The adult measurement, seen through a clear body
A ghost shrimp is fully grown at about one and a half to two inches long, and the first thing a new keeper notices is that you measure this animal partly by faith, because its body is almost entirely transparent. What shows is the outline, a faint internal thread of digesting food, and on a mature female a greenish or yellowish saddle across her back where eggs develop, followed later by eggs carried visibly beneath her tail. Females outgrow males noticeably, finishing larger and much deeper in the body, while males stay nearer the bottom of the size range and look slimmer.
Growing to full size on a scavenger's income
Ghost shrimp reach adult size by moulting, shedding a complete clear shell that looks alarmingly like a dead shrimp until you count legs on the living original nearby. Growth is quick when food is plentiful and water is stable, and this species earns its keep on leftovers, grazing fine debris, fallen food, and soft growth from plants, gravel, and decor with two pairs of small pincered arms. A tank that is too new or too spotless can leave adults underfed despite their scavenging reputation, so a sinking pellet or a little crushed food delivered to the bottom a few times a week keeps a group in condition. Females carrying eggs need that condition most, and a plump, actively foraging adult is the clearest sign the tank's leftovers economy is working.
Where a two-inch shrimp fits in a community
Adult size places the ghost shrimp in an interesting middle ground. At up to two inches it is far too big for tetras, rasboras, and other small-mouthed fish to trouble, and it lives happily alongside the classic peaceful community, tidying the floor beneath them. It remains, however, a soft-bodied crustacean with no real defence beyond a flick of the tail, so genuinely predatory fish, large cichlids, puffers, and big loaches will hunt adults as readily as youngsters, especially during the exposed hours after a moult. Hiding places among plants, moss, and wood let a freshly moulted shrimp sit out the danger until its shell hardens.
Tank size and conditions for adults
Because adults stay small, a group of ghost shrimp fits comfortably in a tank from about ten gallons upward, and floor area and planting matter more than depth. A lid is worth fitting, since a startled shrimp can flick itself out of open water, and filter intakes should be covered with a sponge so neither adults scavenging nearby nor any tiny young are drawn in. Stable, well-cycled water matters more than exact numbers, and copper-based treatments must never reach a shrimp tank, since what is safe for fish can be lethal to invertebrates at any size. Given cover, leftovers, and safety from hunters, adults settle into a constant, watchable patrol of the lower tank, turning over debris in their pincers and inspecting every new object the day it appears.
Buying adults and keeping a colony going
Choose ghost shrimp that are clear rather than milky, active rather than lying on their sides, and busily picking at surfaces, because cloudiness in the body can signal a shrimp in trouble while a transparent, foraging one is in good order. Acclimate them slowly, release them among plants, and expect a moult soon after the move as they adjust. A colony of full-grown females will often produce young in a planted tank, though many are eaten unless cover is dense. Groups like this accumulate useful local knowledge about which fish ignored them and what they fed on, and KinsLe Transferrable Profiles keep that colony record, from tankmates to feeding rhythm, together if the shrimp are ever passed to another keeper.