#lancet fish

[dinoserious]

some kind of manfish; design ive been poking at for like a week

[bethanythebogwitch]

It's October and I want to talk about something creepy, so this Wet Beast Wednesday is about the lancetfish. These things look like what would happen if a fish became a vampire. Lancetfish are the only members of their family, Alepisauridae and consist of two species: The longnose lancetfish Apleisaurus ferox and the shortnose lancetfish Apleisaurus brevirostris. While they are often caught as bycatch, there is still a lot we don't know about them.

(image: a lancetfish held by an angler. Its body is long, skinny, and silvery. Its dorsal fin extends down most of its back and is supported by a series of long, thin spines. Its head is pointed and the moth is very wide. It has a large, green eye. The tail is out of frame)

Lancetfish are long and skinny fish capable of reaching up to 2.08 meters (6.8 ft). Their dorsal fins are especially notable, stretching down most of their backs and being spiny, resulting in one common name for them being the "handsaw fish". The fin likely gives stability when the fish swims fast and can fold down. The fin is situated in a groove so when it folds down, the top of the fish is smooth and reduces drag. Lancetfish are also one of the relatively few fish to have an adipose fin. The mouth is large and opens very wide. It has long, skinny teeth that point backwards and are adapted to hold onto struggling prey. Their bodies have no scales, only smooth skin with pores for the lateral line. The name "Alepisaurus" means "scaleless lizard", a reference to their body shape and lack of scales. The stomach can expand to hold a very large volume. Lancetfish lack swim bladders and are simultaneous hermaphrodites, posessing male and female gonads at the same time. They show some anatomical differences from other hermaphroditic fish, including testicles that are independent from the ovaries.

(image: a lancetfish held by a child on a boat. More detain can be seen on the dorsal fin, which includes four spines that grow long past the webbing. The tail ends in a forked fin.

Lancetfish are found worldwide except for arctic regions and are more common in temperate to tropical waters, but have been found as far north as Greenland. They are found in the mesopelagic (twilight) and bathypelagic (midnight) zones, but sometimes swim closer to the surface and can be found at a huge variety of depths. They are unusually large for fish that live in those areas. They are generally believed to be solitary, but may gather together to mate. They may also be migratory, as they have been reported seasonally appearing and disappearing in some locations. Lancetfish do also travel to colder waters if food is scarce. They are predators with extremely wide diets that include fish, cephalopods, tunicates, and crustaceans. They are also notoriously cannibalistic, as lancetfish show up in the stomachs of other lancetfish very frequently. There have even beec cases of scientists finding a lancetfish inside of a lancetfish inside of a lancetfish. They are so well known for cannibalism that they are often named "cannibal fish". Lancetfish are likely ambush predators. Their muscles are gelatinous, which is unsuitable for chases but does work for sudden bursts of speed. They most likely hang motionless in the water, waiting for prey to pass. How lancetfish reproduce is unknown, but they are probably broadcast spawners.

(image: a lancetfish in its natural habitat. It is suspended vertically in the water, with the head pointing up. Its dorsal fin is folded back)

One interesting feature of lancetfish is how slow their digestion is. Lancetfish are often found with undigested or partially digested food in their stomachs. One hypothesis is that They digest food slowly wile living a low-energy lifestyle to make the energy gained from each meal last as long as possible. Another is that the stomach acts like storage and will only begin digestion if the fish is low on energy. This provides an interesting avenue of research. Lancetfish caught as bycatch or that was up on beaches can be dissected to investigate their stomach contents, which are so much more pristine than those of other species. This means each lancetfish acts as a net, containing tons of specimens that give us a good (if biased) look at the bathypelagic food web and local biodiversity. Scientists are starting to find a lot of plastic in lancetfish stomachs. It is hypothesized that some of this plastic may be ingested by prey who practice daily vertical migration bringing tiny pieces of plastic down into deeper waters where they are ingested by larger predators. Some plastic pieces found may be too large to be explained by this method alone, such as a fragment of a black plastic bag around the same size as a hand towel found in one lancetfish. This is part of growing evidence that shows plastic pollution is not just a problem for the surface as was previously though, but exists throughout the water column.

I told you, its a vampire fish (image: a close-up of a lancetfish head. Its mouth is open, showing the teeth. They are long, skinny, and sharp. Most are short, but a few on the top and bottom are much larger than the others)

Lancetfish are not commercially caught as there is no market for them. Their gelatinous meat is considered unappetizing, though it is also said to taste sweet. They are considered pests in longline fishing industries for taking bait intended for other species. The amount of lancetfish bycatch is increasing, possibly indicating population growth due to overfishing of their competition and prey. Known predators of lancetfish include tuna, cod, opah, salmon sharks, and sea lions. Because of how deep they live, not much is known about any conservation needs

(image: a juvenile lancetfih. Its body is green and translucent and much shorter than that of the adult. The head has the same shape as the adult. The dorsal fin is much smaller and less distinct. The body is curved at the spine and the internal organs are visible through the skin)

[cryptidwithacopiccollection]

@bitchyfoxcandy tumblr ate your ask. Here's daryan :D

Send me an ask and I'll draw a Mer-attorney!

[radialblue]

A hard working fish

[baka-unico]

DEEP SEA FISH #1

Tripod fish, Bathypterois grallator

Pelican Eel,  Eurypharynx pelecanoides

Longnose lancetfish, Alepisaurus ferox

Deep sea fish are so fascinating, I love drawing them and learn about them so much :)

[oakleybillions]

Fish girlfriends....

[whit3f1uffya1paca]

Late again, but im sick so . . . LANCETFISH!

[cloud-pudding]

Day 4: lancet fish