Featured Species: Ornate Eagle Ray (Aetomylaeus vespertilio)

This week’s featured species is one of the most beautiful species of rays I have ever seen and is probably the species I want to personally see the most on a dive. It’s the Ornate Eagle Ray (Aetomylaeus vespertilio), a member of the Myliobatidae family, which if you recall also contains the Bat Eagle Ray (Myliobatis californica) and the Spotted Eagle Ray (Aetobatus narinari). The ornate eagle ray is an impressive ray species. When fully grown, this species can reach incredible lengths, with a disc width of 7.8 feet (2.4 m), and they can reach 13 feet (4 m) from their nose to the tip of their tail! Unlike stingrays, the ornate eagle ray lacks a stinging spine on its very long tail. But their most striking characteristic is their beautiful patterning, made of a complex pattern of lines and reticulations across their backs, which gives them their name sake of Ornate or Reticulated Eagle Ray (Last, Stevens, & Compagno,1995).

Ornate_eagle_ray_(Aetomylaeus_vespertilio)_Baa_Atoll,_Maldives_(2018)
Mart, S. (Photographer). (2018). Ornate eagle ray (Aetomylaeus vespertilio) Baa Atoll, Maldives [Digital Image]. Retrieved from https://commons.wikimedia.org/

The ornate eagle ray has a widespread, yet patchy distribution throughout the Indo-Pacific (Bonfil & Abdallah, 2004). This species is found as far west as the Red Sea and the southwestern coast of Africa and as far to the east as New Zealand. They prefer inner continental slopes and shelves over sandy and muddy substrates (Carpenter, 1998). To date, their population size and structure is unknown. They appear to be naturally uncommon and are rarely observed (White & Kyne, 2016). This makes them intrinsically sensitive to over-exploitation and unregulated fisheries.

Untitled
IUCN (Author). (2016). Geographic Range of Ornate Eagle Ray [Digital Image]. Retrieved from https://www.iucnredlist.org/

Like many species of Myliobatids, the ornate eagle ray has bony, plate-like teeth that are ideal for crushing the hard shells of clams, oysters, and other crustaceans (Parker, 2008). The duck-like snout of the eagle rays are specially adapted for digging into sandy substrates and rooting out these tasty treats. In the video below, you can watch (around the 2 minute mark) as the ornate eagle ray digs its mouth down into the sand and scoops out its food before crushing it.

21e6ab3178be601351e9a2f54a91181e.image.568x550
FossilOneline (Photographer). (n.d.). Ornate Eagle Ray Jaw [Digital Image]. Retrieved from https://fossilsonline.com/

Ihurur Funna (Videographer). (2014). Ornate Eagle Ray [Video Clip]. Retrieved from https://www.youtube.com

 

Due to the rarity of the ornate eagle ray, very little is known about its biology, life history characteristics, and ecology. Its reproductive cycle is a mystery. It is suspected that their reproductive biology resembles that of other Myliobatids, which have low fecundity, bearing litters of up to four pups at a time (Last, Stevens, & Compagno,1995; Carpenter, 1998). Their exact age potential and growth rates are not yet known. Further research into this species in needed.

OrnateEagleRay_01_201907311604_V3
Csotonyi, J. (Artist). (2019). Ornate Eagle Rays [Artist Rendition]. Original Content.

At present, the International Union for the Conservation of Nature (IUCN) classifies the ornate eagle ray as an Endangered species. They are a naturally rare species that is highly susceptible to inshore fisheries and vulnerable to the high level of exploitation throughout its habitat. Presently, the ornate eagle ray faces pressures from multiple fisheries including trawl, gillnets, and trammel nets (White & Kyne, 2016). When they are caught, they are retained and marketed in considerable numbers in Thailand and Malaysia, which are thought to be unsustainable (Carpenter, 1998). They are also utilized for their cartilage and their meat throughout their range, with the notable exception of Australian markets (White, Last, Stevens, & Yearsly, 2006). At the time of this writing, there are no species specific conservation efforts for the ornate eagle ray. It is likely this species requires legal protection to manage their harvest and trade at sustainable levels, though this may prove difficult to enforce in many countries (White & Kyne, 2016).

Aetomylaeus_vespertilio01
Bineesh, K. (Photographer). (2011). Aetomylaeus vespertilio [Digital Image]. Retrieved from https://commons.wikimedia.org/
I’m delighted to announce a partnership with the wonderfully talented Julius Csotonyi! Julius creates stunning shark coloring sheets that are fun and educational for all ages. From time to time you’ll see Julius’ work featured right here and on my other social media platforms! You can find more coloring sheets in the store! You are welcomed to download these beautiful sheets and enjoy them with family and friends.

Aetomylaeus-vespertilio_Csotonyi_01_201907311554.jpg

Ray Stats

Authority: Bleeker, 1852

Family: Myliobatidae, 42 species

Disc Width: 7.8 feet (2.4 m)

Weight: Maximum weight unknown; suspected 500 lbs (230 kg)

Habitat: Inner continental shelf over sandy substrates

Depth: 0 – 360 feet (0 – 110 m)

Reproduction: Reproductive Biology Unknown

Gestation: Unknown

Litter Range: 4 Lower litter sizes suspected based on other myliobatids, which bear up to 4 pups per litter

Home Range: Widespread but patchy throughout Indo-Pacific Ocean

Diet: Crustaceans and bony fishes

IUCN Status: Endangered

(Carpenter, 1998; Bonfil & Abdallah, 2004; Last & Stevens, 2009; White & Kyne, 2016)

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. Proceeds benefit shark research and conservation with a donation to Project AWARE!

Thanks so much for checking out the beautiful Ornate Eagle Ray! If you missed last week’s featured species, please be sure to check out the Sicklefin Lemon Shark! If there is a species of elasmobranch you’d love to know more about, leave me a comment or send me a message! I would love to do a feature on your favorite species. Also connect with me on Instagram and Facebook for even more elasmo fun!

Conservation legislation needs public support in order to become law and help protect the environment and wildlife. Tell your representatives that you care about environmental and wildlife conservation. It only takes a moment to make a change that will last a lifetime. Until next time finactics!

_DSC2870

Featured Image Source

Kydd, A. (Photographer). (2018). Ornate Eagle Ray [Digital Image]. Retrieved from https://www.instagram.com/alexkyddphoto/

Literature Cited

Bonfil, R., & Abdallah, M. (2004). Field identification guide to the sharks and rays of the Red Sea and Gulf of Aden. Food & Agriculture Org..

Carpenter, K. E. (1998). FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Cephalopods, crustaceans, holothurians and sharks2, 687-1396.

Last, P. R., Stevens, J. D., & Compagno, L. J. V. (1995). Sharks and rays of Australia. Reviews in Fish Biology and Fisheries5(1), 136-138.

Parker, S. (2008). The encyclopedia of sharks (2nd ed.). Buffalo, NY: Firefly Books Ltd.

White, W. T., Last, P. R., Stevens, J. D., & Yearsly, G. K. (2006). Economically important sharks and rays of Indonesia(No. 435-2016-33677).

White, W.T. & Kyne, P.M. (2016). Aetomylaeus vespertilioThe IUCN Red List of Threatened Species 2016. Retrieved from https://www.iucnredlist.org/species/60121/68607665

Next Post

Coming Soon…

Previous Post

Featured Species: Sicklefin Lemon Shark (Negaprion acutidens)

 

One thought on “Featured Species: Ornate Eagle Ray (Aetomylaeus vespertilio)

Add yours

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Powered by WordPress.com.

Up ↑

%d bloggers like this: