The ornate eagle ray or reticulate eagle ray (Aetomylaeus vespertilio) is a species of large stingray of the family Myliobatidae. It is a cartilaginous fish, like other sharks, rays, and skates. A. vespertilio is ovoviviparous and they produce 4 to 6 young per breeding cycle. They are often seen alone, but commonly form groups during breeding season in mid summer. There is very little research done on this ray due to the extreme rarity of its sightings.

Appearance

A. vespertilio is the largest of the eagle rays and has a pectoral disc width that can reach greater than 3 m (9.8 ft), and a total body length of up to 6 m (20 ft) due to their long tail. The ornate eagle ray has a clearly distinct pattern of reticulate dark lines and rings on its back. If the extremely long tail is unbroken and it lacks a venomous spine, making it harmless to humans.

Distribution

A. vespertilio can be spotted up to 110 m (360 ft) deep along the coasts of Australia, China, India, Indonesia, Malaysia, Maldives, Mozambique, Palau, Philippines, Seychelles, South Africa, Taiwan, and Thailand. Despite the wide range it can be spotted at, it is rarely observed, and has been suspected to have had a large population decline within the past three generations. Currently, this species is considered "critically endangered" by the International Union for Conservation of Nature (IUCN).[1] There have been fewer than 60 confirmed sightings of A. vespertilio, giving it the nickname "the unicorn of the sea."[2]

Threats

A. vespertilio are estimated to have a low fecundity similar to other myliobatids. They have a generation length of 15 years, and can grow as old as 24 years.

Although A. vespertilio was once common, they are now considered rare in areas such as the Gulf of Thailand. The largest threats they encounter are demersal fisheries,[3] which are used frequently in the areas they live in. When caught, they are mostly retained and sold in fish markets, and their low birth rate makes recovery from over fishing difficult. It has been hypothesized that the A. vespertilio has experience over a 50% decrease in population size over the last 3 generations (45 years)[1] No species-specific conservation measures have taken place.

References

  1. ^ a b c Finucci, B; Rigby, C L; Bineesh, K K; Armstrong, A O (2024). "Aetomylaeus vespertilio". IUCN Red List of Threatened Species. 2024: e.T60121A124440895. doi:10.2305/IUCN.UK.2024-1.RLTS.T60121A124440895.en. Retrieved 2025-03-05.
  2. ^ Ledwidge, Emilie (March 2021). "Issue 17 / Wolf Mother". Oceanographic Magazine. No. 17. Retrieved May 12, 2024.
  3. ^ Brander, K. (2001). "Demersal Species Fisheries". Encyclopedia of Ocean Sciences. pp. 718–725. doi:10.1006/rwos.2001.0449. ISBN 978-0-12-227430-5. Demersal fisheries use a wide variety of fishing methods to catch fish and shellfish on or close to the sea bed. Demersal fisheries are defined by the type of fishing activity, the gear used and the varieties of fish and shellfish which are caught.

Sources

  • Debelius, Helmut (1999). Indian Ocean Reef Guide: Maldives, Sri Lanka, Thailand, South Africa, Mauritius, Madagascar, East Africa, Seychelles. Int'L Book Import. ISBN 978-3-931702-67-0.
  • McGrouther, M. 2018, Australian museum website: Ornate Eagle Ray, Aetomylaeus vespertilio (Bleeker, 1852)
  • Araujo, Gonzalo; Legaspi, Christine; Matthews, Kinsey; Ponzo, Alessandro; Chin, Andrew; Manjaji-Matsumoto, B. Mabel (October 2020). "Citizen science sheds light on the cryptic ornate eagle ray Aetomylaeus vespertilio". Aquatic Conservation: Marine and Freshwater Ecosystems. 30 (10): 2012–2018. Bibcode:2020ACMFE..30.2012A. doi:10.1002/aqc.3457.
  • Venables SK, Conradie J, Marshall AD. First records of the ornate eagle ray Aetomylaeus vespertilio from the Inhambane Province, Mozambique. Journal of the Marine Biological Association of the United Kingdom. 2021;101(7):1085-1088. doi:10.1017/S0025315422000054
Allikas: http://en.wikipedia.org/wiki/Aetomylaeus_vespertilio
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