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Serrasalmus rhombeus (A) and Pygocentrus nattereri (B) are the most common species of piranhas indigenous to the Madeira River
Source publication
Drowned bodies rescued from the rivers of the Amazon basin exhibit several artefacts caused by the actions of the cadaveric ichthyofauna, namely, the “candiru”. This study aims to review and discuss the fish species responsible for the largest number of attacks on bodies in the Madeira River (Porto Velho - Rondônia, Brazil), to describe the feeding...
Citations
... In Bolivia, improved survey efforts during the last decade showed a clear trend towards increased landings of low-value mediumsized migratory species, mainly small characids and curimatids, supplying markets in the lowlands (Coca Méndez et al. 2012, Argote Soliz et al. 2017). Many of these species occupy lower positions in the food web than the traditional species, with an exception being Calophysus macropterus, or blanquillo, a short-lived siluriform species with omnivorous to scavenging habits (Pérez & Fabré 2009, Valente-Aguiar et al. 2020. The fisheries of this small migratory species emerged in the Mamoré River basin, in the last decade, adapting fishing methods practiced in Brazil and Colombia, and was driven by the growing demand of the national market for lowpriced fish. ...
... High mercury concentrations in the blanquillo meat, often above the WHO-limit for safe consumption (0.5 mg/kg), were recorded in Colombia (Salinas et al. 2014, Nuñez-Avellaneda et al. 2014, Mosquera-Guerra et al. 2017) and Brazil (Beltrán-Pedreros et al. 2011. Although it is generally described as an omnivorous species (Garcia et al. 2016;Froese & Pauly 2019), blanquillo has distinct scavenger habits feeding on carcasses of other species (Pérez & Fabré 2009, Valente-Aguiar et al. 2020, and thus might biomagnify mercury (Castro et al. 2016). These findings were used as an argument to prohibit its capture or consumption in some Amazonian countries or regions. ...
Bolivian Amazon small-scale fisheries traditionally focus on large migratory fish species. However, in the last decade there has been a trend of increased landings of low-value medium-sized migratory species, such as blanquillo, Calophysus macropterus. This scavenger species is captured using chicken and bovine waste as bait, and occasionally carcasses from wild species. This study explores the boom of this specialized fishery in Puerto Villarroel, a small harbor on the Ichilo River, using a combination of historical landing data, fisheries statistics obtained by participatory fisheries monitoring, fish market studies and interviews with local key stakeholders. Additionally, mercury contamination of fish meat was evaluated. Blanquillo fishing started in 2008 and boomed around 2015, representing 30% of landings, after which it decreased to fluctuate around 15%. The capture and landing data suggest that this species is mainly captured by non- organized fishers. The market studies conducted between 2015 and 2018 in Cochabamba city and in lowland middle towns showed that on average more than 20% of consumption of Amazon river fish consisted of blanquillo meat. Mercury is accumulated in the muscle tissue at concentrations near the official limit established by WHO for human consumption, whereas in 15% of fish the concentrations exceeded this limit. The paper pieces together the evolution of the blanquillo fishery in Bolivia, and looks at different aspects, including the diversity of fishers involved, possible impacts on other vulnerable species and public health, and potential impacts and effectiveness of different public policy approaches. In conclusion, the present study shows there is an overall need for more consistent and inclusive fisheries regulations in the Bolivian Amazon, as a way to protect aquatic fauna, avoid environmental contamination and secure human health.
... O fato é que muitos ataques de piranhas a humanos ocorrem devido a condições específ icas, como a alta densidade de piranhas em períodos de estiagem e as altas densidades de banhistas que habitualmente lançam restos alimentos na água ocorrendo o ataque às "presas humanas", causando grande comoção pelo derramamento de sangue (Haddad Jr, Sazima, 2010;Mol, 2012). No passado, embora pesquisas tenham conf irmado a clara evidência de que piranhas representam uma ameaça para seres humanos (e.g., Amant, 1967), pesquisas mais recentes apontam que a responsabilidade das piranhas sobre os ataques a humanos seguidos por morte deve ser questionada (Valente-Aguiar et al., 2020). A reputação das piranhas como peixes que atacam, matam e comem pessoas está longe de ser desmistif icada, porém a maioria das mortes humanas atribuídas a piranhas provavelmente são casos isolados delas se alimentando de pessoas afogadas (Sazima, Guimarães, 1987;Mol, 2006). ...
... Aubail et al. (2013) identified a positive correlation of the THg concentration between the skin, liver, and kidneys in different small cetacean species, indicating that skin samples can be used as indicators to infer the concentration of Hg. The reference organs used to investigate trace element bioaccumulation in cetaceans commonly are the kidneys and liver (Aubail et al. 2013), but these only can be collected from carcasses, which are very difficult to find in the Madeira River due to the large number of necrophagous fish species (Brum et al. 2015;Valente-Aguiar et al. 2020). However, for the boto species, there are no data confirming the possibility of using skin samples to infer the Hg concentrations in different organs. ...
In the Amazon, mercury (Hg) contamination comes from ASGM operations along with soil remobilization processes associated with deforestation. The objective of this study was to evaluate the exposure to methylmercury (MeHg) and total mercury (THg) in 88 samples of skin and blubber tissue obtained from live captured river dolphins (Inia boliviensis, Inia geoffrensis, and Inia spp.) in the Madeira River Basin. THg and MeHg measurements were performed by CV-AAS and GC-AFS, respectively. We also calculated the daily intake rate (DIR) of THg (wet weight) by Inia spp. THg levels in blubber tissue of adult river dolphins (Inia spp.) ranged from 0.015 to 3.804 mg kg⁻¹, while MeHg concentrations in blubber tissue varied from 0.04 to 2.65 mg kg⁻¹ and in skin tissue from 0.09 to 0.66 mg kg⁻¹. There were no significant differences in MeHg concentration in blubber (p = 0.616) and skin (p = 0.498) tissue samples between adult males and females in the different sampling locations. The adult animals showed differences in THg and MeHg concentrations significantly higher than in the calves. The estimate of the DIR of the genus Inia ranged from 1.17 to 12.35 μg kg⁻¹ day⁻¹ (bw), from the consumption of fish species with herbivorous to piscivorous habits, respectively. More biological and ecological data, such as the precise determination of age, mediated length, weight, and diet of river dolphins, are necessary to verify the Hg biomagnification. However, our data indicate that bioaccumulation is an active process in the dolphins of the Madeira River Basin.
Graphical abstract
... In particular, bodies of drowning victims retrieved from the Madeira River in Brazil's northern region present at autopsy with lesions caused by the action of scavenger ichthyofauna. The natives and medical examiners of the region use the generic umbrella term "candiru" for several scavenger catfish (due to the presence of barbels) belonging to the Cetopsidae, Pimelodidae and Trichomycteridae families that feed on animal carcasses and solid debris scattered on the riverbed, next to riverine communities [3]. As previously demonstrated, fish from the 2 former families are particularly implicated in the autoptic findings due to their endemic presence in the region [3]. ...
... The natives and medical examiners of the region use the generic umbrella term "candiru" for several scavenger catfish (due to the presence of barbels) belonging to the Cetopsidae, Pimelodidae and Trichomycteridae families that feed on animal carcasses and solid debris scattered on the riverbed, next to riverine communities [3]. As previously demonstrated, fish from the 2 former families are particularly implicated in the autoptic findings due to their endemic presence in the region [3]. Namely, they can consume all of the muscles and viscera of an 80 kg dead human body, leading to complete skeletonization, in a few hours [3,4]. ...
... As previously demonstrated, fish from the 2 former families are particularly implicated in the autoptic findings due to their endemic presence in the region [3]. Namely, they can consume all of the muscles and viscera of an 80 kg dead human body, leading to complete skeletonization, in a few hours [3,4]. In these cases, victim identification may require a multidisciplinary approach, including anthropology, medicine, dentistry, and genetics [5][6][7]. ...
Amazonian’s forensic experts usually experience considerable difficulties in the identification of drowned bodies rescued from the rivers of the Amazon basin, since they are frequently found skeletonized by the action of the cadaverous ichthyofauna. In these circumstances, especially when the soft tissues are completely absent, bones and teeth may represent the unique source of information for the identification of the body. This work reports a case of positive identification of a body skeletonized by scavenger ichthyofauna. The identification was performed by comparing computerized delineation of the dental characteristics of the cadaver with those observed in a smiling photograph of the victim. This report also highlights the ferocity of Cetopsis candiru (candiru cobra), Cetopsis coecutiens (candiru-açu) and Calophysus macropterus (piracatinga).
... The type of catfish referred to as candirus, is a member of the Trichomycteridae and Cetopsidae families 1,2 . The subfamilies Vandelliinae and Stegophilinae (Trichomycteridae) and Cetopsinae (Cetopsidae) are relevant to human medicine, including forensics 1,2,3,4 . Herein, we present a brief essay on candirus and their relationship with human health and death. ...
... The type of catfish referred to as candirus, is a member of the Trichomycteridae and Cetopsidae families 1,2 . The subfamilies Vandelliinae and Stegophilinae (Trichomycteridae) and Cetopsinae (Cetopsidae) are relevant to human medicine, including forensics 1,2,3,4 . Herein, we present a brief essay on candirus and their relationship with human health and death. ...
The type of catfish referred to as candirus, is a member of the
Trichomycteridae and Cetopsidae families1,2. The subfamilies
Vandelliinae and Stegophilinae (Trichomycteridae) and Cetopsinae
(Cetopsidae) are relevant to human medicine, including
forensics. Herein, we present a brief essay on candirus and their
relationship with human health and death. We examined published
accounts and used our personal observations on the subject.
Reports of deaths caused by alligators or crocodiles are rare in the literature. These deaths may be related to sharp force trauma caused by the teeth of these animals, with or without mutilation, or even drowning after seizure and submersion of the victim. It is difficult to forensically identify bodies in cases of mutilation of the upper limbs during the attack or when the corpse is in an advanced stage of skeletonization. Smile photographs are an important source of ante-mortem references for comparison. We report a human identification based on a photograph of a victim, with the absence of limbs caused by an alligator attack and the advanced skeletonization stage due to scavenger fish action in the Amazon within only 36 hours after his disappearance. The description of alligator attacks and the marks observed on the victim's body are essential to help medical and forensic professionals diagnose the injuries found and, consequently, define the cause of death.
