The Spotfin Lionfish (Pterois antennata) is often confused with the Mombasa Lionfish (Pterois mombasae) The easiest way to distinguish the two is on the eye. The Spotfin Lionfish has a bar through the eye that aligns with the antennae and tends to have blue spots on the inside of the pectoral fins.
The Mombasa Lionfish pictured below has at least two or three rows of spots on the pectoral fin. These have all been red, orange, white or brown in the numerous specimens we have sighted in the wild. The extended rays of the pectoral fin are far longer on the Spotfin Lionfish and the eye is markedly smaller than the Mombasa Lionfish.
The Spotfin Lionfish has a bar running almost vertically across its eye lining up with the antennae as can be seen above. On the Mombasa Lionfish we have seen in Tanzania the bar is not as marked as can be seen below. Blue spots on the pectoral fins and a bar through the eye mean that it is a Spotfin Lionfish (Pterois antennata). There are other differences but those are the easy ones to pick out.
Spotfin Lionfish grow up to 16 cm centimeters in length. The body background colour varies between red, orange or dark brown. Lionfish change their skin cuticle every few weeks and are duller in colouration as they head for a cuticle change.
IN THE WILD
The Spotfin Lionfish are generally easy to approach and are usually seen sitting hidden in the coral or in small caves. They are not common in Tanzanian coastal waters but neither are they rare. They seem to be more commonly seen in the spring and summer.
They are usually seen solitary but occasionally in spring they are seen they are seen in small groups of up to three or four fish which appear to be interacting in some way or the other. It is possible this grouping is mating related.
Spotfin Lionfish are found across the West Indian ocean, all the way up the East coast of Africa to the Red sea and are usually found on reef tops from between 12 meters to 25 meters. We have never seen them deeper or shallower than these depths. We have seen them out hunting on night dives.
Spotfin Lionfish prey on small fishes and crustaceans and pretty much anything that fits in their mouth. They use their proportionally large mouths to create a vacuum and suck in and swallow the prey.
Spotfin are oviparous with females producing eggs that when fertilized are released and float near the surface. Little else is known about their reproduction. In spring and summer it is common to see three fish together which are interacting with each other. Usually two will be sitting still and the other is swimming around them. This could be mating related.
They are collected in some areas for the commercial aquarium trade and are sometimes caught by indigenous fishermen. The meat is edible.
Spotfin Lionfish are kept by some collectors and make an attractive feature in the right type of aquarium. They will eat anything that fits in their mouths and will occasionally try their luck with things that will not fit in if they are hungry enough. As a consequence care has to be taken in choosing their tank mates. They are relatively easy to get across onto prepared foods.
SPOTFIN LIONFISH CLASSIFICATION
- The Reef Guide fishes, corals, nudibranchs & other invertebrates: East and South Coasts of Southern Africa by Dennis King & Valda Fraser