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28. Blackchin Guitarfish

Glaucostegus cemiculus

About

Blackchin guitarfish are a large species of guitarfish found in the Eastern Atlantic and Mediterranean Sea. Blackchin guitarfish bury themselves in the oceans sandy bottom and were once a daily sight at fish markets in Southern Europe during the 18th century.

Blackchin guitarfish can reach a little more than 2 meters in length, with females achieving a greater size than males. Similar to other guitarfish species, Glaucostegos cemiculus moves to inshore shallow waters for parturition, where females give birth to litters of between 4 and 7 pups. Pregnant females and reproductively active males move close to land because mating takes place immediately after the females give birth. This means that a large number of individuals are in one place at a time leaving them vulnerable to targeted fisheries. Blackchin Guitarfish have low fecundity and slow growth, meaning they cannot rapidly recover from fishing pressure.

The fins of this species are high priced in the Asian shark fin trade, exceeding €100 per kg. Overfishing and bycatch by trawlers are the main threats for the species, which is highly vulnerable due to the occurrence of reproductive aggregations in shallow habitats. Currently, encountering this species in the Balearic Islands, Alborán and Aegean seas is extremely rare.

In Banc d’Arguin National Park in Mauritania, management measures were introduced to protect this species. Fishing was banned between February and September to avoid the mating season and therefore preventing the capture of pregnant females. Gear restrictions were also introduced, and an increased abundance of Blackchin Guitarfish has been observed, indicating the success of these measures. Extending these conservation measures to the rest of the species range is a priority for the species.

  • Order: Rhinopristiformes
  • Family: Glaucostegidae
  • Population: Unknown
  • Trend: decreasing
  • Size: Up to 242cm (?)
  • Depth Range (m): 1 – 100m

EDGE Score

EDGE Score: 5.84 (?)
ED Score: 42.15 (?)
GE / IUCN Red List (?)
Not Evaluated Data Deficient Least Concern Near Threatened Vulnerable Endangered Critically Endangered Extinct in the Wild Extinct

Distribution

The Blackchin Guitarfish occurs in the Eastern Atlantic from northern Portugal to Angola, and in the Mediterranean Sea, especially the Eastern and Southern coasts.

Habitat and Ecology

The Blackchin Guitarfish is a demersal species, living on sandy bottoms in marine and brackish waters. It moves slowly and buries itself under the sand. It feeds on crustaceans such as prawns and small fish.

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