Thornback ray (Platyrhinoidis triseriata) care guide

Group
Marine fish
Other names
Thornback guitarfish, California thornback, Banjo shark, Round skate, Shovelnose
Family
Platyrhinidae (thornbacks)
Origin
North-east Pacific from Tomales Bay to Magdalena Bay, plus the Gulf of California; sandy and muddy bays, beaches and kelp beds, usually under 6 m.
Water
saltwater
Maximum size
91 cm
Temperature
16–22°C
pH
8.1–8.4
Hardness
Salinity SG 1.023–1.026
Care level
expert
Temperament
peaceful
Reef safe
no

Care

Size: It reaches about 91 cm and needs a very large, long system: it is for public-aquarium-sized systems, not home aquaria. The list suggests at least 360 US gallons (about 1,360 litres) with no decor. Water: a cool-water Californian species. 16–22 °C, pH 8.1–8.4 and SG 1.023–1.026 are general marine guidance. Behaviour: harmless and docile and does well in public aquariums. Its large hooked back thorns snag nets easily, so use a container or soft bag to move it. Identification: not the European thornback ray (Raja clavata), despite the shared name. Conservation: IUCN Least Concern (Data Deficient in Mexican waters). Selling: our policies require the adult size and long-term tank needs to be stated clearly in the listing. Large fish must travel by a specialist live-animal courier (see the Livestock shipping guide). Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies); Wikipedia (en.wikipedia.org/wiki/Platyrhinoidistriseriata). Checked October 2026.

Diet

Worms, crabs, shrimps, isopods, squid and small fish such as anchovies and gobies. Offer chopped shrimp, squid, fish and worms.

Breeding

Gives birth to 1–15 live young (about 11 cm) roughly a year after late-summer mating.

Compatibility and tank mates

Not reef safe: may eat bottom-living fish and crustaceans.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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