Abstract Aerial census for identification and quantification of nesting sites of Golden Eagle was performed through the mountain ranges of the central Baja California Peninsula, Mexico from 5 to 8 April 2021. We identified a total of 113 nests and 12 territories of Golden Eagle on a sampling trajectory of 1,203 km that encompassed a surface of 176,000 ha. The highest abundance of nests (n = 57) was recorded between 29º and 30º N latitudes with elevations ranging between 600 and 700 m (n = 35) in the Valle de Los Cirios Protected Natural Area, which is mainly associated with mountain biotopes with steep cliffs and ample alluvial valleys that promote foraging and nesting sites for this species. The number of nests of Golden Eagle showed an inverse relationship with the altitude along a latitudinal gradient. This study reports new nesting sites of Golden Eagle in the central peninsular region that includes the mountain ranges of Matomí, Jaraguay, and La Libertad.

Resumen Un censo aéreo para la identificación y cuantificación de sitios de anidación de águila real fue realizado a través de los sistemas montañosos de la parte central de la península de Baja California, México, del 5 al 8 de abril de 2021. Identificamos un total de 113 nidos y 12 territorios de águila real a través de una trayectoria de muestreo de 1,203 km que abarcó una superficie de 176,000 ha. La mayor abundancia de nidos (n = 57) fue registrada entre las latitudes 29º y 30º N con elevaciones variando entre 600 y 700 m (n = 35) en el Área Natural Protegida Valle de Los Cirios, la cual está principalmente asociada a biotopos de montaña con acantilados pronunciados y amplios valles aluviales que promueven sitios de forrajeo y anidación para esta especie. El número de nidos demostró una relación inversa con la altitud a través de un gradiente latitudinal. Este estudio reporta nuevos sitios de anidación de águila real en la región central peninsular que incluye de norte a sur a las sierras de Matomí, Jaraguay y La Libertad.

With water quality deteriorating rapidly at a global scale, river sections suited to serve as reference sites are being increasingly lost. It thus becomes critical to develop rapid methods to confirm that previously monitored sites continue meet the requirements of reliable reference sites. In the absence of pristine sites, 9 near-natural sites, as defined by the Kleynhans (1996) classification, were used as reference sites for the Luvuvhu River catchment to compare the quality of physico-chemical factors against a biological metric. Baetid mayfly community structure at a site was chosen as an index of water quality, since this family is common in all types of freshwaters, highly diverse and adapted to unpolluted running water. Baetid larvae were sampled monthly from stones-in-current biotopes across 9 sites for over 1 year, between December 2016 and January 2018. A Spearman's correlation test was used to evaluate the relationship between physico-chemical factors and identify redundant variables. Water quality standards were measured against the national water quality guidelines for aquatic ecosystems. We used a generalized linear model to determine the effect of physico-chemical variables on baetid species, and canonical correspondence analysis to show the relationships between baetid species, sites, and physico-chemical variables. A total of 3 039 individuals belonging to 12 mayfly species were recorded. Our findings indicated that while the physico-chemical factors were highly variable, they were within favourable ranges to reflect reference site conditions. While water temperature was the most important driver of baetid community structure in general, as it negatively affected their abundances, a subset of species (Pseudoponnota sp., Pseudocloeon sp., Acanthiops varius and Demoulinia crassi) showed clear responses to changes in TDS and stream width. We conclude that specific baetid species show good potential as biological indicators of reference sites and chronic water temperature stress, making assessment of reference sites easier.

Abstract The spatial gradients created after the installation of large reservoirs produce a great diversity of biotopes, which affects the distribution and structuring of aquatic communities, mainly fish. Thus, we hypothesized that the fishes living in the lotic stretch (river zone, closest to the natural environment) of the reservoir would have lower overlap and higher niche breadth than fishes living in the lentic stretch. Samples were collected in six sections (lentic and lotic) of the Chavantes Reservoir, middle Paranapanema River. A total of 1478 individuals distributed in 13 species were sampled in both stretches. Many resources were acquired by species, and we observed that nine species present significant differences when comparing the two stretches. Furthermore, only \emph{Schizodon nasutus biotopes communities fish Thus river zone environment Reservoir River 147 1 stretches Furthermore \emphSchizodon emphSchizodon \emph Schizodon emph 14

BACKGROUND: The Eastern Cape province of South Africa has a rich floral diversity, with seven of the country's eight floral biomes represented in the province. The non-acarine arachnid fauna of the province is largely understudied and considerable gaps exist in our knowledge of the distribution, diversity and levels of endemism of the arachnid fauna. OBJECTIVES: To address this, non-acarine arachnids were sampled intensively in the Afromontane forests and surrounding biotopes in the Amathole Mountains over the course of a decade. METHODS: In the present contribution, comprehensive checklists of the non-acarine arachnids (specifically, the orders Amblypygi, Araneae, Opiliones, Pseu-doscorpiones and Scorpiones) of the region are presented, based on a combination of field sampling, provenance data from museum specimen databases, and a review of the historical literature. RESULTS: In total, 398 species of non-acarine arachnids have been recorded from the Amathole Mountains, with spiders (Araneae; 324 species from 51 families) and harvestmen (Opiliones; 41 species from four families) the richest groups. The region is exceptionally rich in harvestmen and pseudoscorpions (Pseudoscorpio-nes; 24 species from 11 families), and might be considered a hotspot of biodiversity and endemism for these taxa. CONCLUSION: As the sampling was concentrated around Hogsback, and most other areas remain undersampled, further efforts should be made to sample all representative biotopes more comprehensively in the mountain range. This will improve understanding of the distribution and endemism of the arachnid fauna and assess the conservation significance of the region from a national perspective.

Abstract Notholebias minimus is an endangered annual killifish endemic to the coastal plains of the State of Rio de Janeiro, Brazil. This study aimed to present new occurrences in the Atlantic Forest biome, provide unprecedented population features (body and egg size, fecundity, sexual ratio, and length-weight relationship – LWR), and compare changes in land use and coverage between 1985 and 2021 in biotopes located inside and outside protected areas. Three new occurrence localities were found in shallow temporary wetlands with acidic pH (6.4 ± 0.2) and low concentrations of dissolved oxygen (2.0 ± 0.9 mg/L). Males and females total length ranged from 11.1 to 31 mm and 11 to 26 mm, respectively. Batch fecundity ranged from 18 to 40 oocytes (24.8 ± 8.8), corresponding to oocytes with sizes between 800–1,006 µm (905 ± 56). Males were significantly larger than females (W = 2193.5, p = 0.0067), but both sexes occurred in similar proportions (p = 0.472). LWR showed positive allometry (b = 3.18). Biotopes located within protected areas exhibited higher conservation. Our discoveries expand the knowledge about habitat and population features of N. minimus and reinforce the importance of establishing protected areas for the conservation of annual fish biotopes. Janeiro Brazil biome body size ratio lengthweight weight LWR, , LWR) 198 202 6.4 64 6 4 (6. 0.2 02 0 2 2.0 20 (2. 09 9 0. mg/L. mgL mg/L . mg L mg/L) 111 1 11. 3 respectively 24.8 248 24 8 (24. 8.8, 88 8.8 8.8) 8001006 800 006 800–1,00 905 (90 56. 56 56) W 21935 2193 5 2193.5 0.0067, 00067 0.0067 0067 0.0067) 0.472. 0472 0.472 472 0.472) b 3.18. 318 3.18 3.18) N 19 6. (6 2. (2 24. (24 8. 800100 80 00 800–1,0 90 (9 219 2193. 0006 0.006 047 0.47 47 3.1 ( 80010 800–1, 21 000 0.00 04 0.4 3. 8001 800–1 0.0 800–

Resumo Notholebias minimus é um peixe anual ameaçado de extinção, endêmico das planícies costeiras do Estado do Rio de Janeiro, Brasil. Neste estudo, objetivamos apresentar novas ocorrências no bioma Mata Atlântica, fornecer características populacionais inéditas (tamanho do corpo e dos ovos, fecundidade, proporção sexual e relação peso-comprimento), e comparar mudanças no uso e cobertura do solo entre 1985 e 2021 em biótopos localizados dentro e fora de unidades de conservação. Registramos três novos locais em áreas úmidas temporárias rasas com pH ácido (6,4 ± 0,2) e baixas concentrações de oxigênio dissolvido (2,0 ± 0,9 mg/L). O comprimento total de machos e fêmeas variou de 11,1 a 31 mm e de 11 a 26 mm, respectivamente. A fecundidade do lote variou entre 18–40 oócitos (24,8 ± 8,8), correspondendo a diâmetros entre 800–1.006 µm (905 ± 56). Os machos foram significativamente maiores que as fêmeas (W = 2193,5; p = 0,0067), mas ocorreram em proporções similares (p = 0,472). A relação peso-comprimento detectou alometria positiva (b = 3,18). Biótopos localizados dentro de áreas protegidas exibiram maior preservação ambiental. Nossas descobertas ampliam o conhecimento sobre as características do habitat e da população de N. minimus e reforçam a importância do estabelecimento de áreas protegidas para a conservação dos biótopos dos peixes anuais. extinção Janeiro Brasil estudo Atlântica tamanho ovos pesocomprimento, pesocomprimento peso , peso-comprimento) 198 202 6,4 64 6 4 (6, 0,2 02 0 2 2,0 20 (2, 09 9 0, mg/L. mgL mg/L . mg L mg/L) 111 1 11, 3 respectivamente 1840 18 40 18–4 24,8 248 24 8 (24, 8,8, 88 8,8 8,8) 8001006 800 006 800–1.00 905 (90 56. 56 56) W 2193,5 21935 2193 5 0,0067, 00067 0,0067 0067 0,0067) 0,472. 0472 0,472 472 0,472) b 3,18. 318 3,18 3,18) ambiental N anuais 19 6, (6 2, (2 184 18– 24, (24 8, 800100 80 00 800–1.0 90 (9 2193, 219 0006 0,006 047 0,47 47 3,1 ( 80010 800–1. 21 000 0,00 04 0,4 3, 8001 800–1 0,0 800–

Resumen Introducción: El análisis de grupos funcionales de alimentación (GFA) en macroinvertebrados acuáticos es importante para comprender la estructura, función y dinámica de los ecosistemas de procesos ecológicos. La modularidad se refiere al grado de compartimentación de las redes alimentarias y varía entre -1 y 1. Una red con un valor de modularidad cercano a 1 es resistente a las alteraciones y puede interpretarse como un factor indicativo para la estabilidad de las comunidades. Objetivo: En este estudio se analizó la estructura trófica de los macroinvertebrados bentónicos, un elemento importante en la calidad ambiental, en el arroyo La Nitrera, el río San Juan y el río Cauca. Métodos: El estudio contó con el apoyo de técnicas de redes ecológicas utilizando el software Gephi. En 2017 y 2018, estudiamos nueve sitios en estaciones secas, lluviosas y de transición, monitoreando cambios en el gradiente de altitud. En cada uno de los sitios se capturaron y determinaron los organismos y se recogió información fisicoquímica e hidráulica. Resultados: El análisis de componentes de varianza permitió explicar la variabilidad de los datos relacionando las siguientes variables ambientales: GFA, diversidad, riqueza, modularidad, estación y tiempo. La ANOVA simple multifactorial indicó que existen cambios significativos en los GFA en relación con la altitud, y la modularidad con el tiempo. La asignación de los GFA se realizó mediante análisis estomacal e información secundaria. Conclusión: La temporada de transición tuvo la mayor modularidad, posiblemente debido a la recolonización de algunos biotopos provocada por la disminución de la velocidad del cauce. La Nitrera y San Juan presentaron valores superiores a los del Cauca, lo que puede indicar que el cambio altitudinal y la velocidad de las corrientes de agua influyen en la compartimentación de la red.

Abstract Introduction: Analysis of functional feeding groups (FFG) in aquatic macroinvertebrates is important in understanding the structure, function, and dynamics of ecological processes in ecosystems. Modularity refers to the degree of compartmentalization of food webs and varies between -1 and 1. A network with a modularity value close to 1 is resilient to disturbances and can be interpreted as an indicating factor for the stability of communities. Objective: In this study, we analyzed the trophic structure of benthic macroinvertebrates in La Nitrera stream, the San Juan River, and the Cauca River in the Colombian Andes. Methods: The study was supported by ecological networking techniques using Gephi software. We studied nine sites in dry, rainy, and transition seasons in 2017 and 2018, monitoring changes in the altitude gradient. At each of the sites, the organisms were captured and determined, and physicochemical and hydraulic information was obtained. Results: The variance component analysis allowed to explain the variability of the data by relating the following environmental variables: FFG, diversity, richness, modularity, season, and time. Simple multifactorial ANOVA indicated that significant changes in FFG were associated with altitude, and modularity to time. The allocation of the FFG was done by stomach analysis and secondary information. Conclusion: The transition season had the highest modularity, possibly due to the recolonization of some biotopes caused by the decrease in the velocity of water currents. La Nitrera and San Juan presented higher values than the Cauca, which may indicate that the altitudinal change and velocity of water currents affects the compartmentalization of the network.

Abstract: The conservation of biodiversity in Mediterranean Chile requires a greater coverage than that represented in the Protected Wild Areas of the State (SNASPE) and Private Protec ted Areas (APP) are complementary alternative for conservation. The study of biodiver sity in APP is scarce, ignoring its contribution to the conservation. The small mammals assemblage of the APP Bioparque Puquén and surroundings was described comparing the species richness, relative abundance and diversity index of Margalef inside and out side the park. Using the Morisita-Horn similarity index and a cluster analysis, the small mammals assemblage was compared between sampling points categorized in different biotopes. Endemic and native species were more abundant outside the APP. There were no significant differences in specific richness or diversity inside and outside the APP. The small mammals assemblage was grouped into biotopes of dense native vegetation and prairies, ravines and seasonal waters. The park would act as buffer area, protecting the nearby areas of the Los Molles-Pichidangui Priority Site. The importance of rocky outcrops as a habitat for endemic species of small mammals and protecting the areas adjacent to the BioParque is discussed.

Resumen: La conservación de la biodiversidad en Chile Mediterráneo requiere una mayor cobertura en el Sistema Nacional de Áreas Silvestres Protegidas del Estado, por lo que las Áreas Pro tegidas Privadas (APP) son alternativas complementarias para la conservación. El estudio de la biodiversidad en las APP es escaso, desconociendo su aporte en la conservación. Se describió el ensamble de micromamíferos del APP Bioparque Puquén y alrededores comparando la riqueza de especies, abundancia relativa e índice de diversidad de Marga- lef al interior y exterior del parque. Mediante el índice de similitud de Morisita-Horn y un análisis de agrupamientos se comparó el ensamble de micromamíferos entre puntos de muestreos categorizados en distintos biotopos. Las especies endémicas y nativas fueron más abundantes fuera del APP. No hubo diferencias significativas en la riqueza específica ni diversidad dentro y fuera del APP. El ensamble de micromamíferos se agrupó en bioto pos de vegetación nativa densa y de praderas, quebradas y aguas estacionales. El parque actuaría como área de amortiguación, protegiendo las áreas aledañas del Sitio Prioritario Los Molles-Pichidangui. Se discute la importancia de los escollos como hábitat de es pecies endémicas de micromamíferos y de proteger las áreas adyacentes al BioParque.

ABSTRACT The Ordovician System is extensively represented in the Precordillera of San Juan Province, Argentina. At the Cerro La Chilca in the Jáchal area, the limestone of the San Juan Formation is paraconformably overlain by interbedded limestone and shale of the Gualcamayo Formation. The present contribution reports new data on the conodont fauna and biostratigraphy of these darriwilian units, revising local and regional chronostratigraphic relationships. New information on the composition of conodont and graptolite associations through the stratigraphic sequence is presented. The presence of Paroistodus horridus horridus, Yangtzeplacognathus crassus, and Histiodella sinuosa constrain the uppermost strata of the San Juan Formation to the lower part of the Y. crassus Zone, according to the Baltoscandian scheme, and to the H. sinuosa Subzone of the Periodon macrodentatus Zone of the North American scheme. In the overlying Gualcamayo Formation the co-occurrence of Y. crassus with Histiodella holodentata enable the recognition of the Y. crassus Zone and the H. holodentata Subzone of the P. macrodentatus Zone. The identification of these zones allows for precise global and regional correlation. A graptolite assemblage that belongs to the epipelagic and deep-water biotopes with some components restricted to low paleolatitudes is recognized. This diverse assemblage is characteristic of the pelagic biofacies. The important diversity of graptolites in this section suggests a favorable environment for their development. Local changes in the taxonomic composition are recognized through the Gualcamayo Formation. When comparing this fauna with that of different study localities from the Central Precordillera (Cerro Potrerillo, Oculta Creek, Cerro Viejo de Huaco and Las Aguaditas Creek) slight differences in the generic composition are observed. Taxonomic differences support the preference of certain associations for particular environments; though, graptolites are more diverse in black shales facies, which represent deeper environments (the Los Azules Formation), in relation to the calcareous-shale facies of the Gualcamayo Formation from Cerro La Chilca and correlative unit at Las Aguaditas Creek.

RESUMEN El Sistema Ordovícico se encuentra ampliamente representado en la Precordillera de la Provincia de San Juan, Argentina. En el cerro La Chilca, área de Jáchal, las calizas de la Formación San Juan infrayacen de manera paraconcordante a las calizas y lutitas de la Formación Gualcamayo. En este trabajo se brindan nuevos antecedentes sobre la bioestratigrafía de conodontes de estas unidades estratigráficas darriwilianas y se revisa su correlación cronoestratigráfica a nivel local y regional. Adicionalmente, se reportan nuevos datos sobre la composición de la asociación conodontes-graptolitos a lo largo de esta secuencia estratigráfica. La presencia de Paroistodus horridus horridus, Yangtzeplacognathus crassus e Histiodella sinuosa restringen los estratos cuspidales de la Formación San Juan a la parte inferior de la Zona de Y. crassus, según el esquema Báltico, y Subzona de H. sinuosa (Zona de Periodon macrodentatus) del esquema norteamericano. En la supra-yacente Formación Gualcamayo la coexistencia de Y. crassus con Histiodella holodentata permite identificar la Zona de Y . crassus y la Zona de Periodon macrodentatus (Subzona de H. holodentata) para esta unidad. Estas zonas permiten realizar una correlación bioestratigráfica precisa a escala regional y global. A su vez, se reconoce una asociación de graptolitos perteneciente a los biotopos epipelágicos y de aguas profundas con algunos componentes de paleolatitudes bajas. Esta diversa asociación es característica de la biofacies pelágica. La gran riqueza y abundancia de graptolitos en esta sección sugiere un ambiente favorable para su desarrollo. Se observan cambios locales en la composición taxónomica de este grupo a través de la Formación Gualcamayo. Al comparar esta graptofauna con la documentada en otras secciones estratigráficas de la Precordillera Central (cerro Potrerillo, quebrada Oculta, Cerro Viejo de Huaco y quebrada de Las Aguaditas) se observan diferencias en la composición genérica de graptolitos. Esto sugiere una preferencia a determinados ambientes; de modo que, los graptolitos son más diversos en las facies pelíticas que representan ambientes más profundos (Formación Los Azules), en relación a las facies calcáreo-pelíticas de las formaciones Gualcamayo en el cerro La Chilca y quebrada Las Aguaditas.

Abstact: We present the study of the fish fauna from La Paz Bay (LPB), based on an updated checklist with notes on zoogeography, conservation and commercial value. The checklist includes 533 species, 314 genera, 123 families, 34 orders and 2 classes: Actinopterygii (467 species) and Chondrichthyes (66 species). The order Perciformes represents 56% of the total ichthyofauna, with 10 families comprising 34% of the species richness. The Cortés (82.4%) and Mexican (68.3%) provinces showed the highest fish affinity as result of the existence of a transitional zone for fishes from temperate and tropical derivation. The ichthyofauna of LPB inhabits mostly over sand-mud (38%), rocky bottoms (30%) and mangrove biotopes (29%). Based on the IUCN Red List, 84% are fish species of least concern and not evaluated, 16% corresponds to another category of risk. The NOM-059-Semarnat-2010 includes 6 teleosts under special protection and 2 threatened chondrichthians. In accordance to the IUCN, 188 species are of commercial value, but at least the artisanal fisheries in LPB catch other 82 species. This study could provide a basis for the formulation of management programs, catch rates or aquaculture projects, excluding those species no distributed in LPB, as well as along the Tropical Eastern Pacific (TEP).

Resumen: Se presenta el estudio de la ictiofauna de bahía de La Paz (BLP), sustentado en una lista taxonómica actualizada con notas zoogeográficas, de conservación e importancia económica. La lista consta de 533 especies, 314 géneros, 123 familias, 34 órdenes y 2 clases: Actinopterygii (467 especies) y Chondrichthyes (66 especies). El orden Perciformes representó 56% de la ictiofauna total, con 10 familias que corresponden al 34% de la riqueza específica. La mayor afinidad íctica con las provincias de Cortés (82.4%) y Mexicana (68.3%), sugiere la existencia de una zona de transición para especies templadas y tropicales. Los hábitats preferenciales son fango arenosos (38%), rocosos (30%) y biotopos de manglar (29%). Según la UICN, 84% son especies de preocupación menor y no evaluadas, el 16% corresponde a otras categorías de riesgo. La NOM-059-Semarnat-2010, incluye 6 teleósteos bajo protección especial y 2 especies amenazadas de condrictios. De acuerdo con la UICN, 188 especies son de interés comercial; adicionalmente, 82 se capturan artesanalmente en la BLP. Los resultados de este estudio servirán de base para la formulación de propuestas de manejo, tasas de captura o planes de maricultivo de especies locales, excluyendo a aquellas cuya distribución no corresponde a la BLP y, en general, al Pacífico oriental tropical (POT).

Rocky reefs are one of the most important biotopes in Guanabara Bay due to their broad distribution and high species diversity. This study aimed to describe the composition and structure of the fish assemblage associated with rocky reefs in Vermelha Beach (RJ/Brazil), an estuarine-marine transitional zone located at the entrance of Guanabara Bay. Fish were surveyed through underwater visual censuses, conducted by snorkeling divers along 10 m²-linear transects (n = 90). A total of 2.487 fishes were recorded belonging to 29 species in 18 families. Except for Atherinella brasiliensis, all other species are intimately associated with rocky reefs. The present work also stresses the importance of further studies to evaluate the role of periodic influences of estuarine and oceanic waters as structuring factors of the fish assemblages associated with rocky reefs at Vermelha Beach and similar ecosystems.

ResumenLas especies Echinometra lucunter, Echinometra viridis, Lytechinus variegatus, Tripneustes ventricosus, and Diadema antillarum son los erizos de mar más comunes en los hábitat litorales del Caribe. Los erizos de mar T. ventricosus y L. variegatus habitan generalmente los pastos marinos mientras que las otras tres especies se encuentran asociadas a sustratos rocosos. Los hábitos alimentarios de estas especies han sido bien documentados y son reconocidas como herbívoros - omnívoros; sin embargo, pocas de estas especies han sido caracterizadas isotópicamente. Utilizamos los isótopos estables para caracterizar estas cinco especies de erizos y establecer las posiciones tróficas para las especies que cohabitan los mismos ecosistemas. También cuantificamos la contribución de los recursos alimentarios para E. lucunter. Los erizos T. ventricosus y D. antillarum mostraron los mayores valores de δ15N y valores similares de δ13C que variaron desde -11.6 ± 0.63 a -10.4 ± 0.99 %; donde el erizo E. lucunter mostró los valores más negativos con -15.40 ± 0.76 %. Las comunidades de algas no mostraron diferencias en valores promedio de δ15N (F= 1.300, df= 3, p= 0.301), pero sí mostraron variaciones en los valores de δ13C (F= 7.410, df= 3, p= 0.001). Los estudios de amplitud de elipses de nicho determinaron que las especies de los biotopos rocosos (D. antillarum, E. lucunter y E. viridis) no mostraron solapamiento de nicho. Similar resultado también se encontró en las especies de erizos que habitan en los pastos marinos. Sin embargo, la distancia entre estas dos especies fue menor respecto a la distancia entre las especies de erizos que habitan en los sustratos rocosos. Nuestros resultados muestran que las especies que habitan en los pastos marinos mostraron valores más elevados de δ13C en comparación con las especies de los sustratos rocosos. No se encontraron diferencias espaciales para E. lucunter en δ15N, pero sí en δ13C. Los modelos de mezcla bayesianos demuestran la plasticidad alimentaria de E. lucunter, especie capaz de utilizar múltiples recursos algales dependiendo de la disponibilidad por sitio. Semejanzas en δ15N entre D. antillarum y T. ventricosus parecen indicar similitudes tróficas entre ambas especies. Si bien T. ventricosus es reconocido como omnívoro, D. antillarum siempre ha sido considerado un herbívoro generalista. Finalmente, la falta de solapamiento entre las especies en los dos biotopos parece indicar una estrategia de partición de recursos para evitar la competencia de nicho entre especies concurrentes.

AbstractThe species Echinometra lucunter, Echinometra viridis, Lytechinus variegatus, Tripneustes ventricosus, and Diadema antillarum are the most common sea urchins of littoral habitats in the Caribbean. T. ventricosus and L. variegatus are associated with seagrass beds, while the other three species usually inhabit hardground substrates. Food preferences of these species are well documented and they are commonly accepted as being primarily herbivorous-omnivorous; nevertheless, few of them have previously been characterized isotopically. We used this approach for assessing the isotopic characterization of five echinoids. We established the trophic position of two groups of co-occurring species and quantified the contribution of food resources in the diet of Echinometra lucunter, considered the most common sea urchin in the Caribbean region. The species T. ventricosus and D. antillarum showed the highest values of δ15N. Sea urchins exhibited similar values of δ13C varying from -11.6 ± 0.63 to -10.4 ± 0.99%. The echinoid E. lucunter displayed the lowest values of carbon, from -15.40 ± 0.76%. Significant differences among species were found for δ15N and δ13C. Seaweed communities exhibited no differences among sites for overall δ15N (F= 1.300, df= 3, p= 0.301), but we found spatial differences for δ13C (F= 7.410, df= 3, p= 0.001). The ellipse-based metrics of niche width analysis found that the hardground biotope species (D. antillarum, E. lucunter, and E. viridis) did not overlap each other. Similar results were obtained for the co-occurring species of the seagrass biotope; however, the distance between these species was closer than that of the hardground biotope species. The Bayesian mixing models run for E. lucunter at all four localities found differences in food resources contribution. The algae D. menstrualis, C. crassa and B. triquetrum dominated in CGD; whereas C. nitens, Gracilaria spp., and D. caribaea represented the main contributor algae to the diet of E. lucunter at LQY. In Culebra Island, no dominance of any particular algae was detected in TMD, where six of the eight species exhibited a similar contribution. Similarities in δ15N between D. antillarum and T. ventricosus may hint towards a similar trophic level for these species, although T. ventricosus is widely accepted as an omnivore, while D. antillarum is considered a generalist herbivore. The lack of overlap among species in the two biotopes seems to indicate a resource partitioning strategy to avoid niche competition among co-occurring species. Rev. Biol. Trop. 64 (2): 837-848. Epub 2016 June 01.

A study of the freshwater mollusc diversity was conducted at selected sites in the relatively pristine Marico River and the impacted Crocodile River, the major tributaries of the Limpopo River. Four surveys were conducted, two in an early (May 2013 and 2014) and two in a late (November 2013 and 2014) low-flow period. Semi-quantitative surveys were done by sampling the vegetation, as well as the substratum, with a standard SASS net for approximately 15 min each. Environmental parameters including water temperature, electrical conductivity (EC) and pH were measured at each site. Molluscs were identified up to species level, sorted, counted, and the presence of juvenile specimens recorded. Historical data for the 1/16th degree square grids (loci), in which each of the sampling sites of the current study was located, were extracted from the National Freshwater Snail Collection at the Unit for Environmental Sciences and Management, Potchefstroom Campus of the North-West University. During this study, 20 and 9 species were recovered from the Marico and Crocodile Rivers, respectively, as compared to 13 and 12 species on record for these loci, respectively. Juvenile specimens were present during the four surveys at most of the sites. Canonical correspondence analyses were applied which revealed that biotopes, water temperature and EC played the most significant role in the distribution and abundance of species. The relatively high mollusc diversity and the fact that juveniles were present throughout the study, demonstrated that current habitat and environmental conditions were suitable to promote recruitment and the sustainability of diverse mollusc populations in the Marico River and its tributaries. However, in contrast to this, the exploitation of and habitat transformation in the Crocodile River has resulted in the decrease of biotopes which eventually could have led to the decrease in diversity and the establishment of P. acuta, an exotic invader species.

Diversity of macrofaunal groups in soft bottoms of the northern and southwestern Cuban shelf was assessed using taxonomic indices that depend on community structure, are independent of habitat type and sampling effort, and have a monotonic response to environmental disturbances. Taxa heterogeneity was significantly higher in sandy-muddy with vegetation, sandy with vegetation, and sandy with vegetation on hard bottom substrates. Biotopes diversity showed a gradient from smaller to greater particle size and from absence to presence of vegetation. Average taxonomic distinctness expected in these zones of the Cuban marine shelf is 92.5 with 95% confidence limits between 76.7 and 100. Sites with average taxonomic distinctness lower than 92.5 and outside the estimated confident limits can be considered environmentally deteriorated or favoring diversity of some particular groups. Dominant groups in this benthos fraction are crustaceans and polychaetes, which is consistent with studies in other tropical and temperate regions. These results constitute a baseline for environmental assessment and monitoring of macrofauna in Cuban soft bottoms, as a key component for marine ecosystems functioning.

Se evaluó la diversidad de la macrofauna en fondos blandos de la plataforma marina cubana norte y suroccidental. Se utilizaron índices de variación taxonómica que aportan una nueva dimensión en la interpretación de la diversidad de las comunidades, que son independientes del tipo de hábitat y del esfuerzo de muestreo, y tienen respuesta monotónica ante las perturbaciones del ambiente. La heterogeneidad de taxones fue significativamente mayor en los biotopos areno-fangoso con vegetación, arenoso con vegetación y arenoso con vegetación sobre fondo duro. La diversidad por biotopos reflejó un gradiente de menor a mayor tamaño de partícula y de ausencia a presencia de vegetación. La distinción taxonómica promedio (Δ+) esperada en estas zonas de la plataforma cubana es de 92,5, con límites de confianza de 95% entre 76,7 y 100. Las estaciones con distinción taxonómica promedio <92,5 y fuera del límite de confianza inferior, se pueden considerar con condiciones ambientales de deterioro o que favorecen la diversidad de algún grupo en particular. Los grupos dominantes en esta fracción del bentos son crustáceos y poliquetos, como ocurre en otras regiones tropicales y templadas. Estos resultados sirven de base para la evaluación y monitoreo ambiental del macrozoobentos como componente clave del funcionamiento de ecosistemas marinos en fondos blandos de Cuba.

Impact of pollution on aquatic biota is usually assessed by comparing the assemblage at an impacted site with those at a control or reference site. In South Africa, except in rivers where not all biotopes are represented, the characterisation of a macroinvertebrate-based pollution effect is usually based on samples collected from three distinct biotopes, i.e., stones, vegetation and sediments. In this study, the influence of reducing the numbers of biotopes on chironomid-based bioassessment of pollution in the Swartkops River was investigated. This paper addresses the following questions: (i) can the chironomid species assemblage from any single distinct biotope analysed separately provide sufficiently accurate results similar to those of the composite-biotope group assemblage, and (ii) can chironomid community types be identified based on their biotope preferences? Chironomid larvae were sampled seasonally from three distinct biotopes: stones (stone-in-and-out-of-current), vegetation (marginal and aquatic), and sediment (gravel, sand and mud, GSM) at one upstream control site, i.e., Site 1, and three downstream sites, i.e., Sites 2, 3 and 4. Site 2 in Uitenhage was impacted by diffuse pollution sources including runoff from road networks. Site 3, also in Uitenhage, was impacted by wastewater effluent discharges as well as diffuse pollution sources, while Site 4 in Despatch was about 2.5 km downstream of Site 3. The multivariate analysis of similarity (ANOSIM) indicated that the chironomid species assemblages based on the composite biotopes were significantly different between all site pairs in terms of species composition and abundance. However, when the assemblages were analysed separately for each of the three distinct biotopes, only the stone-based assemblage indicated significant differences between all of the site pairs similarly to those of the composite biotopes. Thus, the results suggest that, when resources are limited, sampling only the stony benthos could still provide bioassessment results similar to benthos from all three biotopes combined.

O género Campomanesia ocorre em diferentes fitofisionomias do Cerrado, possuindo 25 espécies distribuídas do México à Argentina, sendo 15 nativas do Brasil e com grande potencial económico. Nesse contexto, um dos principais problemas encontrados para a expansão da plantação da espécie é a produção de mudas, pois a multiplicação em larga escala por sementes é inviabilizada, já que estas são recalcitrantes, geram variabilidade entre as plantas. A propagação por estaquia é uma alternativa prática, simples e económica, pois elimina desvantagens do uso da propagação sexuada. O trabalho teve como objetivos avaliar diferentes épocas de enraizamento de estacas, tipos de estacas, reguladores vegetais e concentrações na indução do enraizamento de estacas de gabiroba. Foram instalados três ensaios (dezembro, fevereiro e maio). As estacas foram avaliadas semanalmente a partir da emergência do primeiro gomo, sendo analisadas a percentagem de enraizamento, de abrolhamento, de estacas mortas e o número de gomos. Foi observado que estacas lenhosas de gabiroba são mais aptas a serem usadas na propagação vegetativa desta espécie quando comparadas com estacas herbáceas e que a época de colheita influencia o enraizamento e o abrolhamento das estacas de gabiroba. Já as induções hormonais têm eficiência variando de acordo com a época de colheita.

Campomanesia gender occurs at different biotopes of Cerrado, which have 25 species that are distributed from Mexico to Argentina, from those 15 native from Brazil and with great economic potential. In these circumstances, one of the main problems related to the crop expansion of this specie is cutting production because multiplication on great scale is not possible since seeds are recalcitrant, they promote variability among plants. Cuttings propagation is a practical, simple and economic alternative because it does not have the disadvantage of the use of sexual propagation. The aim of this work was to evaluate different dates of rooting of cuttings, cutting types, plant regulators and their concentrations on root induction of gabiroba cuttings. Three experiments were established (December, February and May). Cuttings were evaluated weekly from emergence to first bud, which rooting, sprouting, died cuttings percentage and number of buds were analyzed. It was observed that woody cuttings are better to be used in plant propagation of this specie when they are compared with herbaceous cutting and that harvest date influences on rooting and sprouting of gabiroba cuttings. Hormonal stimulation is efficient and varies according to harvest date.