The diet of the porcupine ray consists mainly of benthic invertebrates and bony fishes, which it digs up from the sea floor.

The porcupine ray has long been valued for its rough and durable skin, which was made into a shagreen leather once used for various utilitarian and ornamental purposes, such as to cover sword hilts and shields.

Unregulated fishing has led to this species declining in many parts of its range, thus it has been listed as Vulnerable by the International Union for Conservation of Nature.

German naturalists Marcus Elieser Bloch and Johann Gottlob Schneider described the porcupine ray in their 1801 work Systema Ichthyologiae, based on a partial dried skin obtained from Mumbai, India.

[4][5] In 1837, Johannes Peter Müller and Friedrich Gustav Jakob Henle placed the porcupine ray in a new genus, Gymnura.

[7] Urogymnus has traditionally been considered monotypic (only containing U. asperrimus), but several other species were moved to this genus from Himantura in 2016 based on morphology and molecular evidence.

It is found all along the continental periphery of the Indian Ocean, from South Africa to the Arabian Peninsula to Southeast Asia to Ningaloo Reef off western Australia, including Madagascar, the Seychelles, and Sri Lanka; it has colonized the eastern Mediterranean Sea through the Suez Canal.

[11][12] The pectoral fin disc of the porcupine ray is evenly oval, almost as wide as long, and very thick at the center, giving it a domed appearance.

The porcupine ray is plain light to dark gray or brown above, darkening to blackish towards the tail tip, and white below.

[12][13] When feeding, it plows deeply into the bottom, expelling excess sediment from its spiracles in a plume visible from a long distance away.

[2] Parasites documented from this ray include the tapeworm Rhinebothrium devaneyi, the nematode Echinocephalus overstreeti,[15] and the capsalid monogeneans Dendromonocotyle urogymni[16] and Neoentobdella baggioi.

[17] The porcupine ray is aplacental viviparous, with the developing embryos sustained to term by histotroph ("uterine milk") secreted by the mother.

[14] The multispecies coastal fisheries that catch the porcupine ray are largely unregulated, which seems to have resulted in its dramatic decline or local extinction in the Bay of Bengal, the Gulf of Thailand, and likely elsewhere in its range.

Potential additional threats to this species include habitat degradation from coastal development, and depletion of its food supply from overfishing.