The horn shark is preyed upon by larger fishes and the northern elephant seal ("Mirounga angustirostris"), which consumes adults, juveniles, and egg cases. In addition, they are captured and eaten by bald eagles ("Haliaeetus leucocephalus") at Catalina Island, and large marine snails are able to drill into their egg cases to extract the yolk. The tough skin and spines of this species confer some protection; a Pacific angelshark ("Squatina californica") has been filmed engulfing a juvenile horn shark, only to spit it out due to its spines. Known parasites of this species include the tapeworms "Acanthobothrium bajaensis" and "Acanthobothrium puertecitense", the copepod "Trebius heterodonti", and the nematode "Echinocephalus pseudouncinatus", which spends its larval stage inside potential prey such as scallops and sea urchins.