Red Coris Wrasse Care Guide: Coris Gaimard Juvenile to Adult
The juvenile in the shop bag is fire-red with white-edged black saddles, and within two years that same fish becomes a slate-blue adult covered in turquoise spots and a yellow tail band. The red coris wrasse (Coris gaimard) is one of the most visually dramatic transformations in the marine hobby, and it catches owners off guard when their pretty red juvenile starts looking like a different species at 15 cm. This guide from Gensou Aquascaping at 5 Everton Park unpacks the full lifecycle, sand bed requirements and tank mate considerations.
Juvenile and Adult Colour Phases
Juveniles up to 8 cm are bright red-orange with three black-and-white saddle blotches. The transition phase between 10 and 15 cm shows a confusing mix of red base, emerging green spots, and fading saddles. Adults at 20+ cm are slate blue-green with electric turquoise spots, a yellow caudal band and a green-tinted face. The change can take 18-30 months depending on diet and tank size.
Adult Size and Tank Footprint
Wild adults reach 38 cm; captives plateau at 25-30 cm. The minimum reasonable tank is 600 litres with a 180 cm length, deep enough for a 7-10 cm sand bed. They sleep buried in sand each night and bury again at the slightest startle, so a shallow bed produces chronic stress. Tanks under 450 litres should not house this species.
Sand Bed Depth and Type
A minimum 7 cm bed of fine aragonite sand is essential. Coarse crushed coral or bare-bottom tanks make red coris impossible to keep — the fish will scrape itself raw trying to bury. Fine grain sand under 1 mm allows clean burying and emerging without abrasion. Live sand with established fauna also provides a slow trickle of natural prey.
Diet and Hunting Behaviour
Aggressive carnivores. They hunt small inverts, snails, hermit crabs, ornamental shrimp and tube worms relentlessly. Feed twice daily with frozen mysis, brine, krill, chopped silversides and high-quality pellet. They will pick at every rock crevice during the day. Bristleworm populations crash within months — which some hobbyists consider a feature. Quality frozen feeds, pellet rotations and feeder magnets sit in the aquarium equipment range.
Reef Compatibility Caveat
Reef-safe with corals — they ignore SPS, LPS and softies entirely. Not invertebrate-safe at all. Cleaner shrimp, peppermint shrimp, sexy shrimp, fancy hermits and decorative snails will be hunted. They are useful for controlling pyramidellid snails on Tridacna clams and Aiptasia-eating bristleworm overgrowth, so the trade-off makes sense in dedicated SPS systems.
Tank Mates
Generally peaceful with other fish but assertive at feeding. They harass conspecifics and similarly-shaped wrasses, so single specimens are the rule unless the tank exceeds 1000 litres. Pairs with peaceful tangs, large angels, anthias and clownfish work well. Avoid pairing with shy or slow feeders — the coris will outcompete them.
Behaviour and Sand Diving
Red coris dive into sand at any sudden movement. Tap on the glass once and the fish is buried for 20 minutes. They also bury fully every night — do not panic when the new arrival vanishes for hours, it is normal. Fish that fail to bury within the first week are usually stressed by inadequate sand depth.
Water Parameters
Standard reef numbers: 25-26°C, salinity 1.025, pH 8.1-8.4, alkalinity 8-9 dKH, nitrate 2-15 ppm. They tolerate slightly elevated nitrate better than most reef fish. RODI for top-off and salt mixing — Singapore PUB tap with chloramine should never reach the system. Salt mix and quality RODI cartridges sit in the marine saltwater range.
Singapore Sourcing
Red coris are weekly imports from Bali, Cebu and Maldives sources. Iwarna and Aquamarin list juveniles at SGD 60-110 and adults at SGD 200-350. RDC Reef Discus Centre occasionally has them. Always select juveniles still in the bright red phase — buying a transitional specimen with patchy colour is fine for advanced keepers but the awkward in-between phase makes display value low for a year.
Long Term Outlook
Red coris wrasses live 10-15 years and become very interactive with their owner once settled. The dramatic colour shift makes them a long-term investment in a personal display fish. Plan for 600 litres minimum on day one — a juvenile bought for a 200-litre nano will outgrow it within 18 months and rehoming a coris in Singapore is difficult.
Related Reading
emilynakatani
Still Have Questions About Your Tank?
Drop by Gensou Aquascaping — most walk-in questions get answered in under 10 minutes by someone who has set up hundreds of tanks.
5 Everton Park #01-34B, Singapore 080005 · Open daily 11am – 8pm
