The shortnose guitarfish (Zapteryx brevirostris) is a species of fish in the Trygonorrhinidae family found in the southwest Atlantic in coastal parts near sandy sea floors of southern Brazil, through Uruguay, to northeast Argentina. While the guitarfish is reported to range in northeast Argentina, there are reports of them traveling down to the Falkland Islands. This voyage could be due to Brazil's current changing in the summer months. It reaches a length of . Their diet consist of crabs, worms, clams and small fishes. The guitarfish has become critically endangered because of the rapid decline caused by overfishing. The subsequent accidental catch and release of the shortnose guitarfish can also lead to its endangered conservation status.
The average length of the shortnose guitarfish that has been recorded for females is 66.1 cm whereas the male average length is 63.5 cm.
The diet of the shortnose guitarfish includes amphipods, polychaetes, lancelets, decapods, cumaceans and isopods. In layman's terms, this consists mostly of Crabs, worms, clams and small fishes. The diet of the shortnose guitarfish changes as the individual gets larger, larger guitarfish predominantly eat isopods, decapods and polychaetes and less amphipods.
The shortnose guitarfish, like many other rays, have characteristics such as slow growth, later sexual maturity and smaller number of births to young. The estimated gestational length was between 9 and 12 months. As the shortnose guitarfish grow and mature, the females tend to be larger than the males, but the females grow at a slower rate and reach sexual maturity at a later age than males. Sexual maturity for females is reached when they get to an average length of 42 cm while sexual maturity for males is reached at an average length found to be 43.7 cm.
A substrate that is sand-like is beneficial to their growth especially in captivity since they benefit from burying themselves from predators. Without a substrate in their enclosed habitat, they can have weight loss and even be seen doing the "shaking motion" of burying themselves without any substrate present.
There is now growing evidence that the catch and release of many Elasmobranchs can cause psychological harm to the individuals. In addition, shortnose guitarfish are more sensitive to capture during gestation whereas the embryos are likely to be aborted after capture and release. When pregnant females are captured, all of females had abortions of their young and most of the females subsequently died after these abortions. The main cause of death and the cause of the IUCN Endangered list is because of fishing pressures including commercial fishing.