern on its body. As an important part of marine ecosystems, the peacock flounder interacts with many other species in complex food webs. But what exactly is the peacock flounder’s role in the food chain? Is it a secondary consumer?
In this comprehensive guide, we’ll cover everything you need to know about the feeding ecology of the vibrant peacock flounder:
- What is a secondary consumer in ecological terms
- The diet and feeding habits of the peacock flounder
- The peacock flounder’s position in marine and estuarine food webs
- How they interact with primary producers and both primary and tertiary consumers
- Similarities and differences with other common flatfish species
- Threats to the peacock flounder from human activities
By the end, you’ll have a clear understanding of where the peacock flounder sits in coastal food chains and how it connects to the rest of the ecosystem.
What is a Secondary Consumer?
In the study of ecological food chains and food webs, organisms are classified by their feeding position and relationship to plants and other animals. Primary producers like phytoplankton algae and plants form the base of all food chains.
Herbivores that eat these producers directly are called primary consumers. Secondary consumers are carnivores or omnivores that eat primary consumers as their main food source. They occupy the 3rd trophic level in the food chain.
Examples of secondary consumers include predatory fish, snakes, birds of prey, foxes, and small cats in terrestrial ecosystems In marine systems, common secondary consumers are tuna, sharks, squid, and seabirds that prey mainly on smaller fish and invertebrates.
As we’ll see shortly, the peacock flounder neatly fits the definition of a secondary consumer in its coastal habitat.
An Overview of the Peacock Flounder
Before looking at its diet and trophic level, let’s review some key facts about the peacock flounder itself:
- Scientific name: Bothus mancus
- Maximum size: Up to 39 cm length
- Habitat: Coastal waters, estuaries, sandy/muddy bottoms
- Range: Western Atlantic – North Carolina to Brazil
- Body type: Flat and oval-shaped, with both eyes on left side
- Coloration: Eyespot-like markings on dorsal side
- Unique features: Ability to change coloration and bury itself in sediment
The peacock flounder inhabits both subtropical marine waters and brackish estuaries, where it blends into sandy or muddy substrates thanks to its camouflaged eyespots and ability to alter color. It ambushes small prey from its hidden position flat on the bottom.
Now let’s take a closer look at its diet and position in the food web.
Diet and Feeding Habits of the Peacock Flounder
The peacock flounder is a versatile carnivore that feeds on a variety of small marine organisms. Its diet consists mainly of:
- Small fish – juvenile species like anchovies, silversides, and blennies
- Crustaceans – shrimp, crabs, copepods, isopods
- Mollusks – clams, snails, squid, octopus
- Polychaetes – marine worms and bristle worms
- Eggs – from other fish species
Their flat body shape allows them to hide in wait and ambush prey as it passes by. The eyespots on the top of the flounder help camouflage it against predators like larger fish, seabirds, and marine mammals.
Based on its carnivorous diet of smaller fish, shrimp, worms, and other protein-rich foods, the peacock flounder fills the niche of a secondary consumer in its marine and estuarine habitats.
The Trophic Role of the Peacock Flounder in Coastal Ecosystems
Looking at the peacock flounder’s feeding ecology in a broader food web context reveals its keystone position as a secondary consumer between several trophic levels:
1. Primary Producers
While the peacock flounder does not directly consume phytoplankton, algae, seagrasses, and plants, these form the base of the food chain that ultimately sustains them. Small fish and invertebrates feed heavily on these primary producers.
2. Primary Consumers
The peacock flounder preys upon primary consumers like small bait fish (anchovies, herring), mollusks (clams, snails), and some crustaceans. These primary consumers graze directly on algae, phytoplankton, and plant material.
3. Secondary Consumers
As a predator to multiple types of small fish, shrimp, crabs, worms, and other protein-rich prey, the peacock flounder fills the classical secondary consumer niche.
4. Tertiary Consumers
Larger predatory fish, sharks, marine mammals, and seabirds prey upon the peacock flounder, making them tertiary consumers higher up the food chain.
By feeding on primary consumers and serving as food for tertiary predators, the peacock flounder provides an essential link transferring energy between trophic levels in coastal marine ecosystems.
Comparison to Other Common Flatfish Species
The peacock flounder shares some similarities in diet and trophic ecology with other popular flatfish species:
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Like the summer flounder, the peacock flounder ambushes small fish from concealment on the seafloor. Both are secondary consumers.
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Atlantic halibut are more apex predators feeding on large fish and crustaceans. They occupy a higher trophic level than the peacock flounder.
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Yellowtail flounder have a more omnivorous diet including polychaetes and algae. They straddle the secondary and primary consumer levels.
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California halibut feed heavily on anchovies making them more specialized predators than the varied peacock flounder.
So while sharing some overlap, the peacock flounder fills its own unique secondary consumer niche in the ecosystem.
Threats to Peacock Flounder Populations
Some human activities can threaten the supply of prey for peacock flounder and disrupt its position in the coastal food web:
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Overfishing of key small fish species like anchovies and herring diminishes food availability.
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Habitat degradation from pollution, sedimentation, and coastal development can reduce primary productivity and available prey.
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Bycatch from trawl fisheries causes mortality of flounder and prey species.
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Climate change alters water conditions and the abundance of prey populations.
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Invasive species can outcompete native prey fish and invertebrates.
Protecting estuaries and regulating fishing helps maintain ecosystem balance and flounder populations.
Understanding the peacock flounder’s connections and relationships with primary producers, prey, and predators provides insight into the flowing of nutrients and energy through the ecosystem.
While flounder face threats from human impacts, they continue to play a vital role in the food chains that sustain diverse coastal waters.
Economic Importance for Humans: Positive
Peacock flounders are of minor importance in commercial fishing, and they occasionally appear in the aquarium trade. (Froeser and Bailly, 2004).
- Positive Impacts
- pet trade
- food
Bothus lunatusFlounder(Also: Peacock Flounder) Facebook Twitter
Peacock flounders, Bothus lunatus, live in the the West Atlantic Ocean in both tropical and subtropical regions. They are found off the coasts of Florida, Bermuda, and down the coast of South America to Brazil. They have also been recorded in the Central Atlantic near the shelf of Ascension and the St. Helen Islands as well as in the Eastern Atlantic in the Gulf of Guinea. (Evseenko, 2008; Miller, et al. , 1991; Robins and Ray, 1986).
- Biogeographic Regions
- atlantic ocean
- native
Peacock flounders are marine flatfish, living in clear oceanic waters. They live a benthic lifestyle on sand and rock bottoms, including coral reef environments. They can be found at depths as great as 80 m. (Miller, et al. , 1991; Robins and Ray, 1986).
- Aquatic Biomes
- reef
- coastal
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- Range depth
- 0 to 80 m
- 0.00 to 262.47 ft
Adult peacock flounders are round and flat, just like their close relative, and have both eyes on one side of their bodies. The eyes of members of the family Bothidae, like peacock flounders, are on the left side, which is also brighter. Members of this family possess unequal pelvic fins; the fin on the eye-side is longer. Adults average 35 mm in length and can measure as much as 45 mm.
Brown peacock flounders have bright blue rings around their bodies and more blue spots near their heads and fins. There are usually 2 to 3 dark smudges along the lateral line. Unlike other species in the genus Bothus, peacock flounders have a deep notch in front of their eyes. Adult flounders can quickly change color to blend in with the sea floor, just like most other flounders. (Miller, et al. , 1991; Robins and Ray, 1986).
Male and female peacock flounder look similiar, although males have threadlike upper-pectoral fin rays that females lack. Males occasionally have a longer pectoral fin on the eye-side than females. (Evseenko, 2008).
Peacock flounder larvae look very different than adults. Larvae are 5. 5 to 39. 5 mm in length, with each eye on a separate side of the flattened body. In the larval stage, the dorsal and anal fins are fully formed, and the dorsal fin has a long ray that sticks out of it. Larvae are almost free of pigment, making them nearly transparent. A group of melanophores at the base of the long ray of the dorsal fin is the only coloration that can be seen. Larvae also have no teeth. (Evseenko, 2008).
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes shaped differently
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- Range length
- 45 (high) cm
- 17.72 (high) in
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- Average length
- 35 cm
- 13.78 in
Peacock flounders have three stages of life: egg, larval, and adult. Larvae and adults differ in coloration, body shape, and symmetry. As larvae become adults, body depth increases and shape becomes more circular. The swim bladder present in larvae disappears, and adults develop teeth. The movement of the right eye to the left side of the body is another big change in shape. As this migration occurs, peacock flounders become asymmetrical and blind on the right side. Eye migration occurs through a slit formed during separation of the dorsal fin from the cranium. This is a unique way for this species to do things; other species that are closely related do it through a hole in their head. (Evseenko, 2008).
Changes in pigmentation also occur during metamorphosis of peacock flounders. Larval melanophores (pigment cells) are found on both sides of the body, but they are not very many. These cells are found in related flatfishes as well. During metamorphosis, melanophores disappear from the blind side and are present only on the eye-side. The final pattern is determined by differentiation of adult pigment cells. (Bolker and Hill, 2005).
Sex differentiation of peacock flounders is controlled by the endocrine system. Hermaphrodites are rare. Different levels of sex steroid hormones directly affect the development of germ cells, which creates either male or female gonads and the secondary sex traits that go with them. (Devlin and Nagahama, 2002; Konstantinou, 1994).
- Development – Life Cycle
- metamorphosis
Peacock flounders have a “harem” mating system, in which one male mates with multiple females. Several females have sub-territories within a males territory. On average, one male mates with 6 females. Males are defensive of their territory and the females within their territory, denying access to other males.
Mating activities usually begin just before dusk. At this time, a male and a female approach each other with the ocular pectoral fin erect. The two fish arch their backs and touch snouts. After this, the female swims off, and the male sometimes follows her, coming up from the left side to try to get close again. The male’s pectoral fin is up at this point, and the female’s moves up and down, which could mean they want to mate. The male then positions himself underneath the female and mating begins. It starts with a mating rise, when both the female and male rise together in the water column. On average, these rises last about 15 seconds. At the highest point of this rise, which is usually about 2 m above the bottom, gametes from both fish are released at the same time, creating a cloud of sperm and eggs. When the pair comes back from the rise, the male “checks” to make sure mating went well, and then they quickly split up and swim away from each other in different directions. Not all mating rises are successful, and the process of “checking” is thus important. The exact reason why these flounders rise during mating is unknown, but it could be to help the gametes get to more places or to avoid being eaten. (Konstantinou, 1994; Miller, et al. , 1991).
- Mating System
- polygynous
Peacock flounders have extended spawning periods and participate in “serial spawning. ” Females produce eggs in large batches, and therefore many eggs are fertilized at once. A lot of different types of fish, like bothids, soles, tonguefish, and fish that live in warmer waters, use this strategy.
Spawning may be triggered by warming and cooling trends. Individuals in the mid-Atlantic travel north during spring and south during autumn to spawn.
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- Breeding interval
- Peacock flounders breed serially.
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- Breeding season
- Peacock flounders breed year-round.
Peacock flounders spawn by broadcasting, which means they lay a lot of small eggs at once. This suggests that there is no post-zygotic parental involvement. The survival rate for individual zygotes or larvae is very low. (Thresher, 1988).
- Parental Investment
- no parental involvement
- pre-fertilization
- protecting
- male
- protecting
Peacock flounders probably live about the same amount of time as other flounders that live in the same area, but not much is known about their lifespan.
Peacock flounders are solitary, motile, and live a benthic lifestyle.
Male flounders have distinct territories that do not overlap. Each male defends its own territory and exhibits defensive behavior when other males enter their claimed area. Males chase off intruders and display aggressive behavior toward other males. Females, however, do not usually display aggressive behavior. The territories of females are different from those of males. Females have smaller subunits that are marked out for them. Daytime territories are not the same as night retirement sites for members of either sex. Males go to sleep closer to shore, while females go to sleep in deeper water. They return to their daytime homes early in the morning.
When peacock flounders are threatened, they dive into the substrate. They stay hidden, partly covered in sand, until the predator or other disturbance is gone. (Konstantinou, 1994; Miller, et al. , 1991; Shulman, 1985).
Peacock flounders are one type of flatfish that can change their color. They do this to blend in with their background, which is the bottom of the ocean. This behavior is controlled through neurotransmitters, which send signals that mediate changes in the melanophores. Different colors result from different concentrations of pigment granules in different areas. These changes are always reversible. (Bolker and Hill, 2005).
- Key Behaviors
- natatorial
- diurnal
- motile
- territorial
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- Range territory size
- 20 to 360 m^2
Peacock flounders don’t have a very large home range, even though individuals spend their days and nights in different places. Male flounders live in areas that are 50 to 360 square meters in size, and females live in smaller areas within these areas that are 20 to 50 square meters in size. Although peacock flounders occasionally migrate in order to spawn, this is not typical. (Konstantinou, 1994).
Peacock flounders have a lateral line, a sense organ that detects movements and vibrations in the water. The eyes on the top of the adult body are used as visual organs. Potential mates communicate through touch, using the ocular pectoral fin. After the mating process, males perform a behavior called “checking” in order to make sure mating was successful. This is the time when living things send each other some kind of signal. It’s not clear if it’s a chemical signal (pheromonal) or a visual signal. (Konstantinou, 1994).
- Communication Channels
- visual
- tactile
- chemical
- Other Communication Modes
- vibrations
- Perception Channels
- visual
- tactile
- vibrations
- chemical
The food of larval and juvenile peacock flounders is not well documented. However, the diet of juveniles of other flounder species commonly includes drift and benthic algae. (Shulman, 1985).
- Primary Diet
- carnivore
- piscivore
- Animal Foods
- fish
- mollusks
- aquatic crustaceans
- other marine invertebrates
- Plant Foods
- algae
Predators of adult and larval peacock flounders include large fish, sharks, and rays. Adults are also preyed upon by various species of snappers, including mahogany snappers and yellowtail snappers. (Shulman, 1985).
Due to their high risk of being eaten, peacock flounders have changed in a number of ways to protect themselves. One important adaption is their ability to change color to blend in with surroundings. When they are spotted, however, they often dive into the substrate, hiding in the sand to avoid capture. Fish that spawn at dusk are less likely to be eaten while they are mating because there are fewer possible predators in the water at this time. The upward mating rise may also confuse predators. Last but not least, living in shallow water most of the time lowers your risk of being eaten by bigger fish. (Gibson, 1994; Kaufman and Ebersole, 1984; Miller, et al. , 1991).
- Anti-predator Adaptations
- cryptic
- The mahogany snapper (Kytjanus mahogoni), the yellowtail snapper (Olyurus chrysurus), the selachimorpha ray, and the batoidea are all known predators.
Peacock flounders act as prey for larger fish and as predators to smaller fish and marine invertebrates. They do not have significant parasites. (Kaufman and Ebersole, 1984; Shulman, 1985).
Trophic levels | Producer, primary consumer, secondary consumer, tertiary consumer & decomposers
FAQ
What is a secondary consumer for fish?
Are flounders primary consumers?
Is a peacock flounder an omnivore?
What is an example of a secondary consumer?
What is a peacock flounder?
The peacock flounder ( Bothus mancus ), also known as the flowery flounder, is a species of fish in the family Bothidae (lefteye flounders). The species is found widely in relatively shallow waters in the Indo-Pacific, also ranging into warmer parts of the East Pacific.
What do peacock flounder eat?
Different ages of peacock flounder face different kinds of predators. Juvenile peacock flounder face predation from shrimp, crab, and other fish. Adult flounder are prey for a variety of animals; striped bass, cod, bluefish, groupers, moray eels, stingrays, sharks, and more. The peacock flounder can live up to 10 years and breeds year-round.
Do peacock flounder mate?
Adult flounder are prey for a variety of animals; striped bass, cod, bluefish, groupers, moray eels, stingrays, sharks, and more. The peacock flounder can live up to 10 years and breeds year-round. They always mate just before sunset and the mating lasts for a quick 15 seconds, on average.
How long do peacock flounder live?
The peacock flounder can live up to 10 years and breeds year-round. They always mate just before sunset and the mating lasts for a quick 15 seconds, on average. The peacock flounder has been evaluated by the IUCN and, as of 2012, is of least concern when it comes to extinction likelihood.