Malacobdella grossa (Müller 1776)

are eaten by

• Global Biotic Interactions: Gadus morhua Linnaeus 1758 (cabillaud, morue)
• Global Biotic Interactions: Gadus morhua Linnaeus 1758 (cabillaud, morue)

are ectoparasites of

• Global Biotic Interactions: Acanthocardia echinata (Linnaeus 1758) (Acanthocardia echinata)
• Global Biotic Interactions: Mya truncata Linnaeus 1758 (Mye tronquée)
• Global Biotic Interactions: Arctica islandica (Linnaeus 1767) (Cyprine d'Islande)
• Global Biotic Interactions: Zirfaea crispata (Linnaeus 1758) (grand pholade rugueuse)
• Global Biotic Interactions: Cerastoderma edule (Linnaeus 1758) (Coque commune)

have endoparasite

• Global Biotic Interactions: Thigmophrya annella Fenchel 1965
• Global Biotic Interactions: Orchitophrya malacobdellae Jennings 1968

have host

• Global Biotic Interactions: Arctica islandica (Linnaeus 1767) (Cyprine d'Islande)
• Global Biotic Interactions: Arctica islandica (Linnaeus 1767) (Cyprine d'Islande)
• Global Biotic Interactions: Arctica islandica (Linnaeus 1767) (Cyprine d'Islande)
• Global Biotic Interactions: Mercenaria mercenaria (Linnaeus 1758) (Praire)

parasitize

• Global Biotic Interactions: Siliqua patula (Dixon 1789)
• Global Biotic Interactions: Mercenaria mercenaria (Linnaeus 1758) (Praire)