Chain catshark

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The chain catshark (Scyliorhinus retifer) is a small, uniquely patterned shark with a special power: it has the super power of fluorescence! Mikhail Matz, a marine biology professor at the University of Florida first observed this unique property in 2005, catching it on film. No one is sure what the purpose of this unique characteristic is, and more research needs to be done on it.

Also known as the chain dogfish, it has a pretty restricted range (only found in the western Atlantic Ocean in the Gulf of Mexico) which suggests it does not partake in large migrations. One limiting factor for this shark may be temperature, keeping it away from the northern western Atlantic during the winter. They are found swimming on the bottom of outer continental shelves and upper slopes, usually around 58 to 359 meters (190-1,178 ft). It can also be seen at shallower depths. These animals mostly spend their time resting, camouflaging with its surroundings to hide from larger fish and sharks.

Sometimes kept in aquariums, they mostly feed on teleost fish, squid, polychaetes and crustaceans.Females tend to be bigger (0.52 m/1.7 ft) than males (0.50 m/1.64 ft). Mating has been observed in these animals, showing that males bite onto pectoral fins for a better grip and mating occurs repeatedly. The female can store sperm and lay eggs (always in a pair) from different sperm pockets. The two eggs can have a birth interval of a few minute to almost a week! Egg cases are a dark amber color with white bands and two coiled tendrils, allowing them to snag onto rocks or other structures. Embryos take 8-12 months, depending on temperature in the water. Eggs are laid in their blastodisc form.

Bottom trawlers often capture large numbers of juveniles in certain locations (i.e. Virginia near the Chesapeake Bay), leading scientists to believe these are nurseries. As of right now, due to their small size, there is no fishery for these animals besides the aquarium business. The Scyliorhinus retifer is listed as a species of Least Concern (LC) by the IUCN.

ever heard of the chain catshark?

glossary

• Blastodisc form: Refers to a round single-cell layer of cells inside the blastula from which the embryo is going to form.
• Continental shelf: Extends from a continent underwater, resulting in a shallow-water area.
• Continental slope: The steep slope from a continental shelf to the ocean floor; usually around 20 km (12.4 miles) wide and made up of mud and silt substrate. It is an ideal area for deep sea fishing.
• Crustaceans: Group of animals with a hard exoskeleton, jointed legs and segmented body.
• Fluorescence: The emission of light.
• IUCN: International Union for Conservation of Nature.
• Pectoral fins: Fins located behind the gills on either side.
• Polychaete worms: Multi-segmented worms living in all environments in the world's oceans.
• Pup: Give birth to baby sharks (pups).
• Pups: Baby sharks.
• Teleost: Bony fishes.
• Trawl fisheries: Fisheries that pull a fishing net through the water behind one or more boats.

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