Growing Pains for the Groovebelly Stingray – oceanbites

Torres, G. A., Martins, R. S., Fischer, L. G., Cardoso, L. G., Sant’Ana, R., & Mourato, B. (2026). Age and growth of the endemic groovebelly stingray (Dasyatis hypostigma), a closely exploited batoid in the Brazilian Meridional Margin (21–34° S). Journal of Fish Biology, 108(4), 1246–1258. https://doi.org/10.1111/jfb.70305

Sea to Belly

Stingrays in all probability aren’t the very first thing that come to thoughts whenever you suppose of seafood. However, some species are extremely valued round the world for their meat. In southern Brazil, the groovebelly stingray (Dasyatis hypostigma) is usually focused by business fisheries alongside the Brazilian Meridional Margin (BMM).

Despite an estimated 250.3 tonnes caught yearly, the species is usually misreported in catch information. Rather than being recognized individually, groovebelly stingrays are steadily grouped with different stingray species beneath generic labels, making it tough to precisely monitor harvest charges and population trends.

The drawback is compounded by the lack of data on the species’ life historical past, significantly its age and growth. This data is essential for fisheries management as a result of they help decide sustainable harvest ranges and assess a population’s vulnerability to overfishing. To tackle this information hole, Torres et al. sampled groovebelly stingrays from the BMM to develop age and growth fashions that may help future management efforts.

Age Rings

While measuring a stingray’s measurement is easy, figuring out its age is more difficult. Fortunately, researchers can estimate age by analyzing growth bands within the vertebrae. Much like the rings of a tree, these bands are deposited yearly as the animal grows, offering a dependable file of age.

Of the 280 rays sampled, the largest male discovered was 10 years outdated with a disc width (widest distance throughout a ray’s pectoral fins) of 465 mm (18.31 in). On the different hand, the largest feminine was 11 years outdated with a disc width of 580 mm (22.83 in). Most people sampled had been anyplace from one to seven years outdated.

Males had been discovered to grow quicker than females, however reached smaller sizes than females, as indicated by the largest people discovered for every intercourse. This sample, together with estimated growth charges, matched southern populations alongside the coast of Argentina and Uruguay. While this will likely seem to be an apparent conclusion, the huge distinction in latitudes had potential to have an effect on growth charges because of seasonality and/or water temperature.

Selective Limitation

The researchers did be aware their research outcomes could also be restricted by fishing gear selectivity. Specifically, many rays sampled had been between 300 and 450 mm disc width which got here from gillnet gear. Since gillnets are designed with particular mesh sizes, they have a tendency to catch people within a restricted measurement vary. Smaller rays could cross by way of the mesh, whereas bigger people could keep away from changing into entangled altogether. Therefore, there may be a chance that the pattern doesn’t symbolize the full population, with outcomes skewed in direction of medium sized people. Further work ought to goal to pattern from a wide selection of gear varieties to get a more correct distribution of sizes.

Collecting the Pieces

Even with this limitation, this research takes a giant step ahead in understanding the groovebelly stingray population on the Brazilian Meridional Margin. The similarity in growth patterns noticed throughout Brazil, Argentina, and Uruguay could recommend the existence of a giant, interconnected population spanning a lot of the southwestern Atlantic coast. If true, migration from southern parts of the species’ vary might help replenish closely fished areas.

However, extra analysis continues to be needed. Improved reporting of groovebelly stingray landings, mixed with more correct estimates of growth and mortality charges, will permit researchers to raised assess population measurement and long-term stability. Such data will likely be important for guaranteeing that this useful fishery stays sustainable in the future.