The giant Pacific octopus (Enteroctopus dofleini) is a popular exhibit species in many public display aquaria, though information on veterinary care is limited. A retrospective review of electronic records (Tracks©) was conducted looking specifically at time in collection, antemortem clinical signs, and postmortem histopathology. Between March 1, 2004 and March 4, 2012, the National Aquarium housed 18 giant Pacific octopuses, 16 of which died during the review period.
There were seven males, eight females, and one animal whose sex was not noted. Average time in captivity for all animals was 350±174 days (male: 312±108 days, females: 399±220 days). The giant Pacific octopus is semelparous—males and females die after gamete release.1 Nine (56%) of the animals in this review were sexually mature at the time of death, confirmed either by histopathology or observation of gamete release.
Common antemortem clinical signs included anorexia, behavior changes (i.e., decreased interaction with staff, lethargy, and color changes), skin lesions, ocular changes, and self-mutilation. Histopathologic diagnoses included infectious/inflammatory processes affecting multiple organ systems including gastrointestinal, cardiovascular, respiratory, ophthalmic, renal, integumentary, and reproductive. Integumentary lesions of the mantle and arms included focal ulcerations, cellulitis, lacerations, and necrosis. A number of parasitic organisms were noted including Ichthyobodo in the gills, amoeba in multiple organs, dicyemids in renal tissues, ocular nematodes, protozoa in the digestive gland, and helminth-like bacteria in the renal tissues. This information will be useful in refining captive management of the species.
1. Scimeca JM. Cephalopods. In: Lewbart, GA, ed. Invertebrate Medicine. 1st ed. Ames, IA: Blackwell Publishing; 2006:133–142.