Revisiting a medical case of “stinging” in the human oral cavity caused by ingestion of raw squid (Cephalopoda: Teuthida): new data on the functioning of squid’s spermatophores
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Male squid produce intricate spermatophores that, when transferred to the female, undergo the spermatophoric reaction, a complex process of evagination that leads to the attachment of the spermatangium, that is, the everted spermatophore containing the sperm mass. While this process is still not completely understood, the medical literature includes several reports of “oral stinging” (i.e., punctured wounds in the human oral cavity) following consumption of raw male squid, which contains undischarged spermatophores able to inflict such wounds. Here, we revisit a recent medical report of oral stinging by Shiraki et al. (Pathol Int 61:749–751, 2011), providing an in-depth reanalysis of their histological biopsies and revealing vital information on the functioning of squid spermatophores. The morphology of the spermatangia attached within the oral cavity is similar to the condition found in spermatangia naturally attached to female squids. The spermatangia were able to superficially puncture the superficial layers of the oral stratified squamous epithelium, and numerous, minute stellate particles from the squid spermatophore were found adhered to the oral epithelium. These findings corroborate previous hypotheses on the functioning of squid spermatophores, namely that spermatophore attachment generally involves tissue scarification, and that stellate particles play a vital role in the attachment process. Moreover, spermatophore attachment is confirmed to be autonomous (i.e., performed by the spermatophore itself) in another squid species (possibly a loliginid), and the results strongly indicate that the attachment mechanism is not dependent upon a specialized epithelium, nor a mate’s specific chemical stimulus. From the pathological point of view, the best prophylactic measure at present is the removal of the internal organs of the raw squid prior to its consumption.
KeywordsCephalopods Spermatophore Functional morphology Spermatophoric reaction Sperm transfer mechanisms Oral pathology
JEARM was supported by a postdoctoral fellowship from CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior). The comments of two anonymous reviewers improved the manuscript and are greatly appreciated.
- Arkhipkin AI, Laptikhovsky VV (2011) Observation of penis elongation in Onykia ingens: implications for spermatophore transfer in deep-water squid. J Molluscan Stud 76:299–300Google Scholar
- Hamada A, Watanabe N, Yamazaki Y, Yoshiba S, Kobayashi A (1990) A case of punctured wounds in the oral cavity by sperm-bags of squid. Med Entomol Zool 41:279–280 (in Japanese; abstract in English)Google Scholar
- Hess SC (1987) Comparative morphology, variability, and systematic applications of cephalopod spermatophores (Teuthoidea and Vampyromorpha). University of Miami, DissertationGoogle Scholar
- Jereb P, Vecchione M, Roper CFE (2010) Family Loliginidae. In: Jereb P, Roper CFE (eds) Cephalopods of the world. An annotated and illustrated catalogue of species known to date, vol 2: Myopsid and Oegopsid Squids. FAO Species Catalogue for Fishery Purposes, No. 4. FAO, Rome, pp 38–117Google Scholar
- Kawada K, Kawahara M, Akimori T, Yamaguchi T, Okamoto Y, Ishikawa Y (2008) A case of oral stings by spermatophores of Todarodes pacificus. Jpn J Oral Surg 54:423–426 (in Japanese; abstract in English)Google Scholar
- Kawamoto F, Iwata T, Ichihara A, Kumada N, Kano R (1990) A case-report of oral-stings by spermatophores of a squid, Tadorodes pacificus Steenstrup. Jpn J Sanit Zool 41:117–119 (in Japanese; abstract in English)Google Scholar
- Nesis KN (1995) Mating, spawning and death in oceanic cephalopods: a review. Ruthenica 6:23–64Google Scholar
- Roper CFE, Nigmatullin C, Jereb P (2010) Family Ommastrephidae. In: Jereb P, Roper CFE (eds) Cephalopods of the world. An annotated and illustrated catalogue of species known to date, vol 2: Myopsid and Oegopsid Squids. FAO Species Catalogue for Fishery Purposes, No. 4. FAO, Rome, pp 269–347Google Scholar
- Takai K, Nakajima H, Hanaguri M, Kanda T (1989) A case of stinging in the upper gastrointestinal tract by eating raw squids. Jpn J Sanit Zool 40:227 (in Japanese)Google Scholar