Lontra Longicaudis Research Articles

The first genomic resource for the ‘near threatened’ Neotropical otter Lontra longicaudis (Carnivora: Mustelidae): mitochondrial genome characterisation and insights into phylomitogenomic relationships in the family Mustelidae

ABSTRACT The Neotropical otter Lontra longicaudis is a top predator in aquatic ecosystems from North, Central, and South America and is subjected to substantial environmental distress due to historic and contemporary anthropogenic disturbance. Currently, L. longicaudis is considered ‘near threatened’ by the International Union for Conservation of Nature Red List of Threatened Species. This study renders the first genomic resource for L. longicaudis; its mitochondrial genome was assembled and characterised in detail. The AT-rich mitochondrial genome of L. longicaudis was 16,436 bp in length and encoded 13 protein coding genes (PCGs), 22 transfer RNA genes, two ribosomal RNA genes, and a 994 bp long putative control region (CR). The heavy use of CTA (Leu), ATA (Met), and ATC (Ile) codons in PCGs contributes to the AT-rich nature of this genome. Out of 22 tRNAs, tRNA-Ser (AGY) (trnS1) lacked a typical ‘cloverleaf’ secondary structure. In the CR, numerous microsatellites and two tandem repeats were detected as well as multiple ‘hairpin’ structures. Ka/Ks values estimated for all but one PCG were < 1, indicating purifying selection in most PCGs. atp8 experienced neutral selection. A phylogenomic analysis based on PCGs confirms the monophyly of the family Mustelidae and also supports the monophyletic status of the subfamilies Guloinae, Helictidinae, Melinae, Mustelinae and Lutrinae; Ictonychinae was found to be polyphyletic. In the Lutrinae, L. longicaudis had an early branching position. The characterisation of a complete mitochondrial genome in the Neotropical otter L. longicaudis constitutes the first step towards supporting conservation efforts using genomic tools in this and other mustelids inhabiting aquatic neotropical environments under considerable contemporary anthropogenic disturbance.

Optimal foraging of Neotropical otters (Carnivora: Mustelidae) in an urban river and predominance of generalist and sedentary fish in their diet

Optimal foraging of Neotropical otters (Carnivora: Mustelidae) in an urban river and predominance of generalist and sedentary fish in their diet

Status and distribution of Paraguayan Mustelidae

Five species of Mustelidae are known to occur in Paraguay – Tayra Eira barbara, Lesser Grison Galictis cuja, Greater Grison Galictis vittata, Giant Otter Pteronura brasiliensis and Neotropical Otter Lontra longicaudis. However, Paraguayan data regarding the distribution and status of these species in Paraguay is not easily obtainable, and scattered amongst numerous, often obscure publications. Paraguayan literature and specimens were reviewed to compile data on the distribution and status of these species in the country and records are presented in a hierarchical manner reflecting the reliability of each report. Data on these species in Paraguay are sorely lacking and our knowledge of distribution in the country is poor. The specimen record is incomplete and severely biased towards the Chaco region. Most species are apparently widespread and fairly common in the country. Giant Otter has a more restricted distribution, mainly in the Pantanal region. The precise distribution of the Greater Grison is unclear, probably because of widespread confusion of this species with the Lesser Grison.

New records of nematodes from three aquatic mammals in Mexico with notes about the nematode fauna recorded in Mexican waters

Nematodes are among the most common parasites in aquatic mammals. Because of their cuticular covering, these worms are frequently collected from the examination of feces or stranded hosts. This work provides new records of three nematode taxa infecting three different aquatic mammal species (Lontra longicaudis annectens, Trichechus manatus, and Zalophus californianus) in Mexico. Additionally, it brings together all available published records about this country's nematode fauna parasitizing aquatic mammals. The aim is to describe the current state of the art, which sets the basis for the strategic design of future research. Given the diversity of printed sources recording nematode fauna, we gathered literature, including theses and articles in journals profiled in the Journal Citation Reports or similar academic databases. The compiled information shows that 24 nominal nematode taxa have been reported from 11 species of aquatic mammals in Mexico. Our study exhibits irregular patterns of geographic distribution and host spectrum, existing entire marine ecoregions, and numerous host species lacking records.

Neotropical otter population strengthening in the wild / Reforço populacional de lontra neotropical na natureza

This work aims to contribute to the definition of a protocol for the safe release of Lontra longicaudis in the wild. It is used information from the database of the Animal Refuge Conservationist Breeding Center of the Instituto Ekko Brasil/Projeto Lontra. A proposed enclosure is presented, containing a minimum area of 60 m2, for an individual, with a tank occupying at least 40% of the enclosure, with a depth of 1,5 m, a feeding area of 2 m2, in addition to research actions, social mobilization, environmental education, and public policies. The research seeks to create a protocol adapted to the conditions of the Lontra longicaudis species, developed for the southern region of Brazil. It can serve as a subsidy for the definition of a protocol for this purpose for the neotropical otter. Such a protocol, associated with the eight otter birth successes at the Conservationist Animal Refuge, all reaching adulthood, can serve as an important support for the need to reintroduce otters into places where the species has gone extinct.

Study of feces of neotropical otters (Lontra longicaudis) in the Ayuquila-Armería basin, Mexico as biomonitors of the spatiotemporal distribution of pesticides.

The pesticides used have contributed to increasing food production; it has also caused them to be found in most ecosystems and have negative effects on biota. The neotropical otter (Lontra longicaudis) is vulnerable to pesticide accumulation and is characterized by being elusive, so it is necessary to address the use of indirect techniques that evaluate its populations' state in an efficient, logistically simple, and non-invasive way. This study aimed to determine the concentration of 20 pesticides in neotropical otter feces in the Ayuquila-Armería basin and to describe the spatiotemporal variation of these pesticides. The presence of 11 pesticides was determined. Imazalil, picloram, and malathion the pesticides with the highest concentrations; emamectin, λ-cyhalothrin, methomyl, and picloram were present in all samples. Emamectin was the only pesticide that presented significant differences concerning the temporality of the samplings, presenting higher concentrations in the wet season. Molinate concentrations showed significant differences concerning the location of the sampling sections in the basin; the lower part of the basin presented higher concentrations. The distribution of the populations of L. longicaudis in the Ayuquila-Armería basin does not respond to the degree of contamination by pesticides in surface waters or to the proximity to agricultural activities, and this in places with evident chemical and organic contamination and human presence. The use of otter feces for pesticide monitoring is an accepted non-invasive method to assess the degree of exposure and can be used to determine sites with pollution problems.

Confirmed presence of the Neotropical otter, Lontra longicaudis, in Laguna Bacalar, Quintana Roo, Mexico

The Neotropical otter Lontra longicaudis is one of the least studied mammals of the Yucatán Peninsula and its presence in some water bodies of this region is questionable. Laguna Bacalar is the largest freshwater body located in the Yucatán Peninsula and faces several conservation problems due to its high potential for tourism development. We confirmed the presence of L. longicaudis in Laguna Bacalar by conducting interviews with residents, and the search for direct (sightings) and indirect (e.g., footprints) evidence of the species in 2013. We also include recent direct and indirect evidence (2019-2020). We classified the records into levels of certainty, according to the type of evidence (photographs, videos). We obtained 9 records of Neotropical otter through interviews (level 3), 3 sightings and 4 footprints (level 1), and 4 sightings (3 of these with level 2 and 1 with level 3 of certainty). It is necessary to increase the research effort to determine the conservation status and distribution of the Neotropical otter in the lagoon. We recommend making efforts in terms of socialization and education to facilitate the conservation of the Neotropical otters and their habitat in Laguna Bacalar.

Neotropical mustelids: fecal metabolome diversity and its potential for taxonomic discrimination.

Chemical profiles of non-invasive biological material, such as feces, have great potential to study elusive animals or those with low population densities. Here, we use a metabolomic approach to evaluate Neotropical mustelids as a biological model to describe the diversity of the metabolites present in fecal samples, as well as to evaluate the potential of chemical profiles for taxonomic discrimination. We collected fecal samples from captive individuals of 5 species of mustelids occurring in Brazil and analyzed them by liquid chromatography coupled to high-resolution mass spectrometry. Over 200 compounds have been annotated; "bile acids, alcohols and derivatives" was the most expressive class in the metabolome of all the species. We successfully discriminated 3 taxonomic groups: 1-tayra (Eira barbara); 2-otters (Lontra longicaudis and Pteronura brasiliensis; 1); and 3-grisons (Galictis vittata and Galictis cuja). Several compounds seemed to be associated with food intake and the digestive process, while others were found for the first time in Neotropical mustelids. We concluded that mustelids show high metabolome diversity and that species-specific identification through metabolomic profiles is possible, thus contributing to the development and implementation of additional non-invasive approaches in the study of mustelids.

Feeding observations of a Turkey Vulture (Cathartes aura) and a Lesser Yellow-headed Vulture (C. burrovianus) in Belize

I present 2 noteworthy foraging observations of a Lesser Yellow-headed Vulture (Cathartes burrovianus) and a Turkey Vulture (C. aura) in Crooked Tree Wildlife Sanctuary and Cockscomb Basin Wildlife Sanctuary, Belize, respectively. I observed a Lesser Yellow-headed Vulture successfully capture a live fish from the water and a Turkey Vulture feeding on feces of neotropical otter (Lontra longicaudis) along a river. To my knowledge, these observations represent novel reports for each species, and contribute to the understanding of the breadth of foraging behavior of cathartid vultures.

Presence of Neotropical Otter (Lontra longicaudis) at High Elevation between Watersheds

The neotropical otter (Lontra longicaudis) is associated with freshwater systems and is generally found at elevations lower than 1500 masl. Its diet is based on fish and crustaceans. We present 3 photorecords of the neotropical otter at the divide between 2 hydrological basins in the Sierra de Manantlán Biosphere Reserve, Jalisco, México. The photos were taken at an altitude near 2000 masl, and one of them was >600 m from a water source. The area does not present optimal conditions for the presence of otter since water flows are low, fish are absent, and crustaceans are scarce. These records are evidence of the neotropical otter at high altitude in environments where conditions are suboptimal for the species. In addition, the importance of conserving the basin headwaters is discussed, since the headwaters can support movement or occasional stays of the neotropical otter in marginal habitat and thereby maintain the connectivity between basins and facilitate genetic exchange between otter populations.

Mechanisms of coexistence in a diverse Neotropical mammalian carnivore community

Abstract Mammalian carnivore diversity within the Reserva Natural del Bosque Mbaracayú in eastern Paraguay is represented by five families (Canidae, Mephitidae, Mustelidae, Procyonidae, and Felidae) and includes large-bodied, apex predators, several omnivores, and numerous mesocarnivores. The competitive exclusion principle argues that sustained spatial and temporal coexistence of two or more species with identical ecological requirements is unsustainable. The Reserve is a mosaic of habitats that has become isolated due to extensive deforestation of the surrounding Upper Paraná Atlantic Forest. Nevertheless, it is remarkable in that 16 mammalian carnivore species are documented as coexisting within the Reserve. We sought to determine the extent to which this diverse community is mitigating competition through the partitioning of available niche space by assessing dietary ecology of mammalian carnivores present, including diet breadths and dietary overlap, and by examining spatial patterns within the reserve. Feces were collected from all 16 mammalian carnivore species from seven areas within the reserve and specific identifications were confirmed by molecular analyses. Diet breadth, B^, standardized diet breadth, B^A, and Pianka’s Index for dietary overlap, O^, were calculated. A Chi-square goodness-of-fit test was performed to test for randomness of samples associated with survey areas. Diet analyses indicated a spectrum from dietary generalists to specialists. Species segregated into six dietary guilds, defined as groups of species with O^ &amp;gt; 0.5. Four guilds included only one species each (Neotropical otter, crab-eating fox, jaguar, and puma). The low dietary overlap between jaguar and puma contrasts with studies conducted elsewhere. One guild consisted of four highly omnivorous species (maned wolf, Molina’s hog-nosed skunk, crab-eating raccoon, and South American coati). The sixth guild included eight species which mostly consumed small vertebrates, primarily mammals as well as birds and reptiles (bush dog, two mustelines, five small felids). The mustelines (tayra and lesser grison) had extremely high dietary overlap. Although they did not segregate spatially, they are known to occupy distinct niches in vertically stratified forests. The five small felids also showed extremely high dietary overlap. Three of them were found to segregate spatially within the Reserve and two did not, although one (jaguarundi) is known to segregate temporally, being more active diurnally. The exceptionally rich community of mammalian carnivore species at the Reserva Natural del Bosque Mbaracayú appeared to avoid unsustainable competition by a variety of mechanisms, some utilizing different food items, or, in the case of high dietary overlap, utilizing spatial or temporal resources differently.

Behavior of neotropical otter, Lontra longicaudis (Olfers, 1818) (Carnivora, Mustelidae) in captivity / Comportamento da lontra neotropical, Lontra longicaudis (Olfers, 1818) (Carnivora, Mustelidae) em cativeiro

The study of the behavior of the Lontra longicaudis was conducted from January to April 2010. The main objective was to determine the individual and social patterns of three otters in captivity, correlating the data with average temperatures. The methodology was based on random observations, the ad libitum method, and the focal animal method, during which the animals are observed thanks to standardized spreadsheets. The sampling effort was four hours daily, resulting in a total of 196 hours. Twenty-nine listed activities were divided into two categories and ten sub-categories. The adult couple showed a similar pattern of activities. The young female, however, showed a different pattern in the activities, compared with adult animals. There was no difference in activity for day and night. However, on days with lower average temperatures, some activities decreased significantly, such as swimming, diving and rolling in the sand, while resting activities increased.

Guidelines for collection of biological samples for giant otters (Pteronura brasiliensis Gmelin, 1788) and Neotropical otters (Lontra longicaudis Olfers, 1818)

To optimize the health evaluation of Giant and Neotropical otters in the wild and under human care and to guarantee the quality of the information collected and maximize efforts in research projects, Brazilian veterinarians developed two protocols: 1) Protocol for collection, processing and storage of biological samples from live Giant and Neotropical otters, 2) Protocol for collection of biological material during necropsy.

Canine distemper virus and canine adenovirus type-2 infections in neotropical otters (Lontra longicaudis) from Southern Brazil.

All descriptions of infectious diseases affecting otters were published in the Northern Hemisphere, with no occurrence identified in neotropical otters (Lontra longicaudis). Consequently, a retrospective histopathological study using archival tissue samples from six free-living neotropical otters was done to investigate the possible occurrence of disease patterns associated with common viral infectious disease agents of the domestic dogs. Immunohistochemical (IHC) assays were designed to identify intralesional tissue antigens of canine distemper virus (CDV), and canine adenovirus-1 (CAdV-1) and canine adenovirus-2 (CAdV-2). The most frequent histopathological patterns diagnosed were interstitial pneumonia (83.33%; 6/5) and hepatocellular vacuolar degeneration (50%; 3/6). IHC identified intralesional intracytoplasmic immunoreactivity to CDV antigens in all otters evaluated, with positive immunolabeling occurring within epithelial cells of the lungs, stomach, kidneys, and liver, and skin. Intracytoplasmic CAdV-2 antigens were identified within epithelial cells of the peribronchial glands in four otters with interstitial pneumonia. These findings resulted in singular and simultaneous infections in these neotropical otters, represented the first report of concomitant infections by CDV and CAdV-2 in free-living neotropical otters from the Southern Hemisphere, and suggested that this mammalian species is susceptible to infections by viral disease agents common to the domestic dogs and may develop similar histopathologic disease patterns.

Molecular eco-epidemiology of Paracoccidioides brasiliensis in road-killed mammals reveals Cerdocyon thous and Cuniculus paca as new hosts harboring this fungal pathogen.

Wild animals infected with Paracoccidioides brasiliensis represent important indicators of this fungal agent presence in the environment. The detection of this pathogen in road-killed wild animals has shown to be a key strategy for eco-epidemiological surveillance of paracoccidioidomycosis (PCM), helping to map hot spots for human infection. Molecular detection of P. brasiliensis in wild animals from PCM outbreak areas has not been performed so far. The authors investigated the presence of P. brasiliensis through nested-PCR in tissue samples obtained from road-killed animals collected nearby a human PCM outbreak spot, Rio de Janeiro state, Brazil and border areas. Eighteen species of mammals were analyzed: Dasypus novemcinctus (nine-banded armadillo, n = 6), Cerdocyon thous (crab-eating fox, n = 4), Coendou spinosus (hairy dwarf porcupine, n = 2), Lontra longicaudis (Neotropical river otter, n = 1), Procyon cancrivorus (crab-eating raccoon, n = 1), Galactis cuja (lesser grison, n = 1), Tamandua tetradactyla (collared anteater, n = 1), Cuniculus paca (paca, n = 1), and Bradypus variegatus (brown-throated three-toed sloth, n = 1). Specific P. brasiliensis sequences were detected in the liver, spleen, and lymph node samples from 4/6 (66.7%) D. novemcinctus, reinforcing the importance of these animals on Paracoccidioides ecology. Moreover, lymph nodes samples from two C. thous, as well as lung samples from the C. paca were also positive. A literature review of Paracoccidioides spp. in vertebrates in Brazil indicates C. thous and C. paca as new hosts for the fungal pathogen P. brasiliensis.

Evaluation of Giant and Neotropical Otter as environmental assets in Conservation Tourism based on emergy analysis

Abstract Purpose: The main objective of this work is to evaluate the natural capital and ecosystem services of the Aquidauana River and the role of Lontra longicaudis and Pteronura brasiliensis as environmental assets for the development of conservation tourism. Research Methodology: First, a system diagram was built to organize ideas and relationships between components and resource flows. Second, it was to construct tables of emergy flows directly from the diagrams. Quantities of stored emergy of environmental resources are calculated from the sum of the emergy of all inputs and then multiplied by the time it takes to accumulate the storage. Results: The main services with market values ​​provided by the Aquidauana River are water supply, tourism, and fishing. The neotropical otter exhibited the largest asset in the system, followed by the giant otter and the indigenous culture. Limitations: Application of the emergy method to define public policies that lead to the real valuation of environmental assets and promote the social mobilization needed to change adverse realities. Contribution: The giant otter and neotropical otter values represent more than 90% of all values listed as environmental assets in the Aquidauana River System. The results can be important for the definition of public policies aimed at conservation tourism. With an appropriate social mobilization program, associated with economic and environmental education, the local economy could be strengthened, along with the protection of biodiversity.

Airborne vocal communication in adult neotropical otters (Lontra longicaudis).

Most aquatic mammals have complex social and communication systems. Interestingly, little is known about otters’ vocal communication compared to other aquatic mammals. Here, for the first time, we acoustically describe vocalizations of the neotropical otter (Lontra longicaudis), a solitary and endangered New World otter species. We recorded vocalizations and behavioral contexts from six captive neotropical otters at Projeto Lontra, Santa Catarina Island, Brazil. Analysis of acoustic parameters were used to classify the vocalizations according to structure and context. We describe six call types with highly tonal as well as chaotic vocalizations with fundamental frequencies ranging from 90 to 2500 Hz. Additionally, we identified sex differences in the usage of calls. Results suggest that the neotropical river otter has a rich vocal repertoire, similar in complexity to other solitary otter species, but less complex than that of the social giant otter. Despite differences in sociality, phylogeny and ecology, L. longicaudis seems to possess vocalizations homologous to those found in other otters (e.g. hah and chirp), suggesting phylogenetic inertia in otter communicative repertoire. Otters thus offer an interesting but neglected group to explore the evolution of communication systems.

Feeding behavior and trophic niche partitioning between co-existing river otter species

Niche partitioning occurs among coexisting populations to reduce the effects of competitive exclusion among species of similar niche. The aim of the present study is to verify the trophic niche partitioning and feeding behavior between two mustelids, the Giant otter and the Neotropical otter, through the dry and rainy season hydrologic of the Lower Xingu River. Our results suggest that the diets of both mustelids are composed primarily of fish of the family Anostomidae (Headstanders). Despite extensive niche overlap, our results indicate partitioning is facilitated by differences in niche breadth, with potential implications for conservation of both species in the case of declines in prey abundance and diversity. Both species inhabit an area recently impacted by completion of the Belo Monte Hydropower Plant, resulting in large changes to the hydrologic regime. Thus, our results provide important information for conservation efforts regarding the feeding behavior and co-occurrence of both species, as well as providing a baseline for monitoring future health of these mustelid populations. The present study is the first to test the hypothesis of niche partitioning between these two mustelids outside a protected area in the Amazon.

Conservation of Amazonian aquatic mammals

Abstract Aquatic mammals worldwide are highly threatened in freshwater ecosystems where they are affected by direct human activities (e.g. hunting) as well as indirect human alteration of freshwater ecosystems (e.g. dams, mining activity). Although aquatic mammals of the Amazon Basin are experiencing many growing threats, little is known about the escalating impacts on them, current limitations in protection mechanisms, and possible strategies to ensure their conservation. This study synthesizes the available information on Amazonian aquatic mammals, including the ecological characteristics of these species, key threats, population status and conservation prospects. Amazonian aquatic mammals comprise seven species – Inia geoffrensis, Inia boliviensis, Inia araguaiaensis, Sotalia fluviatilis, Trichechus inunguis, Pteronura brasiliensis and Lontra longicaudis – which are characterized by low reproductive rates and keystone ecosystem roles. These species are endangered mainly by biological resource use, natural ecosystem modifications, energy production and mining, and climate change. Although information is sparse, there is evidence that these threats are inducing population declines of Inia spp., and hindering the recovery of populations of P. brasiliensis. Protection mechanisms for these species mostly include national and international laws and agreements, legislation governing environmental licensing and protected areas. Each of these protection mechanisms, however, has limited capacity to protect Amazonian aquatic mammals, largely because they are poorly enforced, lack transnational coordination or require population trend data that do not exist. Reversing the current state of affairs for Amazonian aquatic mammals requires an integrated research and policy approach that, at a minimum, substantially increases the present capacity to monitor their population responses to human impacts, establishes effective enforcement of existing legislation and prevents further impacts from hydropower development. To implement such an approach, information on the ecology of these species is necessary to create public and scientific awareness.

Neotropical otter diet variation between a lentic and a lotic systems

Neotropical otters have been scarcely studied at the northern edge of their distribution in Mexico. The species has nocturnal-twilight habits, and their principal food is fish and crustaceans. The aim of this work was to know the foraging habits of Neotropical otters (Lontra longicaudis) in two monitoring sites one lentic and the other one lotic systems of the Río San Lorenzo, Sinaloa México. From February 2009 to January 2010, we surveyed the area during the four seasons by walking 15 km of the river edge of Río San Lorenzo, and 15 km at the El Comedero reservoir. We collected 318 scats, 155 in the reservoir and 163 in the river. Fish were the most abundant prey item in both places, with a frequency of occurrence of 98.1 % in the river and 100 % in the reservoir. The percentage of occurrence varied largely in the other prey items in both places. Seven taxonomic groups compose their foraging habits in the river (relative frequency in parentheses): fish (64.3 %), insects (9.2 %), mollusks (6.8 %), birds (6.0 %), mammals (5.6 %), crustaceans (5.2 %) and fruits (2.8 %). Five taxonomic groups in the reservoir compose it: fish (65.1 %), birds (22.7 %), mammals (9.2 %), fruits (2.5 %) and insects (0.4 %). The most important fish in the diet belonged to the genus Oreochromis, which includes an introduced species. We conclude that the Neotropical otter is an opportunistic carnivore that preys mainly on fish, probably due to their high availability, but they also forage in other taxa that are available at Río San Lorenzo basin.