Amano shrimp activity does not follow a strict clock
Amano shrimp are active in both halves of the day, and the day-versus-night question has a both-ways answer for this species. In a settled planted tank, amano shrimp graze visibly through the lit hours, picking across surfaces in the open, and they continue feeding after lights-out at a quieter pace. They are not true nocturnal specialists that freeze until dark, nor day animals that sleep all night. What changes with the light is not whether they work but how exposed they feel while doing it, and that distinction explains most of the variation owners report between tanks.
Daytime: the grazing shift you can watch
Under lights, amano shrimp do the work they are bought for. They move methodically over driftwood, rockwork and plant leaves, fanning their small claws to their mouths as they strip biofilm and soft algae, and they will queue along a particularly productive surface. Feeding time sharpens the picture: shrimp converge quickly, and a bold individual will seize food and carry it away from the scrum. Daytime is also when you can assess the group properly, counting members, spotting females carrying eggs under the tail, and noticing the pale empty shells that mark a successful moult. If your amano shrimp are invisible through the day, look for a cause: sparse planting, an aggressive or curious tankmate, or a group too small to feel secure all suppress the daytime shift.
Night: moulting cover and quieter feeding
Darkness in an amano shrimp tank is when vulnerable things happen out of sight. Moulting shrimp shed their old shell and sit soft and exposed while the new one hardens, and they overwhelmingly choose the cover of night and of dense planting to do it. Berried females move about in the evening fanning their eggs, and the whole group keeps grazing the surfaces at a lower intensity rather than resting in any sleep-like state. Shrimp have no eyelids and do not sleep as fish keepers imagine it; night activity is simply daytime work done under safer light levels. A moonlight or dim room light in the evening lets you watch this shift without startling them with a torch beam.
Light, cover and tankmates set the real pattern
The strongest influence on when your amano shrimp appear is the tank around them. Generous cover, a decent-sized group and peaceful tankmates produce shrimp that work openly all day, while a bare tank with boisterous fish pushes the same species into a mostly nocturnal pattern. Sudden light changes matter too: shrimp startle and scatter when full lighting snaps on in a dark room, and a gradual ramp, or feeding after the lights have been on a while, keeps the group calm and visible. Note your own tank's rhythm over a week rather than assuming a species rule, because stocking and planting rewrite the schedule more than instinct does.
Activity changes worth investigating
An amano shrimp group that abruptly stops its daytime grazing, clusters near the surface or the filter outflow, or attempts to leave the water is not having a quiet day; clustering high in the tank can point to low oxygen, and restlessness after a water change or a new plant addition can point to a contaminant. A single shrimp missing for a day or two is usually a moult, but a group-wide shutdown is a water test waiting to happen. Check temperature and basic parameters and review anything dosed into the tank before assuming behaviour has simply changed.
Splitting the watching between household members makes these patterns far easier to catch, and KinsLe's Care Teams lets you assign the daytime count and the evening moult check to whoever is home, with each round marked complete and timestamped against this tank's routine.