This week’s featured species is sometimes confused for a species of ray, but make no mistake, the Eastern Angel Shark (Squatina albipunctata) is all shark that knows take its prey by surprise!
Much like the wobbegongs, the angel shark is a benthic shark that relies on an ambush method of hunting to catch its prey. The angel shark spends the majority of its life laying on the sea floor, buried in the sand or mud, or under small pebbles, or even in sea weeds (Parker, 2008). The angel sharks can pull off the one of the world’s best disappearing acts – and they don’t even have their own show in Vegas! Watch this angel shark disappear into the sandy ocean floor with just a few wiggles of its body!
Pink Tank Scuba. (2015 May 7). Vanishing Angel Shark Scuba Blairgowrie Australia 2015 HD [Video Clip]. Retrieved from https://www.youtube.com/
With all that flattened body and hiding in the sand, the eastern angel shark looks more like a species of ray than a shark. But angel sharks actually developed their extreme body morphology through convergent evolution, meaning they have different ancestral origins than rays and skates but they have developed similar features (Frederico & Hassall, 1998; Aschliman et al., 2012; Klug & Kriwet, 2013). Through DNA testing, we know that sharks and ray share a common ancestor, however early in their evolution Batoidea, the SuperOrder containing skates and rays, and Selachimorpha, the SuperOrder containing sharks, diverged. Angel sharks are part of the Order Squatiniforms, which appears relatively late evolutionarily speaking, in shark evolution (Vélez-Zuazo, & Agnarsson, 2011).
Authority: Last & White, 2008
Family: Squantinidae; 22 species
Length: Up to 4.5 feet (1.4 m)
Weight: Up to 45 lbs (20 kg)
Habitat: Continental shelves and upper slopes
Depth: 300 – 1,000 feet (92 – 305 m)
Gestation: 8 – 12 months
Litter Range: Average litter size is 10 – 15 pups, but can can have up to 20
Home Range: Eastern Australian coast, ranging from Victoria to Queensland; hence the name Eastern Angel Shark
Diet: Bottom and mid-water fishes including smaller sharks, skates, rays, flat fishes, cuttlefish, octopus, crabs, prawns, and crustaceans
IUCN Status: Vulnerable
(Parker, 2008; Pogonoski, Pollard, & Rigby, 2016; Skomal, 2016)
Thank you for checking out this week’s unusual featured species! If you missed last week, the Spiny Dogfish, they are super cute! If there’s a species you are interested in learning more about, let me know. Leave me a comment or send me a message! I’d love to know what you’re interested in knowing more about.
The new Ocean For Sharks Shop is open! There’s handmade ocean inspired plush animals, canvas paintings, and of course my children’s book, Winifred the Wondrous Whale Shark, available in print and PDF. Be sure to stop by. Remember proceeds benefit shark research and conservation with a donation to Project AWARE!
Remember you can make a difference for marine ecosystems by calling your Congress man or woman and tell them that you care about the quality of our waters! Sharks, rays, and other marine organisms cannot speak or be represented in Congress. They need your voice. Get involved and stand up for sharks. Until next time finatics.
Featured Image Source
Murch, A. (Photographer). (n.d.). Eastern Angelshark [Digital Image]. Retrieved from http://www.elasmodiver.com/
Aschliman, N. C., Nishida, M., Miya, M., Inoue, J. G., Rosana, K. M., & Naylor, G. J. P. (2012). Body plan convergence in the evolution of skates and rays (Chondrichthyes: Batoidea). Molecular Phylogenetics and Evolution, 63(1), 28–42.
Frederico, L., & Hassall, G. (Eds.). (1998). Reader’s Digest Explores: Sharks (1st ed.). Reader’s Digest.
Klug, S., & Kriwet, J. (2013). Node age estimations and the origin of angel sharks, Squatiniformes (Neoselachii, Squalomorphii). Journal of Systematic Palaeontology, 11(1), 91–110.
Parker, S. (2008). The encyclopedia of sharks (2nd ed.). Buffalo, NY: Firefly Books Ltd.
Pogonoski, J., Pollard, D.A. & Rigby, C.L. 2016. Squatina albipunctata. The IUCN Red List of Threatened Species 2016: e.T42729A68645549.
Skomal, G. (2016). The Shark Handbook: The Essential Guide for Understanding the Sharks of the World. (2nd ed.). Kennebunkport, ME: Cider Mill Press.
Stevens, J. D. (Ed.). (1997). Sharks (6th ed.). New York: Facts on File.
Tricas, T. C., Deacon, K., Last, P., McCosker, J. E., Walker, T. I., & Taylor, L. (1997). The Nature Company Guides: Sharks and Rays. (L. Taylor, Ed.). Hong Kong: The Nature Company, Time Life Books.
Vélez-Zuazo, X., & Agnarsson, I. (2011). Shark tales: a molecular species-level phylogeny of sharks (Selachimorpha, Chondrichthyes). Molecular phylogenetics and evolution, 58(2), 207-217.