Midnight (Nox) Dwarf Angelfish
Midnight (Nox) Dwarf Angelfish
Goes well with:
FAQs Answers to the most common questions.
Is a Black Nox Dwarf Angelfish reef safe, or will it nip my corals and clams?
It is only “reef safe with caution.” Like most dwarf angelfish, a Black Nox Dwarf Angelfish may behave perfectly for months and then start sampling LPS, zoanthids, soft corals, clam mantles, or even fleshy SPS polyps. Individual personality matters a lot. They are usually the best-behaved around more established reefs with plenty of grazing and rockwork, but they should never be treated as 100% coral-safe.
What tank size and aquascape does a Black Nox Dwarf Angelfish actually need to stay healthy?
A minimum of 55 gallons is the bare floor, but 75 gallons or larger is much better for long-term success. More important than pure volume is a heavy live-rock layout with caves, overhangs, and lots of grazing surface. This species does best when it can pick at film algae and microfauna all day and retreat into rock crevices when startled. Open, bare tanks usually lead to stress and pacing.
What should I feed a Black Nox Dwarf Angelfish so it doesn’t waste away or start nipping corals?
Feed a varied diet several times a day if possible: high-quality angelfish formulas, spirulina-based foods, frozen mysis, enriched brine shrimp, chopped seafood, and algae-based sheets or graze foods. The key is frequent small feedings plus constant rock grazing. A hungry dwarf angel is far more likely to go after corals, so keeping it well-fed is one of the best “reef safety” strategies.
Can a Black Nox Dwarf Angelfish live with other dwarf angelfish?
Usually not unless the tank is large and carefully managed. Dwarf angelfish can be very territorial, especially toward similar body shapes and colors. In smaller systems, a Black Nox Dwarf Angelfish is likely to harass or be harassed by other Centropyge-type angels. If you want multiple dwarf angels, it’s safest in a much larger tank with lots of rock structure, and ideally introducing them at the same time.
Why is my Black Nox Dwarf Angelfish hiding all the time, and how do I get it to come out?
New individuals often hide for the first several days to a few weeks, especially after shipping or when placed in a bright, open tank. They feel safest in dense rockwork with several bolt-holes and low initial disturbance. Dim lighting at first, offering food near the hiding spot, and keeping aggressive tankmates away usually helps. If it keeps hiding long-term, the most common causes are bullying, insufficient shelter, or not enough grazing foods.
All listed sizes are approximate, not guaranteed, and may vary slightly.
The Midnight (Nox) Dwarf Angelfish, Centropyge nox, is a striking saltwater fish distinguished by its nearly uniform jet-black to deep charcoal coloration. Subtle blue highlights may appear around the face and fin margins under strong reef lighting, while the dark body creates a dramatic contrast against brightly colored corals and other marine fish. Its simple yet bold appearance makes it one of the most distinctive dwarf angelfish for established saltwater aquariums.
Native to the Western Pacific, this species occurs from the Ryukyu Islands and Indonesia through the Solomon Islands, Great Barrier Reef, New Caledonia, Palau, and portions of Micronesia. It naturally inhabits coral-rich outer reef slopes, lagoons, and passages where abundant rockwork and invertebrate growth provide shelter and grazing opportunities. With an adult size of approximately 4 inches, the Nox Angelfish combines manageable dimensions with the active, inquisitive behavior typical of Centropyge angelfish, making it well suited to mature fish-only aquariums and carefully planned reef aquariums.
Quick Care Guide
Care Level: Moderate
Minimum Tank Size: 70 gallons
Temperament: Semi-aggressive
Diet: Omnivore
Reef Safe: With Caution
Region: Western Pacific
Scientific Name: Centropyge nox
Tank Requirements
The Midnight Angelfish should be maintained in an established marine aquarium with abundant live rock, caves, overhangs, and narrow crevices. A 70-gallon or larger aquarium provides adequate territory for its adult size while allowing sufficient room to forage and establish secure hiding areas.
Complex rockwork is especially important for this species. In addition to providing shelter, mature live rock supplies natural algae and biofilm that the fish can graze throughout the day. Leave some open swimming space between rock structures while maintaining multiple escape routes and sheltered areas.
Moderate water movement, good oxygenation, efficient filtration, and stable water quality are ideal. Newly introduced specimens may initially remain close to rockwork but typically become increasingly visible as they acclimate.
Diet and Feeding
The Nox Angelfish naturally consumes algae and associated organic material from reef surfaces. In captivity, it should receive a varied omnivorous diet with a strong vegetable component.
Offer spirulina-based flakes or pellets, marine algae, high-quality angelfish preparations, mysis shrimp, enriched brine shrimp, and balanced frozen marine blends. Mature live rock provides additional grazing opportunities and is particularly beneficial between prepared feedings.
Feed two or more small meals daily while allowing the fish to forage naturally throughout the aquarium. A varied diet helps maintain good body condition and supports normal grazing behavior.
Temperament and Tankmates
The Midnight Angelfish is semi-aggressive and can become territorial after establishing itself in the aquarium. Aggression is most commonly directed toward other dwarf angelfish and similarly shaped fish competing for the same rockwork and feeding areas.
It can coexist with many appropriately sized marine community fish, including clownfish, wrasses, gobies, blennies, cardinalfish, chromis, and larger peaceful to semi-aggressive species.
For most home aquariums, keeping a single Nox Angelfish is the simplest approach. Housing multiple dwarf angelfish requires a considerably larger aquarium, extensive rockwork, and careful species selection.
Reef Compatibility
The Midnight Angelfish is best considered reef safe with caution. Like other dwarf angelfish, individual specimens may nip at sessile invertebrates even when otherwise well fed.
Potential targets include soft coral polyps, zoanthids, fleshy large-polyp stony corals, and clam mantles. Some individuals coexist successfully in reef aquariums for extended periods, while others develop persistent picking behavior.
Ornamental shrimp, snails, crabs, and other mobile reef invertebrates are generally at lower risk. Providing abundant mature rockwork and a varied diet may help redirect natural grazing behavior, but complete coral safety cannot be guaranteed.
Water Parameters
Temperature: 75–80°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH
Stable conditions are more important than repeatedly adjusting the aquarium to achieve an exact number. Maintain consistent temperature and salinity along with good oxygenation, efficient filtration, and regular aquarium maintenance.
Common Considerations
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Reef safe with caution: Individual fish may nip soft corals, zoanthids, fleshy stony corals, and clam mantles.
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Territorial behavior: Established specimens can become assertive toward other dwarf angelfish and similarly shaped competitors.
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Mature rockwork recommended: Live rock provides both secure hiding places and important natural grazing surfaces.
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Naturally cryptic behavior: Newly introduced specimens may spend considerable time within rockwork before becoming comfortable in open areas.
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Single-specimen housing: Keeping one dwarf angelfish is generally the most predictable approach unless the aquarium is large enough to support multiple territories.
