Plain maskray
A small, plain-patterned stingray endemic to northern Australia.
The plain maskray (Neotrygon annotata), also called the brown stingray, belongs to the Dasyatidae family. This ray lives only in shallow, soft-bottomed areas off northern Australia. It has a slender build and is listed as Near Threatened by the IUCN, mainly because bottom trawl fisheries accidentally catch it.
This species has a diamond-shaped pectoral fin disc that is grayish green and reaches 24 cm (9.4 in) across. Its short, whip-like tail is marked with alternating black and white bands and has fin folds both above and below. Short rows of thorns run along the back and the tail base, but the rest of the skin is smooth. Like other maskrays, it has a dark mask-like pattern around its eyes, but its overall patterning is plain compared to its relatives.
The plain maskray feeds mostly on caridean shrimp and polychaete worms, with some small bony fish also in its diet. It is viviparous: females give birth to litters of one or two young, which are nourished during pregnancy by histotroph (uterine milk). This ray has no economic value but gets caught as bycatch in bottom trawls. Its gracile body makes it less able to survive such capture than other maskrays. Because of its limited range and low reproductive output, the IUCN considers it Near Threatened.
Quick Facts
- Genus
- Neotrygon
- Species
- annotata
Facts from the source article.
Lore & Background
The plain maskray was first scientifically described by CSIRO researcher Peter Last in a 1987 issue of Memoirs of the National Museum of Victoria. Its specific name annotatus comes from the Latin an ('not') and notatus ('marked'), referring to its plain coloration. The holotype is a male 21.2 cm (8.3 in) across, caught off Western Australia. Last initially placed it in Dasyatis, but in 2008, Last and William White elevated the maskray group to the genus Neotrygon based on morphological and molecular evidence. A 2012 phylogenetic analysis found the plain maskray and the Ningaloo maskray to be the most basal members of Neotrygon, with the lineage diverging ~54 million years ago. The study also revealed two genetically distinct clades, suggesting a cryptic species complex, with the split estimated at ~4.9 million years ago, likely due to coastline changes.
Reader's Guide
The plain maskray is a benthic species that feeds mainly on caridean shrimp and polychaete worms, and to a lesser extent on small bony fishes. It is viviparous, with females producing litters of one or two young nourished via histotroph ('uterine milk'). It lacks economic value but is caught incidentally in bottom trawls, particularly by Australia's Northern Prawn Fishery. Due to its gracile build, it is less able to survive trawling than other maskrays. Its limited distribution, low fecundity, and historical pressure from Japanese, Chinese, and Taiwanese trawlers (1959–1990) have led the IUCN to list it as Near Threatened. The species is the least common of the maskrays in its region and tends to be found farther from shore than its relatives.
Did You Know?
- The plain maskray grows to a maximum disc width of 24 cm (9.4 in).
- Its tail has alternating black and white bands and fin folds above and below.
- Females reach sexual maturity at a disc width of 18–19 cm (7.1–7.5 in), smaller than males.
- A 2012 genetic study suggests the plain maskray may be a cryptic species complex.
More in Reef Sharks and Rays, Part 3 1-24
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