Hidrobiológica (E-Journal)
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Macroalgas arrecifales del Pacífico Centro-Sur de México: Estado del arte: Macroalgas arrecifales del Pacífico tropical mexicano
No full textBackground. The macroalgae of the tropical Mexican Pacific have been studied and results published in numerous texts since the 1940s. Nevertheless, there is no compilation of records of macroalgae from reef communities, nor have specific inventories of reef macroalgae been prepared. Objective. To integrate the knowledge generated on the tropical Mexican Pacific coral reef macroalgae. Carry out an integration of the knowledge generated on reef macroalgae and make inventories of these macroalgae in the reefs of Guerrero and Oaxaca in the Mexican tropical Pacific. Methods. Sørensen›s similarity analysis and Non-Metric Multidimensional Scaling (NDMS) analysis were applied to data of algal composition from different coral reefs to determine their distribution patterns. The ANOSIM analysis method was applied to demonstrate the significant differences between groups. Results. The total number of macroalgal species was 144, 100 Rhodophyta, 32 Chlorophyta and 12 Ochrophyta-Phaeopyceae; 75 were exclusive to Guerrero, 24 to Oaxaca, and the number of shared species was 45. El Zacatoso, Guerrero, had 92 species and was the locality with the greatest specific richness. The Sørensen Index indicated a similarity of more than 50% among most localities, but with a clear separation between the communities of Guerrero and Oaxaca. Four groups were formed by localities’ species with the NMDS analysis without seasonal effect (rainy and dry), ANOSIM shows significant differences among the localities of each group. Conclusion. This work represents the first inventory of the reef-inhabiting macroalgae of Guerrero and Oaxaca, the only states in the Mexican tropical Pacific with specific systematic reports on this type of coral reef algae. This study provides baseline information to develop a regional monitoring program, a diagnosis of the degree of disturbance of coral reefs and generate conservation strategies and plans for these ecosystems.Antecedentes. Las macroalgas del Pacífico tropical mexicano han sido estudiadas y los resultados publicados en numerosos textos desde la década de 1940, sin embargo, no se ha hecho una recopilación de los registros de las macroalgas de las comunidades arrecifales ni se han elaborado inventarios específicos de las macroalgas arrecifales. Objetivo. Realizar una integración del conocimiento generado sobre macroalgas arrecifales y hacer inventarios de estas macroalgas en los arrecifes de Guerrero y Oaxaca en el Pacífico tropical mexicano. Métodos. Se aplicaron análisis de similitud de Sørensen y de Escalamiento Multidimensional No-Métrico (NMDS) a los datos generados sobre la composición algal en estos distintos arrecifes coralinos para determinar sus patrones de distribución. Se aplicó el método de análisis ANOSIM para demostrar las diferencias significativas entre grupos. Resultados. Se registraron 144 especies: 100 Rhodophyta, 32 Chlorophyta y 12 Ochrophyta-Phaeopyceae. En Guerrero se registraron 75 especies exclusivas y en Oaxaca, 24; las especies compartidas fueron 45. La localidad con mayor riqueza fue El Zacatoso, Guerrero, con 92 especies. Con el Índice de Sørensen se encontró un porcentaje de similitud mayor al 50% entre la mayoría de las localidades, aunque se observó una clara separación entre las comunidades de Guerrero y Oaxaca. El NMDS mostró cuatro grupos formados por las especies de las localidades, sin efecto de la temporada (lluvias y secas). El ANOSIM mostró diferencias significativas entre las localidades que forman cada grupo. Conclusión. Se elaboró el primer inventario de las macroalgas arrecifales de Guerrero y Oaxaca, estados en donde hay registros sistemáticos de estas macroalgas en el Pacífico tropical mexicano. Se generó la línea base de información útil para desarrollar un programa de monitoreo en la región, hacer un diagnóstico del estado de perturbación de los arrecifes coralinos y generar estrategias y planes de conservación de estos ecosistemas
Diversity of archaea in tropical and subtropical estuarine-lagoon ecosystems. A synthesis: Archaea in tropical coastal ecosystems
No full textBackground. Tropical and subtropical estuarine ecosystems are among the most productive ecosystems on the planet, their seasonal fluctuations, their permanent or ephemeral connection with the ocean and freshwater discharges, generate a high biodiversity that provides numerous ecosystem services. In these ecosystems, biodiversity research has focused on macro-organisms and less attention has been paid to prokaryotes, particularly the archaea group. Goal. Based on a bibliographic review of the Archaea Domain in estuaries, coastal lagoons and mangroves located in tropical and subtropical zones, to provide a synthesis of the factors that influence the presence and distribution of archaea in these ecosystems and the role they play in biogeochemical cycles. Methods. A search was made of the articles published with the keywords Archaea + tropical coastal ecosystems and Archaea + subtropical coastal ecosystems. Results. The analysis of the environmental sequences obtained, from molecular techniques, in studies of the diversity of prokaryotes in coastal lagoons, estuaries and tropical and subtropical mangroves, have revealed a high diversity of archaea belonging mainly to methanogens and anaerobic methanotrophs (Phyla Euryarchaeota), ammonium-oxidizing archaea (Thaumarchaeota) and representatives of the Superphyllum Asgard. These groups can potentially participate in the carbon, nitrogen, and sulfur cycles, in aerobic or anaerobic conditions, with heterotrophic or autotrophic metabolisms, and their abundance and distribution are related to the physicochemical conditions of the ecosystems. Conclusions. The diversity of Archaea in tropical and subtropical coastal ecosystems is greater than previously recorded. These microorganisms play a vital role in various biogeochemical cycles as well as climate changeBackground. Tropical and subtropical estuarine ecosystems are among the most productive ecosystems on the planet, their seasonal fluctuations, their permanent or ephemeral connection with the ocean and freshwater discharges, generate a high biodiversity that provides numerous ecosystem services. In these ecosystems, biodiversity research has focused on macro-organisms and less attention has been paid to prokaryotes, particularly the archaea group. Goal. Based on a bibliographic review of the Archaea Domain in estuaries, coastal lagoons and mangroves located in tropical and subtropical zones, to provide a synthesis of the factors that influence the presence and distribution of archaea in these ecosystems and the role they play in biogeochemical cycles. Methods. A search was made of the articles published with the keywords Archaea + tropical coastal ecosystems and Archaea + subtropical coastal ecosystems. Results. The analysis of the environmental sequences obtained, from molecular techniques, in studies of the diversity of prokaryotes in coastal lagoons, estuaries and tropical and subtropical mangroves, have revealed a high diversity of archaea belonging mainly to methanogens and anaerobic methanotrophs (Phyla Euryarchaeota), ammonium-oxidizing archaea (Thaumarchaeota) and representatives of the Superphyllum Asgard. These groups can potentially participate in the carbon, nitrogen, and sulfur cycles, in aerobic or anaerobic conditions, with heterotrophic or autotrophic metabolisms, and their abundance and distribution are related to the physicochemical conditions of the ecosystems. Conclusions. The diversity of Archaea in tropical and subtropical coastal ecosystems is greater than previously recorded. These microorganisms play a vital role in various biogeochemical cycles as well as climate chang
Variabilidad iónica en la red hidrográfica de Oaxaca, México: Alternativa gráfica y estadística multivariada
Get PDFBackground. Factors such as lithology, geomorphology, climate and anthropogenic activities, cause ionic variability of surface, subsurface and underground water. The study of this variability allows to know its hydrochemical characteristics for its subsequent use. The interpretation of the ionic variability is carried out by mean of graphic methods, and multivariate statistics have been integrated into these analyses during the last few years. Objective. To perform a chemical analysis, to identify the factors affecting the water, and to prove that complementing the Piper diagram with a multivariate analysis helps to obtain a better interpretation of results. Methods. This work was carried out in the Oaxaca-Puebla hydrographic network, considering the complex relief and the heterogeneous lithological and climate conditions, especially in Oaxaca. A total of 90 samples were collected, three of which were taken in salt flats in Zapotitlán, Puebla and the rest of them in the state of Oaxaca. A Piper diagram was used for water classification, as well as the principal component analysis (PCA) to improve the interpretation of data. Results. The triangular diagram allowed to classify the waters of the hydrographic network into two large groups, calcium-magnesium bicarbonate, and calcium-magnesium sulfate, in addition to the separation of saline waters. The PCA, in addition to showing the same groups of waters, allowed to prove a higher concentration of sodium chloride at the highest point of the salt flat, as compared to the other two that were taken at this site. With the PCA, the water of the Copalita river basin could be classified as calcium-magnesium bicarbonate, coinciding with previous studies. Conclusions. By complementing a Piper diagram with a PCA, the interpretation of the ionic variability of the Oaxaca-Puebla hydrographic network improved.Antecedentes. Factores como la litología, la geomorfología, el clima y las actividades antropogénicas, causan variabilidad iónica del agua superficial, sub-superficial y subterránea. El estudio de dicha variabilidad permite conocer sus características hidroquímicas para su posterior uso o consumo. La interpretación de la variabilidad iónica se realiza mediante métodos gráficos, y en los últimos años se han integrado las est dísticas multivariadas a dichos análisis. Objetivos. Se desea obtener un análisis químico e identificar qué factores afectan el agua y demostrar que el complementar el diagrama de Piper con el análisis multivariado ayuda a obtener una mejor interpretación de resultados. Métodos. El presente trabajo se realizó en la red hidrográfica Oaxaca-Puebla, contemplando el complejo relieve y las heterogéneas condiciones de litología y clima, sobre todo en Oaxaca. Se colectaron 90 muestras en total, de las cuales tres se tomaron en salinas de Zapotitlán, Puebla y el resto en el estado de Oaxaca. Se empleó el diagrama triangular de Piper para la clasificación de las aguas y el análisis de componentes principales (ACP) para mejorar la interpretación. Resultados. El diagrama triangular permitió clasificar las aguas de la red hidrográfica en dos grandes gru pos, bicarbonatadas cálcico-magnésicas y sulfatadas cálcicas-magnésicas, además de la separación de las aguas salinas. Por su parte, el ACP, además de mostrar los mismos grupos de aguas, permitió observar una mayor concentración de cloruro de sodio en el punto más alto de la salinera, en comparación con los otros dos que se tomaron en este sitio. Con el ACP se pudo clasificar el agua de la cuenca del río Copalita como bicarbonatada cálcica-magnésica, lo que coincide con estudios previos. Conclusiones. Finalmente, al complementar el diagrama triangular de Piper con el ACP, se mejoró la interpretación de la variabilidad iónica de la red hidrográfica Oaxaca-Puebla
Effect of diet and temperature on the culture of Alona guttata (Sars, 1862) (Cladocera: Chydoridae) under laboratory conditions: Culture of Alona guttata in laboratory
No full textBackground. Chydoridae is the most diverse family of cladocerans but information about their biology or life cycles is still limited, perhaps because of the hard task that their taxonomy involves or that culture in optimal conditions are not described for several species. Goals. This study examined the effects of culture conditions (algal concentration, algal species, and temperature) on the demography of Alona guttata (Sars, 1862) to obtained their maximal growth rates. Methods. Life table analysis with the chydorid A. guttata were performed as follows: five females per cohort (six replicas) were fed on either Chlorella vulgaris (Beijerinck, 1890) or Nannochloropsis oculata (Hibberd, 1981) at 0.5×106 or 2×106 cells/mL, reared at 20ºC or 25ºC and photoperiod 16:8 h (light: dark). Media was supplemented with an artificial substrate. Then, daily fertility and survival were assessed to estimate the demographic parameters: average lifespan (ALS), life expectancy at birth (LEB), generation time (GT), gross reproductive rate (GRR), longevity, net reproductive rate (NRR), and the intrinsic rate of population increase (r). Results. Significant effects were observed due to the three factors tested and their interactions. Increasing algal concentrations of either C. vulgaris or N. oculata promoted higher fertility and longer survival. Lower temperature extended the ALS and LEB when organisms were fed on the highest algal concentration. The highest r values were observed when Alona was fed on N. oculata at 2×106 cells/mL. Conclusions. The best culture conditions, in terms of the population growth rates of A. guttata, were provided by N. oculata at 2×106 cells/mL at 25°C with the supplementation of artificial substrate.Antecedentes. La familia Chydoridae es la más diversa de los cladóceros pero la información acerca de su biología o sus ciclos de vida es aún limitada, posiblemente por la dificultad que representa su taxonomía o porque las condiciones óptimas de cultivo no han sido descritas para varias especies. Objetivos. Este estudio examina los efectos de las condiciones de cultivo (concentración de algas, especie de alga, y temperatura) en la demografía de Alona guttata (Sars, 1862) para obtener sus mayores tasas de crecimiento. Métodos. Se realizaron análisis de tablas de vida con el quidórido A. guttata de la manera siguiente: cinco hembras por cohorte (seis réplicas) fueron alimentadas con Chlorella vulgaris (Beijerinck, 1890) o Nannochloropsis oculata (Hibberd, 1981), a una concentración de 0.5×106 o 2×106 células/mL, con una temperatura de 20°C o 25°C, y un fotoperiodo de 16:8 h (luz:oscuridad). Al medio de cultivo se adicionó un sustrato artificial. Posteriormente, la fertilidad y supervivencia diarias fueron evaluadas para estimar los parámetros poblacionales: promedio de vida (ALS), expectativa de vida al nacimiento (LEB), tiempo generacional (GT), tasa reproductiva bruta (GRR), longevidad, tasa reproductiva neta (NRR), y la tasa intrínseca de crecimiento poblacional (r). Resultados. Se observaron efectos significativos debidos a los tres factores evaluados y sus interacciones. El aumento de la concentración de las algas C. vulgaris o N. oculata incrementó la fertilidad y supervivencia. La menor temperatura extendió la ALS y la LEB cuando los organismos fueron alimentados con la concentración más alta de algas. Las r más altas se observaron cuando Alona fue alimentada con N. oculata a 2×106 células/mL. Conclusiones. Las mejores condiciones de cultivo, en términos de la tasa de crecimiento poblacional de A. guttata, fueron provistas por N. oculata a 2×106 cells/mL, a 25°C, con la adición del sustrato artificial
Confirmación de la ausencia del alga marina asiática Codium fragile subsp. fragile (Codiaceae, Chlorophyta) en el Pacífico de México, mediante datos moleculares
Get PDFBackground. Codium fragile is a green alga that inhabits the Pacific coast of Baja California, Mexico, whose first records date back to 1909. This species has several subspecies, one of them Codium fragile subsp. fragile, originally from Japan, has proven to be an invasive organism in different parts of the world. Objectives. Confirm the presence or absence of this invasive strain on the coast of the Mexican Pacific, comparing with individuals from Japan, the United States and Mexico using molecular tools. Methods. We analyzed 20 individuals of the different species recorded for the Mexican Pacific and ten outside the region, including two as outgroup. The genomic DNA was extracted using the Sanger method, regions of the psb and 23S markers were amplified, the sequences obtained were edited and aligned in MEGA and MESQUITE, subsequently phylogenetic analyses of maximum likelihood were carried out in PAUP and MEGA and Bayesian inference in MrBayes. Genetic distances were obtained in MEGA and PAUP. Results. It is shown that, genetically, the individuals from Mexico integrate a clade different from the Asian entity, with inter-species genetic distances that were located at 6% for the 23S marker, while for the subclades of C. fragile the distance between them was 0.4%. For psb, the distance was 25% between species and 2.2% between these two subspecies. Conclusions. Individuals from California and Mexico nested in the native clade C. fragile, while others also from California are recognized with that of Japan as belonging to the invasive clade (C. fragile subsp. fragile). At the moment, the absence of this invasive strain in the Pacific of Mexico is confirmed.Antecedentes. Codium fragile es un alga verde que habita en las costas del Pacífico de Baja California, México, cuyos primeros registros datan de 1909. Esta especie que posee varias subespecies, una de ellas Codium fragile subsp. fragile, oriunda de Japón, ha demostrado ser un organismo invasor en diferentes partes del mundo. Objetivos. Confirmar la presencia o ausencia de esta cepa invasora en las costas del Pacífico mexicano, comparando individuos de Japón, Estados Unidos y México mediante el uso de herramientas moleculares. Métodos. Se analizaron 20 individuos de las especies registradas para el Pacífico mexicano y diez fuera de la región, incluyendo además dos como grupo externo. El DNA genómico se extrajo mediante el método Sanger, se amplificaron regiones de los marcadores psb y 23S, las secuencias obtenidas se editaron y alinearon en MEGA y MESQUITE, posteriormente se realizaron análisis filogenéticos de máxima verosimilitud en PAUP y MEGA y de inferencia bayesiana en MrBayes. Las distancias genéticas se obtuvieron en MEGA y PAUP. Resultados. Se demuestra que, genéticamente, los individuos de México integran un clado diferente a la entidad asiática, con distancias genéticas inter-especie que se ubicaron en 6% para el marcador 23S, mientras que para los subclados de C. fragile la distancia entre ellos fue de 0.4%. Para psb, la distancia fue del 25% entre especies y de 2.2% entre estas dos subespecies. Conclusiones. Individuos de California y México se anidaron en el clado nativo C. fragile, mientras que otros procedentes también de California se reconocen con el de Japón como pertenecientes al clado invasor (C. fragile subsp. fragile); así por el momento, se confirma la ausencia de esta cepa invasora en el Pacífico de México
Observaciones exploratorias en taxocenosis de diatomeas bentónicas marinas en un puerto expuesto a residuos mineros: Diatomeas bentónicas en un ambiente marino contaminado
No full textBackground. A recent interest has emerged for studying benthic marine diatoms (BMD) whose environment is influenced by potentially toxic elements (PTE), mainly metals that can alter their taxocoenoses parameters and cause deformities in the diatom frustules. Objective. To explore which particular characteristics may represent a response by BMD to PTE in environments polluted by mining residues, using the typical structure of the diatom taxocoenoses as reference, i.e., floristics, species richness, and diversity and dominance, as well as frequency of deformed frustules. Methods. Rock and sediment samples were taken in May 2015 and January 2016 at Santa Rosalía, BCS, a beach contaminated by mining waste. Results. Between 1 and 7.6% of deformed valves per site were recorded. This frequency of deformed frustules suggests the impact of contamination by EPT in the area. Diversity values of H´ between 1.1 and 4.3 were recorded, which are within the typical intervals of diversity for uncontaminated sites, although EPT concentrations such as Cu 3760 mg kg-1, Zn 2294 mg kg-1, Ni 401 mg kg-1, Pb 216 mg kg-1, recorded in the area exceed the mid-range effect values, indicating that 50% of the biota present would be affected. Conclusions. The high abundance of certain diatom taxa may indicate their ability to resist or tolerate PTE, while those exhibiting deformed frustules could be considered sensitive taxaAntecedentes. Existe un reciente interés por el estudio de diatomeas bentónicas marinas (DBM) y su respuesta a contaminación por elementos potencialmente tóxicos (EPT), principalmente metales que pueden impactar la composición de especies, alterar los parámetros de las asociaciones, y ocasionar deformaciones de las frústulas de diatomeas. Objetivo. Explorar qué cambios en las asociaciones de DBM podrían representar una respuesta a contaminación por EPT en ambientes marinos, usando de referencia la estructura típica de sus asociaciones, incluyendo florística, riqueza, diversidad y dominancia, así como frecuencia de frústulas deformes. Métodos. Se tomaron muestras de roca y sedimento en mayo 2015 y enero 2016 en Santa Rosalía, BCS, una playa contaminada con desechos mineros. Resultados. Se apoyó parcialmente la hipótesis propuesta, i.e., se registró entre 1 y 7.6% de valvas deformes por sitio; esta frecuencia de frústulas deformes sugiere impacto de contaminación por EPT en el área. Se registraron valores de diversidad de H´ entre 1.1 a 4.3, los cuales están dentro de los intervalos típicos de diversidad para sitios no contaminados, a pesar de que concentraciones de EPT como Cu 3760 mg kg-1, Zn 2294 mg kg-1, Ni 401 mg kg-1, Pb 216 mg kg-1, registradas en el área sobrepasan los valores de efecto de rango medio, indicando que un 50% de la biota presente sería afectada. Conclusiones. Las elevadas abundancias de ciertos taxa sugieren su capacidad de tolerar PTE, mientras que aquellos que mostraron deformaciones de sus frústulas podrían considerarse taxa sensibles
Influencia del sustrato y las condiciones ambientales sobre la estructura de asociaciones de diatomeas bentónicas en una laguna costera tropical
No full textBackground: The structure of benthic diatom assemblages (BDA) is related to the type of substrate where they flourish. Goals: assess the degree of variation shown by BDA growing on live and inert substrata from a tropical coastal lagoon (Terminos lagoon). We tested the hypothesis that substrate influence would deem significantly distinct BDA. Methods: diatom samples were collected from live and inert substrata from four sites within Terminos lagoon, México, where physicochemical variables were also measured. Diatom taxa were identified and their relative abundances were estimated and used to compute community parameters (species diversity, equitability, dominance), along with the indicator value (IndVal). Also, similarity between the BDA from the four sites was measured and values were then compared using ANOSIM. Results: Although the IndVal showed a clear separation based on the dominant/constant taxa, ANOSIM indicated that differences between the sites were not significant. This may be related to the characteristic patchy distribution of BDA along environmental gradients. Conclusions: in coastal ecosystems the structure of BDA will be mainly influenced by environmental variables
Variación espacial de ensambles de moluscos bentónicos de fondos blandos del archipiélago Espíritu Santo, golfo de California, México
Get PDFBackground. The Espiritu Santo archipelago is recognized for its high biodiversity as a national park. Studies carried out on soft-bottom mollusks are of the faunistic type, and little is known about the variations in their community structure. Objective. To know the composition and the spatial variation in the structure of the assemblages of soft-bottom mollusks of the archipelago and to describe the possible incidence of the type of substrate in their structuring. Methods. In the infralittoral zone, 66 sampling sites were distributed in nine locations. The mollusks were collected by autonomous diving using a 1 m-2 metal frame and a nucleator to analyze of the sediment texture. The medium-grained sand substrate presented the highest distribution. The ecological indices of abundance, species richness (S), Shannon-Wiener diversity (H´), and Pielou evenness index (J´) were estimated. Results. 23,743 individuals were quantified, belonging to 102 species distributed in three classes, 17 orders, 39 families, and 70 genera. The bivalves were represented by 48 species, 9 orders, 17 families, and 39 genera. The gastropods by 52 species, 7 orders, 21 families and 30 genera, and the scaphopods by 1 species. Significant differences were found between localities for species richness and diversity but not for species equity. Conclusions. Spatial variations were observed in the structure of the mollusks assemblages in the archipelago, which could be due to the combined effect of the sediment texture and the presence of mangroves existing in some locations.Antecedentes. El Parque Nacional Archipiélago Espíritu Santo es reconocido por su elevada biodiversidad. Los estudios realizados sobre los moluscos de fondos blandos son inventarios faunísticos, y se conoce poco sobre la variación de su estructura comunitaria. Objetivo. Conocer la composición y la variación espacial en la estructura de los ensambles de moluscos de fondos blandos de este archipiélago y describir la posible relación con el tipo de sustrato. Métodos. En la zona infralitoral se distribuyeron 66 sitios de muestreo en nueve localidades. La colecta de moluscos se realizó mediante buceo autónomo utilizando un marco metálico de 1m2 y para el análisis de la textura del sedimento un nucleador. Se estimaron los indicadores estructurales de abundancia (N), riqueza de especies (S) y los índices de diversidad de Shannon-Wiener (H´) y de Equidad de Pielou (J´). Resultados. El sustrato de arena de grano medio presentó la mayor contribución. Se cuantificaron 23 743 organismos, registrados en 102 especies distribuidas en tres clases, 17 órdenes, 39 familias y 70 géneros. Los bivalvos estuvieron representados por 48 especies, 39 géneros, 17 familias y nueve órdenes. Los gastrópodos por 52 especies, 30 géneros, 21 familias y siete órdenes y los escafópodos por una especie. Se encontraron diferencias significativas entre las localidades para la riqueza de especies y diversidad, pero no para equidad. Conclusiones. Se observaron variaciones espaciales en la estructura de los ensambles de moluscos en el archipiélago, las cuales pudieron ser debidas al efecto combinado de la textura del sedimento y a la presencia de mangles en algunas localidades
Aspectos ecológicos de la nutria neotropical, Lontra longicaudis annectens (Major, 1897) en la laguna La Lagartera, Campeche, México.: Neotropical otter ecology at Campeche lagoon
No full textBackground. Several works conducted in Mexico have addressed the Neotropical otter (Lontra longicaudis annectens), a protected subspecies (NOM-059-SEMARNAT-2010). Objectives. To know the abundance and distribution of the neotropical otter in the State of Campeche in La Lagartera Lagoon (Palizada River). Methods. During 2017 were searched the lagoon looking for indirect evidence on mangrove, collected and analyzed scats in order to identify preys. Results. Were traveled 1.49 km in each climatic season (nortes, dry, and rainy seasons), on board a small vessel, recording a total of 99 signs (85 scats, five feeding sites, five dens, and four vocalizations). We recorded the distribution of these signs across the sampling area and estimated a relative abundance of 0.30 otters/km. The analysis of 85 scats collected on logs or roots recorded six major prey groups: fish (40 %), crustaceans (26 %), reptiles (15 %), mollusks (11 %), mammals (4 %), birds (3 %) and other unidentified prey (1%). Conclusions. No evidence was found to suggest a variation in the consumption frequencies of the groups of prey by season. The presence and consumption of the “sailfincatfish” was also recorded in all seasons. The presence of four native species and five new records of prey fish was confirmed from otoliths contained in feces. This information highlights the ecological relevance of the species.Antecedentes. En México, existen diversos trabajos sobre la nutria neotropical (Lontra longicaudis annectens), subespecie protegida (NOM-059-SEMARNAT-2010); sin embargo, son pocos los trabajos realizados en el estado de Campeche. Objetivos. Conocer la abundancia y distribución de esta especie en laguna “La Lagartera” (río Palizada). Métodos. Durante 2017 realizaron recorridos en la zona de estudio buscando evidencias indirectas de las nutrias en troncos de mangle analizando heces para conocer las presas. Resultados. Se recorrieron 1.49 km en cada temporada climática (nortes, secas y lluvias), a bordo de una embarcación menor, obteniéndose un total de 99 rastros (85 heces, cinco comederos, cinco madrigueras y cuatro vocalizaciones). Se registró la distribución de estas evidencias dentro del área de muestreo y se estimó una abundancia relativa de 0.30 nutrias/km. El análisis de 85 heces colectadas sobre los troncos y/o raíces, registró seis grupos principales de presas: peces (40 %), crustáceos (26 %), reptiles (15 %), moluscos (11 %), mamíferos (4 %), aves (3 %) y otros no identificados (1 %). Conclusiones. No se encontró evidenciaque determine una variación en las frecuencias de consumo de los grupos presas por temporada. También se registró la presencia y consumo del pez diablo en todas las temporadas. Se confirma por medio de otolitos obtenidos en las heces, la presencia de cuatro especies nativas y cinco nuevos registros de peces presa. Con esta información se resalta el valor ecológico de la especie
