The Tope Shark (also known as the School, Snapper or Soupfin Shark) is a beautiful houndshark of the Triakidae family. They feed on a variety of fish species and take crustaceans and cephalopods when the opportunity arises. This article covers a more in-depth description, behaviour and conservation of the Tope Shark.
Tope Shark Description
The Tope Shark (Galeorhinus galeus) is a houndshark from the family of the Triakidae and the only member of the genus Galeorhinu. Other common names for this specie of shark are the Snapper Shark, Soupfin Shark and School Shark. Tagging studies have shown that the Tope Shark can travel long distances, with some individuals tagged from the United Kingdom being found as far away as the Canary Islands, Iceland and Azores. They prefer to live in temperate seas in a depth of approximately 800 meters and can grow a length of up to 2 meters.
Tope Sharks are ovoviviparous and feed both in midwater and closer to the bottom of the seabed. The IUCN classifies this species of shark as vulnerable on its Red List of Endangered Species. It is often caught in fisheries for its meat, fins and liver, which is high in vitamin A.
Tope Shark Appearance
The Tope Shark is a small shark with a shallow body and an elongated snout. The large mouth is crescent-shaped and the teeth are similar in size and shape on both jaws. They are triangular in shape, small and flat, with an oblique back angle, serrated and notched. The spiracles are small. The first dorsal fin is triangular with a straight front edge and is positioned just behind the pectoral fins. The second dorsal fin is approximately the same size as the anal fin and is positioned immediately above it. The terminal lobe of the caudal fin is serrated and is as long as the rest of the fin.
School sharks are a dark grey-blue colour on the upper surface (dorsal) and white on the belly (ventral surface). Juveniles have black markings on their fins. Mature male sharks are between 135-175 cm long (53-69 inches) and mature females are between 150-195 cm (59-77 inches) long.
Geographical Location Of Tope Shark
The Tope Shark has a wide distribution and is mainly found near the seafloor around coasts in temperate seas, down to depths of approximately 800 m (2,600 ft). It is present in the North-Eastern Atlantic and in the Mediterranean Sea, where it is rare, and in the South-Western Atlantic, where it is present between Patagonia and the southern regions of Brazil. Tope Sharks have also been seen around the coast of Namibia and South Africa. It is present in the North-Eastern Pacific, between British Columbia and Baja California, and in the South-East Pacific off the coast of Chile and Peru. It is also found on the coasts of southern Australia, including Tasmania and New Zealand.
Behaviour & Life Cycle
Tope Sharks feed mainly on smaller fish, such as midshipmen, sardines, rockfish, flatfish, and squid. Feeding takes place in open water and on the seabed, with sardines and cuttlefish being pelagic and the rest benthic species. A study of the stomach contents of fish caught in California showed that Tope Sharks are not picky eaters and eat any type of fish that are abundant at the time in their current area.
The Tope Shark is ovoviviparous, meaning that their eggs are internally fertilized and remain in the uterus, where the developing fetus will get nourishment from the large yolk sac. The gestation period is approximately one year and the number of developing pups varies with the size of the mother and averages between 6 – 12 newborns. Young from the same litter may have different parents, possibly because females can store sperm for a long time after mating. Females have traditional birthing areas in sheltered bays and estuaries where young are born. The newborns remain in these nursery areas alone when the adults move to deeper water.
Conservation
Tope Sharks are widespread, but they are at risk of overfishing in many parts of the world, where they are targeted for their liver oil, meat and fins. They are caught with gillnets, longlines and trawling nets. The IUCN lists them on its Red List of Threatened Species as critically endangered.
Puppies caught in coastal zones are subject to siltation and their habitat may deteriorate. Deep-sea cables and magnetic fields can cause currents that disrupt migration routes.
In 2010 Greenpeace International added the Tope Shark to its red list of seafood to avoid. In June 2018, the New Zealand Department of Conservation classified them as ‘non-threatened’ (with the qualifications ‘Conservation Dependent’ and ‘Threatened Overseas’ in the New Zealand Threat Classification System).
Worldwide, there is a great demand for fins and they are increasingly threatened. Like all sharks, they grow slowly, produce few offspring per year and are vulnerable to fishing. They are protected in European waters and are not targeted, but can be captured if caught as bycatch or illegal trawling. In order to protect this species, they should never be eaten as shark fin soup or other by-product uses.