Molecular Detection and Characterization of Mycoplasma spp. in Marine Mammals, Brazil.

Mycoplasma spp. are wall-less bacteria able to infect mammals and are classified as hemotropic (hemoplasma) and nonhemotropic. In aquatic mammals, hemoplasma have been reported in California sea lions (Zalophus californianus) and river dolphins (Inia spp.). We investigated Mycoplasma spp. in blood samples of West Indian manatees (Trichechus manatus), pinnipeds (5 species), and marine cetaceans (18 species) that stranded or were undergoing rehabilitation in Brazil during 2002-2022. We detected Mycoplasma in blood of 18/130 (14.8%) cetaceans and 3/18 (16.6%) pinnipeds. All tested manatees were PCR-negative for Mycoplasma. Our findings indicate that >2 different hemoplasma species are circulating in cetaceans. The sequences from pinnipeds were similar to previously described sequences. We also detected a nonhemotropic Mycoplasma in 2 Franciscana dolphins (Pontoporia blainvillei) that might be associated with microscopic lesions. Because certain hemoplasmas can cause disease and death in immunosuppressed mammals, the bacteria could have conservation implications for already endangered aquatic mammals.

The deep dive of organohalogen compounds: Bioaccumulation in the top predators of mesopelagic trophic webs, pygmy and dwarf sperm whales, from the Southwestern Atlantic ocean.

Kogia sima and Kogia breviceps are apex predators of mesopelagic trophic webs being far from most anthropogenic threats. However, chemical pollutants and naturally synthesized compounds may travel long distances. This study aimed to use kogiid whales as sentinels of mesopelagic trophic webs in the Southwestern Atlantic Ocean. Persistent organic pollutants (POPs), e.g., polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and metabolites, mirex, hexachlorobenzene (HCB), polybrominated diphenylethers (PBDEs), pentabromoethylbenzene (PBEB) and hexabromobenzene (HBB), and the naturally produced methoxylated BDE (MeO-BDEs) were determined in the blubber of 16 K. sima and 15 K. breviceps. Among the organochlorine compounds, DDTs were the main group found in K. sima and in K. breviceps (1636.6 and 3983.3 ng g-1 lw, respective medians), followed by PCBs (425.9 and 956.1 ng g-1 lw, respectively), mirex (184.1 and 375.6 ng g-1 lw, respectively), and HCB (132.4 and 340.3 ng g-1 lw, respectively). As for the organobromine, the natural MeO-BDEs were predominant (1676.7 and 501.6 ng g-1 lw, respectively), followed by PBDEs (13.6 and 10.3 ng g-1 lw, respectively) and PBEB (2.2 and 2.9 ng g-1 lw, respectively). In general, POPs concentration was higher in K. breviceps than in K. sima. Conversely, MeO-BDEs concentration was higher in K. sima than in K. breviceps. Differences in concentrations in these sympatric odontocetes were attributed to distinct species, sampling sites, and biological parameters and suggest some level of niche segregation. It is noteworthy the long-range reach and bioaccumulation of these synthetic compounds in an unexplored habitat, that present an increasing economic interest.

Short-Finned Pilot Whale Strandings Associated with Pilot Whale Morbillivirus, Brazil.

Cetacean morbillivirus (CeMV) causes illness and death in cetaceans worldwide; the CeMV strains circulating in the Southern Hemisphere are poorly known. We detected a pilot whale CeMV strain in 3 short-finned pilot whales (Globicephala macrorhynchus) stranded in Brazil during July-October 2020. Our results confirm this virus circulates in this species.

Herpesvirus and adenovirus surveillance in threatened wild West Indian (Trichechus manatus) and Amazonian manatees (Trichechus inunguis), Brazil.

THE FAMILY TRICHECHIDAE (ORDER SIRENIA) COMPRISES THREE SPECIES: African (Trichechus senegalenses), West Indian (T. manatus), WIM)], and the Amazonian manatees (T. inunguis, AMM). Whereas WIM inhabits both riverine and coastal systems in the western Atlantic, AMM is the only exclusively freshwater sirenian, endemic to the Amazon River Basin. The study of infectious agents is essential to species conservation, especially considering that both species are classified as Vulnerable by the IUCN Red List and as Endangered by the Brazilian Red List. The current knowledge about viral agents in sirenians is scarce. Herpesviruses and adenovirus are DNA viruses able to infect and cause disease in a wide range of hosts. Herein, we used panPCR protocols to survey herpesvirus and adenovirus in blood samples of wild WIM (n = 23) and AMM (n = 26) under human care in Brazil. Herpesvirus DNA was detected in one juvenile female WIM (1/23; 4.3%; 95% CI -4.7 - 13.3) from Ceará state and in four AMM (two juvenile females, a juvenile male, and an adult female; 4/26; 15.4%; 95% CI 0.5 - 30.3) from Amazonas state. The two different gammaherpesvirus DNA polymerase sequence types identified (one per species, a sequence type in a WIM and another one in three AMM) were highly similar (99% nucleotide identity) to Trichechid herpesvirus 1, reported in West Indian manatees of Florida (USA), and 100% identical when translated into amino acids. A herpesviral glycoprotein B sequence was identified in two AMM. None of the samples was positive to adenovirus. To the authors' knowledge, this is the first herpesvirus detection in manatees from South America, expanding the herpesvirus geographical range, and the first in WIM and AMM worldwide. Our findings suggest (i) that West Indian and Amazonian manatees are possibly the natural hosts of the detected herpesvirus, and (ii) coevolution of that gammaherpesvirus with Trichechus. Future studies are necessary to characterize the obtained virus and elucidate potential pathological effects (if any) in these species.

Hemotropic Mycoplasma spp. in Aquatic Mammals, Amazon Basin, Brazil.

Hemotropic Mycoplasma spp. (hemoplasmas) are uncultivable bacteria that infect mammals, including humans. We detected a potentially novel hemoplasma species in blood samples from wild river dolphins in the Amazon River Basin, Brazil. Further investigation could determine pathogenicity and zoonotic potential of the detected hemoplasma.

Use of the FLOTAC technique as a new coproparasitological diagnostic method in aquatic mammals and comparison with traditional methods.

The inadequate choice of a diagnostic method or the option for techniques that have low sensitivity and specificity may limit the diagnosis of parasitic agents that affect aquatic mammals. The aim of this study was to evaluate the performance of the FLOTAC technique and compare it with three traditional methods (Willis, sedimentation and centrifugation- flotation) used in the diagnosis of gastrointestinal parasites in aquatic mammals. For this, 129 fecal samples from 12 species were collected. Each sample was submitted to laboratory processing using the Willis, Hoffman techniques, Faust method and FLOTAC. Sensitivity, specificity, real prevalence, estimated prevalence, positive predictive value, negative predictive value, correct classification (accuracy) and incorrect classification were evaluated to compare the different diagnostic methods. The highest frequency of positive samples occurred using FLOTAC (46.51%), compared to Hoffman (23.25%), Faust (10.07%) and Willis techniques (6.97%). In the samples analyzed, the occurrence of Strongylidae eggs and Eimeriidae oocysts was frequently observed. The FLOTAC technique proved to be the most appropriate technique and due to its efficacy, is strongly recommended for coproparasitological evaluations in aquatic mammals.

Highly divergent herpesviruses in threatened river dolphins from Brazil.

River dolphins are a highly threatened polyphyletic group comprised of four odontocete families: Iniidae, Pontoporiidae, Lipotidae, and Platanistidae, the first two endemic to South America. To address the knowledge gap regarding infectious agents in this cetacean group, we surveyed the presence of herpesviruses by PCR in skin and/or blood samples of live-captured Amazon (Inia geoffrensis, n = 25) and Bolivian (Inia boliviensis, n = 22) river dolphins of the Amazon basin and in selected tissue samples of franciscanas (Pontoporia blainvillei, n = 27) stranded or bycaught in southeastern Brazil. Additionally, available franciscana tissue samples were examined by histopathology. Herpesvirus DNA was amplified in 13 Bolivian river dolphins (59.1%, 95% CI 38.5-79.6%) and 14 franciscanas (51.9%, 95% CI 33.0-70.7%). All Amazon river dolphins were herpesvirus-negative. Two different herpesviruses were found in Bolivian river dolphins: a previously known gammaherpesvirus detected in blood and/or skin samples of all positive individuals and a novel alphaherpesvirus in the skin of one animal. A new gammaherpesvirus was found in several franciscana samples-the first herpesvirus recorded in Pontoporiidae. Intranuclear inclusion bodies consistent with herpesvirus were observed in the lymph node of one franciscana. The high divergence among the obtained herpesviruses and those previously described can be explained by viral-host coevolution, and by the fact that these populations are fairly isolated.

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.

Novel herpesviruses in riverine and marine cetaceans from South America.

Herpesvirus (HV) infections in cetaceans are frequently associated with skin and mucosal lesions. Although HV infections have been reported worldwide, their occurrence in southern Atlantic marine mammals is still poorly understood. We tested skin, oral and genital mucosal beta-actin PCR-positive samples from 109 free-ranging Brazilian cetaceans using a universal herpesvirus DNA polymerase PCR. Herpesvirus-positive skin samples from a Guiana dolphin (Sotalia guianensis), a dwarf sperm whale (Kogia sima), a Bolivian river dolphin (Inia boliviensis), and a lingual sample from an Atlantic spotted dolphin (Stenella frontalis) were histologically evaluated. Additional tissue samples from these animals were also PCR-positive for HV, including a novel sequence obtained from the dwarf sperm whale's stomach and mesenteric lymph node. Four novel HV species were detected in the Guiana dolphin (one), the dwarf sperm whale (two) and the Bolivian river dolphin (one). The cutaneous lesions (marked, focally extensive, chronic proliferative dermatitis) of the Guiana dolphin and the Bolivian river dolphin were similar to previous HV reports in cetaceans, despite the absence of intranuclear inclusion bodies. This is the largest HV survey in South American cetaceans and the first detection of HV infection in riverine dolphins worldwide.

Survey of Brucella spp. and Leptospira spp. antibodies in cetaceans and manatees of the Amazon basin and Atlantic Ocean, Brazil.

Aquatic mammals can act as sentinels of emerging and resurging pathogens in the environment. Brucella spp. and Leptospira spp. are 2 zoonotic pathogens relevant to aquatic mammals, and their detection can be used to assess pathogen exposure. In this study, serum from 84 individuals-63 cetaceans (families Iniidae, n = 37; Delphinidae, n = 22; and Kogiidae, n = 4) and 21 West Indian manatees Trichechus manatus-was tested by the Rose Bengal Test (RBT) and a commercial competitive enzyme-linked immunosorbent assay (c-ELISA) for detecting Brucella spp. antibodies, and the microscopic agglutination test (MAT) for screening Leptospira spp. exposure. Overall, 4.8% (3/63) of cetaceans were positive by RBT and 15.9% (10/63) by c-ELISA for Brucella spp. Serum from 8 c-ELISA positive cetaceans (with available serum) was further tested via serum agglutination test (SAT) and 1 individual was positive. c-ELISA was more sensitive than RBT. Exposure to Brucella spp. was found in 5 cetacean species: Clymene dolphin Stenella clymene, short-finned pilot whale Globicephala macrorhynchus, pygmy killer whale Feresa attenuata, melon-headed whale Peponocephala electra and Atlantic bottlenose dolphin Tursiops truncatus in the Atlantic Ocean, Brazil, expanding the range of known Brucella seropositive aquatic hosts. No evidence of Brucella spp. exposure was found in Iniidae and Kogiidae odontocetes and manatees. Antibodies against Leptospira spp. were not detected in cetaceans and sirenians by MAT. These results contribute to the evaluation of different Brucella spp. serological methods in cetaceans and manatees and highlight the epidemiology of zoonotic pathogens in aquatic mammals of the southwestern Atlantic Ocean and the Amazon basin.

Histological characterization of reproductive tract and fetal annexes of the West Indian Manatee (Trichechus manatus) from Brazil / Caracterização histológica do trato reprodutor e anexos fetais do peixe-boi marinho (Trichechus manatus) do Brasil

The West Indian manatee (Trichechus manatus) is one of the most threatened aquatic mammals in Brazil, and is currently classified as "endangered" (MMA). The objective of this study was to characterize histologically the reproductive tract and fetal annexes of stranded manatees in northeastern Brazil. Tissue samples were collected from the reproductive tract of 23 manatees, which were fixed in 10% buffered formalin, processed using standard histological protocols and stained with hematoxylin eosin. We qualitatively described the histological and histomorphometric characteristics of each structure. Six ovaries were analyzed. In four ovaries, we found a large number of primordial and primary follicles. Two ovaries were different from the others: one had inflammatory infiltration and the other had a thickening in the cortex and absence of follicles. We also analyzed seven uteri (of which four were in the proliferative phase, two in the secretory phase, and one in the recovery phase), four placentas, one vagina, six testes (four were in the immature phase, one in the pubertal phase, and one in the mature phase), two epididymides, two penises, and one umbilical cord. The histological and morphometric findings in our work will support future analyses of the reproductive tract of T. manatus from Brazil.(AU)

O peixe-boi marinho (Trichechus manatus) é um dos mamíferos aquáticos mais ameaçados do Brasil e, atualmente é classificado como "em perigo" (MMA). O objetivo deste estudo foi caracterizar histologicamente o trato reprodutor e os anexos fetais de peixes-bois marinhos encalhados no Nordeste do Brasil. Foram coletadas amostras de tecidos do trato reprodutor de 23 peixes-bois marinhos (T. manatus), que foram fixadas em formol tamponado a 10%, processados usando protocolos histológicos padrão e corados com hematoxilina eosina. Foi realizada a descrição qualitativa das características histológicas e histomorfométricas de cada estrutura. Foram analisados seis ovários. Em quatro ovários, foi encontrado um grande número de folículos primordiais e primários. Dois ovários eram diferentes dos outros: um tinha infiltração inflamatória e o outro tinha um espessamento no córtex e ausência de folículos. Também foram analisadas sete amostras uterinas (das quais quatro estavam na fase proliferativa, duas na fase secretória e uma na fase de recuperação), quatro placentas, uma vagina, seis testículos (quatro na fase imatura, um na fase puberal e um na fase madura), dois epidídimos, dois pênis e um cordão umbilical. Os achados histológicos e morfométricos em nosso trabalho apoiarão futuras análises do trato reprodutivo de T. manatus do Brasil.(AU)

Integrative taxonomy of anisakid nematodes in stranded cetaceans from Brazilian waters: an update on parasite's hosts and geographical records.

Anisakidae are represented mainly by species of Anisakis Dujardin, 1845, Pseudoterranova Krabbe, 1878, and Contracaecum Railliet and Henry, 1913. Integrative taxonomy, based on morphological and genetic approaches, can provide a precise identification of species, increasing the knowledge of their systematics, biology, and evolution. In this study, integrative taxonomy was applied in order to identify, at generic and/or specific taxonomic level, 245 anisakids from 63 cetaceans of 12 different species, which stranded in the Brazilian coast. Parasites from nine hosts were preserved by freezing and, from 54 hosts, were fixed in 70% ethanol (n = 43) or alcohol-formalin-acetic (n = 11) for a period varying from 6 to 19 years. The morphological analysis allowed the identification of 171 specimens at genus level: 120 as Anisakis sp. clade I, 47 as Anisakis sp. clade II, and four as Pseudoterranova sp. From those 15, specimens were identified at species level, seven as Anisakis typica, seven as Anisakis paggiae and one as Anisakis brevispiculata. Moreover, 74 specimens were identified as belonging to Anisakidae family. The genetic analysis based on cox2 gene allowed the identification/confirmation of Anisakis typica (n = 33), Anisakis paggiae (n = 1), and for the first time in the Brazilian coast, Anisakis brevispiculata (n = 4) and Anisakis ziphidarum (n = 1). Additionally, a probably new Anisakis species, genetically close to A. paggiae, is reported infecting a dwarf sperm whale. The results clearly indicated that the preservation of nematodes influenced significantly on the level of taxonomic definition, in both morphological and, mainly, genetic analyses. Pseudoterranova sp. was identified for the first time in the spinner dolphin, Stenella longirostris. The detection of nine A. paggiae specimens, in three Kogia breviceps animals, substantiates the austral occurrence of this species. The identification of A. brevispiculata in Kogia sima and K. breviceps confirms Kogiidae whales as their most common hosts. Anisakis typica was corroborated as a generalist species, the most widely distributed in the Brazilian coast, infecting a broad variety of Delphinidae and Kogiidae, with two new geographical records in Stenella frontalis and Lagenodelphis hosei. The study showed a new scenery of parasite diversity of marine anisakids, updating the Anisakis species distribution.

Guiana Dolphins (Sotalia guianensis) and DR-CALUX for Screening Coastal Brazilian Environments for Dioxins and Related Compounds.

Guiana dolphin is the top predator of highest toxicological concern in Brazil and many studies on levels of persistent, bioaccumulative, and toxicant (PBT) pollutants have been performed on the species. However, due to high costs of the analyses, only one investigation comprised the determination of dioxins and related compounds (DRCs) in Guiana dolphin tissues. The dioxin responsive-chemically activated luciferase gene expression (DR-CALUX(®)) cell bioassay was used in the present study for the analyses of hepatic samples from 28 male Guiana dolphins in order to screen estuarine environments for DRCs, comprising three regions (Northeastern, Southeastern, and Southern) and four states [Paraná (PR), Rio de Janeiro (RJ), Espírito Santo (ES), and Ceará (CE)] of Brazil. High bioanalytical equivalent (BEQ) concentrations [dioxins (pg BEQ/g lipid)] were found, varying from 1.94 to 15.6 pg BEQ/g. A significant negative correlation between BEQ concentrations and total length was found in Guiana dolphins from Brazil (all analysed dolphins). This pattern also was verified for RJ state, pointing to (1) chemically induced developmental disruption or to (2) increasing efficiency of the detoxifying activity with the growth of the animal. Comparison was performed with literature data and significantly higher BEQ levels were found in Brazilian Guiana dolphins than in those reported for North Sea harbour porpoises. Higher levels were found in Southeastern (the most PBT-contaminated area of the country) than in Southern region. However, it is not possible to affirm that Guiana dolphins are more contaminated by DRCs in SE than in S region, because individuals were lengthier in S than in SE region. Our results seem to have mirrored dolphin exposure to PCBs in Brazil according to the literature. Further studies are required for investigating the hypotheses 1 and 2 mentioned above.

Morphology of mucosa-associated lymphoid tissue in odontocetes.

This study describes the mucosa-associated lymphoid tissue (MALT) in odontocetes from the Brazilian coast and freshwater systems. Seven species were evaluated and tissue samples were analyzed by light, scanning and transmission electron microscopy, and immunohistochemistry. Laryngeal tonsil was a palpable oval mass located in the larynx, composed of a lymphoepithelial complex. Dense collections of lymphocytes were found in the skin of male fetus and calf. Clusters of lymphoid tissue were found in the uterine cervix of a reproductively active juvenile female and along the pulmonary artery of an adult female. Lymphoid tissues associated with the gastrointestinal tract were characterized by diffusely arranged or organized lymphocytes. The anal tonsil was composed of an aggregate of lymphoid tissue occurring exclusively in the anal canal, being composed of squamous epithelium branches. MALT was present in different tissues and organic systems of cetaceans, providing constant protection against mucosal pathogens present in their environment.

Toxic heritage: Maternal transfer of pyrethroid insecticides and sunscreen agents in dolphins from Brazil.

Pyrethroids (PYR) and UV filters (UVF) were investigated in tissues of paired mother-fetus dolphins from Brazilian coast in order to investigate the possibility of maternal transfer of these emerging contaminants. Comparison of PYR and UVF concentrations in maternal and fetal blubber revealed Franciscana transferred efficiently both contaminants to fetuses (F/M > 1) and Guiana dolphin transferred efficiently PYR to fetuses (F/M > 1) different than UVF (F/M < 1). PYR and UVF concentrations in fetuses were the highest-ever reported in biota (up to 6640 and 11,530 ng/g lw, respectively). Muscle was the organ with the highest PYR and UVF concentrations (p < 0.001), suggesting that these two classes of emerging contaminants may have more affinity for proteins than for lipids. The high PYR and UVF concentrations found in fetuses demonstrate these compounds are efficiently transferred through placenta. This study is the first to report maternal transfer of pyrethroids and UV filters in marine mammals.

Morphological and genetic identification of Anisakis paggiae (Nematoda: Anisakidae) in dwarf sperm whale Kogia sima from Brazilian waters.

Anisakid nematodes have been identified in a wide variety of fish and marine mammal species. In Brazil, Anisakis physeteris, A. insignis, A. typica, A. nascetti, and those of the A. simplex complex have been reported infecting fishes and cetaceans. In this study, specimens collected from a dwarf sperm whale Kogia sima (Owen, 1866) stranded on the northeastern coast of Brazil were identified through morphological and genetic analyses as A. paggiae. Anisakids were examined through differential interference contrast light and scanning electron microscopy (SEM). Morphological and morphometric analysis revealed that these specimens belonged to Anisakis sp. clade II and more specifically to A. paggiae, exhibiting a violin-shaped ventriculus and 3 denticulate caudal plates, which are taxonomic characters considered unique to this species. Genetic analysis based on the mtDNA cox2 gene confirmed our identification of A. paggiae. Phylogenetic trees using both maximum likelihood and neighbor-joining methods revealed a strongly supported monophyletic clade (bootstrap support = 100%) with all available A. paggiae sequences. Integrative taxonomic analysis allowed the identification of A. paggiae for the first time in Brazilian waters, providing new data about their geographical distribution. Moreover, here we present the first SEM images of this species.

Organochlorine concentrations (PCBs, DDTs, HCHs, HCB and MIREX) in delphinids stranded at the northeastern Brazil.

Organochlorine compounds are highly persistent in the environment, causing bioaccumulation and biomagnification through the marine food chain. To verify the bioaccumulation pattern of DDT and its metabolites, as well as PCBs, Mirex, HCHs and HCB, samples of subcutaneous adipose tissue from 25 Guiana dolphins (Sotalia guianensis), two Fraser's dolphins (Lagenodelphis hosei), two spinner dolphins (Stenella longirostris), one spotted dolphin (Stenella frontalis), and one striped dolphin (Stenella coeruleoalba) were analyzed. The collected specimens were found stranded in northeastern Brazil between 2005 and 2011. The concentrations were reported in µg·g(-1) lip, varying from 0.02 to 17.3 for ΣPCB, from 0.003 to 5.19 for ΣDDT, from 0.005 to 0.16 for ΣHCH, from 0.002 to 0.16 for HCB, and from 0.02 to 2.38 for Mirex. The PCBs dominated the bioaccumulation pattern for both the Guiana and spinner dolphins; for the other species, DDT was the major compound. A discriminant function analysis revealed the differences in the organochlorine accumulation patterns between the Guiana dolphin (S. guianensis) and the continental shelf/oceanic dolphins (S. frontalis and S. longirostris). The results also show that the concentrations of organochlorine compounds found in the delphinids in northeastern Brazil were lower than the delphinids found in other regions of Brazil, as well as other locations worldwide with intense agroindustrial development and/or a larger population.

Genetic analysis of Anisakis typica (Nematoda: Anisakidae) from cetaceans of the northeast coast of Brazil: new data on its definitive hosts.

Anisakids from 5 different species of cetacean, Kogia breviceps, Peponocephala electra, Stenella clymene, Stenella longirostris and Steno bredanensis, were submitted to genetic analysis. Adults and larvae fixed in ethanol-formalin-acetic acid or in 70% ethanol for periods ranging from 10 months to 10 years were isolated from 9 cetaceans stranded on Ceará coast, Northeast Brazil. The 18S rDNA gene, ITS1, and specific Anisakis typica ITS regions were amplified by PCR. 18S rDNA and ITS1 region confirmed Anisakis sp. morphological identification but also detected the presence of Aspergillus sp. in longer preserved samples. All samples were identified as A. typica by ITS species-specific PCR. The study report three new definitive hosts of A. typica from the Brazilian Atlantic coast by genetic analysis: P. electra, K. breviceps, and S. clymene.