Marine Invertebrate

Blue Tunicate

Rhopalaea spp.

Care guide, husbandry, breeding, disease, sourcing, and tankmate intelligence on Blue Tunicate - written by the Fast Aquatics editorial team and cross-verified against vendor records on the live marketplace.

Blue Tunicate at a glance
Adult size: 2 inches · Minimum tank/pond: 55 gallons · Difficulty: expert · Diet: plankton filter feeder · Lifespan: 1-3 years.

Blue Tunicate (Rhopalaea spp.) is a marine invertebrate kept by aquarists for reef-tank cleanup, biological control of pests, or aesthetic display. Demanding requirements make this species best for keepers with established mature systems and proven track records.

Where Blue Tunicate comes from

Blue Tunicate (Rhopalaea spp.) is native to Indo-Pacific reef ecosystems, with wild populations distributed across coral reefs, sandy lagoons, and rocky tide pools. Captive specimens are typically wild-collected; some species are starting to be aquacultured but most Blue Tunicate sold today still comes from wild reef collection. Sustainable sourcing matters - look for vendors who can verify their collection practices, and consider aquacultured alternatives when available.

Blue Tunicate tank size and setup

Blue Tunicate requires a minimum of 55 gallons for healthy adults. The minimum is based on the species' adult size (2 inches), territorial range, and behavior pattern. Most Blue Tunicate sold at small juvenile size will reach full adult size within 12-24 months and the system must be sized to the adult, not the juvenile.

For a Blue Tunicate setup: mature reef tank with stable parameters, live rock for cover, sandbed substrate (1-2"), reef-grade lighting if photosynthetic, and a fully-cycled biological filter at least 6 weeks old. Newly-cycled tanks under 6 weeks crash the parameters that Blue Tunicate depends on.

Browse our 55-gallon aquarium guide for the complete equipment list.

Water parameters for Blue Tunicate

Blue Tunicate requires standard reef parameters held tightly stable:
Temperature: 76-80°F (24-27°C)
Specific gravity: 1.025 (refractometer-measured)
pH: 8.1-8.4
Alkalinity: 8-9 dKH
Calcium: 420-450 ppm
Magnesium: 1300-1400 ppm
Ammonia + nitrite: Both 0 ppm
Nitrate: Under 10 ppm
Copper: 0 (lethal to invertebrates)

Blue Tunicate is sensitive to copper - never medicate the display tank with copper if Blue Tunicate is present. Stable parameters beat perfect parameters.

What Blue Tunicate eats

Blue Tunicate is a plankton filter feeder. Filter-feeds on suspended plankton and dissolved organics. Target-feed live phytoplankton, rotifers, or commercial reef foods (Reef Roids, Coral Frenzy) 2-3x weekly to ensure adequate nutrition. Feed Blue Tunicate appropriately for its size + activity level. Overfeeding is the #1 cause of water-quality crashes in tanks of all sizes.

Blue Tunicate tankmates and compatibility

Blue Tunicate is generally peaceful and compatible with most reef community species. Avoid keeping with predatory fish that view inverts as food: large wrasses (especially halichoeres + thalassoma), triggerfish, pufferfish, and certain large angelfish. Multiple Blue Tunicate can share a tank but compete for food.

Browse care guides for tankmate-compatibility tables for Blue Tunicate and similar species.

Blue Tunicate adult size and lifespan

Blue Tunicate reaches 2 inches at adulthood with a captive lifespan of 1-3 years with proper care. Many marine inverts molt periodically; provide adequate calcium and a stable parameter regime to support healthy molts.

Can you breed Blue Tunicate?

Blue Tunicate breeding in captivity ranges from straightforward (some shrimp, snails) to nearly impossible (most starfish, urchins) due to pelagic larval requirements. Captive-bred specimens are increasingly available from sustainable aquaculture facilities; check with vendors before assuming wild-caught origin.

Common Blue Tunicate diseases and problems

Blue Tunicate is sensitive to copper, ammonia spikes, low oxygen, and rapid parameter swings. NEVER use copper medications in a tank with Blue Tunicate. Symptoms of stress: reclusive behavior, color loss, refusal to feed, abnormal molting (incomplete or stuck molts). Most Blue Tunicate deaths trace back to acclimation shock or parameter mismatch - drip-acclimate over 45-60 minutes when adding to a new tank.

Where to buy Blue Tunicate online

Blue Tunicate is sold at LFS (local fish stores), online retailers, and direct from breeders/wholesalers. Pricing varies widely by source, size, and quality:

Budget tier: $40-200
Mid-tier: $100-500
Premium tier: $300-2000

Browse live Blue Tunicate from vetted Fast Aquatics vendors with carrier-tracked overnight shipping (FedEx Priority + UPS Next Day), climate-aware hold logic, and a 4-hour DOA window with photo-evidence claims. Captive-bred or aquacultured specimens cost more upfront but arrive healthier and integrate faster.

Blue Tunicate FAQ

How big does Blue Tunicate get?

2 inches at adulthood within 12-24 months.

How long does Blue Tunicate live?

1-3 years with proper care.

What is the minimum tank/pond size?

55 gallons, with larger systems strongly recommended.

Is Blue Tunicate hard to keep?

Blue Tunicate is rated expert difficulty.

What does Blue Tunicate eat?

Blue Tunicate is a plankton filter feeder; appropriate diet matches its natural feeding pattern.

Where can I buy Blue Tunicate?

Browse live Blue Tunicate from vetted Fast Aquatics vendors with carrier-tracked Buyer Protection and a 4-hour DOA window.

How much does Blue Tunicate cost?

$40-2000 depending on source and quality.

Do I need to quarantine Blue Tunicate?

Yes - quarantine new Blue Tunicate for 4-6 weeks in a separate tank before adding to your display.

Is Blue Tunicate reef safe?

Generally yes - Blue Tunicate is reef-safe and suitable for established reef tanks.

Other species in the same category with care profiles on Fast Aquatics. Click any name for the full husbandry breakdown.

Chalice CoralDwarf OctopusOctopus mercatorisFlamingo Tongue SnailCyphoma gibbosumSea RobinToadstool Leather CoralRhomboid Fairy Wrasse

Sources and references

Blue Tunicate taxonomy and care recommendations cross-checked against the following authoritative references and our internal vendor + breeder database.

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More resources for Blue Tunicate keepers

Common diseases
Helpful calculators
Key terms

Browse the full disease database, calculator collection, aquarium glossary, or Q&A library for additional reference.

Deep-dive Q&A on Blue Tunicate

Answers to the questions experienced keepers ask after the basic care guide.

How long does Blue Tunicate take to acclimate to a new tank?

Drip acclimation over 60 to 90 minutes is the safest approach for Blue Tunicate. Match temperature first (15 minute float), then drip 2 to 3 drops per second from the display sump until the bag volume has tripled. Test salinity (or freshwater hardness) at the end - if it is within 0.001 SG (or 2 dGH) of the display, transfer the specimen with a net rather than pouring shipping water in.

What is the best filtration setup for Blue Tunicate?

Aim for biological + mechanical + chemical staging. Canister or sump-driven filtration sized for 5x to 8x display turnover per hour, mechanical floss replaced weekly, and carbon or GAC swapped every 4 to 6 weeks. Blue Tunicate responds well to stable nitrate (under 20 ppm) more than to any specific filter brand - stability beats peak performance.

Does Blue Tunicate need a protein skimmer?

For saltwater specimens, yes - a properly-sized skimmer rated for 1.5x to 2x display volume keeps dissolved organics low and reduces nuisance-algae triggers. Freshwater specimens do not need skimmers; a well-stocked plant grow-out + canister with chemical media achieves the same end. Blue Tunicate kept without adequate organic export tends to show stress within 90 days.

Can Blue Tunicate be kept in a planted tank?

Compatibility with planted tanks depends on the species behavior + water chemistry overlap. Plant-safe specimens leave foliage alone; some pick at soft-tissue plants like vallisneria or anubias. Check the species page profile + the planted-tank compatibility note before stocking Blue Tunicate in a high-tech CO2-injected setup with valuable cultivars.

What is the ideal lighting for Blue Tunicate?

For freshwater specimens with no plant requirements, a basic LED at 30 to 50 PAR at substrate is sufficient and reduces algae. For saltwater + reef specimens, target 100 to 250 PAR depending on photo-tolerance, with a sunrise/sunset ramp + a 8 to 10 hour photoperiod. Blue Tunicate tolerates a wider lighting band than most keepers expect; consistency matters more than peak intensity.

Does Blue Tunicate prefer high or low water flow?

Most aquarium species evolved in moderate flow with localized turbulence rather than uniform high flow. Aim for 20x to 40x display turnover for reef specimens, 4x to 6x for community freshwater. Blue Tunicate shows stress fins (clamped, frayed) when flow is mismatched - dial back if you see this within 14 days of introduction.

What temperature shift will stress Blue Tunicate?

Sustained drift above +/- 2 F from target is the threshold most keepers miss. Blue Tunicate tolerates day-night swings of 1 to 2 F without issue but a 4 F shift over 2 hours triggers ich + bacterial bloom risk. Use a controller-driven heater (not the built-in dial) and a backup thermometer at the opposite end of the tank.

What are the top 3 diseases that hit Blue Tunicate the most?

For freshwater fish: ich, columnaris, and fin rot are the top three; quarantine + UV sterilizer prevents the majority. For marine fish: ich (Cryptocaryon), velvet (Amyloodinium), and bacterial infections; tank-transfer method or copper QT during the 30-day acclimation cycle prevents nearly all outbreaks. For inverts + corals: tissue necrosis, parasitic isopods, and protozoan blooms.

Can Blue Tunicate be bred in captivity?

Captive breeding success varies enormously by species - some breed readily in community tanks (livebearers, cherry shrimp, clownfish) while others have never been captive-bred (most reef fish + most marine inverts). Check the species-specific care guide for the breeding-method note + larval-rearing protocol. Blue Tunicate kept in pairs or small groups often spawns even without intent if conditions are right.

What are the best tankmates to avoid for Blue Tunicate?

Avoid same-species rivals (especially male-male pairings for territorial species), known fin-nippers (tiger barbs, certain pufferfish), and anything that out-competes for food or out-grows the tank. Blue Tunicate also struggles with hyper-aggressive cichlids in freshwater and damselfish in saltwater - both will hold territory at the expense of every other tankmate.

Is Blue Tunicate safe to keep with cleaner shrimp or cleaner wrasses?

Most ornamental specimens accept cleaner shrimp + cleaner gobies; cleaner wrasses (Labroides) often die in captivity and are not recommended. Blue Tunicate kept with cleaner pairs typically benefits from parasite control + stress reduction, but verify the cleaner does not get eaten by checking the species size + temperament chart.

What is the realistic lifespan of Blue Tunicate with proper care?

Captive lifespan tracks closely to wild lifespan when water chemistry, diet, and tankmate stress are managed. Most aquarium fish live 5 to 12 years; long-lived species (large cichlids, pufferfish, some tangs) reach 15+ years. Blue Tunicate kept in a stable, properly-sized system should live within 80% to 100% of the species lifespan ceiling - early death usually traces back to chronic-stress causes (parameters, tankmates, diet) rather than disease.