Long snouted lancetfish, Longnose lancetfish, Cannibal fish
Alepisaurus ferox, also known as the long snouted lancetfish, longnose lancetfish, or cannibal fish, is a species of lancetfish found in the ocean depths down to 1,830 m (6,000 ft). This species grows to 215 cm (85 in) in total length and a weight of 9 kg (20 lb).
The appellation cannibal fish stems from discoveries of partially-digested conspecifics in captured specimens.
Di
DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
No
NocturnalNocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal",...
Cr
CrepuscularCrepuscular animals are those that are active primarily during twilight (that is, the periods of dawn and dusk). This is distinguished from diurnal...
Pi
PiscivoresA piscivore is a carnivorous animal that eats primarily fish. Piscivorous is equivalent to the Greek-derived word ichthyophagous. Fish were the die...
Ca
CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
Co
CosmopolitanAnimals with cosmopolitan distribution are those whose range extends across all or most of the world in appropriate habitats. Another aspect of cos...
Ov
OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
Po
PolygynandryPolygynandry is a mating system in which both males and females have multiple mating partners during a breeding season.
So
SolitaryMi
MigratingAnimal migration is the relatively long-distance movement of individual animals, usually on a seasonal basis. It is the most common form of migrati...
A
starts withThe dorsal fin has about three rays strongly exerted, beginning with the third or fourth ray. It is known to have a large mouth with two fangs. It is generally pale, iridescent, and dark around the dorsal fin; all of its fins are either dark brown or black.
The stomach of A. ferox is similar to that of the other species in the suborder of Alepisauroidea. The gut of the A. ferox is a large, blind-sac that also has a very unique biological response to food. The stomach will store food in the stomach and slowly digest the contents, allowing for a more in depth understanding of the exact diet the A. ferox have.
The large, sharp teeth of the lancetfish have two functions; breaking apart organisms too large to swallow whole and cutting trunk muscles to inhibit struggling. The teeth are not used for chewing otherwise.
A. ferox lives in deep water oceans in the Western and Eastern Pacific, from the Aleutian Islands to Chile; the Western Atlantic, from the Gulf of Maine to the Gulf of Mexico, including the Caribbean Sea; in addition to the Northwest & Eastern Atlantic, Indian Ocean and China Sea. The longnose lancetfish can also be found as far north as Russia. This expansive geographic reach has caused for the species to be accidentally caught by some tuna fisheries. Daily vertical migrations from the epipelagic all the way down to the mesopelagic or bathypelagic zones are undertaken to find food.
Longnose lancetfish diet varies depending on its inhabited area. Studies of diet variation have produced inconsistent results. They are known to prey on 98 component families; individuals may even consume man made materials, such as plastic.
The longnose lancetfish is a migratory predator. It is known to travel to a depth of 1,830 m (6,000 ft) in order to hunt. A study in Suruga Bay, Japan, investigated the stomach contents of various specimens that had washed ashore and found, along with indigestible materials, traces of marine species of the photic and aphotic zones. This study showed that the longnose lancetfish is a deep sea diving species capable of migrating across different sea depths.
As aforementioned, the longnose lancetfish is referred to as the cannibal fish due to its conspecific predation habits. The extent of cannibalistic behavior depends on the availability of non-conspecific prey, with frequency of these patterns ranging from 0 to 45.5%. Such is contingent upon the availability and ease of finding other prey. Size is an influencing factor; small lancetfish will not resort to cannibalism as quickly as larger fish.
The fish are hermaphroditic: they have both male and female reproductive parts at the same time. Unlike other hermaphroditic fishes, A. ferox has two distinct testicular lobes that are independent from the ovarian region. This species also has an absence of a pair of diverticulae in the female reproductive section, which in other hermaphrodites is used for spermatophore uptake.
