Ningaloo maskray

Lore & Background

The first known sighting of the Ningaloo maskray was during a study of Ningaloo Marine Park's sharks and rays, funded by the Western Australian Marine Science Institute (WAMSI). It was described by Peter Last, William White, and Melody Puckridge in a 2010 article for the scientific journal Aqua. The type specimens are two adult males, one 30 cm and the other 29 cm across, both collected from Five Fingers Reef near Coral Bay, Western Australia.

A 2012 phylogenetic study, based on mitochondrial and nuclear DNA, concluded that the Ningaloo maskray and the plain maskray (N. annotata) are the most basal members of their genus. The Coral Bay population showed deep differences in mitochondrial DNA from the Shark Bay population, indicating that they belong to different lineages. Whether they represent separate species is ambiguous, as rays from the two locations do not differ physically or in known nuclear DNA markers. This genetic divergence suggests that the Ningaloo maskray population had once been divided by sea level changes; using different methods of estimation, this event is thought to have occurred either c. 11 Ma, during the Miocene, or 3–2 Ma, during the Pliocene.

The Ningaloo maskray has a diamond-shaped pectoral fin disc about 1.1 times wider than long, with straight to slightly convex leading margins and rounded outer corners. The eyes are large and protruding, with large crescent-shaped spiracles behind. The whip-like tail bears two very slender stinging spines on the upper surface. The upper surface of the disc is yellowish brown with numerous dark orange and light blue spots; there is a darker mask-like marking across the eyes as in other Neotrygon species, though it may be hard to discern. The tail has alternating black and white bands behind the stings.

Reader's Guide

The Ningaloo maskray is notable for its highly specific habitat preferences, being found only on reddish sand near reefs in inshore waters less than 5 m deep. Its coloration grants it excellent camouflage within this habitat. Compared to other maskrays, it has more protruding eyes that allow it to bury itself deeper in the substrate while remaining aware of its surroundings. Because it lives in such shallow waters, it is generally not susceptible to fisheries. Conversely, its narrow habitat preferences may render it vulnerable to habitat degradation. This species is protected to some extent as its range includes the World Heritage Sites of Ningaloo Reef and Shark Bay. The International Union for Conservation of Nature (IUCN) presently lacks sufficient data to assess its conservation status, listing it as Data Deficient due to lack of information. The genetic divergence between the Coral Bay and Shark Bay populations, possibly caused by historical sea level changes, adds scientific interest to this species, though whether they represent separate species remains ambiguous.

Did You Know?

• A 2012 phylogenetic study found that the Coral Bay and Shark Bay populations show deep differences in mitochondrial DNA, possibly due to a historical division by sea level changes estimated to have occurred either c.
• This species can bury itself deeper than other maskrays thanks to its protruding eyes.