The Shortfin Scorpionfish, Scorpaenodes parvipinnis also known as the Lowfin Scorpionfish is another of the smaller scorpionfish. Because many of them are distinctly colored with a large white saddle behind the head they can be very easy to identify. They are fairly common at night on the reef edges and rubble in Tanzanian waters.
The Shortfin Scorpionfish has a typical Scorpionfish shape with a proportionally large head and mouth. The pectoral fins are rounded, resembling a fold out fan but these are usually folded back. The tail is small in comparison to the head and they are poor swimmers. They grow up to 9.5 cm in length. As mentioned above they have a white saddle behind the head and the rest of the body is red orange or sometimes brown. There is sometimes a light bar on the caudal peduncle.As their name suggests they have a very short dorsal fin.
Scorpionfish have a cuticle of skin that covers the body and this is changed every few weeks giving them a resilience against parasites. It is thought by some that they change their texture and color to suit their surroundings on these cuticle changes. As they near a skin change so the colors become less vibrant and they appear more dull.
IN THE WILD
The Shortfin Scorpionfish seem to be nocturnal in habit and we have only seen them out at night. They are usually found near the edge of the reef and over rubble adjacent to the reef. They will initially rely on their camouflage when approached by a diver. Provided that they do not feel too threatened they will usually sit dead still. If that does not work for them they will hop away and go under an overhang or into a hole. They seem more common in the 12 to 20 meter range.
Shortfin Scorpionfish have a wide range and are found across the Indo Pacific area, all the way up the East coast of Africa from South Africa to the Red sea and across to southern Japan and northern Australia and Hawaii.
Shortfin Scorpionfish are ambush predators that 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. Prey is swallowed whole and is sucked into the mouth.
Shortfin Scorpionfish are oviparous with females producing eggs that when fertilized are released and float near the surface. Little else is known about their reproduction.
Shortfin Scorpionfish may be kept by some collectors in specialized aquariums, but they are not at all common in the trade. They will eat anything that fits into their rather large mouths so care would have to be taken in this regard
SHORTFIN SCORPIONFISH CLASSIFICATION
COASTAL FISHES OF THE WESTERN INDIAN OCEAN Page 535