Hooked on fish blood: the reliance of a gill parasite on haematophagy.

Parasitism involves diverse evolutionary strategies, including adaptations for blood feeding, which provides essential nutrients for growth and reproduction. (Polyopisthocotyla: Microcotylidae), an ectoparasitic flatworm, infects the gills of gilthead seabream (), significantly affecting fish health, welfare and Mediterranean cage farm profitability. Despite its impact, limited information exists on its feeding behaviour.