Application · Algaephyte
Bivalve hatcheries do not buy larval food in a bag. Oyster, mussel, clam and scallop larvae can only eat what is alive, small enough for the gut, and swimming in the water column around them — live microalgae, dosed continuously, at a mix that changes as the animal grows. Getting that ration right, at consistent density and purity, is most of what a hatchery does.
This page describes that ration stage by stage, and how Algaephyte — the same sensing, digital-twin and safety-gated dosing architecture we run on Spirulina — applies to producing it.
A note on scope, because we would rather be accurate than impressive: Algaephyte version one ships configured for Arthrospira platensis. Arthrospira is not a bivalve larval feed — its filaments are far too large for a first-feeding gut. What transfers to a hatchery is the platform: the sensors, the physics twin, the contamination vision, the fail-closed pumps and the telemetry. The strains below are the standard live feeds; running them is a new twin and a new vision class, which we are building toward with pilot partners.
The table below reflects typical published hatchery practice for oysters, mussels and clams, drawn from standard aquaculture hatchery manuals. These are starting points, not prescriptions: every hatchery validates locally against its species, water and batch.
| Larval stage | Typical species mix | Typical feed density | Why this mix |
|---|---|---|---|
| D-stage veliger first 24–48 h after hatching |
Isochrysis galbana (T-Iso) 50–100%, optionally blended with Pavlova lutheri | 10–50k cells/mL, renewed 1–2× daily | Smallest cells (≈3–6 µm) fit a newly feeding gut; flagellate lipids drive first growth. |
| Early umbo veliger | T-Iso ≈60% + Chaetoceros muelleri ≈40% | 20–60k cells/mL | Diatom sterols and pigments add shell and tissue growth on top of the flagellate base. |
| Late umbo / eyed veliger | Chaetoceros up to 50–70%, T-Iso for the remainder | 40–80k cells/mL | The gut now handles diatoms; energy demand peaks before metamorphosis. |
| Pediveliger / settlement | Mixed flagellate + diatom; Tetraselmis suecica sometimes added | 50–100k cells/mL | Highest ration of the cycle; a broader species mix hedges settlement success. |
| Juvenile / nursery | Mixed live cultures plus biofilm diatoms on settling surfaces | Frequent, ad libitum | Feeding matures and moves partly onto surfaces as grazing behaviour develops. |
| Broodstock conditioning | Pavlova · T-Iso · Chaetoceros ≈ 1:1:1 | ≈1–3% of dry meat weight daily | A mixed diet builds the lipid-rich gametes that set the next larval run up to succeed. |
Three constraints move the ratio as larvae grow. First, mechanics: a first-feeding veliger retains particles of a few micrometres, so the ration opens with small flagellates and only admits larger diatoms once the gut can keep them. Second, nutrition: flagellates such as T-Iso and Pavlova carry the long-chain fatty acids early tissue wants; diatoms such as Chaetoceros contribute sterols and pigments that support shell and somatic growth. Third, demand: feed density climbs toward metamorphosis, then changes character entirely when feeding moves from swimming to surfaces.
A hatchery ration is only as good as the cultures behind it. Crashes, contamination and density drift in the feed cultures are the failures that actually close hatcheries. Algaephyte's architecture attacks exactly that:
That last point is the honest boundary of this application today. T-Iso, Pavlova and Chaetoceros grow in different media, at different salinities and temperatures, with different failure modes than alkaline freshwater Arthrospira. The platform is strain-agnostic; the twins and vision models are not, and building them for hatchery strains is work in progress we expect to validate with pilot partners.
If you run a hatchery, nursery or shellfish farm and want to talk about a pilot feed-culture deployment, use the pilot access form or email service@orrbiologicals.com with your species, volumes and larval cycle. The rest of the system — the Algaephyte platform and its safety gates — is documented on the main page, and the field notes cover how we actually run cultures.