Lancetfish grow up to 6.5 feet (2 meters) in length. It inhabits all the oceans of the world except the Polar Regions and it is very widely distributed, often getting caught on fishing nets as by-catches. Despite this, very little is known about the biology of the lancetfish. Its dorsal fin is long and very high and is soft rayed throughout. It has a slender body that is flattened from side to side and is silver in colour. Other than the fact that the lancetfish is oviparous (egg-laying), its reproductive system is still somewhat of a mystery.
It has a large mouth and sharp teeth – adaptations for a life of predation. It has watery muscles that are not suitable for fast swimming therefore it is believed to be an ambush predator. Its narrow body and silvery coloration would provide a good cover and the large dorsal fin would provide acceleration. Since it has a large mouth and sharp teeth it can engulf the prey before it would have the chance to escape.
Studies made on stomach contents determined that the lancetfish feeds on planktonic crustaceans, squid, salp, and other fish. Opah, fur seals, sharks, albacore and yellowfin tuna prey on the lancetfish. The flesh of the fish is edible to humans but it is watery and gelatinous.
Lancetfish are featured in the following book:
25 Deep Sea Creatures
The YouTube video playlist below contains videos about Lancetfish. Details of the videos featured are underneath.
- Lancet Fish 3 by salmoncrazyy
- 090531 Cape Lookout by viabledaddy
- Unusual and Weird Deep Sea Creatures by foxfaunavideo