Larval Rearing Feed Schedule Example for Fish

A larval rearing feed schedule example is only useful if it accounts for the point where most batches fail: the larvae may be alive, but the available prey is either too large, too sparse, nutritionally weak, or delivered after the feeding window has passed. For marine fish larvae, feed timing, prey density, and water quality must be managed as one operating system. Feeding more does not correct a poor schedule. It often creates an ammonia problem that finishes the batch.

This practical framework is designed for small marine fish larvae with a first-prey window in the rotifer and copepod nauplius range. It is a starting protocol, not a substitute for species-specific validation. A clownfish, dottyback, wrasse, or pelagic ornamental may all require different prey sizes, light levels, enrichment profiles, and weaning dates.

What a larval feeding schedule must control

A rearing schedule has three jobs. First, it keeps suitable prey in the larval strike zone from first feeding until the larvae can reliably take larger prey. Second, it maintains prey quality through phytoplankton feeding or a defined enrichment program. Third, it prevents the system from accumulating excess feed, waste, and bacterial load faster than water exchange and filtration can remove them.

The right target is not maximum prey density. It is a stable, measurable density of correctly sized live feed. Check density at least twice daily during the highest-risk period, usually the first three to seven days after hatch. A morning count alone can be misleading when larvae clear the tank aggressively during the light cycle.

Prey size matters as much as prey count. Many newly feeding larvae cannot effectively capture standard rotifers or Artemia nauplii even when those feeds are present in large numbers. Copepod nauplii can be particularly valuable where a smaller, more natural prey item improves first-feeding response. Their movement pattern and nutritional profile can also support species that perform poorly on rotifers alone.

Larval rearing feed schedule example: hatch through weaning

The schedule below assumes larvae are held in a clean, gently aerated marine rearing tank and begin feeding one to three days after hatch. Use actual hatch and first-feeding observations to set Day 1. Do not rely solely on calendar age.

| Rearing stage | Primary live feed | Working target in tank | Feeding frequency | Primary control point |
|---|---|---:|---|---|
| Hatch to first feeding | No prey or light green water, species dependent | 0 to 1 rotifer per mL | Monitor only | Confirm yolk absorption and swim bladder development |
| Days 1-3 | Small rotifers and/or copepod nauplii | 5-10 rotifers per mL or 1-3 nauplii per mL | 3-4 additions daily | Maintain prey availability throughout the photoperiod |
| Days 4-7 | Rotifers plus copepod nauplii | 8-15 rotifers per mL; 2-5 nauplii per mL where used | 3-4 additions daily | Increase prey only if gut fullness and water quality support it |
| Days 8-14 | Larger copepod stages, enriched Artemia, selected microdiets | 0.5-2 Artemia per mL, adjusted to larval size | 2-3 additions daily | Begin gradual transition, not an abrupt feed swap |
| Weaning phase | Artemia, copepods, and microdiet | Species and size dependent | 2-4 feed events daily | Confirm dry-feed acceptance before reducing live feed |

These numbers are operational starting points, not universal prescriptions. A species with very small mouth gape may need lower-density, smaller prey more frequently. A highly visual feeder in a large tank may require a higher standing density to achieve the same encounter rate. Tank geometry, stocking density, light intensity, and circulation all change what the larvae can actually capture.

Days 0-3: protect first feeding

The first feeding period is where schedule discipline matters most. Stock live feed before the larvae begin active hunting, but do not allow the tank to become a dense, deteriorating soup of rotifers, algae, and waste. For many species, a lightly tinted water column can improve visual contrast and stabilize live-feed nutrition, provided the phytoplankton is clean and the system can handle the organic load.

Start conservatively and verify larval guts. Full, consistently colored digestive tracts are more useful than assumptions based on feed added. If larvae are hunting but guts remain empty, investigate prey size, prey distribution, light intensity, and circulation before increasing density. If larvae have full guts but mortality rises and water quality drifts, the problem may be dissolved oxygen, ammonia, bacterial pressure, or handling stress rather than nutrition.

Use multiple small additions instead of one large morning dose. This keeps prey available late in the photoperiod without creating an early spike in waste. It also gives the crew a chance to correct course after each count.

Days 4-7: build prey diversity without losing control

As larvae grow, their energy demand rises quickly. This is the window to introduce a second prey size or prey type while retaining the first feed until the cohort is visibly competent on the new item. Removing rotifers too early is a common avoidable loss. Some larvae will take Artemia or larger copepod stages before the entire batch can do so consistently.

A mixed live-feed approach often produces a more reliable transition. Small rotifers maintain access for slower-growing individuals, while copepod nauplii and early copepodites provide a more varied prey field. Where species-specific performance supports it, true single-species copepod cultures make this process easier to standardize because prey size and behavior are known rather than variable.

For operations using live copepods, purity and freshness are production variables, not marketing language. A verified culture helps maintain predictable prey size, while actively feeding animals arrive with better short-term nutritional condition than animals held in depleted carrier water. PodDrop produces isolated copepod cultures for applications where that control matters.

Days 8-14: transition carefully to larger prey and prepared diets

By the second week, many marine larvae can begin taking enriched Artemia, larger copepod stages, or an appropriately sized microdiet. The key word is begin. Live feed should overlap with the new feed long enough to prove that the cohort is eating and growing on it.

Do not judge weaning by whether a few aggressive larvae consume dry feed. Confirm broad acceptance across the tank. Watch for uniform gut fill, reduced size spread, stable daily survival, and normal swimming behavior after live-feed density is reduced. If smaller larvae fall behind, extend the overlap rather than forcing the schedule forward.

Microdiets are useful because they can reduce live-feed demand and support scalable production. They also create a different waste profile. Fine particles settle, collect in tank corners, and can drive bacterial growth if mechanical removal is inadequate. Increase siphoning and exchange capacity as dry feed becomes a larger fraction of the ration.

Measure the schedule, not just the outcome

A schedule should be recorded as a set of inputs and responses. At minimum, log feed type, prey density before and after feeding, estimated ration added, water temperature, dissolved oxygen, pH, ammonia, and daily mortality. For high-value batches, include larval size distribution, gut fullness scores, and notes on feeding behavior.

The most useful adjustment is usually a small one. If prey is disappearing by midday but water quality is stable, add a midday top-up. If prey remains high at lights-out and ammonia rises overnight, reduce the total standing density or improve removal. If growth is uneven, look first at prey size distribution and tank circulation before assuming the batch needs more total food.

Water exchange should support feeding, not erase it. Heavy exchange immediately after adding delicate live feed can reduce encounter rates and waste money. Many facilities time exchange, siphoning, and feed additions so larvae receive a clean tank and then a predictable prey field. The exact sequence depends on the system, but the sequence should be deliberate and repeatable.

A schedule is a controlled starting point

The best larval rearing programs do not chase a fixed number from a chart. They use a documented schedule, measure whether larvae are actually feeding, and make controlled adjustments before a small issue becomes a mortality event. Start with prey that fits the larvae in front of you, maintain it at a verified density, and let gut fullness, growth, and water quality determine the next move.