The thresher shark, or Alopias, are a kind of large mackerel shark in all temperate and tropical oceans in the world. The thresher shark is not technically a type of shark, its a family name for three sharks, the common thresher, the pelagic thresher and the bigeye thresher. All three kinds of thresher share the same defining feature of the thresher family, a long whip-like tail they use to hunt and stun prey. Threshers are pretty much harmless to humans if left unprovoked, may divers describe them as shy, and when they are caught they are said to be nuisances and even when dead many don’t want them as the flesh has a reportedly mushy texture. These sharks have been marked as vulnerable, as their populations are decreasing.
The Common Thresher – Alopias Vulpinus
Common Threshers, also known as Atlantic threshers, are often found on the continental shelf of north America and Asia, go south and you’ll find the other kinds of thresher shark. Their size ranges from the males 10.5 to the female’s 8.5-14.8 feet. The longest reported thresher was 24.9 ft and the heaviest was 750lbs
The Pelagic Thresher – Alopias Pelagicus
Unlike the other threshers the Pelagic Thresher likes to inhabit the surface waters of the more open ocean, but sadly there is not a lot of data regarding the habitat of this specific thresher. The pelagic thresher closely resembles the common thresher, but is distinguished by the dark patches of skin above the pectoral fin and the general absence of labial furrows (the outer edge of a sharks mouth, my personal nickname is the sharks “frown” or “smile”). The pelagic thresher is able to live in much cooler waters because of a special circulatory system named the “retia mirabillia”.
The Bigeye Thresher – Alopias Superciliosus
The bigeye is very similar to the other thresher except (and you’ll never guess this) is has particularly large eyes adapted to a low light, and a large snout. This shark is found in the more tropical waters and has a much smaller range than the other threshers. this shark has been known to to surface at night to hunt and feed. The bigeye has been considered commercially important in the Cuban longline fishery where it s often caught at night, it is still considered a nuisance and bycatch in waters off the US.
(this is a project page for school, if you want better or more info go to https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/alopias-vulpinus/ )