Sotalia Guianensis Research Articles

Total tin (TSn) biomagnification: Evaluating organotin trophic flow and dispersion using hepatic TSn concentrations and stable isotope (C, N) data of nektonic organisms from Brazil

A previous investigation of our research team has demonstrated the suitability of using hepatic total tin (ΣSn) concentrations for evaluating dolphin exposure to organotins (OTs). The present study develops the previous technique into three different approaches that comprise data: (1) on hepatic ΣSn concentrations of 121 Guiana dolphins (Sotalia guianensis) from five different coastal areas (CAs): (2) on ΣSn, δ13C and δ15N for 40 dolphins from Rio de Janeiro state (RJ), including ten different delphinid species; as well as (3) on hepatic ΣSn concentrations and δ15N values on 31 individuals from five different fish species from Sepetiba Bay (SB, Rio de Janeiro-RJ, Brazil). Hepatic ΣSn concentrations of Guiana dolphins from Guanabara Bay (GB, RJ) were significantly higher than those found in other four CAs from S and SE Brazilian regions. Significant positive correlations were found between ΣSn concentrations and δ13C data in delphinid species, demonstrating a coast-ocean gradient in dolphin exposure to OTs in RJ state. Significant and positive correlations were observed between ΣSn concentrations and both δ15N and Trophic Position (TP) values of fish, as well as high values were found for Trophic Magnification Factor (TMF = 3.03) and Trophic Magnification Slope (TMS = 0.14), demonstrating OT biomagnification in SB ichthyofauna.

Occurrence of Guiana dolphin (Sotalia guianensis) in southeast of Brazil: Driven by prey distribution or human fishing activity?

Abstract This study used models to assess how the type of prey caught by artisanal fishermen influenced the occurrence of Guiana dolphins (Sotalia guianensis) in the region of the estuarine lagunar comple.x of Cananéia (São Paulo, Brazil). The data were collected from January 2012 to November 2014, during three fieldwork expeditions per season (spring, summer, autumn, winter). Mullets (Mugil liza) were the fish with the highest association to dolphins, followed by Oligoplites spp. and Lobotes spp.; Mugil curema and shrimp, on the other hand, negatively influenced their distribution. The presence of fish‐weir fisheries in the estuary also had a positive influence on the occurrence of dolphins, since this fishing gear is used as a barrier, minimizing the potential for their prey to escape.

Pyrethroid insecticides along the Southwestern Atlantic coast: Guiana dolphin (Sotalia guianensis) as a bioindicator

The presence of pyrethroid compounds in hepatic tissue of Guiana dolphins (Sotalia guianensis) is reported for the first time. Twelve pyrethroids were determined in 50 animals from eight locations of the Brazilian coast. The highest average concentration of total pyrethroids (∑PYR) was 1166 ng.g−1 lw, with values ranging from 148 to 5918 ng.g−1 lw, in Ilha Grande Bay, Rio de Janeiro State, while the Espírito Santo State had the highest median, 568 ng.g−1 lw. Permethrin was the predominant compound in most areas, contributing for 42% to 81% of the ∑PYR, whereas cypermethrin was the most abundant compound in Guanabara and Sepetiba bays (79% and 81%, respectively), both located in Rio de Janeiro State. Biological factors were not correlated with pyrethroids concentration. Tetramethrin and es/fenvalerate compounds were negatively correlated to the age, suggesting degradation/metabolization capacity in these animals that increases throughout life. Despite being metabolized and excreted, the wide use of these pollutants is reflected in relevant concentrations found in Guiana dolphins. This is the first study evaluating pyrethroids in a representative number of hepatic samples and covering >2600 km of coast. The overall lack of information on pyrethroids in cetaceans highlights the importance of understanding the profile and distribution of these pollutants in dolphins which exclusively inhabit the Southwestern Atlantic coast.

The lungworm, Halocercus brasiliensis (Nematoda: Pseudaliidae), from Guiana Dolphins Sotalia guianensis from Brazil with Pathological Findings.

The Guiana dolphin, Sotalia guianensis, is a small cetacean species found on the Atlantic coast of Central and South America from Honduras to Santa Catarina State, Brazil. The nematode Halocercus brasiliensis infects this cetacean, resulting in lung pathologies and death. The present study aimed to conduct a morphological and morphometric study of specimens of H. brasiliensis collected from S. guianensis from the coast of the state of Espírito Santo, Brazil. For this study, 7 dolphins were collected and examined for the presence of lung parasites. Nematodes were collected and processed for light microscopy, and lung fragments were processed for histological analysis. The nematodes were identified as H. brasiliensis according to their morphology and morphometry. The histopathological analysis revealed mineralization of the bronchiolar cartilage and inflammatory process. The parasitic infections by H. brasiliensis in S. guianensis can contribute to the debilitating status of these cetaceans, resulting in their stranding and accidental capture in fishing nets.

Acoustic Description of Beach-Hunting Guiana Dolphins (Sotalia guianensis) in the Cananéia Estuary, Southeastern Brazil

Acoustic Description of Beach-Hunting Guiana Dolphins (Sotalia guianensis) in the Cananeia Estuary, Southeastern Brazil

Modelling habitat use by the Guiana dolphin, Sotalia guianensis, in south‐eastern Brazil: Effects of environmental and anthropogenic variables, and the adequacy of current management measures

Abstract Species distribution modelling has been used to identify critical habitats for the delimitation of Marine Protected Areas. Although Marine Protected Areas may often overlap with the distribution of key marine species, illegal human activities often continue within these areas, causing negative impacts on the local biodiversity. A generalized linear model with spatial eigenvector mapping was used to investigate, for the first time, the influence of environmental variables and anthropic activities on the number of Guiana dolphin, Sotalia guianensis sightings/grid, and to determine whether a Marine Reserve, in south‐eastern Brazil, is adequate for the protection of the local population. Data were collected between May 2007 and October 2013 onboard a 7.5‐m vessel with an inboard engine. The models for the different periods (annual, dry, and rainy seasons) all indicated that depth, the distance to seafood farms and fishing grounds, and mean sea surface temperatures influenced the distribution of the dolphins within the study area. The annual and seasonal models predicted that the dolphins prefer a continuous area between Cedro and Pico Islands, a large area that lies outside the limits of the Marine Reserve. Although the habitat of Ilha Grande bay is still much less degraded than that inhabited by other nearby Guiana dolphin populations, the results of the present study indicate that anthropic activities in this area influence habitat use by the dolphins. Less than 30% of the area used by the dolphins is protected by the Tamoios Ecological Station (ESEC Tamoios). Sotalia guianensis is classified as ‘Vulnerable’ in Brazil, although the marine reserve (ESEC Tamoios) does not protect the core area used by the local dolphin population. The results of the present study provide specific locations for the creation of a new multiple‐use MPA, as suggested by the Brazilian National Action Plan for the Conservation of Small Cetaceans, or the inclusion of a special management programme for the area between Cedro and Pico islands to better protect the dolphins in the ESEC Tamoios buffer zone. The continuation of surveys to better understand the current and future impacts of human activities, and the development of a closer interaction with both the local community and local stakeholders will help to safeguard Ilha Grande Bay and the local Guiana dolphin population.

Fatal asphyxia due to laryngeal displacement by large-sized prey in a Guiana dolphin (Sotalia guianensis), Brazil

ABSTRACT: The Guiana dolphin (Sotalia guianensis) is a small odontocete distributed from Santa Catarina state, Brazil, to Honduras. Although it is currently considered “near threatened” by the International Union for Conservation of Nature, considerable knowledge on health and disease aspects of this species has been gained over the last decade. The main threats for the species are represented by multiple anthropic factors. Guiana dolphins feed on a variety of taxa, primarily teleosts, crustaceans, and cephalopods. Herein, we reported a case of severe laryngeal displacement and esophageal impaction with ulceration associated with a deglutted adult leatherjacket (Oligoplites sp.). This fish species is not a common prey item of Guiana dolphins’ diet. Severe upper aerodigestive compromise likely led to death by mechanical asphyxia (choke) in this dolphin. This report attested the occurrence of upper aerodigestive dysfunction due to overzealous feeding in Guiana dolphin and contributed to general knowledge on pathology of the species.

Ontogeny of the skull of Sotalia guianensis (Cetartiodactyla: Delphinidae) on the Northern coast of Brazil

ABSTRACT This study aimed to investigate the ontogenetic development of the skull in the Guiana dolphin (Sotalia guianensis Van Bénéden, 1864 ) through the comparison of 29 morphological non-metrical characters together with the estimated age of 54 specimens derived from four areas on the northern coast of Brazil. The state of each character was associated with the age of each specimen to assess the formation of bone structures, and the degree of fusion of the sutures in each state of the character studied. Nineteen qualitative morphological characters presenting state ontogenetic variations have been analyzed statistically. The analysis depicted that the characters associated with the parietal-frontal suture, parietosupraoccipital, parietoexoccipital, supraoccipital-exoccipital and basioccipital-pterygoid varied according with the age. The results suggest that the physical maturity of the cranium was more premature in the specimens from the Northern Coast, suggesting a geographical adjustment of the species, or a biological response to an intense pressure of by-catch in fisheries over decades on the populations.

Intraspecific Aggression Towards Common Bottlenose Dolphin Calves, Northern Gulf of Mexico

Infanticide has been widely documented throughout the animal kingdom, and has generally been viewed as an evolved, or adaptive behavior for the perpetrators. Infanticide motivated by increased sexual access to females with calves, or the elimination of potential genetic competition in the form of calf-directed aggression or infanticide, has been proposed for delphinids including killer whales, Indo-Pacific humpback dolphins, Guiana dolphins, and bottlenose dolphins. However, reports of intraspecific aggression towards bottlenose dolphin calves are relatively infrequent, and accounts of confirmed infanticide are rarer still. Reporting instances of intraspecific calf-directed aggression aids researchers to better understand the socio-behavioral context of these aggressive interactions. Here, we report an incident of conspecific aggression towards a calf in a small group of common bottlenose dolphins near Sabine Lake, northwestern Gulf of Mexico. We discuss the behavioral context, and surveyed other researchers to attempt to gauge the prevalence of perceived aggressive interactions among the bottlenose dolphin groups they study in the northern Gulf of Mexico.

Diet and foraging opportunism of the Guiana dolphin (Sotalia guianensis) in the Abrolhos Bank, Brazil

AbstractDiet analysis allows exploring how coastal dolphins interact with the environment and their role in the marine food webs. We studied the diet and feeding ecology of the Guiana dolphin, Sotalia guianensis, through analysis of stomach content from 42 animals stranded on the eastern coast of Brazil. A total of 1,336 semidigested prey items (fish, otoliths, cephalopod beaks, and crustaceans) were identified. Teleost fish comprised the most frequent food item (92% of the total), followed by cephalopods, and crustaceans. Prey belonged to 34 taxa and richness in individual stomachs varied from 1 to 15 prey taxa. Prey were generally small, but showed a significant trend to increase in size with dolphin length. The main prey of Guiana dolphins were demersal, estuarine, and sound‐making fish such as catfish and sciaenids. No sex‐related differences in diet were found. Diet composition varied seasonally and occurrence of prey items was coherent with breeding or high abundance periods of some fish species and squids. Our study shows the importance of demersal prey from estuarine and soft‐sediment habitats to Guiana dolphin in the Abrolhos Bank and reveals that feeding habits are generalist and opportunistic, with diet reflecting the seasonal abundance and availability of prey.

Revisão das Informações do Boto-Cinza (Sotalia guinensis) na Costa Brasileira

Os cetáceos, como o golfinho Sotalia guianensis (boto-cinza), são animais marinhos cujas populações vem diminuindo devido aos impactos antrópicos em seus ambientes. Assim, verificar o conhecimento sobre a espécie e suas áreas de proteção é importante para adotar novas medidas se preservação da espécie. Para isto, foi verificada a ocorrência do boto-cinza em unidades de conservação federais pelo endereço eletrônico do ICMBio e realizada uma revisão bibliográfica dos dados ambientais da espécie ao longo da costa brasileira. Foram identificadas 21 unidades de conservação com áreas terrestres e marinhas que possui registro para a espécie, sendo que destas, 15 são unidades de conservação de uso sustentável. Já em relação aos dados ecológicos, a espécie foi encontrada em sua maioria em águas rasas (menor que 10metros), com temperatura média da água variando de 21,9 a 24,2º. Em algumas áreas observou-se que o golfinho usa áreas maiores em estações diferentes, além de sua frequência em relação a sazonalidade também variar dentre os locais estudados. Ainda, foi identificado relações com a precipitação e maré. Apesar de apresentarem respostas diferentes as variáveis, os estudos indicam que o comportamento das populações de Sotalia guianensis pode ser explicado pela distribuição de suas presas, as quais também variam ao longo da costa brasileira.

Active contour-based detection of estuarine dolphin whistles in spectrogram images

An algorithm for detecting tonal vocalizations from estuarine dolphin (Sotalia guianensis) specimens without interference of a human operator was developed. The raw audio data collected from a passive monitoring sensor in the Cananéia underwater soundscape was converted to spectrogram images. Detection is a four-step method: first, ridge maps are obtained from the spectrogram images; second, a probabilistic Hough transform algorithm is applied to detect ridges similar to thick line segments, referred to as line-like, which are adjusted to the geometry of the whistles in the images via an active contour algorithm; third, feature vectors are built from the geometry of each detected whistle, with 9 descriptive features; and fourth, the detections are fed to a random forest classifier to parse out mistakes by the detection process. We developed a system for classifying the characteristic patterns detected as Sotalia guianensis whistles or random empty detections. We obtained accuracy of 0.977 and F1-score of 0.981.

Trophic dynamics in two South American estuaries encompassing industrial development and a biodiversity hotspot

Abstract Estuaries are critical to the life histories and development of many marine species, and support some of the most productive aquatic ecosystems. However, owing to their geographic accessibility, many estuaries face considerable anthropogenic threats, which can be exacerbated in developing nations. Understanding the ecological implications of anthropogenic activities as a precursor to dedicated conservation activities requires comprehensive assessments of baseline trophic relationships. This study addresses a shortfall in such information for two tropical, coastal ecosystems globally identified as priority areas for biodiversity conservation: the Paranaguá estuarine complex; and the Cananéia–Iguape estuarine lagoon system in southern Brazil. Ecological relationships were investigated through carbon and nitrogen stable isotope (δ13C and δ15N) determination in sediments, plant fragments and the muscle tissues of marine species occupying different trophic levels, including benthic invertebrates, ichthyofauna (Stellifer rastrifer, Paralonchurus brasiliensis, and Isopisthus parvipinnis), and delphinids (Sotalia guianensis and Pontoporia blainvillei). Isotope ratios facilitated distinguishing plant fragments, sediments (which were terrestrially influenced) and biota (predominantly marine influenced). However, despite variation among anthropogenic stressors, isotope ratios did not vary between the studied estuaries, implying similar impacts on trophic relationships which might reflect some inter‐estuary mixing. All ichthyofauna and the delphinids had similar generalist diets and shared the same trophic niche, which may reflect their consistent spatio‐temporal distributions and habitat patterns in the estuaries. The data illustrate the utility of isotopically characterizing biodiversity‐hotspot estuaries as a mechanism for rapidly assessing ecological relationships between key species and regional habitats. Such an approach can be used to evaluate ecological connectivity as a baseline for management and might be applied more broadly, embracing multiple regions as part of estuarine and coastal biome conservation efforts.

Guiana Dolphin (Sotalia guianensis) in the southern Gulf of Venezuela: Seasonal distribution, group size, and habitat use

Small cetaceans, such as the Guiana dolphin (Sotalia guianensis), do not migrate long distances to forage but use rather small areas subject to food source variations. Information on their distribution, behaviour, habitat use, and estimated population density play an important role in the identification of critical areas and regulating human activities within. Here we examine the seasonal variations, group size, and distribution of Guiana dolphin in the southern Gulf of Venezuela, to identify their critical habitats and thus aid mitigation planning. We used boat-based surveys with a follow-group protocol where observers monitor groups of animals for 30 min, from a distance of 20 to 30 m, gathering the following data: date, time observed, GPS position, estimated number of individuals, presence of calves, behavioural observations (when possible); and environmental parameters (sea-surface temperature, water transparency, salinity, sea state [Beaufort], and cloud cover). We found that Guiana dolphins did not use the studied area (6.33 km2) homogeneously but rather aggregated in north of Zapara Island’s retaining wall. The highest density of dolphins was between 301 and 573 individuals within 4.22 km2 approximately off north of Zapara Island, and the lowest (1 - 150 individuals) at the entrance of the main navigation channel. The group size was considerably larger in the wet season (mean ± SD = 6.4 ± 1.9 individuals, range = 1 to 80) than the dry season (2.2 ± 2.7 individuals, range = 1 to 27). The number of sightings differed among seasons (dry/wet), there were more sightings in the wet season (1.3414 ± 0.4389 groups, range = 1 to 5) than dry season (1.1233 ± 0.7418 groups, range = 1 to 5). Our data suggest this population might be highly adapted to local conditions and prey movements, and use the areas intensely year around, particularly during the wet season.

Multi-species okadaic acid contamination and human poisoning during a massive bloom of Dinophysis acuminata complex in southern Brazil

On June 2016, a major bloom of Dinophysis acuminata complex was noticed over the coast of Paraná State (PR), southern Brazil, an area unprotected by any official monitoring program. Here we report the results of an extensive sampling effort that ultimately led PR authorities to issue the first State shellfish-harvesting ban due to multi-species okadaic acid (OA) contamination. During its peak, the bloom covered an area of 201 km2 (∼2.0–3.5 × 54.0 km), attaining unprecedentedly high cell densities along the shallow (<15 m) continental shelf (mean 2.2 × 105, maximum 2.1 × 106 cells L−1) and adjacent sandy beaches (mean 2.8 × 105, maximum 5.2 × 106 cells L−1). Only OA was detected in suspension (max. 188 ng L−1). Toxin levels measured in bivalves were several times greater than the regulatory limit of 160 ng g−1, reaching up to 3600 ng g−1 in Crassostrea gasar, by far the highest OA concentrations ever reported in oysters worldwide, 7700 ng g−1 in brown mussels, Perna perna, and lower levels in clams, Anomalocardia brasiliana, and mangrove mussels, Mytella spp. Nine cases of human intoxication were officially reported and five people were hospitalized with typical symptoms of Diarrhetic Shellfish Poisoning linked to the consumption of contaminated bivalves. All bivalves quickly converted most of the OA into its esterified form, DTX-3, and eliminated the toxins only a few weeks following the bloom, with C. gasar being the slowest-detoxifying species. Lower OA levels were accumulated in zooplankton, gastropods and several novel toxin vectors, including benthic organisms such as sand dollars Mellita quinquiesperforata and the ghost-shrimp Callichirus major, which may act as a good indicator of the presence of toxins in sandy beaches, and pelagic fish species that can serve as potential alternative sources of OA to humans (Chaetodipterus faber and Mugil liza). Monitoring toxin contamination in seafood other than bivalves is thus recommended to ensure comprehensive human health protection during massive Dinophysis blooms. Additionally, since OA was also present at low concentrations in the liver of Guiana dolphins Sotalia guianensis and penguins Spheniscus magellanicus, exposure to biotoxins should be considered in conservation actions involving threatened and near-threatened marine organisms in this region.

Environmental factors related to group size and habitat use of Guiana dolphins from São Marcos Bay, Amazon coast

Environmental changes can affect the social structure and disrupt habitat use of marine mammal species. An impact on the social dynamics of dolphins, including group size structure, may attenuate the feeding success and increasing predation risk, especially considering species exhibiting small home ranges, which impose particular habitat dependency and high vulnerability to environmental changes. In this regard, the Guiana dolphin (Sotalia guianensis, Van Beneden, 1864) is a particularly endangered species due to its coastal distribution and considerable small home range. The aim of this study was first to conduct a spatial assessment of the dolphin groups sighted in the Sao Marcos Bay (SMB; Northeastern Brazil), one of the most important port areas in Brazil. The results show an overlap between the distribution of the dolphin groups and the port activities area, which includes the loading zone at the main port area and the navigation channel used by large cargo ships and other vessels. Also, a GLM regression was conducted to identify the best combination of selected variables that best predict the group size of the dolphins. The predictor variables included: salinity, sea surface temperature, depth, water transparency, distance from the main port area, and the feeding activity of the groups sighted. The results indicated that larger dolphin groups were found in areas closer to the main port area and were associated with foraging activities. Therefore, the results suggest that this dolphin population might be exposed to threats linked to the port activities, which may include noise pollution, vessel collision, and chemical pollution.

High-frequency social communication in Sotalia guianensis.

This study aimed to investigate the use of high ultrasonic frequencies (above 40 kHz) in the Sotalia guianensis whistle repertoire. The whistles were classified as high-frequency (HF) whistles and very high-frequency (VHF) whistles. Seven parameters were extracted and a general linear mixed effects model was performed between the total number of whistles and VHF ones. Frequency parameters of HF and VHF whistles were the highest reported for this species so far. However, VHF whistles were rare and occurred in situations of high acoustic activity, which may represent a strategy used by dolphins to deal with higher levels of vocalization rates.

Toxoplasma gondii in cetaceans of Brazil: a histopathological and immunohistochemical survey.

Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. In cetaceans, T. gondii infection is a significant cause of morbidity and mortality. Despite the worldwide range and broad cetacean host record of T. gondii infection, there is limited information on toxoplasmosis in cetaceans from the Southern hemisphere. We investigated the occurrence of T. gondii by histopathology and immunohistochemistry in tissue samples of 185 animals comprising 20 different cetacean species from Brazil. Three out of 185 (1.6%) animals presented T. gondii-associated lesions: a captive killer whale Orcinus orca, a free-ranging common bottlenose dolphin Tursiops truncatus and a free-ranging Guiana dolphin Sotalia guianensis. The main lesions observed in these animals were necrotizing hepatitis, adrenalitis and lymphadenitis associated with protozoal cysts or extracellular tachyzoites presenting immunolabeling with anti-T. gondii antibodies. This study widens the spectrum of species and the geographic range of this agent in Brazil, and provides the first reports of T. gondii infection in a captive killer whale and in a free-ranging common bottlenose dolphin in South America.

Molecular, serological, pathological, immunohistochemical and microbiological investigation of Brucella spp. in marine mammals of Brazil reveals new cetacean hosts.

Brucella-exposure and infection is increasingly recognized in marine mammals worldwide. To better understand the epidemiology and health impacts of Brucella spp. in marine mammals of Brazil, molecular (conventional PCR and/or real-time PCR), serological (Rose Bengal Test [RBT], Competitive [c]ELISA, Serum Agglutination Test [SAT]), pathological, immunohistochemical (IHC) and/or microbiological investigations were conducted in samples of 129 stranded or by-caught marine mammals (orders Cetartiodactyla [n=124], Carnivora [n=4] and Sirenia [n=1]). Previous serological tests performed on available sera of 27 of the 129 animals (26 cetaceans and one manatee), indicated 10 seropositive cetaceans. Conventional PCR and/or real-time PCR performed in cases with available organs (n=119) and/or blood or swabs (n=10) revealed 4/129 (3.1%) Brucella-infected cetaceans (one of them with positive serology; the remaining three with no available sera). Pathological, IHC and/or microbiological analyses conducted in PCR/real-time PCR and/or seropositive cases (n=13) revealed Brucella-type lesions, including meningitis/meningoencephalitis, pneumonia, necrotizing hepatitis, pericarditis and osteoarthritis in some of those animals, and positive IHC was found in all of them (excepting two live-stranded animals without available organs). Brucella spp. culture attempts were unsuccessful. Our results demonstrated exposure, asymptomatic, acute and chronic Brucella sp. infection in several cetacean species in the Brazilian coast, highlighting the role of this pathogen in stranding and/or death, particularly in Clymene dolphin (Stenella clymene) and short-finned pilot whale (Globicephala macrorhynchus) off Ceará State. Novel hosts susceptible to Brucella included the franciscana (Pontoporia blainvillei), the Guiana dolphin (Sotalia guianensis) and the spinner dolphin (Stenella longirostris). Additionally, three coinfection cases involving Brucella spp. and cetacean morbillivirus, Edwarsiella tarda and Proteus mirabilis were detected. To the best of our knowledge, this is the first long-term and large-scale survey of Brucella spp. in marine mammals of South America, widening the spectrum of susceptible hosts and geographical distribution range of this agent with zoonotic potential.

Debris ingestion by carnivorous consumers: Does the position in the water column truly matter?

The hypothesis that carnivorous consumers associated with the seabed are more likely to ingest marine debris was tested based on stomach content analysis of fish (Trichiurus lepturus and species of Ariidae) and cetaceans (Sotalia guianensis and Pontoporia blainvillei). Among 596 stomach contents, only 22 (3.7%) contained debris. The debris was flexible plastic, nylon yard, paper, latex, styrofoam and cigarette filter. The proportion of stomach contents with debris varied among species: P. blainvillei (pelagic demersal consumer) presented the highest frequency of ingestion (15.7%), while T. lepturus (pelagic consumer), S. guianensis (pelagic consumer) and Ariidae (demersal consumer) presented similar frequencies (1.3–1.8%). Therefore, a feeding site in the water column does not predict the probability of debris ingestion. Concerning these species, this probability seems to be more associated with prey-capture strategies (or feeding behavior), regardless of debris availability in the environment.