Trout no longer stop at 2.5 kilos. From three kilos on they become the salmon trout — the same species, but a growth form of its own with its own model, reaching up to ten kilos and 110 centimetres. You will not buy one, though: those ten kilos are breeding work.

The salmon trout: same species, twice the length

Until now it ended at 2.5 kilos and 48 centimetres — that is table size, not what a rainbow trout reaches under good conditions. From three kilos on it therefore changes shape and model.

• Past three kilos it is a different animal. Its own model, its own body shape, up to ten kilos and 110 centimetres.
• It grows in length, not in girth. Keeping the same body shape, 110 centimetres would weigh around 30 kilos. Large trout stretch instead — and that is exactly what the new growth curve does.
• Below that, nothing changes. A 2.5-kilo trout still measures its 48 centimetres, and the transition at three kilos is seamless: no fish jumps in size when the model switches.

The male wears a kype

• Males past three kilos look different. They get their own model with the hooked lower jaw salmonids develop for spawning — the kype. In the tank, females and males are now told apart at a glance.
• Its jaw now has a real joint. The mouth used to be moved by an approximation the kype kept defeating: either it distorted as the mouth opened, or it stayed rigid while the rest of the jaw dropped. Now the lower jaw and its hook rotate around the joint while snout and skull stay put.

Those ten kilos belong to your own breeding line

• Bought fingerlings will not get there. Traded stock tops out around 3.2 kilos — just into the new growth form, and no further.
• Breeding potential now reaches the species maximum. Seeing ten kilos means building a line: five to six generations on average, carrying the two best animals of each spawn forward.
• And then it takes time. A fingerling with full potential reaches three kilos in ten days, five in twenty and eight in seven weeks — the last one and a half kilos take longer than the first eight. Premium feed is worth around 15 percent.

Large females carry more eggs

• The hard cap at 90 eggs is gone. It already applied just under three kilos, so a ten-kilo female produced exactly as much as a three-kilo one — all that breeding work counted for nothing at spawning time.
• The count now keeps rising, just more slowly. Three kilos give 90 eggs, five kilos 122, seven kilos 150 and ten kilos 185 — around 83 fry from a single spawn.

Large fish swim like large fish

• Turning circle, braking distance and tail beat now follow body length. They were set in fixed metres, which stops working at a metre of fish: it turned on the spot and wriggled at the rate of a fingerling. A large animal now visibly draws wider arcs and beats more slowly.
• Plus details that only show at this size: the fish avoid walls earlier, keep their distance from the pond bank, and no longer overlap when a tank gets crowded.

A busier main menu

• The fish now spread across the whole picture. They used to swim in a narrow band straight through the centre — in the rearmost row they did not even use a third of the screen height. The swimming space now follows what the camera actually sees at each distance.
• And there are more of them. On the larger area the old stock looked lost, so nineteen instead of twelve animals now drift through the menu and loading screen.

Odds and ends

• The large fish arrive everywhere. Harvest tub, packing table and processing show the salmon trout with its own model instead of an oversized table trout.
• Mouth and gill covers breathe in the same rhythm. They ran off two separate clocks, and surfacing for air could make the rhythm jump. Both now come from one source.