Histologic lesions of cestodiasis in octopuses

Abstract

Parasitism of cephalopods is common, including infection with Aggregata spp., Ichthyobodo spp., dicyemids, cestodes of the orders Tetraphyllidea and Trypanorhynchidea, and various crustaceans. Cestodiasis in octopuses is reported, although a full histologic description of lesions has not been previously described. Cestodiasis was identified in 10 octopuses of 4 different species, which included 4 common octopuses ( Octopus vulgaris), 3 Caribbean reef octopuses ( Octopus briareus), 2 two-spot octopuses ( Octopus bimaculoides), and 1 giant Pacific octopus ( Enteroctopus dofleini). Larval cestodes were present in the cecum ( n = 5), intestines ( n = 4), digestive gland ( n = 3), chitinous alimentary tract ( n = 2), renal appendage ( n = 1), and salivary duct ( n = 1). In 5 cases, larval cestodes invaded tissue and were associated with hemocytic inflammation and tracts of necrotic tissue in the intestines ( n = 3), digestive gland ( n = 3), and/or renal appendage ( n = 1). When present in the chitinous alimentary tract (esophagus, stomach) or cecum, larval cestodes were in the central lumen and not associated with lesions. One adult cestode was identified in the mantle cavity and was not associated with lesions. Other common concurrent parasitic infections included enteric Aggregata spp. infection, branchial Rickettsia-like organism infection, enteric nematodiasis, and an arthropod-associated branchitis.

A retrospective study of pathologic findings in cephalopods (extant subclasses: Coleoidea and Nautiloidea) under laboratory and aquarium management

“…Comparatively, histomorphologically similar Rickettsia or Chlamydia-like organisms in mollusks have been identified as gammaproteobacterial-Endozoicomonadaceae. 10,27,39 Such organisms are not necessarily correlated with disease; 21,23 however, heavy infections may contribute to pathology, 21,27 and a generalized tissue distribution was identified in a single coconut octopus in this study.…”

“…This reinforces the hypothesis that such infections should generally be considered incidental, although a recent publication has drawn attention to associated inflammation and necrosis in some cases of cestodiasis in octopuses. 23 Ocular cataracts were seen in 2 cuttlefish and a single common octopus, which could have impaired vision and potentially affected feeding. A recent study of cephalopod ocular pathology identified inflammatory lesions, particularly anterior uveitis, as a frequent presentation, with cataracts in a substantial proportion (36%) of the 33 diagnostic specimens included from mixed cephalopods.…”

“…This reinforces the hypothesis that such infections should generally be considered incidental, although a recent publication has drawn attention to associated inflammation and necrosis in some cases of cestodiasis in octopuses. 23…”

“…Epitheliocystis-like lesions (ELLs)/Rickettsia-like organisms (RLOs) 21,23 were detected in 3.2% (11/340) of octopuses (Fig. 4a) and 1.5% (2/130) of cuttlefish (Fig.…”

Special focus issue on invertebrate pathology: A growing discipline requiring veterinary diagnosticians

“…Its articles were selected to familiarize the readership with emerging issues and pertinent questions, including how to perform mortality investigations in invertebrates. 14,21 It includes several case studies, 1,2,3,9,11,13,17 which demonstrate how traditional investigative and descriptive pathology methods can effectively improve our understanding of invertebrate diseases, even in the face of the many challenges posed by invertebrates. Articles, including studies on arachnids and giant African millipedes, 7,20 bring together current knowledge so as to enable diagnosticians wishing to engage in important frontiers.…”