Clearfin Lionfish
Pterois radiata
The White-Spined Spider (8 inches / 20 cm). Highly venomous and extremely demanding. Its spines lack webbing, making it look like a glowing skeleton in the dark.
Water Temperature
24 - 27 °C
pH Value
8.1 - 8.4
Water type
Freshwater
Tank level
Bottom and middle
Adult size
25 cm
Minimum tank volume
>= 300 L
Minimum group
>= 1
GH
15 - 30 dGH
KH
7 - 15 dKH
TDS
295 - 600 ppm
Conductivity
461 - 938 uS/cm
Species description
Geographical Origin and Habitat: Red Sea, Indo-Pacific and South Africa. Lives hunting in lagoon reefs and on reef slopes rich in overhanging rocks and caves, often with dim light.
Taxonomy and Morphology: Radiata Lionfish (Pterois radiata). Lionfish / Scorpionfish. Compared to the volitans, it has two distinctive traits: it has no fleshy membranes between the dorsal spines (which are completely bare like needles) and two clear white horizontal stripes on the caudal peduncle.
Social Behavior: Static predator. Spends most of the day suspended upside down under rocky overhangs or wedged in caves. Becomes active at dusk, using its huge radial pectoral fins to corner fish and swallow them.
Coloration and Sexual Dimorphism: Reef Tiger. Intense red-burgundy background (instead of brown) crossed by 5-6 snow-white vertical lines (without intermediate spots). Dazzling white dorsal needles. No obvious sexual dimorphism.
Care, breeding and tankmates
Aquarium Setup: Predator tank (120 cm / 48 inches). Mandatory: the rockwork must form wide caves, grottos and massive arches (Caves) to allow him to hide from the daylight he hates. Without hiding places, the fish will die of stress.
Diet and Feeding: Carnivorous swallowing machine. Eats whole prey. The most difficult of the lionfish to wean: often initially accepts only ghost-shrimp (live shrimp) or guppies, before being patiently accustomed to slices of fish, peeled shrimp and squid offered on an invisible stick.
Water Quality: Very high organic load (Heavy Bioload). Although resistant, it produces colossal digestive waste in single solutions. The skimmer must be highly oversized so as not to let ammonia spike after every meal.
Compatibility and Cohabitation: Reef Safe with reservations (Invertebrates at risk). Does not touch corals, but swallows ANY shrimp (Lysmata, Stenopus) or crab. Fish tankmates must be AT LEAST half his size, otherwise they will disappear at night.
Aquarium Breeding: Unknown in private closed systems. Oviparous species with pelagic fertilization. Males form harems in nature, with nocturnal rituals and ascents to the surface that require immense water columns.
Risks and Diseases: Lethal Weapon for Humans (Envenomation). The exposed dorsal needles inject a powerful neurotoxin. The P. radiata is smaller than the volitans, but statistically "stings" more often due to its taking refuge in narrow cavities. NEVER put blind hands in the rocks; the pain is described as excruciating, with vomiting, tachycardia and local necrosis (immersing in very hot water destroys the venom proteins, then run to the ER).
Geographic Origin and Distribution
Red Sea, Indo-Pacific and South Africa. Lives hunting in lagoon reefs and on reef slopes rich in overhanging rocks and caves, often with dim light.
Origin
Tropical oceans and reefsNorth AmericaAfrica and Madagascar
Fish profile
- Temperament
- Semi-aggressive
- They are slow-moving, calculated, and generally peaceful towards anything they cannot eat. They possess highly venomous dorsal spines used purely for defense. Extreme caution must be exercised during tank maintenance.
- Diet
- Omnivore
- They are obligate carnivores that prey on live crustaceans and smaller fish. In captivity, they must be weaned onto frozen silversides, shrimp, and squid. Use a feeding stick to stimulate their hunting instinct.
- Life expectancy
- 10-15 years
- This lionfish has a remarkable lifespan in captivity, capable of reaching 10 to 15 years under attentive care and with pristine water quality management. As long-lived predators, their health depends heavily on a balanced diet and a spacious environment that minimizes stress. Fin rot infections and digestive issues caused by improper diets are the most common causes of early mortality. Long-term chemical stability is essential for this species.
- Adult size
- 25 cm
- The catalog's scalar value is 25 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 24 cm for this species, recorded as total length (TL). The taxonomic record consulted is Pterois radiata (v25.04); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
- Sex ratio
- Solitary
- They are generally solitary and keeping a specific sex ratio is unnecessary. Multiple lionfish can be kept in very large tanks. Ensure all individuals are similar in size to prevent cannibalism.
- Feeding frequency
- Twice daily
- Adults should only be fed two to three times a week. Overfeeding leads to fatty liver disease and premature death. Juveniles can be fed small meals every other day.
- Bioload
- The Clearfin Lionfish produces a very high bioload. They consume large, meaty meals and produce significant waste. A heavily oversized protein skimmer and strict maintenance are essential.
- Flow
- Stagnant
- They prefer low to moderate water flow. Strong currents make it difficult for them to hover and stalk prey. Gentle circulation around the live rock is perfectly adequate.
- Reproduction
- Oviparous
- Breeding in the home aquarium is essentially undocumented. They are pelagic spawners that release gelatinous egg masses. Rearing the larvae requires specialized setups generally unavailable to hobbyists.
- Compatibility & tankmates
- They are predatory and will eat any fish or shrimp that fits in their mouth. They must be kept with large, robust, and moderately aggressive fish. They are technically reef safe regarding corals.
- Tank level
- Middle/Bottom
- They utilize the entire water column but favor resting upside down in caves. They often perch on rockwork during the day. At dusk, they actively patrol the mid-water looking for prey.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 3.6 ± 0.59 se
- Resilience
- Medium (1.4 - 4.4 years)
- Phylogenetic uniqueness (PD50)
- 0.5078
- Bayesian Length-Weight
- a = 0.01, b = 3.02
- VulnerabilityLow vulnerability (14 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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