Coral Reef Fish: Species Selection and Compatibility for Marine Aquariums

Selecting fish for a coral reef aquarium requires matching species to the specific conditions of the tank, the coral inhabitants, and the behavioral needs of each fish. This article provides a practical framework for choosing reef-compatible fish species based on diet, temperament, and reef safety, with attention to the ecological roles these fish perform in natural systems. The guidance applies to home aquarists, veterinary students, veterinary technicians, and veterinary professionals who advise on marine aquarium husbandry.

Reef aquariums present a unique challenge because the fish and the corals must coexist in a closed system. In natural reefs, fish and coral communities shape each other through complex interactions. Corals create the structural complexity that provides habitat and food for many fish species, while fish populations influence coral health through grazing, nutrient cycling, and predation [3]. Understanding these natural relationships helps aquarists make informed stocking decisions that support both fish welfare and coral health.

At a Glance: Reef-Safe Fish Selection Criteria

The following table summarizes the primary factors to evaluate when selecting fish for a coral reef aquarium. Each factor requires observation of the individual fish and knowledge of the species' natural history.

Understanding Natural Reef Fish Communities

Ecological Roles of Reef Fish

Reef fish perform distinct functional roles that maintain ecosystem balance. Herbivorous fish control algal growth, which supports coral recruitment and survival. Research across reefs in the Dominican Republic demonstrated that herbivory rates are best predicted by both herbivore biomass and herbivore species richness, and higher herbivory rates were linked to reduced algal turf height and enhanced juvenile coral recruitment [8]. In an aquarium, herbivorous fish such as tangs and surgeonfish serve the same functional purpose by controlling nuisance algae.

Predation is another critical ecological process. Small predators dominate fish predation on coral reefs, with the average fish predator measuring just 3.65 cm and the average prey just 1.5 cm [4]. This finding has practical implications for aquarium stocking because small predatory fish, such as dottybacks and small wrasses, can prey on tiny tank inhabitants including ornamental shrimp and small gobies. Aquarists should not assume that small fish are automatically safe with small invertebrates.

Depth and Habitat Preferences

Reef fish communities change with depth, and these patterns influence which species adapt well to aquarium conditions. Research on reef fish assemblages along depth gradients found that species richness and functional diversity decrease with depth, and deeper reef communities are less influenced by regional factors than shallower reefs [5]. Shallow-water species are generally more adaptable to aquarium conditions because they naturally experience greater environmental variability. Deep-water species may require cooler temperatures, lower light, and different water chemistry than typical reef aquariums provide.

Coral-Fish Interactions

The relationship between corals and fish is bidirectional. Coral species composition strongly affects the diversity and structure of reef fish communities [22]. Some fish species depend on specific corals for shelter, spawning sites, or feeding territories. When selecting fish for a reef aquarium, consider whether the coral species present will support the fish species being considered. For example, clownfish species have specific host anemone preferences, and some damselfish species establish territories within particular branching corals.

Coral restoration research highlights that adding live coral cover and complexity can enhance fish assemblages [3]. In an aquarium, providing adequate live rock structure and healthy coral growth creates the habitat complexity that allows multiple fish species to establish territories and reduces aggression.

Core Principles of Reef-Safe Fish Selection

Defining Reef Safety

Reef safety means the fish will not consume, damage, or stress the corals and other sessile invertebrates in the aquarium. Some fish species are obligate coral predators and must never be housed with live corals. Others may occasionally nip at polyps or mucus layers without consuming coral tissue. Still others are completely safe because their natural diets consist of plankton, algae, or detritus.

The concept of reef safety extends beyond direct coral consumption. Fish that produce excessive waste can degrade water quality and harm corals through elevated nutrient levels. Fish that are highly active or territorial can physically damage corals through constant contact. Fish that stir up sediment can smother low-growing polyps. Each of these behaviors must be considered when evaluating a species for a reef aquarium.

Diet and Feeding Behavior

Diet is the most reliable predictor of reef safety. Herbivorous fish that graze on algae are generally safe for corals, though some species may inadvertently consume small polyps while grazing. Planktivores that feed on suspended particles do not threaten corals. Carnivores that prey on small fish and invertebrates may be safe for corals but dangerous for ornamental shrimp, crabs, and small fish.

Some fish species have specialized feeding behaviors that create risk. Parrotfish scrape algae from surfaces and can damage coral skeletons while feeding. Butterflyfish species vary widely in their diets, with some being obligate coral polyp feeders and others being safe planktivores. Angelfish species are often considered risky because many species graze on sponge and may nip at coral polyps, particularly large-polyp stony corals and soft corals.

Temperament and Aggression

Temperament determines whether a fish will coexist peacefully with tank mates. Aggression in reef fish serves territorial and social functions. Some species are highly territorial and will attack conspecifics or fish with similar body shapes. Others are peaceful community fish that ignore tank mates.

Research on interspecific aggression in coral reef fish demonstrates that aggressive behavior is regulated by complex physiological mechanisms that vary by species [10]. This finding underscores the importance of observing individual fish behavior instead of relying solely on species-level generalizations. Two fish of the same species may display different aggression levels depending on individual temperament, tank size, and social context.

Social Structure and Grouping

Many reef fish species have specific social requirements. Some species must be kept singly, while others thrive in pairs or groups. Anthias species are naturally found in large schools and require groups in aquariums. Clownfish form pair bonds and may become aggressive toward other clownfish. Many damselfish species are solitary and territorial.

Understanding the natural social structure of a species prevents common stocking errors. Adding a single fish from a schooling species can cause chronic stress and disease susceptibility. Adding multiple fish from a territorial species can trigger lethal aggression. Research the social requirements of each species before purchase.

Practical Workflow for Stocking a Reef Aquarium

Step 1: Define Tank Parameters

Measure and record the aquarium volume, dimensions, filtration capacity, lighting intensity, and current water parameters. These factors determine which fish species can be supported. A small tank of 100 liters cannot support large swimming species such as tangs or angelfish. A tank with intense lighting may support photosynthetic corals but may stress fish species that prefer shaded habitats.

Record the following baseline parameters before adding fish:

Step 2: Inventory Existing Livestock

Document all current fish, corals, and invertebrates in the aquarium. Note the size, age, and observed behavior of each fish. This inventory serves as the baseline for compatibility decisions. A fish that has been established in the aquarium for years may be more territorial than a newly introduced fish of the same species.

Step 3: Research Candidate Species

For each candidate species, gather information on adult size, diet, temperament, social structure, reef safety, and water quality requirements. Use multiple sources including field guides, scientific literature, and experienced aquarists. The marine aquarium trade includes hundreds of species, and vulnerability to overharvesting varies significantly among them [16]. Choose species that are known to be sustainably collected when possible.

Step 4: Evaluate Compatibility

Compare the candidate species against the existing livestock inventory. Consider the following compatibility questions:

• Does the candidate species require the same water temperature and chemistry as the existing livestock?
• Will the candidate species compete with existing fish for food or territory?
• Is the candidate species large enough to prey on existing fish or invertebrates?
• Will existing fish view the candidate species as a threat or competitor?
• Does the candidate species have any known negative interactions with corals or invertebrates?

Step 5: Establish Quarantine Protocol

All new fish should be quarantined before introduction to the display aquarium. Quarantine prevents the introduction of pathogens that can devastate an established reef system. Non-tuberculous mycobacteria, including Mycobacterium marinum, are important pathogens in aquarium fish and can affect both fish and humans [19]. A quarantine period of four to six weeks allows observation for clinical signs of disease before the fish enters the display system.

Step 6: Introduce Fish Gradually

Add fish to the display aquarium one at a time, with observation periods between introductions. This approach allows the existing fish to establish a social hierarchy without the stress of multiple new arrivals. Introduce peaceful species first and territorial species last. Observe feeding behavior and interactions for at least one week before adding the next fish.

Step 7: Monitor and Adjust

After each introduction, monitor water quality daily and observe fish behavior for signs of stress or aggression. Be prepared to remove a fish that is being severely harassed or that is causing damage to corals. Have a plan for rehoming fish that prove incompatible.

Species Selection by Category

Herbivorous Fish

Herbivorous fish are generally excellent choices for reef aquariums because they control algae growth and do not consume corals. Tangs and surgeonfish are popular herbivores that require substantial swimming space. Rabbitfish are hardy herbivores that can be kept in smaller systems. Blennies and some gobies graze on algae and are suitable for nano reefs.

Research on herbivory in natural reefs shows that multiple grazer species are necessary to maximize the process of herbivory [8]. In an aquarium, keeping a mix of herbivorous species with different grazing strategies can provide more effective algae control than a single species. For example, a tang that grazes on macroalgae and a blenny that grazes on microalgae can complement each other.

Herbivorous fish require regular feeding of plant-based foods to supplement their natural grazing. Provide nori, spirulina-based flakes, and fresh vegetables. Without adequate plant matter in the diet, herbivorous fish may develop nutritional deficiencies.

Planktivorous Fish

Planktivorous fish feed on suspended particles and are generally safe for corals. Anthias, chromis, and some wrasses are planktivores that add color and activity to reef aquariums. These fish require frequent small feedings of appropriately sized foods.

Many planktivorous species are schooling fish that require groups. Anthias species should be kept in groups of five or more, with one male and multiple females. Chromis species also school and should be kept in groups. Keeping a single fish from a schooling species can cause chronic stress.

Omnivorous Fish

Omnivorous fish consume both plant and animal matter. Many popular reef fish fall into this category, including clownfish, damsels, and some gobies. Omnivores are generally adaptable to aquarium conditions and accept a variety of prepared foods.

Reef safety varies among omnivorous species. Some omnivores may nip at coral polyps or consume small invertebrates. Observe individual fish behavior and be prepared to remove fish that damage corals.

Carnivorous Fish

Carnivorous fish require animal-based protein in their diets. Some carnivores are reef-safe because they prey only on small fish and invertebrates that are not part of the aquarium community. Others are dangerous to ornamental shrimp, crabs, and small fish.

Lionfish and groupers are carnivores that may be kept in fish-only systems but are not appropriate for reef aquariums with small fish or invertebrates. Hawkfish are carnivores that may prey on small shrimp but are generally safe with corals. Wrasses vary widely in their diets, with some species being safe planktivores and others being predators of small invertebrates.

Fish to Avoid in Reef Aquariums

Certain fish species are known to be incompatible with coral reef aquariums. These include:

• Butterflyfish species that are obligate coral polyp feeders
• Large angelfish species that graze on coral polyps and sponge
• Parrotfish that scrape coral skeletons while feeding
• Triggerfish species that crush corals and invertebrates
• Pufferfish that may nip at corals and invertebrates
• Moorish idols that require specialized diets and are difficult to keep

Research from natural reef systems shows that some fish species can inhibit coral restoration efforts through their feeding behaviors [3]. The same principle applies in aquariums, where certain fish species can damage or destroy corals.

Compatibility Chart for Common Reef Fish

The following table provides compatibility guidance for commonly available reef fish species. This chart represents general patterns and individual fish may vary.

Water Quality Management for Reef Fish

Temperature and Salinity

Reef fish are adapted to stable tropical water conditions. Most reef aquariums are maintained at 24 to 27 degrees Celsius with a specific gravity of 1.023 to 1.026. Temperature fluctuations stress fish and increase disease susceptibility. Use a reliable heater with a thermostat and monitor temperature daily.

Salinity should be measured with a refractometer or hydrometer and adjusted slowly. Rapid salinity changes can cause osmotic stress and death. When performing water changes, match the salinity of the new water to the aquarium water.

Nitrogen Cycle and Waste Management

Fish produce ammonia through gill excretion and waste breakdown. In a properly cycled aquarium, beneficial bacteria convert ammonia to nitrite and then to nitrate. Elevated ammonia or nitrite levels are toxic to fish and require immediate intervention.

Nitrate levels should be maintained below 20 parts per million for most reef fish. Regular water changes, protein skimming, and biological filtration help control nitrate. Some fish species are more sensitive to elevated nitrate than others, and chronic exposure can cause poor appetite, faded coloration, and increased disease susceptibility.

Dissolved Oxygen

Reef fish require adequate dissolved oxygen for respiration. Surface agitation, protein skimmers, and water movement from powerheads provide oxygenation. Overcrowding, high water temperature, and organic waste accumulation can deplete dissolved oxygen. Signs of low oxygen include fish gasping at the surface, rapid gill movement, and lethargy.

Alkalinity and Calcium

While alkalinity and calcium are primarily managed for coral health, they also affect fish welfare. Stable alkalinity between 8 and 12 dKH and calcium between 380 and 450 parts per million support both coral growth and fish health. Rapid fluctuations in these parameters can stress fish.

Feeding Protocols for Reef Fish

Feeding Frequency and Portion Size

Most reef fish benefit from two to three small feedings per day instead of one large feeding. Small frequent feedings more closely mimic natural foraging behavior and reduce waste. Feed only what the fish consume within two to three minutes per feeding.

Planktivorous fish require more frequent feedings because their natural diet consists of continuously available suspended particles. In an aquarium, these fish may need four or more feedings per day to maintain condition.

Food Types

Provide a varied diet that meets the nutritional needs of each species. High-quality flake and pellet foods serve as staples for most omnivorous and herbivorous fish. Frozen foods such as mysis shrimp, brine shrimp, and cyclops provide protein for carnivorous and omnivorous species. Nori and other seaweed products are essential for herbivorous fish.

Live foods such as copepods and amphipods are necessary for some species. Mandarin fish and some dragonets feed exclusively on small crustaceans and require an established population of live pods in the aquarium. Without adequate live food, these fish will starve even when prepared foods are offered.

Nutritional Considerations

Herbivorous fish require plant-based foods with adequate fiber. Carnivorous fish require high-protein foods. Omnivorous fish benefit from a mix of plant and animal matter. Vitamin and mineral supplementation may be beneficial, particularly for fish that are eating prepared foods exclusively.

Observe each fish during feeding to ensure it is consuming adequate food. Fish that are not eating may be stressed, ill, or competing unsuccessfully for food. Address feeding problems promptly to prevent weight loss and nutritional deficiencies.

Disease Prevention and Management

Quarantine Protocols

Quarantine is the most important disease prevention measure for reef aquariums. All new fish should be quarantined in a separate system for four to six weeks before introduction to the display aquarium. During quarantine, observe fish for clinical signs of disease including:

• White spots or patches on the body or fins
• Rapid gill movement or gasping at the surface
• Clamped fins or lethargy
• Loss of appetite
• Abnormal swimming behavior
• Visible parasites or lesions

Non-tuberculous mycobacteria are important pathogens in aquarium fish and can cause chronic progressive disease [19]. Mycobacterium marinum is the most common species isolated from ornamental fish and is potentially dangerous for both fish and humans [19]. Fish infected with mycobacteria may show weight loss, skin lesions, and fin erosion. Because mycobacterial infections are difficult to treat, prevention through quarantine and good husbandry is essential.

Common Diseases in Reef Fish

Marine ich, caused by Cryptocaryon irritans, is one of the most common diseases in reef aquariums. Clinical signs include white spots on the body and fins, flashing or rubbing against surfaces, and respiratory distress. Marine velvet, caused by Amyloodinium ocellatum, produces a fine gold or velvet-like coating on the skin and is often fatal if untreated.

Brooklynella is a protozoan infection that causes excessive mucus production, respiratory distress, and skin lesions. Uronema is another protozoan that causes tissue destruction and is often secondary to stress or injury. Bacterial infections can cause fin rot, ulcers, and systemic disease.

Treatment Considerations

Treatment of fish diseases in a reef aquarium is complicated by the presence of corals and invertebrates. Many medications are toxic to invertebrates and cannot be used in the display aquarium. Treatment should be performed in a quarantine system whenever possible.

Veterinary consultation is recommended for fish that do not respond to basic supportive care or that show signs of systemic disease. A veterinarian can perform diagnostic testing, prescribe appropriate medications, and guide treatment. Do not administer medications without a confirmed diagnosis and veterinary guidance.

Welfare Considerations for Reef Fish

Sourcing and Sustainability

The marine aquarium trade harvests millions of live coral reef fish annually, and wild-caught fish dominate public and private aquarium markets [16]. The sustainability of this trade varies by species and collection location. Some species are collected in large numbers and may be vulnerable to overharvesting [16].

Research on the aquarium trade in Indonesia, the second-largest exporting country of marine aquarium fish, shows that catching and selling fish for the aquarium trade represents an average of nearly 20% of gross annual income for participating fishers and provides livelihood diversity [18]. Choosing sustainably sourced fish supports these livelihoods while minimizing impacts on wild populations.

When purchasing fish, ask the retailer about the collection method and origin. Choose captive-bred fish when available. Many clownfish species, some gobies, and several other species are now bred in captivity and are generally hardier than wild-caught specimens.

Transport and Acclimation

Fish experience significant stress during collection, transport, and acclimation. Proper acclimation reduces this stress and improves survival. Float the transport bag in the aquarium to equalize temperature, then slowly add small amounts of aquarium water to the bag over 30 to 60 minutes. Do not pour transport water into the aquarium because it may contain ammonia or pathogens.

After acclimation, release the fish into the aquarium and observe for signs of stress. Dim the lights for the first few hours to reduce stress. Do not feed the fish for the first 24 hours to allow the digestive system to adjust.

Space and Environmental Enrichment

Reef fish require adequate space to swim, hide, and establish territories. Overcrowding causes chronic stress, aggression, and disease. Provide live rock structures with caves, overhangs, and crevices that allow fish to hide and establish territories. The structural complexity of the aquarium environment directly affects fish welfare.

Research on artificial reef structures shows that fish have preferences for specific reef types and that reef spacing affects fish behavior [14]. In an aquarium, providing a variety of hiding places and visual barriers reduces aggression and allows multiple species to coexist.

Handling and Capture

Minimize handling of fish whenever possible. When fish must be moved or captured, use gentle techniques that avoid damage to the skin and fins. Never use nets with rough mesh that can damage the protective mucus layer. Use containers or soft mesh nets designed for aquarium fish.

Common Failure Patterns in Reef Fish Selection

Overstocking

Adding too many fish to an aquarium causes water quality deterioration, aggression, and disease. The general guideline is one inch of adult fish length per 20 liters of water, but this guideline must be adjusted for species-specific requirements. Large swimming species require more space than small sedentary species.

Signs of overstocking include elevated nitrate and phosphate, aggressive behavior, poor appetite, and disease outbreaks. If these signs appear, reduce the fish load or increase filtration and water change frequency.

Incompatible Species Combinations

Adding fish species that are naturally antagonistic causes chronic stress and injury. Common incompatible combinations include multiple territorial species in a small tank, fish with similar body shapes that compete for territory, and predators housed with their natural prey.

Research on fish predation in coral reefs shows that small predators are abundant and that predation is a major process shaping fish communities [4]. In an aquarium, small predatory fish can eliminate ornamental shrimp, small gobies, and other vulnerable tank mates.

Inadequate Quarantine

Skipping quarantine introduces pathogens that can devastate an established aquarium. The cost of treating a disease outbreak in the display aquarium far exceeds the cost of maintaining a quarantine system. Always quarantine new fish for at least four weeks.

Improper Feeding

Feeding the wrong foods or feeding insufficient amounts causes nutritional deficiencies and starvation. Some fish species have specialized dietary requirements that cannot be met with prepared foods alone. Research the dietary needs of each species before purchase.

Ignoring Adult Size

Many juvenile fish are small and appealing, but they grow to sizes that exceed the capacity of the aquarium. A fish that is 5 centimeters at purchase may reach 30 centimeters as an adult. Research the adult size of each species and ensure the aquarium can accommodate it.

Records and Measurements

Maintaining Stocking Records

Keep detailed records of all fish in the aquarium, including species, purchase date, source, size at purchase, and observed behavior. These records help identify patterns and support veterinary diagnosis. Record any disease outbreaks, treatments, and outcomes.

Water Quality Logs

Maintain a water quality log that records all test results, water changes, and equipment maintenance. This log provides a historical record that helps identify trends and diagnose problems. Test water parameters on a regular schedule and record the results.

Observation Records

Document observations of fish behavior, appetite, and appearance. Note any changes from normal behavior, as these may be early signs of disease or stress. Photographs and video recordings can help document changes over time.

Professional Escalation Criteria

When to Consult a Veterinarian

Consult a veterinarian with fish experience when:

• A fish shows signs of systemic disease including lethargy, loss of appetite, or abnormal swimming
• A fish has visible lesions, ulcers, or growths that do not resolve with supportive care
• Multiple fish in the aquarium are affected by the same clinical signs
• A fish dies without an obvious cause
• You are considering medication and need guidance on diagnosis and treatment
• You suspect a zoonotic disease such as Mycobacterium marinum infection

When to Seek Immediate Veterinary Care

Seek immediate veterinary care when:

• A fish is gasping at the surface or showing severe respiratory distress
• A fish is unable to maintain normal swimming position
• A fish has severe external bleeding or trauma
• Multiple fish are dying rapidly
• Water quality parameters indicate a severe toxicity event

Zoonotic Disease Considerations

Several fish diseases can affect humans. Mycobacterium marinum causes skin infections in humans, typically appearing as nodules or lesions on the hands or arms [19]. People with open wounds should avoid contact with aquarium water. Wear gloves when cleaning the aquarium or handling fish. Wash hands thoroughly after aquarium maintenance.

Limitations of Current Knowledge

Individual Variation

Species-level generalizations about temperament and reef safety do not account for individual variation. Two fish of the same species may behave differently based on individual temperament, prior experience, and environmental conditions. Observe each fish individually and be prepared to adjust stocking decisions based on observed behavior.

Captive Versus Wild Behavior

Fish behavior in aquariums may differ from behavior in natural reefs. The confined space, artificial lighting, and altered social structure of an aquarium can change fish behavior. Research on natural reef fish communities provides useful context, but aquarium observations are the most reliable guide for stocking decisions.

Data Limitations in the Aquarium Trade

The marine aquarium trade is considered data-limited, and the sustainability of many species is not well understood [16]. Vulnerability assessments suggest that most traded species fall into least or moderately vulnerable categories, but some species are high priority for localized assessment and management [16]. Choose species with known sustainable sources when possible.

Evolving Research

Research on reef fish ecology continues to reveal new information about fish behavior, disease, and husbandry. Environmental DNA methods are providing new insights into reef fish diversity and distribution [21]. Stay informed about current research and be willing to adjust husbandry practices as new evidence emerges.

Frequently Asked Questions

What does reef safe mean for aquarium fish?

Reef safe means the fish will not consume, damage, or stress corals and other sessile invertebrates in the aquarium. The term also considers whether the fish will prey on ornamental shrimp, crabs, and other invertebrates. Some fish are completely reef safe, while others are safe with caution because they may occasionally nip at corals or consume small invertebrates. Research each species before purchase and observe individual fish behavior.

How many fish can I keep in my reef aquarium?

The number of fish depends on tank volume, filtration capacity, and species-specific requirements. A general guideline is one inch of adult fish length per 20 liters of water, but this must be adjusted for species that require more swimming space or that produce more waste. Overstocking causes water quality deterioration, aggression, and disease. Start with a small number of fish and add gradually while monitoring water quality and fish behavior.

Which fish are safest for a coral reef aquarium?

Peaceful herbivorous and planktivorous fish are generally the safest choices for coral reef aquariums. Clownfish, firefish gobies, royal grammas, and chromis are reliable choices for most systems. Tangs and surgeonfish are safe for corals but require large tanks. Avoid obligate coral feeders such as many butterflyfish species and large angelfish that graze on coral polyps.

Can I keep multiple tangs in the same aquarium?

Multiple tangs can be kept together in a large aquarium, but they are territorial and may fight. Tangs of different body shapes and colors are more likely to coexist than tangs of similar appearance. Introduce all tangs at the same time to prevent one fish from establishing dominance over the territory. A tank of at least 600 liters is recommended for multiple tangs.

How long should I quarantine new fish?

Quarantine new fish for four to six weeks before introduction to the display aquarium. This period allows observation for clinical signs of disease and prevents the introduction of pathogens. During quarantine, observe the fish daily for white spots, respiratory distress, appetite changes, and abnormal behavior. Do not add fish to the display aquarium until the quarantine period is complete and the fish appears healthy.

What should I do if a fish is attacking my corals?

Remove the fish from the display aquarium immediately if it is causing damage to corals. Place the fish in a quarantine system or rehome it to a fish-only aquarium. Do not attempt to train a fish to stop eating corals, as this behavior is instinctive and difficult to modify. Research the reef safety of all fish before purchase to prevent this situation.

Are captive-bred fish better than wild-caught fish?

Captive-bred fish are generally hardier and better adapted to aquarium conditions than wild-caught fish. They are less likely to carry parasites and diseases, and they adapt more quickly to prepared foods. Captive breeding also reduces pressure on wild populations. Choose captive-bred fish when available, particularly for species that are commonly bred such as clownfish and some gobies.

What are the signs of stress in reef fish?

Signs of stress in reef fish include hiding more than usual, reduced appetite, rapid gill movement, clamped fins, faded coloration, and erratic swimming. Stressed fish are more susceptible to disease and may show clinical signs of infection

Related Veterinary Guides

• Discus Fish Care: Tank Setup, Water, Diet, and Health
• Molly Fish Care Guide
• Oscar Fish Care Guide
• Platy Fish Care Guide
• Swordtail Fish Care Guide

References and Further Reading

• Merck Veterinary Manual. Merck Veterinary Manual.
• Animal Health and Welfare. World Organisation for Animal Health.
• Interactions between coral restoration and fish assemblages: implications for reef management.. Journal of fish biology, 2020.
• Small predators dominate fish predation in coral reef communities.. PLoS biology, 2022.
• Assembly rules of coral reef fish communities along the depth gradient.. Current biology : CB, 2023.
• Quantitative species-level ecology of reef fish larvae via metabarcoding.. Nature ecology & evolution, 2018.
• Fish and coral communities shape elasmobranch reef use in southern Mozambique.. Scientific reports, 2025.
• Tropical fish diversity enhances coral reef functioning across multiple scales.. Science advances, 2019.
• Coral reef fish density at a tourist destination responded rapidly to COVID-19 restrictions.. Oecologia, 2024.
• The serotonin blocker Ketanserin reduces coral reef fish Ctenochaetus striatus aggressive behaviour during between-species social interactions.. PeerJ, 2024.
• Impacts of local anthropogenic stressors outpace those of climate on coral reef collapse in the northern South China Sea.. 2026.
• &lt,i&gt,Lobosorchis labri&lt,/i&gt, n. sp. (Trematoda: Cryptogonimidae): a host switch from snappers (Lutjanidae) to wrasses (Labridae).. 2026.
• Considering ecological traits of fishes to understand microplastic ingestion across Pacific coastal fisheries.. 2026.
• Study of the Behavioral Characteristics of &lt,i&gt,Lutjanus erythropterus&lt,/i&gt, on the Basis of the Distance and Structure of Artificial Reefs.. 2025.
• A General Food Chain Model for Bioaccumulation of Ciguatoxin into Herbivorous Fish in the Pacific Ocean Suggests Few &lt,i&gt,Gambierdiscus&lt,/i&gt, Species Can Produce Poisonous Herbivores, and Even Fewer Can Produce Poisonous Higher Trophic Level Fish.. 2025.
• Evaluating Species at Risk in Data-Limited Fisheries: A Comprehensive Productivity-Susceptibility Analysis of the Most Traded Marine Aquarium Fish. bioRxiv, 2024.
• Comparative assessment of the U.S. State of Florida’s Marine Life regulations for its commercial marine aquarium fish fishery. Marine Policy, 2023.
• Catching Dory: selling aquarium fish supports coastal livelihoods in Indonesia. npj Ocean Sustainability, 2024.
• Isolation and identification of non-tuberculous mycobacteria from aquarium fish in Ilam, Iran. Journal of Clinical Tuberculosis and Other Mycobacterial Diseases, 2024.
• Abundance and diversity of reef fish species and their relationship with corals along the eastern coast of Sri Lanka. Journal of Coastal Conservation, 2024.
• Species diversity of coral reef fishes around the West Island of Sanya City, South China Sea, based on environmental DNA. Biodiversity Data Journal, 2022.
• Strong effects of coral species on the diversity and structure of reef fish communities: A multi-scale analysis. Plos One, 2018.
• THE CHARACTERISTICS OF SPECIES COMPOSITION AND SUCCESSION OF CORAL REEF FISHES IN XISHA EAST ISLAND. Acta Hydrobiologica Sinica, 2023.
• Diversity and abundance of coral reef fish species in the coastal waters of salahutu sub-district, central moluccas regency - indonesia. Ecology Environment and Conservation, 2018.

This article is educational and is not a substitute for veterinary diagnosis or treatment. Contact a veterinarian for advice about an individual animal.