Egg-Cellent Find For Shark Relatives

There are over 1,000 species of cartilaginous fish roaming in our oceans. These fish include sharks and their relatives, the batoid fishes (including skates, rays, guitarfishes, and sawfishes) and chimaeras. Skates and rays are often known as #flatsharks on social media since both animals are usually flat and sport a long tail.

One of these species is the flapper or common skate (Dipturus intermedius), previously considered part of the Dipturus batis species complex. They are the largest member of the family Rajidae found in Europe and once had a widespread range but is now classified as Critically Endangered by the International Union for Conservation of Nature (IUCN) due to their low intrinsic population growth rate and sensitivity to overfishing. Although flapper skates were effectively extirpated across much of their historical range, small populations have persisted in these European shelf waters. One of these areas is along the western and northern coasts of Scotland which is where marine biologist Dr. Lauren Smith and her team recently discovered over a hundred egg cases belonging to these vulnerable animals.

Volunteer divers and scientists, with the help of local scallop divers, found the so-called mermaid purses nestled between rocks for protection. Measuring over 25 cm long and taking almost 18 months to hatch, the observers noticed the egg cases were of different sizes and ages, indicating that the site is probably used by a resident population of this endangered skate and probably has been for multiple years. “This is the biggest and most important egg laying site discovered to date,” explained Smith. “Unfortunately, both the purses themselves and the newly hatched young are so large that they can be caught in bottom towed gear and destroyed – a single pass with a dredge could obliterate the site!”

The discovery comes almost a year after the research team recorded egg cases at the same site in November 2019 and reported the findings to Marine Scotland since the flapper skate is one of 81 Priority Marine Features the Scottish Government is committed to protecting. However, according to Smith, no action has been taken by Marine Scotland to protect this site. Fortunately, other conservation measures have been put in place such as it being illegal for fishers to commercially target the flapper skates since 2009. But even this can’t protect them from being captured as bycatch from multiple fisheries.

Capable of reaching over 8.2 feet (2.5 meters) in length, this animal is at greater risk of extinction than the mountain gorilla or the