# Ornamental Fish Breeding and Hatchery Management ## Key Takeaways - Broodstock selection is foundational, emphasizing disease-free individuals with desirable genetic traits from known lines to ensure higher fertilization rates and uniform offspring quality. Conditioning protocols involve maintaining specific temperature (24-28°C for tropical), photoperiod (12-14 hours), and water quality parameters (Ammonia/Nitrite < detectable), coupled with high-protein diets (40-50%) and live/frozen foods for 2-4 weeks. - Spawning methods range from natural pair spawning for most egg-layers, utilizing species-specific substrates (cones, mops, caves), to hormone induction (hCG, GnRHa) under veterinary supervision for difficult species, requiring precise dosage and administration protocols. - Egg incubation necessitates controlled conditions, with static methods for adhesive eggs (using methylene blue for fungal prevention) and flow-through systems for non-adhesive eggs, maintaining stable temperatures (within 1°C of spawning) and dissolved oxygen (>5 mg/L). - Larval rearing is critical, requiring immediate provision of appropriate live feeds (infusoria, rotifers, Artemia) within 24 hours of hatching to prevent starvation, alongside stringent water quality management (Ammonia/Nitrite < 0.1 mg/L, Nitrate < 20 mg/L) and gradual weaning to prepared diets. - Disease prevention hinges on strict quarantine protocols (2-4 weeks), disinfection of equipment, maintaining optimal water quality, and daily monitoring for early detection of common issues like Ichthyophthirius (white spots) or fungal infections, with treatment always under veterinary guidance. - Water quality management is paramount, requiring daily monitoring of key parameters (Temperature, pH, Ammonia, Nitrite, Dissolved Oxygen) and effective filtration (mechanical, biological, chemical), supplemented by regular water exchanges (10-30% daily for larvae, 10-20% weekly for broodstock). --- Ornamental fish breeding and hatchery management involves the controlled reproduction, egg incubation, larval rearing, and health maintenance of aquarium fish species for commercial or hobbyist production. This guide covers broodstock selection, spawning methods, egg incubation, larval rearing, live feed production, and disease management, drawing on established aquaculture practices from sources including the Food and Agriculture Organization (FAO) and USDA research programs. The information is intended for both hobbyists and commercial producers seeking practical, evidence-based approaches to improve hatchery outcomes. ## At a Glance | Management Area | Key Decision | Common Outcome | |-----------------|--------------|----------------| | Broodstock Selection | Choose mature, disease-free fish with desirable traits from known genetic lines | Higher fertilization rates and uniform offspring quality | | Spawning Method | Use natural pair spawning for most egg-layers, hormone induction for difficult species | Improved spawning success in captive conditions | | Larval Rearing | Provide appropriate live feed (infusoria, rotifers, Artemia) within 24 hours of hatching | Reduced early mortality and faster growth | | Disease Prevention | Maintain quarantine protocols and optimal water quality parameters | Lower incidence of bacterial and parasitic outbreaks | ## Broodstock Selection and Conditioning Broodstock selection is the foundation of a successful ornamental fish hatchery. The FAO Cultured Species database provides information on over 500 aquatic species, including many ornamental fish, and emphasizes that genetic quality and health status directly affect spawning success and fry quality. Producers should select broodstock from known sources with documented lineage to avoid inbreeding depression and maintain desirable traits such as color intensity, fin shape, and growth rate. ### Selection Criteria Select broodstock based on the following observable characteristics: - Body conformation and symmetry without deformities - Bright, uniform coloration consistent with the species standard - Active swimming behavior and feeding response - No visible signs of disease such as fin rot, white spots, or abdominal swelling - Appropriate size and age for the species (typically 6-12 months for most livebearers and egg-layers) For species with documented breeding programs, such as the Malaysian Mahseer (*Tor* sp.), research published in *Asian Fisheries Science* (2023) describes broodstock development programmes that include genetic management and reproductive conditioning. While this research focuses on a food fish species, the principles of selective breeding and broodstock conditioning apply directly to ornamental fish production. ### Conditioning Protocols Conditioning broodstock for spawning requires controlled environmental parameters and nutritional support. Maintain separate conditioning tanks with the following baseline conditions: - Temperature: 24-28°C for tropical species, adjusted per species requirements - Photoperiod: 12-14 hours of light per day to simulate breeding season - Water quality: Ammonia and nitrite below detectable levels, pH 6.5-7.5 - Feeding: High-protein diets (40-50% protein) supplemented with live or frozen foods such as bloodworms, brine shrimp, and daphnia Conditioning duration varies by species but typically ranges from 2-4 weeks. Record daily observations of feeding activity, color intensity, and behavioral changes such as courtship displays or territorial aggression. ## Spawning Methods and Systems Ornamental fish exhibit diverse spawning strategies, and hatchery design must accommodate these differences. The USDA Agricultural Research Service (ARS) Aquaculture program conducts research on reproductive technologies for aquatic species, including hormone induction and environmental manipulation. While specific protocols are not detailed here, the general approaches include natural spawning, semi-natural spawning, and hormone-induced spawning. ### Natural Spawning Systems For egg-laying species such as angelfish (*Pterophyllum scalare*), discus (*Symphysodon* spp.), and many tetras, provide spawning substrates that mimic natural conditions. Common substrates include: - Spawning cones or tiles for cichlids - Fine-leaved plants or spawning mops for egg-scatterers - PVC pipes or caves for cave-spawning species Set up breeding tanks with gentle water flow, stable temperature, and dim lighting. Introduce conditioned pairs in the evening, as many species spawn at dawn. Monitor for spawning activity within 24-48 hours. Remove adults after spawning to prevent egg predation, unless the species exhibits parental care. ### Hormone-Induced Spawning For species that do not spawn readily in captivity, hormone induction may be necessary. The FAO Animal Production and Health division provides resources on reproductive management in aquaculture, including the use of hormones under veterinary supervision. Hormone-induced spawning should only be performed by trained personnel following local regulations. Common hormones include human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone analogs (GnRHa). Dosage and administration routes vary by species and must be determined by a qualified aquatic veterinarian. ### Spawning Records Maintain detailed records for each spawning event: | Record Field | Example Entry | |--------------|---------------| | Species | *Pterophyllum scalare* | | Pair ID | Pair 3A | | Spawning date | 2024-03-15 | | Water temperature | 27.5°C | | Number of eggs | 350 | | Fertilization rate | 92% | | Hatching rate | 85% | ## Egg Incubation and Hatching Egg incubation conditions directly affect hatching success and larval quality. Most ornamental fish eggs are demersal (sinking) or adhesive and require specific water parameters and protection from fungal infection. ### Incubation Systems Use one of the following incubation methods based on egg type and species requirements: - **Static incubation**: For adhesive eggs on substrates, maintain gentle aeration and daily water changes of 10-20%. Add methylene blue at 2-3 ppm to prevent fungal growth (consult a veterinarian for approved treatments). - **Flow-through incubation**: For non-adhesive eggs, use egg incubation jars or baskets with upward water flow to keep eggs suspended. Flow rate should be sufficient to prevent settling but not so high as to damage eggs. - **Parental incubation**: For mouthbrooding species such as some cichlids, allow the female to hold eggs in her buccal cavity. Remove the female after 10-14 days when fry are free-swimming. ### Incubation Parameters Monitor and record the following parameters daily: - Temperature: Maintain within 1°C of spawning temperature - Dissolved oxygen: Above 5 mg/L - Light: Dim or dark conditions for most species - Fungal growth: Remove infected eggs immediately with a pipette Hatching time varies by species and temperature. For example, zebrafish (*Danio rerio*) eggs hatch in 48-72 hours at 28°C, while angelfish eggs hatch in 60-72 hours at 27°C. Record hatching time and calculate hatching rate as a percentage of fertilized eggs. ## Larval Rearing Larval rearing is the most critical phase in ornamental fish production. The USDA National Agricultural Library's Animal Health and Welfare resources emphasize that proper nutrition and water quality during early life stages are essential for survival and growth. Larval mortality is highest during the first week after hatching, primarily due to starvation, poor water quality, or disease. ### First Feeding Most ornamental fish larvae exhaust their yolk sac within 24-72 hours after hatching and require immediate feeding. Provide appropriately sized live feeds: - **Infusoria**: For larvae with small mouth gapes (e.g., betta, gourami, tetras). Culture infusoria by soaking hay, lettuce, or rice straw in water for 3-5 days. - **Rotifers**: For slightly larger larvae. Culture *Brachionus* spp. using commercial or homemade culture media. - **Artemia nauplii**: For most egg-laying species after 3-5 days. Hatch Artemia cysts in saltwater (25-30 ppt) at 28°C for 24 hours. Feed larvae small amounts frequently (4-6 times daily) to maintain prey density in the water column. Avoid overfeeding, which degrades water quality. ### Water Quality Management Larvae are highly sensitive to water quality fluctuations. Maintain the following parameters: - Temperature: 26-28°C for tropical species - pH: 6.5-7.5 - Ammonia: Below 0.1 mg/L - Nitrite: Below 0.1 mg/L - Nitrate: Below 20 mg/L Perform daily water changes of 10-30% using aged or treated water at the same temperature. Use gentle aeration to maintain dissolved oxygen above 5 mg/L without creating strong currents that exhaust larvae. ### Weaning to Prepared Diets Gradually wean larvae from live feeds to prepared diets starting at 10-14 days post-hatch. Begin by offering finely ground flake or powdered feed alongside live feeds. Reduce live feed proportion over 5-7 days. Monitor feeding response and growth. Some species, such as discus, require extended live feed periods and may not accept prepared diets until 4-6 weeks of age. ## Live Feed Production Reliable live feed production is essential for hatchery success. The FAO Cultured Species database includes information on feed organisms used in aquaculture, and the ARS Aquaculture program researches live feed alternatives. Establish separate culture systems for each live feed type to ensure consistent supply. ### Rotifer Culture Rotifers (*Brachionus* spp.) are a staple first feed for many marine and freshwater ornamental fish larvae. Culture rotifers in tanks or containers with the following conditions: - Salinity: 15-25 ppt for marine rotifers, freshwater strains available - Temperature: 25-28°C - Feeding: Microalgae (*Nannochloropsis*, *Chlorella*) or commercial rotifer feed - Harvest: Daily partial harvest of 20-30% of culture volume Maintain multiple culture tanks in a staggered schedule to ensure continuous production. Monitor rotifer density daily and harvest before density exceeds 200 rotifers/mL to prevent culture crash. ### Artemia Hatching Artemia (brine shrimp) nauplii are widely used for larval fish and are relatively easy to produce. Hatch Artemia cysts in conical-bottom containers with the following protocol: - Salinity: 25-30 ppt - Temperature: 28-30°C - Aeration: Strong aeration to keep cysts suspended - Light: Continuous light during hatching period - Harvest: After 24 hours, separate nauplii from cyst shells using light attraction or a separation funnel Calculate hatching efficiency as a percentage of cysts that produce nauplii. Store unhatched cysts in a cool, dry place. ### Microalgae Culture Microalgae serve as feed for rotifers and as a water quality conditioner in larval tanks. Culture *Nannochloropsis* or *Chlorella* in sterile containers with artificial seawater or freshwater media. Provide continuous light and aeration. Harvest algae at peak density (typically 5-7 days) and use immediately or refrigerate for short-term storage. ## Disease Management Disease outbreaks can devastate hatchery production. The USDA National Agricultural Library's Animal Health and Welfare resources provide guidance on biosecurity and disease prevention in aquaculture. The FAO Animal Production and Health division also addresses aquatic animal health management. ### Prevention Strategies Implement the following biosecurity measures: - Quarantine all new fish for 2-4 weeks before introducing to broodstock or production systems - Disinfect equipment, nets, and containers between uses - Maintain separate tools for each tank or system - Control access to hatchery areas - Monitor water quality daily and correct deviations immediately ### Common Diseases | Disease | Signs | Management | |---------|-------|------------| | Ichthyophthirius (Ich) | White spots on body and fins | Increase temperature gradually to 30°C, consult veterinarian for treatment | | Fin rot | Frayed, discolored fins | Improve water quality, isolate affected fish | | Fungal infections | Cotton-like growth on eggs or fish | Remove infected material, improve water flow | | Bacterial infections | Red spots, ulcers, abdominal swelling | Isolate affected fish, consult veterinarian | ### Treatment Considerations When disease is suspected, first isolate affected fish and improve water quality. Do not administer medications without a confirmed diagnosis and veterinary guidance. Many treatments are toxic to eggs and larvae at standard doses. Record all disease incidents, treatments, and outcomes for future reference. ## Water Quality Management Water quality is the single most important factor in hatchery success. The ARS Aquaculture program conducts research on water quality management in recirculating systems, which are commonly used in ornamental fish hatcheries. ### Key Parameters Monitor the following parameters at least daily: - Temperature: Use calibrated thermometers or digital probes - pH: Test daily, maintain stability within 0.2 units - Ammonia: Test daily, keep below 0.1 mg/L - Nitrite: Test daily, keep below 0.1 mg/L - Nitrate: Test weekly, keep below 50 mg/L - Dissolved oxygen: Maintain above 5 mg/L - Alkalinity: Test weekly, maintain 50-150 mg/L as CaCO3 ### Filtration Systems Use mechanical, biological, and chemical filtration to maintain water quality: - Mechanical filtration: Remove solid waste using sponge filters, bead filters, or settling tanks - Biological filtration: Provide surface area for nitrifying bacteria using bio-balls, ceramic rings, or fluidized bed filters - Chemical filtration: Use activated carbon to remove dissolved organic compounds, replace monthly ### Water Exchange Perform regular water exchanges to remove accumulated waste and replenish minerals. Exchange 10-30% of system volume daily for intensive larval rearing systems. For broodstock and grow-out systems, exchange 10-20% weekly. Use aged or dechlorinated water at the same temperature as the system. ## Hatchery Records and [Data Management](/blog/guides/data-management-basics-principles-processes-and-best-practices) Systematic record-keeping enables producers to identify trends, troubleshoot problems, and improve production efficiency. The FAO Cultured Species database and ARS research programs emphasize the importance of data collection in aquaculture management. ### Essential Records Maintain the following records for each production cycle: - Broodstock inventory and spawning history - Egg production and hatching rates - Larval survival and growth rates - Feed consumption and conversion ratios - Water quality parameters - Disease incidents and treatments - Sales and inventory data ### Record Format Use standardized forms or digital spreadsheets for consistency. Record data daily and review weekly for trends. Example record format for larval rearing: | Day Post-Hatch | Survival (%) | Average Length (mm) | Feed Type | Water Temperature (°C) | Notes | |----------------|--------------|---------------------|-----------|------------------------|-------| | 1 | 100 | 3.2 | Yolk sac | 27.5 | All larvae hatched | | 3 | 95 | 3.8 | Infusoria | 27.3 | First feeding observed | | 7 | 88 | 4.5 | Rotifers | 27.6 | Good feeding response | | 14 | 82 | 6.1 | Artemia | 27.4 | Weaning to prepared feed | ## Common Failure Patterns Understanding common failure patterns helps producers anticipate and prevent problems. The following patterns are observed in ornamental fish hatcheries: ### Low Fertilization Rates Low fertilization rates (below 50%) may result from poor broodstock condition, improper gamete handling, or environmental stress. Check broodstock nutrition, water temperature, and spawning behavior. For species that require manual stripping, ensure gametes are mixed within 30 seconds of collection. ### High Larval Mortality High mortality during the first week post-hatch is often due to starvation or poor water quality. Confirm that appropriate live feed is available within 24 hours of hatching. Test water quality parameters and increase water exchange if ammonia or nitrite is elevated. ### Fungal Infections on Eggs Fungal infections on eggs indicate poor water quality or damaged eggs. Remove infected eggs immediately and improve water flow around eggs. Consider prophylactic treatment with approved antifungal agents under veterinary guidance. ### Cannibalism Cannibalism among larvae and fry is common in some species, particularly cichlids and catfish. Grade fish by size regularly and separate larger individuals. Provide adequate feeding frequency and density to reduce aggression. ## Limitations and Professional Escalation Hatchery management has inherent limitations that producers must recognize. Not all species reproduce readily in captivity, and some require specialized facilities or expertise beyond the scope of a small-scale operation. ### When to Seek Professional Help Escalate to a qualified aquatic veterinarian or aquaculture extension specialist in the following situations: - Persistent disease outbreaks despite biosecurity measures - Unexplained mortality exceeding 20% in any life stage - Suspected genetic problems such as high deformity rates - Need for hormone induction or advanced reproductive technologies - Regulatory compliance issues related to water discharge or species permits ### Regulatory Considerations Check local regulations regarding the culture and sale of ornamental fish species. Some species may be restricted or require permits. The FAO provides resources on aquaculture regulations and best practices through its Animal Production and Health division. ## Spawning Induction Decision Framework: Environmental vs Hormonal Methods Selecting the appropriate spawning induction method directly affects hatchery efficiency, broodstock health, and offspring quality. Ornamental fish species vary widely in their reproductive responsiveness to environmental manipulation versus hormonal intervention. The FAO Cultured Species database documents that many ornamental species spawn naturally when provided with optimal environmental cues, while others require hormonal assistance due to captive adaptation challenges. The USDA Agricultural Research Service (ARS) Aquaculture program investigates reproductive technologies that help producers match induction methods to species-specific requirements. This section provides a practical decision framework for choosing between environmental and hormonal spawning induction, including a record system for tracking induction success and troubleshooting protocols for common failures. ### Decision Criteria for Induction Method Selection The primary decision point is whether the target species has a documented history of natural spawning in captivity. For species such as guppies (*Poecilia reticulata*), mollies (*Poecilia* spp.), and many tetras, environmental manipulation alone typically achieves reliable spawning. For species with poor captive spawning records, including some cichlids, catfish, and marine ornamentals, hormonal induction may be necessary. The research published in *Advances in Marine and Brackishwater Aquaculture* (2015) describes reproductive challenges in marine ornamental species that often require hormonal intervention. Use the following criteria to select the appropriate method: **Environmental induction is appropriate when:** - The species has been bred in captivity for multiple generations - Broodstock are in good condition with visible secondary sexual characteristics - Water temperature, photoperiod, and spawning substrate can be precisely controlled - The producer has at least 6-8 weeks for conditioning and observation **Hormonal induction is appropriate when:** - The species has no documented captive spawning history - Broodstock show no spawning behavior after 4 weeks of environmental conditioning - The producer has access to a qualified aquatic veterinarian - Local regulations permit hormone use in ornamental fish production ### Environmental Induction Protocol Environmental induction relies on mimicking natural spawning triggers. The FAO Animal Production and Health division provides resources on environmental management for aquaculture reproduction. Implement the following stepwise protocol: 1. **Temperature manipulation**: Gradually increase water temperature by 1-2°C per day over 3-5 days to simulate seasonal warming. For tropical species, raise temperature from 24°C to 28°C. Monitor broodstock behavior for courtship displays. 2. **Photoperiod adjustment**: Extend daylight hours to 14-16 hours per day using timers. Use gradual transitions between light and dark periods to avoid stress. Some species respond to simulated dawn and dusk periods. 3. **Water change stimulation**: Perform a 30-50% water change with slightly cooler water (1-2°C below tank temperature). This mimics rainfall and triggers spawning in many characins and cyprinids. 4. **Substrate introduction**: Add spawning substrates such as spawning mops, cones, or plants 24-48 hours after temperature and water change cues. Observe for egg deposition within 72 hours. 5. **Record outcomes**: Document whether spawning occurred, the latency period, egg quantity, and fertilization rate. If no spawning occurs within 7 days, repeat the protocol once before considering hormonal induction. ### Hormonal Induction Protocol Hormonal induction requires veterinary oversight and adherence to local regulations. The Research and Innovation in Malaysian Mahseer, *Tor* sp., Broodstock Development Programme published in *Asian Fisheries Science* (2023) describes hormone administration protocols that can be adapted for ornamental species. While specific dosages are not provided here, the general protocol includes: 1. **Veterinary consultation**: Obtain a prescription and administration protocol from a qualified aquatic veterinarian. Provide the veterinarian with species, broodstock weight, and conditioning history. 2. **Hormone preparation**: Prepare hormones according to veterinary instructions. Common hormones include human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone analogs (GnRHa). Store hormones at recommended temperatures. 3. **Administration**: Inject hormones intramuscularly or intraperitoneally as directed. Record injection time, dose, and broodstock identification. Observe for spawning within 12-48 hours depending on the hormone and species. 4. **Post-spawning care**: Remove broodstock from spawning tanks after egg deposition. Monitor for stress or injury. Provide clean water and reduced feeding for 24-48 hours. 5. **Record outcomes**: Document spawning success, egg quality, fertilization rate, and any adverse effects on broodstock. Report outcomes to the veterinarian for future protocol adjustments. ### Induction Success Record System Maintain a standardized record for each induction attempt to identify effective protocols and troubleshoot failures. Use the following record format: | Record Field | Example Entry | |--------------|---------------| | Species | *Symphysodon aequifasciatus* | | Pair ID | Discus Pair 7B | | Induction method | Environmental | | Conditioning duration | 4 weeks | | Temperature range | 26-28°C | | Photoperiod | 14 hours light | | Water change trigger | 40% change, 1°C drop | | Spawning latency | 48 hours | | Eggs produced | 200 | | Fertilization rate | 85% | | Hatching rate | 78% | | Notes | Pair spawned on spawning cone | For hormonal induction records, add fields for hormone type, dose, administration route, and veterinarian contact information. ### Troubleshooting Induction Failures When induction fails, systematically evaluate potential causes using the following troubleshooting guide: **No spawning after environmental induction:** - Check water quality parameters: ammonia, nitrite, nitrate, pH, and dissolved oxygen - Verify photoperiod accuracy and light intensity - Assess broodstock condition: are fish showing courtship behavior or secondary sexual characteristics? - Consider species-specific requirements: some fish require specific substrate types or water hardness - Extend conditioning period by 2-4 weeks before repeating induction **No spawning after hormonal induction:** - Confirm hormone storage and handling followed veterinary instructions - Verify injection technique and dose accuracy - Check broodstock weight against dose calculation - Assess broodstock health: stressed or diseased fish may not respond - Consult veterinarian for protocol adjustment or alternative hormones **Low fertilization rates (below 50%):** - Evaluate broodstock nutrition: increase protein and fatty acid content in diet - Check gamete quality: males may require additional conditioning - Verify water temperature and quality during spawning - For manually stripped species, ensure gametes are mixed within 30 seconds **High egg mortality or fungal infection:** - Improve water flow around eggs - Remove dead or infected eggs immediately - Consult veterinarian for approved antifungal treatments - Reduce egg density in incubation systems ### Limitations and Professional Escalation Environmental induction has limitations for species that require precise hormonal triggers or have complex reproductive behaviors. Hormonal induction carries risks of broodstock stress, injury from handling, and potential reduced offspring quality if protocols are not followed correctly. The USDA National Agricultural Library's Animal Health and Welfare resources emphasize that any hormone use should be under veterinary supervision to ensure animal welfare and regulatory compliance. Escalate to a qualified aquatic veterinarian or aquaculture extension specialist in the following situations: - Repeated induction failures (three or more attempts) with the same species - Broodstock mortality or injury during handling or injection - Suspected hormonal overdose or adverse reactions - Need for species-specific protocols not available in published literature - Regulatory questions about hormone use or species permits The FAO provides additional resources on reproductive management through its Animal Production and Health division, and the ARS Aquaculture program offers research updates on emerging reproductive technologies. Producers should consult these sources and local experts when developing induction protocols for new or challenging species. ## Frequently Asked Questions ### What is the most important factor for successful ornamental fish breeding? Water quality is the most critical factor. Maintaining stable temperature, low ammonia and nitrite, and adequate dissolved oxygen supports healthy broodstock, egg development, and larval survival. Monitor water parameters daily and correct deviations immediately. ### How do I select good broodstock for my hatchery? Select broodstock based on body conformation, color intensity, active behavior, and absence of disease. Choose fish from known genetic lines to avoid inbreeding. Condition broodstock with high-protein diets and appropriate environmental parameters for 2-4 weeks before spawning. ### What live feeds do I need for ornamental fish larvae? The required live feeds depend on larval mouth size. Infusoria or rotifers are suitable for small-mouthed larvae. Artemia nauplii are appropriate for most species after 3-5 days. Establish separate culture systems for each feed type to ensure consistent supply. ### How do I prevent fungal infections on fish eggs? Maintain good water quality and water flow around eggs. Remove infected eggs immediately with a pipette. Consult a veterinarian for approved antifungal treatments. Avoid overcrowding eggs in incubation systems. ### When should I wean larvae from live feeds to prepared diets? Begin weaning at 10-14 days post-hatch for most species. Offer finely ground prepared feed alongside live feeds and gradually reduce live feed proportion over 5-7 days. Monitor feeding response and growth during the transition. ### How often should I change water in larval rearing tanks? Perform daily water changes of 10-30% for intensive larval rearing systems. Use aged or treated water at the same temperature as the system. Increase water exchange if ammonia or nitrite levels rise above 0.1 mg/L. ### What records should I keep in my hatchery? Maintain records of broodstock inventory, spawning events, egg production and hatching rates, larval survival and growth, feed consumption, water quality parameters, disease incidents, and sales data. Review records weekly to identify trends and problems. ### When should I consult a veterinarian for my hatchery? Consult a veterinarian for persistent disease outbreaks, unexplained mortality exceeding 20%, suspected genetic problems, or when considering hormone-induced spawning. A veterinarian can provide diagnosis, treatment recommendations, and guidance on regulatory compliance. ## Related Farming Guides - [Lentivirus Production](/blog/guides/plaque-assays-planning-controls-and-reporting-viral-titer) - [Poultry Hatchery Management Incubation Sanitation And Chick Quality](/knowledge/animal-farming/poultry/poultry-hatchery-management-incubation-sanitation-and-chick-quality) - [Aquaponics Fish Health And System Management](/knowledge/animal-farming/aquaculture/aquaponics-fish-health-and-system-management) - [Pullet Rearing Management For Laying Hens](/knowledge/animal-farming/poultry/pullet-rearing-management-for-laying-hens) - [Freshwater Prawn Farming Stocking Shelter Feeding And Harvest Management](/knowledge/animal-farming/aquaculture/freshwater-prawn-farming-stocking-shelter-feeding-and-harvest-management) ## Related Clinical & Scientific Guides * [Pond Sediment Management and Dredging Options](/knowledge/animal-farming/aquaculture/pond-sediment-management-dredging-options) * [Indoor Aquaculture Facilities: Lighting and Insulation](/knowledge/animal-farming/aquaculture/indoor-aquaculture-facilities-lighting-insulation) * [Greenhouse Aquaculture: Extending Growing Seasons](/knowledge/animal-farming/aquaculture/greenhouse-aquaculture-extending-growing-seasons) ## References and Further Reading - [www.fao.org](https://www.fao.org/fishery/en/culturedspecies) - [www.ars.usda.gov](https://www.ars.usda.gov/animal-production-and-protection/aquaculture) - [FAO Animal Production and Health](https://www.fao.org/animal-production/en). Food and Agriculture Organization of the United Nations. - [Animal Health and Welfare](https://www.nal.usda.gov/animal-health-and-welfare). USDA National Agricultural Library. - [Research and Innovation in Malaysian Mahseer, Tor sp., Broodstock Development Programme](https://doi.org/10.33997/j.afs.2023.36.4.004). Asian Fisheries Science, 2023. - [Advances in marine and brackishwater aquaculture](https://doi.org/10.1007/978-81-322-2271-2). Advances in Marine and Brackishwater Aquaculture, 2015. > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.