General: Angel sharks

2/17/2016

These sharks, in the genus Squatina, are unusual in that like the wobbegong shark are flat. Sometimes called "monkfish" (they’re not; there’s a separate genus Lophius that is properly called "monkfish"), they have broad pectoral fins, resembling rays. There are 23 species in this genus (at least, thus far that have been discovered). It’s the only one in its family (Squantinidae) and in the order Squantiniformes.

They are a pretty cosmopolitan animal, found in temperate/tropical seas. They prefer shallow waters, but of course there’s that one mopey shark that decides, “Yo, I want to be 1,300 m (4,300 ft) away from the rest of you." So, it hangs out in the deep.

Although relatively flat, their rear rounds out, looking more like a typical shark. But until a typical shark, the lower caudal fin of their tail is longer than the upper caudal fin. Looking like a ray, one big difference is that angel sharks lack gills on their underbelly- instead, the gill slits are on their back!

These sharks are pretty small… and by pretty small I mean they grow up to 1.5 m (about 5 ft… so Melissa's height aka small). The Japanese angel shark, Squatina japonica, can reach 2 m (6.7 ft) though.

As seen in many horror-story-worthy videos of the goblin shark, they too have pretty extensible jaws. Clearly these sharks don’t swim fast, and rely on ambushing their predators, their jaws literally becoming traps of death. Long and needle-like teeth included. And like many ambush predators, they bury themselves in the sand/muddy substrate and then lie and wait…. until chomp. Their diet includes fish, crustaceans and many molluscs. Yummy.

These sharks are viviparous with yolk-sac; litter sizes can reach up to 13! Like many bottom-dwelling sharks, they are pretty harmless… until they are stepped on and/or harassed. Don’t mess with the shark, guys, it has powerful jaws and painfully sharp teeth.

Once a “junk fish” caught as bycatch by fishermen, the continued fishing of this animal radically reduced numbers, and eventually called for fishery management. In 2008, the UK government fully protected the angel shark under the Wildlife and Countryside Act. The IUCN assessment varies depending the species.

species

Squatina aculeata (sawback angelshark)
Squatina africana (African angelshark)
Squatina albipunctata (eastern angelshark)
Squatina argentina (Argentine angelshark)
Squatina armata (Chilean angelshark)
Squatina australis (Australian angelshark)
Squatina caillieti
Squatina californica (Pacific angelshark)
Squatina dumeril (sand devil)
Squatina formosa (Taiwan angelshark)
Squatina guggenheim (spiny angelshark)

Squatina japonica (Japanese angelshark)
Squatina legnota (Indonesian angelshark)
Squatina mexicana (Mexican angelshark)
Squatina nebulosa (Clouded angelshark)
Squatina oculata (Smoothback angelshark)
Squatina pseudocellata (Western angelshark)
Squatina punctata (Angular angelshark)
Squatina squatina (Angel shark)
Squatina tergocellata (Ornate angelshark)
Squatina tergocellatoides (Ocellated angelshark)
Squatina heteroptera (Gulf angelshark)

did you know these #flatsharks?

glossary

Bycatch: The part of a fishery’s catch that is made up of non-target species.
Cosmopolitan: Worldwide distribution.
Crustaceans: Group of animals with a hard exoskeleton, jointed legs and segmented body.
Genus: A group of organisms ranking above a species and below a family.
IUCN: International Union for Conservation of Nature.
Molluscs: The largest marine phylum; invertebrate animals, many of which have shells.
Viviparous with yolk-sac: Also known as aplacental viviparous and previously known as ovoviviparous/ovoviviparity; it is the production of eggs that are fertilised and hatch inside the female shark but the embryos lack a placental connection to the oviduct or uterus and so do not feed off the mother.