Melanosuchus Research Articles

Postcranial skeleton of Campinasuchus dinizi (Crocodyliformes, Baurusuchidae) from the Upper Cretaceous of Brazil, with comments on the ontogeny and ecomorphology of the species

The Baurusuchidae is one of the most representative families of Crocodyliformes from the Upper Cretaceous of Brazil. Amongst the ten recognized species of the family in the world, eight are recovered from Bauru Basin outcrops. Despite its relative diversity and abundance, information on postcranial elements of species of the family is scarce in the literature. Campinasuchus dinizi is a baurusuchid found in the neocretaceous redstones of the Adamantina Formation of Bauru Basin (SE Brazil). The postcranial skeleton of the species is described based on five specimens, with the following bone elements identified: proatlas, intercentrum of the atlas; pedicles of the atlas; odontoid process; axis; three postaxial cervical vertebrae; nine dorsal vertebrae; eight caudal vertebrae; seven ribs and gastralia fragments; eleven chevrons; twelve osteoderms; pectoral and pelvic girdle; humerus; radius; ulna; manus; femur; tibia; fibula; and pes. Campinasuchus dinizi has the smallest and most delicate postcranial skeleton when compared with examined Baurusuchidae, with an inferred body mass of approximately 28 kg. Some elements of the postcranial skeleton of C. dinizi are also comparatively more robust (e.g. neural spines higher and more developed; vertebral body thicker; pelvic girdle more proeminent; limbs more elongated) than in some notosuchians, such as Mariliasuchus amarali and Notosuchus terrestris, and extant crocodyliforms such as Caiman latirostris and Melanosuchus niger. The mostly straight limbs of C. dinizi indicate a terrestrial habit, and suggests a semi-upright to upright posture during locomotion. The first descriptions of postcranial bones of a young specimen of C. dinizi and osteoderms of Pissarrachampsinae as well as comments about the distinct anatomy of some of those elements are also presented.

Fatty Acid Profile of the Amazon Caiman Protein Concentrate

Some species of fish and other aquatic organism are important sources of protein and fatty acids that are beneficial to human health and can be industrially processed. The fatty acid profile of Melanosuchus niger (native to the Brazilian Amazon flooded forest) was determined in samples of a protein concentrate (PC) there was obtained from processing residues. The PC was prepared from cooked muscle portions and NaCl (1.5%) using an adiabatic process. Saturated fatty acids such as stearic acid (0.59%) and palmitic acid (1.43%) were present. The levels of the unsaturated fatty acids omega-6 (ω-6) and omega-3 (ω-3) linolenic acids were 0.32% and 0.15%, respectively. In conclusion, Black caiman PC seems to provide essential fatty acids for human nutrition. Clinical studies are necessary to assess the influence of fatty acids from Amazon Caimans on human diet and the feasibility of obtaining new products such as nutraceuticals.

Osteologia de Melanosuchus niger (Crocodylia: Alligatoridae) e a evidência evolutiva

RESUMO: O objetivo foi realizar a descrição anatômica do esqueleto de Melanosuchus niger, com o intuito de contribuir com informações evolutivas sobre a espécie. Utilizaram-se três espécimes adultos de M. niger, com comprimento médio de 2,40m, provenientes da coleção biológica do Lapas-UFU. Na cintura peitoral, a escápula é maior do que o coracóide. Já nos elementos da cintura pelvina, o púbis não participa da formação do acetábulo, o contato com o ilío, ocorre por ligamentos, e sua articulação com o ísquio, permite movimentos dorso-ventrais. Nos membros torácicos, o úmero figura como elemento do estilopódio, a ulna e rádio como elementos do zeugopódio. No carpo há o ulnar do carpo, fusão do radial+intermédio, fusão dos distais do carpo 3+4+5 e o pisiforme; possui cinco metacarpos, numerados lateromedialmente e a fórmula falângica 2:3:4:3:2. Nos membros pelvinos, o estilopódio é formado pelo fêmur e o zeugopódio pela tíbia e fíbula. No tarso há a fusão do intermédio+central, fibular do tarso, distal do tarso 3, distal do tarso 4; possui quatro metatarsos longos I, II, III e IV, sendo os metatarsos II e III maiores que os demais. O metatarso V é um osso bastante reduzido e o pé possui a fórmula falângica 2:3:4:4. No crânio, a abertura nasal é única, o palatino, vômer, pterigóide, pré-maxila e maxila formam a estrutura óssea do palato secundário; o osso parietal é o único elemento no teto craniano. No esqueleto pós- axial em pares de costelas distintas que se articulam com as vértebras cervicais, dorsais, lombares, sacrais e caudais. A gastrália é formada por sete fileiras de ossos finos localizados entre o púbis e a região caudal do esterno.

Caiman hunting in Central Amazonia, Brazil

Hunting caimans (Caiman spp.) with baited hooks in the Brazilian Amazon represents one of the largest illegal wildlife industries in the world. Our objective was to evaluate the effects of water level, distance from settlements, and hunting effort on caiman meat production. In 2008, we accompanied 31 caiman hunting expeditions in and around a wetland protected area located in the Amazon-Purus interfluve in Brazil. We measured and weighed all captured caimans. We used simple and multiple linear regressions to analyze our data. The hunting technique is not selective for the capture of spectacled caimans (Caiman crocodilus) or black caimans (Melanosuchus niger) and occurs throughout the year. Fresh-meat production was similarly correlated with individualś weights for both species. Hunting success was strongly related to river level, distance from human settlements, and hunting effort. We estimated an annual production of 37,050 kg of meat from the study area, representing 3,562 caimans harvested and gross earnings of $18,500 (U.S.). Caiman hunting was the principal source of income for hunters and their families but resulted in low returns, and large black caiman were not taken, indicating possible overhunting. © 2016 The Wildlife Society.

Ontogeny of the Appendicular Skeleton in Melanosuchus niger (Crocodylia: Alligatoridae).

The objective of the present study was to analyze chondrogenesis and the ossification pattern of the limbs of Melanosuchus niger in order to contribute with possible discussions on homology and the fusion pattern of autopodial elements and phylogeny. In the Reserva Extrativista do Lago Cuniã, Rondônia, Brazil, six nests were marked and two eggs removed from each nest at 24-hour intervals until hatching. Embryos were cleared using KOH; bone tissue was stained with alizarin red S and cartilage with Alcian blue. Routine staining with HE was also performed. In the pectoral girdle, the scapula showed ossification centers before the coracoid process. In the pelvic girdle, the ilium and the ischium were condensed as a single cartilage, although ossification took place through two separate centers, forming distinct elements in the adult. The pubis developed from an independent cartilaginous center with free end, which reflects its function in breathing. In the initial stages, the stylopodium and the zeugopodium developed from the condensation of a Y-shaped cartilage in the limbs, and differentiation of the primary axis and digital arch were observed. The greatest changes were observed in the mesopodia. In their evolution, Crocodylia underwent a vast reduction in the number of autopodial elements as a consequence of fusions and ossification of some elements. This study shows that the chondrogenesis and ossification sequences are dissociated. Moreover, the differences between M. niger and other species show clear variation in the patterns for these events in Alligatoridae.

English

Some species of fish and other aquatic organism are important sources of protein and fatty acids that are beneficial to human health and can be industrially processed. The fatty acid profile of Caiman crocodilus and Melanosuchus niger (native to the Brazilian Amazon flooded forest) was determined in samples of a commercial cut (tail fillet) and fat (fat body and somatic fat) of these two species. There were no statistically significant differences in the total lipid content between them (p ≥ 0.05) and both had higher levels of palmitic, stearic (saturated), and oleic (unsaturated) acids. However, omega 3 (ω-3) and omega 6 (ω-6) were not detected in the samples of the commercial cut; they were present only in the fats evaluated. Clinical studies are necessary to assess the influence of fatty acids from Amazon Caimans on human diet and the feasibility of obtaining new products such as nutraceuticals.   Key words: Black caiman, spectacled caiman, omega 3, omega 6.

Growth rates of black caiman (Melanosuchus niger) in the Rupununi region of Guyana

We conducted a study of black caiman (Melanosuchus niger) growth rates using data from a long-term mark-recapture study carried out in the Rupununi region of Guyana between 2005 and 2015. In contrast to previous studies, growth rates of black caiman declined with increasing size and this decline occurred more rapidly for females. Size-at-age models predicted that males and females reach asymptotic sizes of 178.2-189.0 cm SVL and 140.1-143.4 cm SVL, respectively. Our results suggest that growth rates of black caiman in the Rupununi region follow the same general patterns as for other crocodilians, and that disparities with previous black caiman studies may be largely related to density-dependent factors, among other possibilities. However, future studies that include large black caiman of known ages are needed to validate our findings.

Concentrações bioquímicas séricas de jacaré-açú (Melanosuchus niger) machos, adultos de vida livre

Resumo: O jacaré-açu (Melanosuchus niger), pertencendo à família Aligatoridae, é considerado o maior predador aquático da América Continental. Como todos os répteis, possui particularidades para o uso de energia, controlando sua temperatura corporal nas variações climáticas. Essas variações podem revelar a situação metabólica atual desse animal, justificando o estudo de tais parâmetros. A importância desse trabalho se justifica pela escassez de estudos disponíveis na literatura. Nesse sentido, determinamos o perfil bioquímico de compostos sanguíneos de 12 jacarés açu, com peso de 77,66±8,92 kg, os quais foram: uréia (3,41±0,66), albumina (24,85±0,63), proteína total (63,83±16,97), ácido úrico (0,25±0,09), glicose (6,99±0,77), colesterol total (2,20±0,27), triglicérides (0,58±0,07), TGO (138,83±9,16) e TGP (12,47±2,82).

Field and experimental evidence of a new caiman trypanosome species closely phylogenetically related to fish trypanosomes and transmitted by leeches.

Trypanosoma terena and Trypanosoma ralphi are known species of the South American crocodilians Caiman crocodilus, Caiman yacare and Melanosuchus niger and are phylogenetically related to the tsetse-transmitted Trypanosoma grayi of the African Crocodylus niloticus. These trypanosomes form the Crocodilian clade of the terrestrial clade of the genus Trypanosoma. A PCR-survey for trypanosomes in caiman blood samples and in leeches taken from caimans revealed unknown trypanosome diversity and frequent mixed infections. Phylogenies based on SSU (small subunit) of rRNA and gGAPDH (glycosomal Glyceraldehyde Phosphate Dehydrogenase) gene sequences revealed a new trypanosome species clustering with T. terena and T. ralphi in the crocodilian clade and an additional new species nesting in the distant Aquatic clade of trypanosomes, which is herein named Trypanosoma clandestinus n. sp. This new species was found in Caiman yacare, Caiman crocodilus and M. niger from the Pantanal and Amazonian biomes in Brazil. Large numbers of dividing epimastigotes and unique thin and long trypomastigotes were found in the guts of leeches (Haementeria sp.) removed from the mouths of caimans. The trypanosomes recovered from the leeches had sequences identical to those of T. clandestinus of caiman blood samples. Experimental infestation of young caimans (Caiman yacare) with infected leeches resulted in long-lasting T. clandestinus infections that permitted us to delineate its life cycle. In contrast to T. terena, T. ralphi and T. grayi, which are detectable by hemoculturing, microscopy and standard PCR of caiman blood, T. clandestinus passes undetected by these methods due to very low parasitemia and could be detected solely by the more sensitive nested PCR method. T. clandestinus n. sp. is the first crocodilian trypanosome known to be transmitted by leeches and positioned in the aquatic clade closest to fish trypanosomes. Our data show that caimans can host trypanosomes of the aquatic or terrestrial clade, sometimes simultaneously.

Riscos na qualidade sanitária da carne de jacaré da Amazônia Central

Determining caiman meat quality is a major problem when establishing the production chain of wild populations. In Brazil, there are no protocols for this type of meat. The slaughter and processing were performed using a simplified, traditional floating raft system and a water treatment system that used both filtration and chemicals. The animals were caught using a hook, harpoon, resting pole, and cable snare. The wild caimans of two species (Melanosuchus niger and Caiman crocodilus) were captured in the region of the Piagacu-Purus Sustainable Development Reserve in Central Amazon during three harvesting events. After each event, we progressively improved the meat-processing protocol. Microbiological testing of the meat was performed as described in norms and Brazilian legislation for fish meat. As a result, we achieved improvements in the sanitary quality of the meat of the killed animals for 57%, 76.5% and 100% of the samples obtained during the first, second, and third harvesting events, respectively. There were significant differences in the microbiological quality of the meat, with a reduction in the disapproval of the samples. The process of capturing animals, the cable snare, and the restraining pole were the factors that least affected the quality of the meat; in addition, animals between 81 and 100 cm of CRC had a lower risk of microbiological contamination. We can conclude that health surveillance activities, such as hand hygiene when handling meat, improvements in water quality, selection of animals of the most appropriate size for slaughter, and capture by less invasive methods can reduce the potential for microbiological contamination of the meat contribute to decrease the potential for microbiological contamination of meat.

Mercury concentrations in different tissues of turtle and caiman species from the Rio Purus, Amazonas, Brazil.

Total mercury (Hg) concentrations of muscle, liver, blood, and epidermal keratin were measured in typically consumed, economically and culturally important species of turtle (Podocnemis unifilis and Podocnemis expansa) and caiman (Melanosuchus niger and Caiman crocodilus) from the Rio Purus in the Amazon basin, Brazil. Methylmercury (MeHg) concentrations were also measured in muscle tissue, representing the first analysis of MeHg concentrations in Amazonian reptile species. In muscle tissues Hg was mostly MeHg (79-96%) for all species. No correlations existed between animal size and total Hg or MeHg concentrations for any species other than M. niger, possibly as a result of growth dilution or the evolution of efficient Hg elimination mechanisms. Significant linear correlations were found between total Hg concentrations in all pairs of nonlethally sampled tissues (keratin and blood) and internal tissues (muscle and liver) for M. niger and between keratin and internal tissues for P. expansa, indicating that nonlethally sampled tissues can be analyzed to achieve more widespread and representative monitoring of Hg bioaccumulation in Amazonian reptiles. Although mean Hg concentrations in muscle for all species were below the World Health Organization guideline for safe consumption (500 µg kg(-1)), mean concentrations in caiman liver were above the safe limit for pregnant women and children (200 µg kg(-1)). No significant differences were found between total Hg and MeHg concentrations in tissues from wild-caught and farm-raised P. expansa, suggesting that farming may not reduce Hg exposure to humans.

Similarity of Crocodilian and Avian Lungs Indicates Unidirectional Flow Is Ancestral for Archosaurs

Patterns of airflow and pulmonary anatomy were studied in the American alligator (Alligator mississippiensis), the black caiman (Melanosuchus niger), the spectacled caiman (Caiman crocodilus), the dwarf crocodile (Osteolaemus tetraspis), the saltwater crocodile (Crocodylus porosus), the Nile crocodile (Crocodylus niloticus), and Morelet's crocodile (Crocodylus moreletii). In addition, anatomy was studied in the Orinoco crocodile (Crocodylus intermedius). Airflow was measured using heated thermistor flow meters and visualized by endoscopy during insufflation of aerosolized propolene glycol and glycerol. Computed tomography and gross dissection were used to visualize the anatomy. In all species studied a bird-like pattern of unidirectional flow was present, in which air flowed caudad in the cervical ventral bronchus and its branches during both lung inflation and deflation and craniad in dorsobronchi and their branches. Tubular pathways connected the secondary bronchi to each other and allowed air to flow from the dorsobronchi into the ventrobronchi. No evidence for anatomical valves was found, suggesting that aerodynamic valves cause the unidirectional flow. In vivo data from the American alligator showed that unidirectional flow is present during periods of breath-holding (apnea) and is powered by the beating heart, suggesting that this pattern of flow harnesses the heart as a pump for air. Unidirectional flow may also facilitate washout of stale gases from the lung, reducing the cost of breathing, respiratory evaporative water loss, heat loss through the heat of vaporization, and facilitating crypsis. The similarity in structure and function of the bird lung with pulmonary anatomy of this broad range of crocodilian species indicates that a similar morphology and pattern of unidirectional flow were present in the lungs of the common ancestor of crocodilians and birds. These data suggest a paradigm shift is needed in our understanding of the evolution of this character. Although conventional wisdom is that unidirectional flow is important for the high activity and basal metabolic rates for which birds are renowned, the widespread occurrence of this pattern of flow in crocodilians indicates otherwise. Furthermore, these results show that air sacs are not requisite for unidirectional flow, and therefore raise questions about the function of avian air sacs.

English

The Amazon region is recognized as source of fish for the food industry. The interest in new products made from exotic animal meat has increased. The present study was carried out to evaluate carcass and meat characteristics of Amazon caiman. Samples (n=184) of Melanosuchus niger were collected from a protected area in the Amazonas State (Brazil). The meat was analyzed for proximate composition: Moisture content 78.17%, protein 19.23%, lipids 1.09%, and ash 0.73%. The yield of the carcasses and cuts were evaluated, and the average yield of carcass was 57.02%. The tail cuts had the highest yield. The results obtained can be useful for new Amazon basin products as well as for product labeling. Key words: Amazon, acu, crocodilian, protein, harvesting.

Lesões pulmonares associadas ao parasitismo por Sebekia oxycephala (Pentastomida) em jacarés-açu (Melanosuchus niger Spix, 1825) oriundos de vida livre na Amazônia brasileira

O presente estudo objetivou descrever as lesões pulmonares macro e microscópicas associadas ao parasitismo por Sebekia oxycephala em 100 espécimes de jacarés-açu (Melanosuchusniger), abatidos na Reserva de Desenvolvimento Sustentável Mamirauá, situada no Estado do Amazonas, Brasil. Durante a avaliação macroscópica, exemplares dos parasitos encontrados no tecido pulmonar foram coletados individualmente em AFA (Álcool etílico - Formalina - Ácido acético glacial) e formol a 5% para avaliação parasitológica e classificação taxonômica. Amostras de tecido pulmonar de todos os animais, independentemente da ocorrência de lesões macroscópicas, foram fixadas em formol 10% e incluídas em parafina. Secções histológicas coradas por Hematoxilina-Eosina destas amostras foram avaliadas por meio de microscopia óptica. Macroscopicamente, 4 dos 100 animais (4%) apresentaram espécimes de pentastomídeos no parênquima pulmonar. Os parasitos foram classificados taxonomicamente como pertencentes à espécie Sebekia oxycephala. Nenhuma alteração macroscópicas foi observada, porém, microscopicamente, lesões pulmonares foram encontradas em 37% dos casos, sendo que, lesões inflamatórias associadas ao parasitismo corresponderam a 75,6% dos mesmos (28/37). Nestes, segmentos degenerados e ovos de S. oxycephala encontravam-se envolvidos por cápsula de tecido conjuntivo fibroso e infiltrado inflamatório predominantemente composto por células gigantes do tipo corpo estranho. Três espécimes apresentaram espessamento de septos alveolares e sete exemplares continham infiltrado inflamatório granulocítico multifocal no parênquima pulmonar. As lesões associadas ao parasitismo, de modo geral, apresentaram intensidade discreta e parecem não representar uma causa importante de doença pulmonar entre a população estudada. Esta é a primeira descrição de lesões pulmonares em M. niger associadas ao parasitismo por S. oxycephala na Amazônia brasileira.

Anti-inflammatory activity of animal oils from the Peruvian Amazon

Ethnopharmacological relevanceAnimal oils and fats from the fishes Electrophorus electricus and Potamotrygon motoro, the reptiles Boa constrictor, Chelonoidis denticulata (Geochelone denticulata) and Melanosuchus niger and the riverine dolphin Inia geoffrensis are used as anti-inflammatory agents in the Peruvian Amazon. The aim of the study was to assess the topic anti-inflammatory effect of the oils/fats as well as to evaluate its antimicrobial activity and fatty acid composition. Materials and methodsThe oils/fats were purchased from a traditional store at the Iquitos market of Belen, Peru. The topic anti-inflammatory effect was evaluated by the mice ear edema induced by arachidonic acid (AA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) at the dose of 3mg oil/ear. Indomethacine and nimesulide were used as reference anti-inflammatory drugs. The application resembles the traditional topical use of the oils. The antimicrobial effect of the oils/fats was assessed by the microdilution test against reference strains of Escherichia coli, Staphylococcus aureus and Salmonella enteritidis. The fatty acid composition of the oils/fats (as methyl esters) was determined by GC and GC–MS analysis after saponification. ResultsAll oils/fats showed topic anti-inflammatory activity, with better effect in the TPA-induced mice ear edema assay. The most active drugs were Potamotrygon motoro, Melanosuchus niger and Geochelone denticulata. In the AA-induced assay, the best activity was found for Potamotrygon motoro and Electrophorus electricus oil. The oil of Electrophorus electricus also showed a weak antimicrobial effect with MIC values of 250µg/mL against Escherichia coli ATCC 25922 and Salmonella enteritidis-MI. The main fatty acids in the oils were oleic, palmitic and linoleic acids. ConclusionsTopical application of all the oils/fats investigated showed anti-inflammatory activity in the mice ear edema assay. The effect can be related with the identity and composition of the fatty acids in the samples. This study gives support to the traditional use of animal oils/fats as ant-inflammatory agents in the Peruvian Amazon. However, new alternative should be encouraged due to the conservation status of several of the animal sources of the crude drugs.

Mercury contamination in alligators (Melanosuchus niger) from Mamirauá Reservoir (Brazilian Amazon) and human health risk assessment.

Mercury (Hg) concentrations in muscles of wild alligators (Melanosuchus niger) from the Mamirauá Reservoir (a reference area in the Brazilian Amazon) and the human health risks associated with its consumption were assessed. The mean Hg concentration in alligator muscles was 0.407 ± 0.114 μg/g (N = 61). Close to 5 % of the muscle samples showed Hg levels above the World Health Organization guideline for fish consumption (0.5 μg/g). A positive and significant relationship was observed between Hg concentrations in muscle and the age of the specimens. The dose-response approach suggests that close to 27.4 years is required for half of the exposed specimens to attain 0.5 μg/g. The hazard quotient (HQ) is a risk indicator which defines the ratio of exposure level and a toxicological reference dose. HQ resulted above the unity for all the specimens when the ingestion rate for riverine communities (200 g of muscle per day) is considered, indicating the existence of hazard. When the ingestion rate for market consumers (28.57 g/day) is considered, the risks are much lower (mean HQ = 0.55), suggesting that such group is not at risk. The establishment of local and regional ingestion rates for riverine populations and market consumers is extremely recommended.

An evaluation of the use of reptile dermal scutes as a non-invasive method to monitor mercury concentrations in the environment

Reptiles are ideal organisms for the non-invasive monitoring of mercury (Hg) contamination. We have investigated Hg bioaccumulation in tissue layers of reptile dermis as a basis for establishing a standardized collection method for Hg analysis. Tissue samples from freshwater turtle species Podocnemis unifilis and Podocnemis expansa and caiman species Melanosuchus niger and Caiman crocodilus, all from the Amazonian region, were analysed in this study. We first tested the relationships between Hg concentrations in keratin and bone to Hg concentrations in muscle to determine the best predictor of Hg concentration in muscle tissue. We then investigated the potential for measuring Hg concentrations across turtle carapace growth rings as an indicator of longer term changes in Hg concentration in the environment. Hg concentrations were significantly lower in bone (120ngg−1 caimans and 1ngg−1 turtles) than keratin (3600ngg−1 caimans and 2200ngg−1 turtles). Keratin was found to be a better predictor of exposure to Hg than muscle and bone tissues for both turtles and caimans and also to be a reliable non-invasive tissue for Hg analysis in turtles. Measurement of Hg in carapace growth rings has significant potential for estimating Hg bioaccumulation by turtles over time, but full quantification awaits development and use of a matrix-matched reference material for laser ablation ICPMS analysis of Hg concentrations in keratin. Realising this potential would make a valuable advance to the study of the history of contamination in mining and industrial sites, which have until now relied on the analysis of Hg concentrations in sediments.

Síntese das Características da Ordem Crocodylia, Fatores de Influência em Estudos Populacionais e Aspectos de Seleção e uso de Habitat para Caiman crocodilus e Melanosuchus nigerno Estado do Tocantins, Brasil

Este estudo objetivou apresentar uma síntese das características dos crocodilianos (Ordem Crocodylia), com enfoque nas espécies de ocorrência (Caiman crocodilus e Melanosuchus niger) no entorno do Parque Nacional do Araguaia e do Parque Estadual do Cantão, Estado do Tocantins, Brasil. Também, foi abordado aspectos de influência na seleção e uso de habitat por crocodilianos e fatores ambientais de interferência nas populações. Levantamentos populacionais de crocodilianos foram executados nos anos de 2010, 2011 e 2012 entre períodos de cheias e secas, com contagens de animais, registro dos microhabitats (leito, vegetação marginal, vegetação flutuante, praia e vertente) e coleta das temperaturas do ar e da água e nível fluviométrico.

The phylogeography of trypanosomes from South American alligatorids and African crocodilids is consistent with the geological history of South American river basins and the transoceanic dispersal of Crocodylus at the Miocene

BackgroundLittle is known about the diversity, phylogenetic relationships, and biogeography of trypanosomes infecting non-mammalian hosts. In this study, we investigated the influence of host species and biogeography on shaping the genetic diversity, phylogenetic relationship, and distribution of trypanosomes from South American alligatorids and African crocodilids.MethodsSmall Subunit rRNA (SSU rRNA) and glycosomal Glyceraldehyde Phosphate Dehydrogenase (gGAPDH) genes were employed for phylogenetic inferences. Trypanosomes from crocodilians were obtained by haemoculturing. Growth behaviour, morphology, and ultrastructural features complement the molecular description of two new species strongly supported by phylogenetic analyses.ResultsThe inferred phylogenies disclosed a strongly supported crocodilian-restricted clade comprising three subclades. The subclade T. grayi comprised the African Trypanosoma grayi from Crocodylus niloticus and tsetse flies. The subclade T. ralphi comprised alligatorid trypanosomes represented by Trypanosoma ralphi n. sp. from Melanosuchus niger, Caiman crocodilus and Caiman yacare from Brazilian river basins. T. grayi and T. ralphi were sister subclades. The basal subclade T. terena comprised alligatorid trypanosomes represented by Trypanosoma terena n. sp. from Ca. yacare sharing hosts and basins with the distantly genetic related T. ralphi. This subclade also included the trypanosome from Ca. crocodilus from the Orinoco basin in Venezuela and, unexpectedly, a trypanosome from the African crocodilian Osteolaemus tetraspis.ConclusionThe close relationship between South American and African trypanosomes is consistent with paleontological evidence of recent transoceanic dispersal of Crocodylus at the Miocene/Pliocene boundaries (4–5 mya), and host-switching of trypanosomes throughout the geological configuration of South American hydrographical basins shaping the evolutionary histories of the crocodilians and their trypanosomes.

Local Community Involvement as a Basis for Sustainable Crocodilian Management in Protected Areas of Central Amazonia: Problem or Solution?

Amazon floodplains have a long history of exploitation of crocodilians, particularly of large species such as the black caiman ( Melanosuchus niger) and spectacled caiman ( Caiman crocodilus). Historically, legal but uncontrolled trade resulted in a drastic reduction of wild populations of both species, which eventually led to the collapse of the commercial trade. In 1967, prohibition of commercial use of wild fauna through changes in Brazilian and international laws allowed caiman populations to slowly recover across much of their original range. Several studies on caiman populations greatly improved knowledge about the species, offering scientific bases for crocodilian management in the wild. Although protective legislation should only be altered using extreme caution, the creation of Sustainable Development Reserves (SDR) at the end of last century made it possible to manage wildlife for commercial purposes, albeit under strict population monitoring regimes. This category of protected area was established to improve welfare of local communities and strengthen their participation in conservation. Along with involvement in caiman monitoring programs, the engagement of local hunters and buyers is essential for participatory management plans. Even with development of SDRs, monitoring of crocodilian populations is still restricted to a few State Reserves, and traditional knowledge of stakeholders has been insufficiently incorporated into management and monitoring activities. We believe that stronger participation of local actors can help to improve the experimental harvesting initiatives that have been carried out thus far by local authorities. Community-based monitoring programs, which reflect local reality, are being developed in a simple and cost-effective way.