Polka-dot Loach

With golden yellow spots and wavy lines on a dark brown to black background, the polka-dot loach is one of the most patterned botias. It was introduced to science in 2004; before that it was sold in the trade as "Botia sp. Angelicus", and that name is still widely used.

Juveniles have dark bands on the body and are confused with the golden zebra loach at this stage. In the kubotai the bands split in two at an early age and form pointed tips; as the fish ages the dark areas widen, the yellow pattern becomes thinner and a spotted look emerges. Adults reach 13–15 cm.

It lives in flowing, clear, well-oxygenated streams in the upper tributaries of the Salween basin on the border between Myanmar and Thailand. The bottom consists of sand, gravel and large stones; the fish hide among and under the stones.

• Volume: at least 240 liters and 120 cm of length for a group of 5–6; floor area matters more than depth.
• Water: 23–27°C, pH 6–7.5, soft to moderately hard. A 30% water change every week.
• Flow: Moderate to strong flow and plenty of oxygen. A powerful canister filter or an additional circulation pump is suitable.
• Decor: Rounded stones, roots and caves with narrow openings. Every individual should be able to find a shelter of its own.
• Lid: A tight lid is essential; it jumps.

An omnivore leaning toward meaty foods. Sinking granules and tablets should be the staple; frozen bloodworms, brine shrimp, mysis and tubifex should be given regularly. It also nibbles blanched zucchini, cucumber and spinach. It hunts small snails, but it should not be expected to end an infestation on its own.

Peaceful but curious and active; it can disturb very small, calm fish. Jostling within the group is natural and usually harmless. In an aquarium with enough hiding places it is often seen during the day as well.

Good companions: danios, devarios, rasboras, medium-sized barbs, large tetras, other medium-sized botias.

Avoid: snails, shrimp, slow long-finned fish such as bettas and fancy goldfish, large cichlids that claim the bottom.

The polka-dot loach is a social schooling fish: at least 5–6, ideally 8–10 individuals. One or two individuals become stressed, hide and grow prone to disease. In a large group a pecking order forms; the fish rest together, feed together and play. It may also swim with other botia species, but enough of its own kind is still needed.

There is no known reliable record of it being bred in the aquarium. The fish sold are collected from the wild.

• White spot: Common in newly arrived botias; quarantine is essential.
• Medication sensitivity: Its scales are very small; start medications at half the dose and raise the temperature slowly.
• Wasting: Internal parasites are common in wild-caught fish. Do not buy a fish with a sunken belly or one that refuses food.

Mature females have a fuller body and a rounded snout. Males have a slightly longer snout and appear to have fleshier lips. The difference can only be seen in adults and when they are compared side by side.