Which sea creature feeds on it's mate's blood?

Deep-Sea Anglerfish Have Unusual Sex Lives. The Females Are Up To 20 times bigger than the males! When a tiny male meets a female he clamps on to her side with his powerful jaws and won't let go. Eventually he becomes fused to her body and feeds on her blood. The female has a handy supply of sprem to fertilize her eggs.but has to carry the "hanger-on" wherever she goes.

img source: https://oceantoday.noaa.gov/fullmoon-anglerfish/welcome.html