Thornback Ray

Selsey has several different rays in its waters, but the Thornback is the most often encountered by divers and fisherman.

This nocturnal hunter spends the day buried in the sand and has evolved over time so when buried, as they prefer, their breathing holes called spiracles are located behind the eyes and above the sand. These also help with a developed sense of smell that they use to hunt prey, preferring to eat crustacea, worms, molluscs, and echinoderms. 

Image courtesy of Cat Briggs 

Like all sharks and rays, they start life in an egg case called a Mermaids Purse. Each purse contains just one embryo which develops in the case for between 4-6 months. After that time, a perfect miniature ray will hatch out to begin life. They may start small but the largest ever recorded weighed an immense 18kg. Living for up to 12 years, most reach about a metre across.  One adult is likely to lay only 140 eggs a year and males do not reach maturity until 8 years old, that is potentially as few as 560 rays that he will sire in a lifetime. 

If you have any questions about different Rays found off Selsey, then contact Anya Frampton, Selsey's resident SSI Marine Ecology Instructor at Mulberry Marine Experiences.

Image courtesy of Anya Frampton