Psammobatis rutrum

Common Name

Spade Sandskate

Year Described

Jordan, 1891

Identification

Disk heart-shaped with broad, rounded pectoral fins and a weakly concave anterior margin of disk (more concave in males). Snout short and soft with convex lateral edges. Conical snout tip slightly projects and sometimes has a filamentous tip. Skin with sparse denticles in juveniles but becomes smooth with age with some denticles around the margins. Ventrum quite smooth. Multiple orbital thorns in a crescent shape around each orbit. A patch of thorns on the scapular region. There are a few nuchal thorns on midline. There are up to five rows of small thorns along the midline. Tail rather slender and 1.5 times longer than disk length, with 3-5 rows of thorns. Caudal fin well developed and almost the size of the dorsal fins. Dorsal fins are paired far back on tail, close together, and very small. Pelvic fin with two portions separated with a deep notch. Claspers large. Mouth narrow. Nasal flaps broad with fringes. Teeth are conical and sharp (43-66 in upper jaw).

Color

Dorsum brown with dense faint pale spots and dark speckles. No consistent pattern. Tail faintly banded with speckles. Belly white.

Size

A small species: maximum size to 32cm TL.

Habitat

Coastal from 30-150m. Benthic.

Range

Southwestern Atlantic: S. Brazil to N. Argentina.

References

Last, P.R., White, W.T., Carvalho, M.R. de, Séret, B., Stehmann, M.F.W & Naylor, G.J.P (Eds.). 2016. Rays of the World. CSIRO Publishing, Melbourne.

Other Notes

The only similar species is the similarly small Psammobatis extenta, which has smoother skin, less teeth rows, and a different coloration.