CASE REPORT PATHOLOGY/BIOLOGY Jennifer P. Pascali, 1 Ph.D.; Guido Viel, 2 M.D., Ph.D.; Giovanni Cecchetto, 2 M.D., Ph.D.; Nicola Pigaiani , 3 M.D.; Stefano Vanin, 4 Ph.D.; Massimo Montisci , 2 M.D., Ph.D.; and Paolo Fais, 5 M.D., Ph.D. The Red Swamp Crayfish Procambarus Clarkii (the Louisiana Crayfish) as a Particular Scavenger on a Human Corpse ABSTRACT: An 85-year-old man was found deceased floating in an irrigation ditch 18 days after his disappearance. During crime scene investigation, specimens of the red swamp crayfish Procambarus clarkii were found in proximity of the body. The feeding activity of these nonendemic crayfishes contributed to the formation of specific injuries on the body and in the production of a large substance defects inside the corpse. The aim of this paper was to illustrate the scavenging activity of P. clarkii on a human body and highlight the potential postmortem artefacts caused by this species. This is the first report on a real case of postmortem injuries produced by P. clarkii crayfishes on a submerged human body. So far, crustaceans are not considered useful for the estimation of the minimum postmortem interval. However, the important modifications on the corpses deriving from the activity of these animals should be kept in consideration. KEYWORDS: forensic science, forensic pathology, Procambarus clarkii, scavenging, crayfish, postmortem interval The knowledge of the extent and characteristic pattern of wounds caused by animal activity on corpses is very useful in differential analysis of separating postmortem artefacts from inju- ries that might have been inflicted during life (1–4). The feeding activity on human and animal cadavers by wild- life varies greatly depending on the geographical, faunal, sea- sonal, and environmental conditions (e.g., indoors, outdoors, and buried). In inland waters, postmortem lesions are mainly related to rat and fish feeding activity but also to dogs or foxes in the cases of bodies lying on river or lake banks (5). Only a few cases of scavenging by crustaceans have been reported in foren- sic literature (3,6–10). The red swamp crayfish Procambarus clarkii (Girard, 1852) is an endemic species with origin in northern Mexico and South, Southeast of United States of America and was initially intro- duced for commercial reasons in European inland waters. It is typically dark red, with long claws and head, small or no spines on the sides of its carapace (Fig. 1). Procambarus clarkii is also known as Louisiana crawfish. Due to some peculiar characteristics, such as the growth rapidity up to 12.5 cm, the prolific lifecycle, the plasticity of fitness to a variety of environ- ment, this species has become harvested in Louisiana, U.S.A., in the 18th century. The P. clarkii was first introduced in Italy in 1990s for com- mercial purposes in Tuscany, into Massaciuccoli Lake, but soon it escaped from control and now it is considered an infesting ani- mal all over Italy, including Sicily and Sardinia. It has rapidly colonized many Italian habitats, such as rivers, sewers, swamps at the expense of native crayfishes (11). All over Europe, this crayfish is considered one of the most invasive animals and its diffusion is strictly monitored by the European Community (12). Nevertheless, the food industry of this crayfish became estab- lished neither in EU nor in Italy and most of harvested speci- mens are now exploited for recreational pursuit in fish tank. Although some crayfish are known to feed on vegetation, the red swamp crayfish is carnivorous, eating insect larvae, tadpoles, and snails (13,14). When traditional food sources are scarce, the crayfish eat the remains of dead animals and worms as well (13,14). From the medico-legal aspects, the activities that this specimen may undertake on cadavers should be considered as a new potential source of artefacts, especially in Italy and EU. Although crustacean postmortem damages are mentioned in several forensic textbooks (5,15,16), we have found no specific references to P. clarkii scavenging activity except for few con- gress communications reporting P. clarkii scavenging activity on pig carcasses used as human model (15–17). A literature search, performed in February 2019, in PubMed, using a combination of MeSH terms and free text protocols (“Astacoidea”[Mesh] OR crayfish OR “Procambarus clarkii”) AND (forensic OR legal OR scaveng*) displayed 17 records, none of which was related to the scavenging activity of this species on human corpses. 1 Forensic Toxicology Unit, Department of Health Sciences, University of Florence, Largo Brambilla 3, 50134, Florence, Italy. 2 Section of Legal Medicine, Department of Cardiac, Thoracic and Vascu- lar Sciences, University of Padova, Via Falloppio 50, 35121, Padova, Italy. 3 Unit of Forensic Medicine, Department of Diagnostics and Public Health, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy. 4 School of Applied Sciences, University of Huddersfield, Queensgate, HD1 3DH, Huddersfield, U.K. 5 Unit of Legal Medicine, Department of Medical and Surgical Sciences, University of Bologna, Via Irnerio 49, 40126, Bologna, Italy. Corresponding author: Jennifer P. Pascali, Ph.D. E-mail: jennifer.pascali@ gmail.com Received 18 April 2019; and in revised form 10 July 2019; accepted 11 July 2019. 323 © 2019 American Academy of Forensic Sciences J Forensic Sci, January 2020, Vol. 65, No. 1 doi: 10.1111/1556-4029.14145 Available online at: onlinelibrary.wiley.com