SOS Animal — Fish

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Fish & Aquatic Triage

A health assessment tool for your aquarium fish and axolotls.
Quickly identify emergency situations and common diseases.

90%

Of problems are water quality related

Ich

Most common aquarium disease

0/0

Target ammonia & nitrite levels

Disclaimer — This tool provides indicative guidance only. It does not replace the expertise of a veterinarian specializing in aquatic medicine or an experienced aquarist. If in doubt, consult a professional.

Fundamental advice — Before any medication, always test your water parameters (ammonia, nitrite, nitrate, pH, temperature). 90% of health problems in fish originate from poor water quality.

In case of mass die-off or abnormal behaviour in all fish: immediately perform a 50% water change (dechlorinated water, same temperature) and check your parameters.

Step 1 of 5 — Animal type

What type of fish / aquatic animal?

The type of animal helps determine the most likely diseases and appropriate treatments.

Tank size (in litres)

How long has the tank been set up?

Step 2 of 6 — History

History & Tank Treatments

The tank's history and current treatments are essential for aquatic diagnosis.

Current treatments in the tank

Tank history

Tank maintenance

Step 3 of 6 — Water parameters

Have you tested the water recently?

Water parameters are essential for diagnosing the cause of the problem.

⚠ PARAMETER ALERT: Ammonia and/or nitrite detected! This is the most common cause of fish mortality. Immediately perform a 50% water change with dechlorinated water at the same temperature. Stop feeding for 24-48 hours.

Step 4 of 6 — Number of fish affected

How many fish are affected?

The number of affected individuals helps determine whether the cause is environmental (collective) or individual.

Step 5 of 6 — Observed symptoms

What symptoms do you observe?

Check all symptoms present. The more precise you are, the better the guidance.

🏊 Behaviour

🧬 Skin / Scales

👁️ Eyes

🦞 Axolotl specific

🐟 Nutrition & Water Quality

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Daily Feeding

Essential rules for optimal nutrition

Optimal frequency: 2 times a day (morning + early evening).

Golden rule: only give the amount that the fish consumes within 5 minutes maximum. Remove excess with a fine net to preserve water quality.

A high nutritional density food allows you to properly feed the fish with small quantities, reducing waste in the water.

Feed types by species:

Flakes — surface-feeding fish (guppies, platies, neons)
Sinking granules — mid-water and bottom-dwelling fish (corydoras, loaches)
Sticks — large fish (cichlids, discus)
Tablets / wafers — bottom-feeding fish (plecos, bristlenose catfish)

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Colouration & Protein Needs

Key nutritional indicators by species

Colouration: Carotenoids in the diet maintain and enhance the natural vivid colours of fish — fading can indicate a nutritional deficiency or stress.

Protein requirements by species (aquatic nutrition research data):

Species	Recommended protein
Guppy (Poecilia reticulata)	30 – 40 %
Goldfish (Carassius auratus)	25 – 35 %
African cichlids	35 – 45 %
Barbs	30 – 40 %
Discus	45 – 50 %

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Holidays (up to 10 days)

Feeding your fish while you're away

Slow-release feeding block — dissolves slowly to release nutrients in a controlled manner.

Important: do not overfeed before departure. The holiday block is sufficient for regular feeding during your absence.

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Water Quality — Critical for Health

Parameters to monitor regularly

Essential parameters:

Freshwater pH

6.5 – 7.5

Saltwater pH

8.1 – 8.4

Tropical temperature

22 – 26 °C

Coldwater temperature

18 – 22 °C

Ammonia (NH3/NH4+)

< 0.02 mg/L

Nitrite (NO2-)

< 0.1 mg/L

Nitrate (NO3-)

< 40 mg/L

freshwater (< 20 reef)

Hardness (GH/KH)

Species-dependent

Test kits: Home water test kits allow you to measure these parameters in minutes. Tests available: pH, ammonia, nitrite, nitrate, hardness, phosphate.

Recommended monitoring: weekly for mature aquariums, daily during cycling.

🛡

Water Conditioner & Protection

Stress reduction and mucous membrane protection

A water conditioner based on protective polymers (forming a protective film on gills and skin) has been scientifically validated to reduce stress in fish during transport and water changes.

Study published in 2019 (Aquaculture, vol. 514): significant improvement in behaviour and reduction of stress markers in ornamental fish treated with a protective polymer conditioner.

Water quality and feeding: a high nutritional quality food generates less waste in the water — overfeeding is the leading cause of pollution in the aquarium.

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Welfare & Enrichment

A true companion animal

The ornamental fish is the most common pet in the United Kingdom (+60% of households in 2022). Aquatic welfare is gaining legal importance.

Environmental enrichment (decorations, plants, swimming space) is essential, and nutrition also contributes: foraging is a natural enriching behaviour.

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Scientific Studies

Reference publications in aquatic nutrition

Systematic review — Live fish transport Vanderzwalmen M et al. — Water and feed additives for live fish transport — Reviews in Aquaculture, 2019. Systematic review of welfare during transport.

Validation of protective polymer conditioner Vanderzwalmen M et al. — Effect of a water conditioner on ornamental fish behaviour during transport — Aquaculture, 2019; vol. 514. Experimental study demonstrating stress reduction.

Aquatic microbiome — Public database Publication of 50 bacterial genomes of the aquatic microbiome — open-access database for fish health research.

Doctoral thesis — Nutrition and welfare PhD project (University of the West of Scotland) — Role of diet in ornamental fish welfare. Ongoing research on the nutritional impact on welfare indicators.

📊 Scientific Resources — Fish & Aquatics

Fish Disease Image Database

CEFAS / Aquatic Health

Diagnostic images

Database of fish disease images for visual identification of common pathologies.

Access resources ↗

Ornamental Fish Disease Guide

University of Florida IFAS

Clinical guides

Comprehensive fact sheets on ornamental fish diseases: diagnosis, treatment, prevention.

Access fact sheets ↗

Axolotl Health Research

Ambystoma Genetic Stock Center

Research data

Reference centre for axolotl research: genetics, health, regeneration.

Access centre ↗

Ichthyophthirius (Ich) Research

Journal of Fish Diseases

Scientific publications

Research on the life cycle, pathogenesis, and treatment of white spot disease.

Access journal ↗

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Mass die-off?

If all your fish are dying rapidly: immediate 50% water change, stop feeding, check filtration and heater.

Useful Contacts

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Exotic Pet / Aquatic Veterinarian

Consult an exotic pet or aquatic medicine veterinarian for serious cases

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Aquarium Hobbyist Associations

Advice from fellow aquarists, forums, meetups

aquariophilie.org

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Your Specialist Pet Shop

Advice on available treatments and water testing

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Veterinary Emergencies

In case of animal emergency, a free national 24/7 hotline