ABSTRACT
Resumen Introducción: En Costa Rica, las turberas de altura se localizan en la Cordillera de Talamanca de 2 400 a 3 200 m. Se forman a partir de depósitos de materia orgánica en descomposición, con oxígeno reducido y baja disponibilidad de nutrientes. Objetivo: Evaluar la variación en la composición de macroinvertebrados acuáticos según parámetros fisicoquímicos de calidad del agua superficial en turberas de altura, Costa Rica. Métodos: Se colocaron 32 sustratos artificiales en las turberas para ser colonizados por macroinvertebrados. Se realizaron evaluaciones fisicoquímicas mensuales del agua superficial en ocho turberas con visitas mensuales durante la estación lluviosa. Se utilizaron los índices ICA-NSF y BMWP-CR para evaluar la calidad del agua. Resultados: Se registraron un total de diez familias correspondientes a siete géneros. Las familias más representativas fueron Chironomidae y Limnephilidae. La calidad del agua se clasificó según el ICA-NSF como de "calidad media" y como de "calidad regular a mala" según el BMWP-CR. Conclusiones: Las turberas de altura son ecosistemas poco estudiados, esta investigación evidencia la necesidad de diseñar metodologías e índices que evalúen la fauna acuática. Las turberas son diferentes entre sí, y las familias de macroinvertebrados encontrados son tolerantes a las características fisicoquímicas del agua. Es necesario realizar estudios periódicos que evalúen la calidad del agua y su relación con los macroinvertebrados acuáticos para entender la dinámica de las turberas, generar conocimiento e incrementar su protección.
Abstract Introduction: In Costa Rica, high peatbogs are located in the Cordillera de Talamanca from 2 400 to 3 200 m. They are formed from deposits of decomposing organic matter, with reduced oxygen and low nutrient availability. Objective: To evaluate the variation in the composition of aquatic macroinvertebrates according to physicochemical parameters of superficial water quality in high altitude peatbogs, Costa Rica. Methods: 32 artificial substrates were placed in the peatbogs to be colonized by macroinvertebrates. Monthly physicochemical evaluations of surface water were performed in eight peatbogs with monthly visits during the rainy season. The ICA-NSF and BMWP-CR indexes were used to evaluate the water quality. Results: A total of ten families corresponding to seven genera were recorded. The most representative family was Chironomidae and Limnephilidae. Water quality was classified according to the ICA-NSF as "medium quality" and as "regular to poor quality" according to BMWP-CR. Conclusions: The high peatbogs are poorly studied ecosystems; this research shows the need to design methodologies and indices to evaluate the aquatic fauna. The peatbogs are different from each other, and the families of macroinvertebrates found are tolerant to the physicochemical characteristics of the water. Periodic studies that evaluate water quality and its relationship with aquatic macroinvertebrates are necessary to understand the dynamics of peatlands, generate knowledge and increase their protection.
Subject(s)
Animals , Wetlands , Invertebrates/anatomy & histology , Substrates for Biological Treatment , Ecosystem , Costa RicaABSTRACT
Abstract The drift movement consists of the displacement of the organisms inside the water column which allows its passive locomotion. This movement will result in a variation of the communities of organisms along the river, generating spatial patterns. Based on this, we tested the hypotheses a) the drift of individuals in an upstream-downstream direction creates a nestedness pattern, when the upstream is a subset of downstream communities of aquatic insects; b) there will be an increase in the number of individuals and genera as we approach the most downstream point. The present study was carried out in seven sampling points distributed along the Xingu River. The sampling occurred at night in the central area of the river. The number of genera along the river remained constant, and the nestedness distribution of the communities in the upstream-downstream gradient was not observed. Based on the results, it is possible to visualize a turnover of genera in the longitudinal gradient of the river, but with an accumulation of genera in the downstream region. Organisms that are transported by the flow of the water current respond to the characteristics of the body of water by adapting to the type of environment in which they are found.
Resumo O movimento de deriva consiste no desprendimento dos organismos dentro da coluna de água, o que permite a sua locomoção passiva. Este movimento resultará numa variação das comunidades de organismos ao longo do rio, gerando padrões espaciais. Com base nisto, testamos as hipóteses a) o movimento de indivíduos em direção montante-jusante criará um padrão aninhado, no qual as comunidades de insetos aquáticos a montante são um subconjunto das comunidades a jusante; b) haverá um aumento no número de indivíduos e gêneros à medida que nos aproximamos do ponto mais a jusante. O presente estudo foi realizado em sete pontos de amostragem distribuídos ao longo do rio Xingu. A amostragem ocorreu durante a noite no canal central do rio. O número de gêneros ao longo do rio se manteve constante, e não observamos uma distribuição de aninhamento das comunidades no gradiente ascendente e descendente do rio. Com base nos resultados, é possível visualizar uma substituição dos gêneros no gradiente longitudinal do rio, porém ocorrendo um acúmulo de gêneros na região mais a jusante. Os organismos que são transportados pelo fluxo da corrente de água respondem as características do corpo de água adaptando-se ao tipo de ambiente em que se encontram.
ABSTRACT
ABSTRACT The male and female of a new species in the long-horned caddisfly genus Nectopsyche Müller, 1879 are described from southeastern Brazil. The new species has male genitalia similar to species of the candida-group, but has several endothecal spines in the phallic apparatus similar to those of gemma-group species. The color pattern of the scales and hairs on the head, thorax and forewings is similar to that of Nectopsyche splendida (Navás, 1917), as both species have bands of metallic silver-iridescent scales interleaved with black areas on the forewings. Additionally, we present illustrations of the male and female genitalia of N. splendida and expand the knowledge of its distribution.
ABSTRACT
ABSTRACT Despite the growing number of studies on mayflies (Ephemeroptera), especially in terms of description of new species and distributional records, the knowledge generated remains scattered across specialized literature. This dispersion poses a challenge for non-specialists, such as ecologists, hindering their ability to promote studies and conservation actions. In order to fill this gap, we are launching EphemBrazil: an online database focusing on the distribution of mayflies in Brazil. The main objectives of this platform are to compile a dataset of distributional information for the valid species of Ephemeroptera in Brazil, provide open access to this dataset through an interactive and easily updated website, and offer dynamic distributional maps for species, genera, and families of Brazilian mayflies. EphemBrazil aims to facilitate the retrieval and access of distributional and basic taxonomic information for the order.
ABSTRACT
ABSTRACT A new species of Gripopteryginae stonefly, Tupiperla claudius sp. nov. (holotype male deposited in DZUP: Brazil, Paraná State, Piraquara municipality, Pico do Marumbi State Park), is described and diagnosed based on seven adult males. The new species differs from its congeners by the long T10 extension, dorsally with straight lateral margins and tip truncated, protruding into a pair of short downward teeth in lateral view; paraproct long, surpassing the T10 extension dorsally, with a basal membranous-like area and a row of minute spines on the middle of the appendage length dorsally. Specimens of T. claudius sp. nov. from the Protected Area Mananciais da Serra in the Serra do Mar represent the very first gripopterygids recorded in the state of Paraná and are also a remarkable record for the genus for the southern Brazilian Atlantic Forest.
ABSTRACT
ABSTRACT Sixteen species of the microcaddisfly Ochrotrichia Mosely, 1934 (Hydroptilidae) have been recorded so far in Brazil, mainly distributed in the Atlantic Forest of southeastern Brazil. In order to reduce the Linnean and Wallacean shortfalls for the Ochrotrichia Brazilian fauna, we diagnose, describe, and illustrate three new species based on adult males from three protected and preserved areas of the Cerrado biome of Federal District (Central-West region), Minas Gerais (Southeast region) and Tocantins (North region) states; all of them named in honor of three great Brazilian entomologists viz., Ochrotrichia froehlichi sp. nov., Ochrotrichia machadoi sp. nov. and Ochrotrichia nessimiani sp. nov. They can be recognized mainly by the morphology of the tergum X, number, and position of the spine-like setae of the inferior appendages. This contribution represents the first record of Ochrotrichia for the Central-West region, increasing the number of species of this genus in Cerrado biome from one to four, and is the first report of a microcaddisfly for the Federal District. In addition, the genus is reported for the first time from Paraná, São Francisco, and Tocantins hydrographic basins. Finally, we provide a checklist of the Ochrotrichia species from Brazil.
ABSTRACT
ABSTRACT The genus Nectopsyche is widely recognized by its striking adults, with colored setae and scales, even metallic and/or iridescent. It is primarily distributed in the Neotropical region, with a few species found in the Nearctics. Nectopsyche has more than 100 described species, with 26 of them recorded in Brazil. In Pará state, one of the largest Brazilian' states, only three species have been recorded. In contribution to the taxonomic knowledge about the Neotropical caddisflies, especially those of the Amazonian region, we propose two new species of Nectopsyche from Pará state based on male specimens: Nectopsyche tridentata n. sp. and Nectopsyche froehlichi n. sp. In addition, Nectopsyche acutiloba, Nectopsyche adusta, Nectopsyche jenseni, and Nectopsyche quatuorguttata are recorded for the first time in the state of Pará. Our results increase the number of Nectopsyche species recorded in Brazil to 28, and the number of recorded species in the state of Pará to eight.
ABSTRACT
ABSTRACT The male and female imago stage and a new species of the Hermanella complex are described based on material from Pará State, Northern Brazil: Hydromastodon cf. mikei (Thomas & Boutonnet, 2004) and Paramaka froehlichi sp. nov. The male imago of Hydromastodon cf. mikei can be distinguished from Hydromastodon sallesi by the following combination of characters: (1) body color pattern, especially abdominal terga translucent white with terga I to IV washed with black on posterior margin; (2) compound eyes anteriorly rounded; (3) medial projection of the styliger plate short; and (4) penis lobes close to each other and with posterolateral projection as long as ½ of its length. The male imago of Paramaka froehlichi sp.nov. can be distinguished the from the other species of the genus by the following combination of characters: (1) fore and hind wings with membrane brown; (2) legs uniformly yellowish-white, without distal band; (3) abdominal terga II to VI with marks more expanded laterally, median line absent; (4) medial projection of the styliger plate broad; (5) base of telopenis arising at distal ⅔ of penis lobe; and (6): body size of 6.1 to 7.6 mm.
ABSTRACT
ABSTRACT Insects are fundamental to biodiversity conservation in almost all ecosystems, and their population decline, and extinction directly result from environmental impacts. These facts are aggravated by the lack of knowledge of insect biodiversity, the so-called biodiversity deficits, especially the Linnean and Wallacean shortfalls. In freshwater ecosystems, biodiversity loss is higher among aquatic insects, and caddisflies comprise one of the most vulnerable orders. In this way, research focusing on describing new caddisfly species and understanding their distribution ranges will increase knowledge of caddisfly biodiversity. In the past 14 years, the team from the Laboratório de Entomologia Aquática "Prof. Dr. Claudio Gilberto Froehlich" (LEAq, Universidade Federal da Bahia, Brazil) and collaborators have been addressing these issues, resulting in 55 described species of caddisflies. Taxa in other insect orders have also received attention and an additional 16 species have been described (eight mayflies, four stoneflies, four neuropteran spongillaflies, and antlions). Here, eight caddisfly species are described and illustrated (Atopsyche froehlichi sp. nov., Austrotinodes zeferina sp. nov., Cernotina kariri sp. nov., Neoathripsodes froehlichi sp. nov., Notalina claudiofroehlichi sp. nov., Oecetis marcus sp. nov., Phylloicus froehlichi sp. nov., and Polycentropus claudioi sp. nov.), five of them in honor of LEAq's patron. In addition, new distributional data are presented for 10 known species. A checklist of the caddisfly fauna of Bahia state is also presented, with 138 species, around 75% and 30% of them recorded and described by the LEAq team, respectively. Currently, for caddisflies, Bahia is the fifth most species-rich state in Brazil, and the first in the Brazilian Northeast region.
ABSTRACT
Abstract: Here we present the first Odonata (Insecta) species list for the state of Acre, Northern Brazil, adding ecological aspects and notes on its taxonomy and conservation status. Regarding Odonata samplings, Acre is one of the least explored states in the northern region of Brazil and an area of geographic importance, as it is a transition between the Andean and Amazon regions. Collections were carried out in 35 streams, distributed in nine municipalities. We also supplemented our database from the review of secondary literature and data from biological collections. We recorded 140 species, distributed in 55 genera, of which 16 species are new records for the state, making Acre state the second in the number of recorded species in northern Brazil. Of the recorded species, 113 are classified within some threat category of the IUCN red list and 110 in the ICMBio national list. Analyzing the taxonomic information on each recorded species, knowledge of females and larvae is still very limited and, most of the time, only available to adult males. For the first time, the occurrence of Drepanoneura loutonivon Ellenrieder & Garrison (2008) is reported for Brazil, and we also present photos of its main morphological characters, with comments on its biology. Our study shows the importance of conducting biodiversity research in poorly studied areas; such as the state of Acre, and serves as a basis for future expeditions in the region.
Resumo: Apresentamos a primeira lista de espécies de Odonata (Insecta) para o estado do Acre no Brasil, adicionando aspectos ecológicos e notas sobre o seu estado de conservação. O Acre é um dos estados com o menor esforço de coleta da região Norte do Brasil e uma área de importância geográfica, pois é uma transição entre os Andes e a Amazônia. Foram realizadas coletas em 35 riachos, distribuídos em nove municípios e também complementados com informações de dados secundários de revisão na literatura e bases de dados de coleções biológicas. Registramos 140 espécies, distribuídas em 55 gêneros, das quais 16 espécies são novos registros para o estado, tornando-o o segundo em número de espécies na região Norte do Brasil. Das espécies registradas, 113 estão classificadas dentro de alguma categoria de ameaça da lista vermelha da IUCN e 110 na lista nacional do ICMBio. Analisando as informações do conhecimento das espécies, o conhecimento das fêmeas e larvas ainda muito limitado e na maioria das vezes disponíveis apenas para os machos adultos. Pela primeira vez é registrada a ocorrência da Drepanoneura loutoni von Ellenrieder & Garrison (2008) no Brasil, também apresentamos fotos das principais estruturas, com comentários sobre sua biologia. Nosso trabalho mostra a importância da realização de estudos de biodiversidade em áreas ainda pouco estudadas como a do estado do Acre e serve como base para futuras expedições na região.
ABSTRACT
ABSTRACT The small mayfly genus UlmeritusTraver, 1956 currently includes three species of Neotropical Leptophlebiidae (Ephemeroptera) distributed in southern South America in the Pampean and Atlantic Forest dominions: U. carbonelli (Uruguay), U. balteatus (Brazil and Uruguay) and U. saopaulensis (Brazil). Ulmeritus saopaulensis is a poorly known endemic species from Brazil. Based on material from a single locality in Minas Gerais, we complement the knowledge on this species with a redescription of adults and nymphs and describe the eggs for the first time. The confusing nomenclatural history and the correct spelling of the specific name saopaulensis is discussed in light of International Code of Zoological Nomenclature. This paper points out that in despite of recent advances on the knowledge of this genus a full taxonomic review and phylogenetic analyses are pending to solve species delimitation and evolutionary relationships.
ABSTRACT
ABSTRACT A new species of Sisyra Burmeister is described from the tropical rainforest of Tambopata National Reserve, Madre de Dios region, Peru. Sisyra tambopatensis sp. nov. is described based on a male specimen, which greatly differs from its congeners in the overall shape of the male gonocoxite 9. In addition, an identification key to the Neotropical species of Sisyra is provided.
ABSTRACT
Abstract: Urbanization significantly increases the rates of environmental disturbance, being one of the main causes of habitat loss and biodiversity. The growing trend of converting the natural landscape into areas for real estate speculation in the coastal region of the southernmost part of Brazil is a current concern, as the region is home to unique ecosystems, such as dunes, wetlands and large brackish lagoons. As they are organisms sensitive to environmental changes, variations in the structure of Odonata communities are used as indicators of habitat quality reflecting the human impact on the environment. Here we assessed how the Odonata community is affected by the growing urbanization around natural ponds on the coast of the state of Rio Grande do Sul, testing the hypothesis that the increase in the percentage of urbanization negatively influences the Odonata community, following the same pattern found for other groups of invertebrates. The collections took place in 28 coastal ponds, which were classified as urbanized and non-urbanized based on the surrounding ground cover. Anisoptera's richness, abundance and composition were influenced by urbanization, but the same was not found for Zygoptera. The analysis of indicator species specifies three species associated with non-urbanized areas: Erythrodiplax sp.1, Erythemis credula and Telebasis corallina. Our study highlights the importance of Odonata as organisms that indicate environmental integrity and reinforces the need for urban planning strategies that favor the conservation and maintenance of the environments affected by urbanization.
Resumo: A urbanização aumenta significativamente as taxas de perturbação ambiental, sendo está uma das principais causas da perda de habitat e biodiversidade. A tendência crescente de conversão da paisagem natural em áreas para especulação imobiliária na região costeira do extremo sul do Brasil é uma preocupação atual, pois a região abriga ecossistemas únicos, como dunas, áreas úmidas e grandes lagoas salobras. Como são organismos sensíveis às alterações ambientais, as variações na estrutura das comunidades de Odonata são utilizadas como indicadores de qualidade do habitat refletindo o impacto humano no ambiente. Nós avaliamos como a comunidade de Odonata é afetada pela crescente urbanização em torno de lagoas naturais no litoral do estado do Rio Grande do Sul, testando a hipótese de que o aumento do percentual de urbanização influencia negativamente a comunidade de Odonata, seguindo o mesmo padrão encontrado para outros grupos de invertebrados. As coletas ocorreram em 28 lagoas costeiras, que foram classificadas como urbanizadas e não urbanizadas com base na cobertura do solo no entorno. A riqueza, abundância e composição de Anisoptera foram influenciadas pela urbanização, mas o mesmo não foi encontrado para Zygoptera. A análise de espécies indicadoras especifica três espécies associadas a áreas não urbanizadas: Erythrodiplax sp.1, Erythemis credula e Telebasis corallina. Nosso estudo destaca a importância dos Odonata como organismos indicadores de integridade ambiental e reforça a necessidade de estratégias de planejamento urbano que favoreçam a conservação e manutenção dos ambientes afetados pela urbanização.
ABSTRACT
Introducción: La estructura, diversidad taxonómica y diversidad funcional del ensamblaje de macroinvertebrados acuáticos son estimadores sensibles a las variaciones del medio circundante. El ambiente físico es un factor fundamental, donde el sustrato y la dinámica hidráulica modifican la disponibilidad de recursos, la estructuración, el funcionamiento de la comunidad y del ecosistema. Objetivo: Determinar la estructura, diversidad taxonómica y diversidad funcional del ensamblaje de macroinvertebrados bajo diferentes condiciones abióticas en el río Hato Laguna, tributario del Lago de Tota. Métodos: Se recolectaron 120 muestras biológicas en cuatro momentos de muestreos en dos tramos en el río. Se midieron in situ profundidad, velocidad del flujo, ancho de canal y rugosidad del sustrato. Los rasgos funcionales evaluados fueron: longitud corporal, forma corporal, tipo de respiración, movilidad, gremio trófico y grupos funcionales alimenticios. Resultados: Se identificaron un total de 38 taxones; los órdenes Diptera, Coleoptera y Trichoptera presentaron la mayor riqueza de familias y géneros. Hubo mayor abundancia de Orthocladiinae, Andesiops sp. y Simulium sp. en condiciones de alta velocidad del flujo en los tramos altos; Nectopsyche sp. fue abundante en los tramos bajos relacionados con menores velocidades y mayor ancho del canal. Según los índices de diversidad taxonómica se presentó variación por tramos y muestreos sin observarse tendencias. En los tramos altos, el gremio trófico MOPF (colectores), respiración por tegumento y tamaño del cuerpo pequeño fueron característicos. En los tramos bajos, el ensamblaje fue de tipo raspador con respiración por branquias y forma del cuerpo aplanada. La riqueza, divergencia y equidad funcional fueron mayores en el tramo alto. En el Análisis de Correspondencia Canónica, los mayores valores de ancho y velocidad se relacionaron con categorías adherido al sustrato y endobentónico, mientras que valores bajos de ancho y rugosidad se relacionaron con las categorías de forma del cuerpo aplanado, recurso alimentario micrófitas y tamaño del cuerpo máximo. Conclusiones: El sistema presentó variación en las condiciones abióticas, en la estructura, diversidad taxonómica y funcional de los macroinvertebrados. Se resalta el papel de la velocidad del flujo como una variable determinante de la estructura y función del ensamblaje de macroinvertebrados. Asimismo, se destaca la diversidad funcional como una expresión de los rasgos descritos, por lo cual se relaciona en los tramos altos con la dominancia de taxones como Orthocladiinae, Chironominae, Simulium sp.y Andesiops sp.
Introduction: The structure, taxonomic diversity and functional diversity of the aquatic macroinvertebrate assemblages are estimators sensitive to variations in the surrounding environment. The physical environment is a key factor, where the substrate and hydraulic dynamics modify the availability of resources, the structuring, the functioning of the community and the ecosystem. Objective: Determine the structure, taxonomic diversity and functional diversity of the macroinvertebrate assemblages under different abiotic conditions in the Hato Laguna river, a tributary of Lake Tota. Methods: 120 biological samples were collected in four sampling events in two reaches in the river. Depth, flow velocity, channel width and roughness of the substrate were measured in situ. The functional traits evaluated were: body length, body shape, type of breathing, type of locomotion, trophic guild and functional feeding groups. Results: A total of 38 taxa were identified; Diptera, Coleoptera and Trichoptera orders presented the highest abundance of families and genera. Orthocladiinae, Andesiops sp. and Simulium sp. were more abundant groups under high-velocity conditions in the upper reaches. Nectopsyche sp. was abundant in the lower sections related to lower velocity and greater channel width. According to the taxonomic diversity indices, variation by reaches and samplings was presented without observing trends. In the upper reaches, the MOPF trophic guild (collectors), in tegument respiration, and small body size were characteristic. In the lower reaches, the assembly was of the scraper type with gill breathing and flattened body shape. The richness, divergence and functional evenness were higher in the upper reaches. In the Canonical Correspondence Analysis, the highest values of width and speed were related to categories attached to the substrate and endobenthic, while low width and roughness were related to the categories of flattened body shape, microphytes food resource, and maximum body size. Conclusions: The system presented a variation in the abiotic conditions, in the structure, taxonomic and functional diversity of the macroinvertebrates. The role of the flow velocity as a determining variable of the structure and function of the community is highlighted. Likewise, functional diversity stands out as an expression of the described traits, which is why it is related in the upper reaches with the dominance of taxa such as Orthocladiinae, Chironominae, Simulium sp. and Andesiops sp.
ABSTRACT
Introducción: La familia Naucoridae, de distribución mundial, se encuentra dividida en cinco subfamilias, de las cuales cuatro de ellas y seis géneros han sido reportados hasta la fecha en Centroamérica. El género Interocoris (Laccocorinae) es monotípico y anteriormente sólo se había registrado en México. Objetivo: Reportar el primer registro confirmado de I. mexicanus para Costa Rica y Centroamérica, así como proporcionar descripciones complementarias de los adultos, ninfa V y microhábitat asociado. Métodos: Se realizó una comparación de la morfología externa (medidas y proporciones) de los ejemplares recolectados en dos localidades de Costa Rica con la información y el material tipo de I. mexicanus, recolectado en México. Resultados: A partir de la comparación morfológica se obtuvo una identificación positiva de la especie, por lo que se reporta por primera vez a I. mexicanus de Costa Rica y Centroamérica. Los especímenes recolectados coincidieron en general con las mediciones y relaciones del material tipo de I. mexicanus, con ligeras diferencias, algunas de ellas incluso reportadas para los ejemplares de la serie tipo en la descripción original. Se presentan descripciones complementarias de adultos y se describe por primera vez la morfología de la ninfa V. Conclusiones: Con este nuevo registro se expande significativamente el rango del género Interocoris, así como de la especie I. mexicanus desde México a Costa Rica. Además, se aumentan a seis los géneros de Naucoridae en Costa Rica y a siete en Centroamérica.
Introduction: The family Naucoridae, of worldwide distribution, is divided into five subfamilies, with four of them and six genera reported to date in Central America. The genus Interocoris (Laccocorinae) is monotypic and was only recorded from Mexico. Objective: To report the first confirmed record of Interocoris mexicanus from Costa Rica and Central America, and to provide complementary descriptions of adults and nymphal instar V and associated microhabitat. Methods: A comparison of the external morphology (measurements and proportions) was made of specimens collected from two localities in Costa Rica with the type material of I. mexicanus from Mexico. Results: A positive identification of the species was obtained from the morphological comparison, which is why it is reported for the first time from Costa Rica and Central America. The specimens collected generally coincided with the measurements and relationships of the type material of I. mexicanus, with slight differences, some of them even reported for the specimens of the type series in the original description. Complementary descriptions of adults are presented and the morphology of nymph V is described for the first time. Conclusions: With this new record, the range of the genus Interocoris as well as the species I. mexicanus is expanded significantly from Mexico to Costa Rica. In addition, the reported number of genera of Naucoridae is increased to six in Costa Rica and to seven in the Central American region.
ABSTRACT
Introducción: La distribución de los macroinvertebrados acuáticos en los ríos puede estar determinada por el tipo del sustrato, la forma del canal del río, el régimen hidrológico y las interacciones con factores bióticos y abióticos. En Costa Rica se desconoce en gran parte de los ríos, las variaciones en la distribución de los macroinvertebrados acuáticos producto de las transiciones y consecuentes variaciones en características fisicoquímicas e hidrológicas. Objetivos : 1) Estudiar el cambio del ensamblaje de macroinvertebrados acuáticos en dos sitios dentro del cauce del Río Naranjo, durante los cuatro periodos hidrológicos del año; 2) determinar la relación entre las variables fisicoquímicas, sustrato y el caudal con el ensamblaje. Metodología: El estudio se realizó en el Río Naranjo, Costa Rica, en dos sitios de muestreo durante un año, evaluando los cuatro periodos hidrológicos del año. En cada sitio de muestreo se obtuvieron valores de velocidad y profundidad del agua, caudal, oxígeno disuelto, pH, conductividad, sulfatos, amonio, nitrato, silicatos, fosfatos y sustrato, y se obtuvo una muestra de macroinvertebrados acuáticos por cada tipo de microhábitat determinado por la velocidad del agua. Se realizó una prueba PERMANOVA de dos vías, para determinar si existe una diferencia entre la abundancia de macroinvertebrados acuáticos, por periodo y entre sitios. Se hizo un análisis de correspondencia canónica para observar la relación entre los macroinvertebrados acuáticos y los factores ambientales. Por último, se realizó una prueba de Spearman para determinar la relación positiva o negativa de las variables con los macroinvertebrados Resultados: Hubo una mayor abundancia durante la estación seca, mientras que durante la transición de la estación seca a la lluviosa se registró la menor abundancia de organismos. El ACC indicó que el primer eje presentó una relación positiva con el sustrato limo y arena, y una relación negativa para las variables velocidad de corriente y sustrato rocoso. El segundo eje presentó una relación positiva con el caudal y los nitratos, y negativa para el sustrato canto rodado. La mayoría de los organismos mostraron una respuesta negativa al aumento del flujo y los nitratos. Discusión: Conforme aumenta el caudal, aumenta la velocidad del agua y no todos los organismos registrados en el Río Naranjo cuentan con características para sobrevivir a estas condiciones. Además, la profundidad también aumenta junto con la fuerza de arrastre, provocando el movimiento de los sustratos de menor tamaño y una remoción de organismos. El aumento de nitratos puede generar una disminución de los organismos más sensibles como Plecoptera y Ephemeroptera. A pesar de las variaciones fisicoquímicas y de caudal registradas en el Río Naranjo, éstas no fueron lo suficientemente fuertes como para variar el ensamblaje de macroinvertebrados acuáticos, por lo que la cuenca por el momento no cuenta con factores estresantes que elimine organismos durante uno o varios meses del año.
Introduction: The distribution of aquatic macroinvertebrates in rivers may be determined by the type of substrate, the shape of the river channel, the hydrological regime, and interactions with biotic and abiotic factors. Variations in the distribution of aquatic macroinvertebrates due to transitions and variations in physicochemical and hydrological characteristics are unknown in most rivers. Objectives: 1) to study the change in the aquatic macroinvertebrates assemblages in two sites in Naranjo River, during the four hydrological seasons; 2) to determine the relationship between the physicochemical variables, substrate and flow with the assemblages. Methodology: The study was conducted in the Naranjo River, Costa Rica, at two sampling sites during one year, evaluating the four seasons of the year. In each station we measure, values of water velocity and depth, flow rate, dissolved oxygen, pH, conductivity, sulfates, ammonium, nitrate, silicates, phosphates, and substrate were obtained, and a sample of aquatic macroinvertebrates was obtained for each type of microhabitat determined by water velocity. Two-way PERMANOVA was made to determine if there is a difference among aquatic macroinvertebrate abundance, per period and between sites. Canonical correspondence analysis was used to observe the relationship between aquatic macroinvertebrates and environmental factors. Finally, a Spearman's rank correlation coefficient was performed to determine the positive or negative relationship of variables with macroinvertebrates. Results: There was a greater abundance during the dry season, while during the transition from dry to the rainy season, the lowest abundance of organisms was recorded. The CCA indicates that the first axis presented a positive relationship with the silt and sand substrate and a negative relationship for the current velocity and rock substrate variables. The second axis showed a positive relationship with flow and nitrates and negative for the pebble substrate. Most organisms showed a negative response to increased flow and nitrates. Discussion: As flow increases, current velocity increases, and not all organisms recorded in the Naranjo River have the characteristics to survive these conditions. In addition, the depth also increases along with the drag force, causing movement of smaller substrates and removal of organisms. Increased nitrates can lead to a decrease in more sensitive organisms, such as Plecoptera and Ephemeroptera. In spite of the physicochemical and flow variations registered in the Naranjo River, these were not strong enough to vary the assemblages of aquatic macroinvertebrates, so the basin does not have stressful factors that eliminate organisms during one or several months of the year.
ABSTRACT
Introducción: Existen diferentes metodologías para la recolecta de macroinvertebrados acuáticos (p.e., la red D y Red Surber), sin embargo, algunas de estas no son efectivas en todos los cuerpos de agua o representa un riesgo para la persona que adquiere la muestra. Los sustratos artificiales pueden emplearse en ríos profundos, contaminados o con presencia de cocodrilos. En Costa Rica hay estudios donde se utilizó los sustratos artificiales, para determinar la riqueza y abundancia en humedales tipo lago y lagunas, no obstante se desconoce la efectividad de un tipo de sustrato sobre otro y en sistemas lóticos. El objetivo del estudio fue demostrar la efectividad de tres tipos de sustratos artificiales. Métodos: las muestras se obtuvieron de manera bimensual entre los años 2013 y 2017, en el Río Parismina, Costa Rica, en cuatro sitios a lo largo del río y se evaluó los sustratos piedra, madera y hojas. Se aplicó una prueba de Kruskal-Wallis para determinar las diferencias entre la abundancia y el tipo de sustrato, como también para determinar la diferencia entre la abundancia y el sitio de muestreo. Además, para determinar si existe una diferencia entre los sustratos por sitio, se aplicó una prueba Permanova de dos vías. Un análisis de correspondencia múltiple para determinar el grado de asociación de la comunidad con respecto al tipo de sustrato. Resultados: Un total de 1159 organismos fueron recolectados, siendo Diptera y Ephemeroptera los órdenes más abundantes. La madera y hojas fueron los sustratos con mayor biodiversidad, como también los sitios con mayor vegetación. Conclusiones: El uso en conjunto de los tres tipos de sustratos artificiales, es efectivo para obtener una mayor riqueza de organismos, ya que se observó afinidad por un sustrato según el género de macroinvertebrado acuático.
Introduction: Different methodologies exist for sampling aquatic macroinvertebrates, however, some of these (e.g., kick-net, Surber) are not well suited for deep, contaminated rivers or rivers with presence of crocodiles, which represent a risk to the person who must take the sample. One alternative is to use artificial substrates. The use of artificial substrates to evaluate the aquatic macroinvertebrate biodiversity in wetlands has been studied previously in Costa Rica, but no research has been conducted to determine which types of substrates are most effective. The present study aimed to evaluate the effectiveness of three artificial substrates (i.e., stones, leaves and wood). Methods: Samples of the three substrates were taken bi-monthly between 2013 and 2017 in four sites of the Parismina River. A Kruskal-Wallis test was applied to determine differences between the macroinvertebrate abundance among substrate type. Beside to determine if there is a difference between substrates per site, a two-way PERMANOVA test was applied and a multiple correspondence analysis was used to correlate the substrate type with the macroinvertebrate community. Results: A total of 1 159 organisms were collected, with Diptera and Ephemeroptera being the most abundant. Wood and leaves were the substrates with greatest biodiversity and abundance of organisms; in addition the two sites with greatest vegetation were the most diverse. Conclusions: Most of the organisms were registered on any of the three types of artificial substrates, thus we recommend the joint use of the three types of substrates for biomonitoring or taxa richness studies.
ABSTRACT
Los humedales costeros son ecosistemas sensibles de alta productividad por los servicios ecosistémicos que brindan: purificación del agua, reducción de las inundaciones, protección de las costas marinas y; además, son lugares de gran diversidad biológica. El objetivo del presente estudio fue determinar la estructura comunitaria de los macroinvertebrados acuáticos en relación con las variaciones espaciales en la zona litoral del humedal costero Santa Rosa en Lima, Perú. El estudio fue realizado en seis periodos bimestrales desde agosto 2015 a junio 2016. Se establecieron ocho estaciones de muestreo: tres estaciones en la laguna principal, tres estaciones en el brazo de la laguna y dos estaciones en pozas pequeñas aisladas. Los muestreos se realizaron con una red tipo D de 250 μm de apertura de malla y tres réplicas por cada estación. Las ocho estaciones evaluadas se caracterizaron ambientalmente y se registraron los parámetros fisicoquímicos del agua para cada estación. Se recolectaron en total 28 655 macroinvertebrados distribuidos en 76 géneros. Los órdenes de mayor riqueza fueron: Diptera y Coleoptera con 24 y 19 géneros respectivamente. De estos últimos, los más abundantes fueron: Buenoa (Hemiptera: Notonectidae), Ischnura (Odonata: Coenagrionidae), Chironomus y Goeldichironomus (Diptera: Chironomidae). Estos cuatro representaron el 62.43 % de la abundancia total. En cuanto a la variación espacial, la mayor parte de las estaciones de estudio compartieron la misma estructura y composición de macroinvertebrados debido a que se conectan al cuerpo de agua principal de manera temporal o permanente, lo cual les confirió una estabilidad y resiliencia mayor. Solo las estaciones con una baja profundidad, menor extensión, escasa vegetación acuática e impacto antropogénico mayor se apartaron del conjunto general. A pesar de los variados impactos producidos por la agricultura, ganadería y la actividad urbana que sufre el humedal, se observó que las estaciones más profundas y con cobertura vegetal son más resilientes que las zonas expuestas al impacto y con menor volumen de agua y vegetación. Por otro lado, los parámetros fisicoquímicos del agua en la primera estación (E1) se diferencian al resto de la comunidad por su ausencia de impacto.
Coastal wetlands are sensitive ecosystems of high productivity due to ecological services they provide: water purification, flood reduction, and protection of marine coasts. In addition, these zones are places of great biological diversity. The objective of the present study was to determine the community structure of the aquatic macroinvertebratesin relation to the spatial variations in the littoral zone of the Santa Rosa coastal wetland in Lima, Peru. The study was carried out during six bimonthly periods from August 2015 to June 2016. We established eight sampling sites: three sites in the main lagoon, three sites in the lagoon arm and two sites in isolated small pools. We carried out the sampling with a D-frame of 250 μm mesh aperture with three replicates for each site. The eight evaluated sites were environmentally characterized, and the physicochemical parameters of the water were recorded for each sampling site. We collected 28 655 macroinvertebrates distributed in 76 genera. Diptera and Coleoptera were the orders with the greatest richness: 24 and 19 genera respectively. The most abundant genera were: Buenoa (Hemiptera: Notonectidae), Ischnura (Odonata: Coenagrionidae), Chironomus and Goeldichironomus (Diptera: Chironomidae); these four represented 62.43 % of the total abundance. In the spatial variation, most sites shared the same structure and composition of macroinvertebrates. This was expected because they are connected to the main water body temporarily or permanently, which consequently gives them greater stability and resilience. The sites with shallow depth, smaller extension, scarce aquatic vegetation and greater anthropogenic impact were the only ones with results separated from the general set. Due to the variety of environmental impacts produced by agriculture, livestock, and urban activity on the wetland, it was observed that the sites with deeper and more abundant vegetation were more resilient than the areas exposed to environmental impacts and with less water and vegetation. On the other hand, the physicochemical parameters of water at one site (E1) differentiate the community in the absence of impact.
ABSTRACT
ABSTRACT Biotic factors such as predation, although important drivers of the black fly community, are rarely investigated in the literature. This study aimed to test the hypothesis that the patterns of co-occurrence of black fly larvae and its potential predators is not random and that there is a correlation between its frequencies and Simuliidae larvae abundances. Larvae were sampled from two localities in the Pedra Branca State Park, Rio de Janeiro, Brazil, during the dry season in june 2018. We collected Simulium pertinax Kollar, 1832, Simulium subpallidum Lutz, 1910, Simulium (Inaequalium) sp., Simulium (Psaroniocompsa) sp. and Simulium (Trichodagmia) sp. The predators families present were Perlidae, Hydropsychidae, Leptoceridae, Libellulidae and Chironomidae. The null models showed that species co-occurred significantly more than expected by chance. The canonical correlation analyses for the Vargem Grande and Pau da Fome areas area showed a significant relationship between black fly abundances and predator abundances. In Vargem Grande the abundance of Chironomidae showed a highly significant positive correlation to S. (Psaroniocompsa) sp., while Hydropsychidae was significantly correlated to Simulium sp. On the other hand, in Pau da Fome Libellulidae was significantly correlated to S. (Psaroniocompsa) sp. and Simulium sp. and Chironomidae correlated significantly to Simulium sp. The result is consistent with what would be expected of organisms that exercise mutual population regulation, although other factors than biotic interactions may be causing these patterns. However the lack of mechanistic evidences on the effect of biotic interactions on black fly populations pose a challenge on the understanding of these patterns.
ABSTRACT
Abstract: Here we provide a checklist of the odonates from Amazonas state, Brazil. We registered 324 species and 101 genera, making Amazonas the Brazilian state with the most Odonata species recorded. The families with the highest number of species were Coenagrionidae with 32 genera and 101 species, followed by Libellulidae with 28 genera and 100 species and Gomphidae with 12 genera and 45 species. Some regions of Amazonas state remain poorly explored, such as the southern area, and large municipalities, such as São Gabriel da Cachoeira. This work underlines the importance of the biological diversity from Amazonas state and the Amazonian Biome for Odonata species richness in Brazil and shows that many areas in the world's largest tropical forest have not yet been sampled.
Resumo: Aqui nós apresentamos a lista de espécies de libélulas presentes no estado do Amazonas, Brasil. Nós registramos 324 espécies e 101 gêneros, tornando o estado com o maior número de espécies de libélulas registradas no país. As famílias com maior número de espécies foram Coenagrionidae, com 32 gêneros e 101 espécies, seguido por Libellulidae, com 28 gêneros e 100 espécies e Gomphidae com 12 gêneros e 45 espécies. Regiões do estado do Amazonas permanecem pouco exploradas, como a parte sul e os municípios com grande extensão territorial, como São Gabriel da Cachoeira. Este trabalho reconhece a importância da diversidade biológica do estado do Amazonas e do bioma Amazônico para a riqueza de espécies de Odonata no Brasil e mostra que ainda existem muitas áreas não amostradas na maior floresta tropical do mundo.