Effect of sublethal concentrations of glyphosate-based herbicides (Roundup Active®) on skin of the tropical frog (Dendropsophus molitor).

In Colombia, glyphosate (GP) is used to control weeds, with Roundup Active® being the most widely used. This use has affected aquatic ecosystems, causing malformations in amphibians. The Savannah frog (D. molitor) is a tropical frog inhabiting the mountain of Colombia. In the present study, we determined the effect of sublethal concentrations of GP (Roundup Active®) on the skin of D. molitor. Twenty-four tadpoles were exposed to concentrations of GP (T1: 0, T2: 1.4, T3: 3.6, and T4: 5.6 a.e mg/L) during 31 days. In 10 individuals per treatment, two skin regions were evaluated: dorsal cranial and caudal ventral to determine histopathological alterations. Morphometric analysis of the layers of the skin was performed: epidermis, dermis, and hypodermis-muscular. T1 did not present histopathological alterations. Since T2 was identified, glandular cell hyperplasia and hypertrophy increased melanophores and melanin accumulations in the highest concentrations of GP. The ultrastructure revealed an increase in excretory glands in the dermis. In the other layers, an increase of melanophores and melanocyte clusters was observed accompanied by vacuolization of basal cells. The morphometry showed an increase in the thickness of the dermis in the dorso-cranial region in T2 compared to the other treatments, while the ventral caudal region exhibited a variation in the thickness of the dermis from T2 and a decrease in T4. Despite evaluating sublethal concentrations, the skin of D. molitor tadpoles presents histopathological, ultrastructural, and morphometric alterations that could affect the survival of the species in the natural environment.

Effect of glyphosate (Roundup Active®) on liver of tadpoles of the colombian endemic frog Dendropsophus molitor (amphibia: Anura).

Glyphosate-based herbicide (GBH) using is increasing on a global scale. Few studies have investigated the sub-lethal effects of GBH in endemic amphibian species. The present work tested the GBH Roundup Active® on the tadpoles of Dendropsophus molitor. The exposure was in a range of plausible environmental concentrations (0-0.75 µg a.e./L) during a month. D. molitor is an endemic tropical frog of South America. The exposure from 325 µg a.e./L caused histological alterations in the liver. The high-resolution optical microscopy (HROM) detected sinusoidal dilatation and cytoplasmic vacuolization. The transmission electron microscopy (TEM) showed disorganization of the endoplasmic reticulum. Since the liver is essential for detoxification, these results suggest choric effects. Exposure to another GBH has caused histological alterations in liver tadpoles liver in a previous study, but, this study tested another endemic South-American frog for only 96h. The present work applied HROM to observe lipid alterations since it does not use organic solvents; and TEM for the ultrastructural observation of hepatocytes. Environmental risk of GBH can improve by including sub-lethal effects in endemic species.

Anatomía general, histología y morfometría del sistema digestivo del pez Pterophyllum scalare (Perciformes: Cichlidae) / Gross anatomy, histology and morphometry of the digestive tract in the fish Pterophyllum scalare (Perciformes: Cichlidae)

Introducción: El pez escalar (Pterophyllum scalare) es una de las principales especies de peces ornamentales comercializados de Sur América. Objetivo: Describir histológica y morfométricamente el tracto digestivo del pez tropical P. scalare. Métodos: Se utilizaron 19 individuos adultos, y se calculó el coeficiente intestinal. Se realizó una descripción macroscópica e histológica del esófago, estómago e intestino (región anterior parte a, anterior parte b, media y posterior). Las muestras fueron procesadas en parafina, se obtuvieron cortes de 5 µm, que fueron teñidos con H&E y P.A.S. Se realizó conteo de células P.A.S +. Para la morfometría se digitalizaron los cortes y se midió el área y perímetro del lumen, y el área tisular para cada región. Resultados: P. scalare presenta un esófago corto, un estómago en forma de saco ciego poco muscular junto a un intestino con una longitud similar a su tamaño, coeficiente intestinal (1.66 +/- 0.52). Se identificaron cuatro capas constitutivas: mucosa, submucosa, muscular y en algunas regiones serosa. El esófago se destacó por ser la región con mayor número de células caliciformes P.A.S. + y mayor área tisular. En cuanto al área y perímetro luminar, la región anterior parte a del intestino fue la de mayor valor. Conclusiones: A partir del coeficiente intestinal (1.66 +/- 0.52), y las características histológicas y morfométricas de los órganos evaluados, se puede decir que P. scalare presenta un hábito alimenticio omnívoro con preferencia de presas blandas.

Introduction: Ornamental Angel fish (Pterophyllum scalare) is one of the main commercialized species from South America, with an important number of national and international dealers. Objective: To make a histological and morphometric description of P. scalare digestive tract. Methods: Nineteen adult individuals were used. Intestinal coefficient values were obtained, and a macroscopic and microscopic description of esophagus, stomach, and intestine (anterior, middle and posterior) was carried out. Samples were processed for paraffin embedding, and 5 µm sections were stained with H&E and P.A.S. Positive P.A.S. cells were counted. Lumen area and tissue area were measured in representative digitalized sections from each region. Results: P. scalare exhibited a short esophagus, followed by a blind bag shaped, scarcely muscular stomach, and a short intestine (intestinal coefficient 1.66 +/- 0.52). Four constitutive tissue layers were identified: mucosa, submucosa, muscular and in some areas also a serosa layer. Esophagus exhibit abundant globet P.A.S. + cells and shows the larger tisular area was observed. Luminal area and perimeter are larger in anterior intestinal region. Conclusions: The intestinal coefficient value (1.66 +/- 0.52), and the histological and morphometric characteristics of the evaluated organs, suggest that P. scalare is omnivorous with soft prey preferences.

Cambios en los niveles de nutrientes en solución hidropónica de espinaca baby (Spinacia oleracea L.), para su futura aplicación en acuapónia / Changes in nutrient levels in hydroponic solution of baby spinach (Spinacia oleracea L.), for future application in aquaponics / Mudanças nos níveis de nutrientes em solução hidropônica de spinaca baby (Spinacia oleracea L.), para sua futura aplicação na acuapónia

Resumen La espinaca es una planta de alto valor nutricional, mostrando gran acogida en su presentación "baby". La producción en hidroponía está limitada por la solución nutritiva, siendo la acuaponía un potencial complemento a este factor limitante. El objetivo de esta investigación fue definir los cambios de niveles de nutrientes en la solución hidropónica en espinaca baby. Se trabajó con 24 plántulas de espinaca en hidroponía de cama flotante usando solución "La Molina" en tanques de 50 L; se realizaron 5 repeticiones y 3 réplicas. Para cada réplica se cosechó cada tres semanas, registrando semanalmente variables fisicoquímicas de la solución. Además, se llevó a cabo un muestreo al inicio y final de cada réplica, evaluando las siguientes variables: número y longitud de hojas, área foliar, peso fresco y seco de la parte aérea. Se obtuvo en orden descendiente la siguiente extracción de macronutriente: N>K+>Ca2+>P y micronutrientes: Mn2+>Fe2+. Durante el ciclo de cultivo el pH de la solución osciló entre 6.00-6.97, el oxígeno disuelto entre 4.93-7.54 mg/L y la conductividad disminuyó constantemente a lo largo del ciclo, inició en 1558-1592 µS/cm y finalizó entre 1140-1275 µS/cm. Se obtuvo un TCC= 0.00002-0.00003 g/cm2/día; TRC=0.16, 0.15 y 0.14 g/g/día y TAN=0.006, 0.005 y 0.006 g/cm2/día para las réplicas 1, 2 y 3, respectivamente. Este estudio revela que esta planta podría tener buenos rendimientos en un sistema acuapónico, especialmente por los requerimientos de N, Ca2+>P, no obstante, se deberían adicionar bajas cantidades de algunos micronutrientes, que suelen ser escasos en los sistemas acuapónicos.

Abstract Baby spinach has a high nutritional value, and good entry in specialized markets. Its hydroponic production is limited by nutrient solution, and the aquaponic systems can avoid this limitation. The goal in this work was to evaluate nutrient level changes in hydroponic solution during baby spinach crop. 24 spinach plants were planted in 50 L tanks in floating hydroponic beds, using a modified "La Molina" nutrient solution. They were carried out 5 replications and 3 harvest. Water physicochemical values were registered every week, and plants were harvested after three weeks. Plant samples were also taken before planting (initial time) and after three weeks. Number of leaves, leaf length, leaf area, fresh and dry weight of the aerial part of each plant were recorded. The macronutrient extraction was obtained in descending order: N> P>K+> Ca2+ and micronutrients: Mn2+>Fe2+. pH values were maintained between 6.00-6.97, and DO levels were 4.93-7.54 mg/L. Initial conductivity was about 1558-1592 µS/cm and finally diminished to 1140-1275 µS/cm. CGR= 0.00002-0.00003 g/cm2/day; RGR=0.16, 0.15 y 0.14 g/g/day and NAR=0.006, 0.005 y 0.006 g/cm2/day for replica 1, 2 and 3 respectively. This study reveals that this plant could have good field performance in aquaponic system, especially due to the requirements of N, Ca2+>P, however low amounts of some micronutrients should be added, which are usually scarce in aquaponic systems

Resumo O espinafre é uma planta de alto valor nutricional, apresentando grande aceitação em sua apresentação "baby". A produção de hidroponia é limitada pela solução nutritiva, com a aquaponia sendo um complemento potencial para esse fator limitante. O objetivo desta pesquisa foi definir as alterações dos níveis de nutrientes na solução hidropônica em espinafre bebê. Trabalhamos com 24 mudas de espinafre em hidroponia de leito flutuante usando solução "La Molina" em tanques de 50 L; 5 repetições e 3 repetições foram realizadas. Para cada replicação, foi colhida a cada três semanas, registrando-se variáveis ​​físico-químicas semanais da solução. Além disso, foi realizada uma amostragem no início e no final de cada réplica, avaliando-se as seguintes variáveis: número e comprimento de folhas, área foliar, massa fresca e seca da parte aérea. A seguinte extração de macronutrientes foi obtida em ordem decrescente: N> K +> Ca2 +> P e micronutrientes: Mn2 +> Fe2 +. Durante o ciclo de cultivo, o pH da solução variou entre 6,00-6,97, o oxigênio dissolvido entre 4,93-7,54 mg/L e a condutividade diminuiu constantemente ao longo do ciclo, começando em 1558-1592 µS/cm e terminando entre 1140-1275 µS/cm. Obteve-se um TCC = 0,00002-0,00003 g / cm2 / dia; CRT = 0,16, 0,15 e 0,14 g / g / dia e TAN = 0,006, 0,005 e 0,006 g / cm2 / dia para os replicados 1, 2 e 3, respectivamente. Este estudo revela que esta planta pode ter bons rendimentos em um sistema aquapônico, especialmente por causa das exigências de N, Ca2+>P, porém pequenas quantidades de alguns micronutrientes devem ser adicionadas, que geralmente são escassas em sistemas aquapônicos.

Glyphosate commercial formulation effects on preoptic area and hypothalamus of Cardinal Neon Paracheirodon axelrodi (Characiformes: Characidae)

In Colombia the use of glyphosate commercial formulations (Roundup™) for spraying have left deleterious effects on animals and humans. Much of this spraying takes place at the Orinoco basin, habitat of one of the most exported ornamental fish in Colombia, Cardinal neon. To evaluate the effect of Roundup Activo™ four experimental treatments were carried out with 0 mg/L (T1), 0.1 mg/L (T2), 1 mg/L (T3) and 5 mg/L (T4) during 30 days of exposure. The fishes were processed for high-resolution optical microscopy. The main finding of Roundup Activo™ exposure was an increase in mast cells number in brain blood vessels and some neuronal nuclei of the preoptic and posterior diencephalic areas, including hypothalamus. A correlation between concentrations and mast cells number was observed, with the largest mast cells number in T4 treatment. Mast cells presence is a stress benchmark, suggesting the beginning of allergic, inflammatory and apoptotic events. Presence of mast cells in these brain areas may lead to alterations on reproduction, visual and olfactory information integration among other processes. These alterations may result in diminished survival, affecting the conservation of this species in its natural habitat.(AU)

En Colombia, el uso de formulaciones comerciales de glifosato (Roundup™) para la fumigación ha producido efectos nocivos en animales y humanos. Gran parte de esta fumigación se realiza en la cuenca del Orinoco, hábitat de uno de los peces ornamentales más exportados de Colombia, el Neón Cardenal. Para evaluar el efecto de Roundup Activo™ se realizó un experimento con cuatro tratamientos 0 mg/L (T1), 0,1 mg/L (T2), 1 mg/L (T3) y 5 mg/L (T4) durante 30 días. Los peces fueron procesados para microscopía óptica de alta resolución. El principal hallazgo fue el aumento del número de mastocitos en los vasos sanguíneos cerebrales y algunos núcleos neuronales del área preóptica y diencefálica posterior, incluido el hipotálamo. Identificamos una correlación entre las concentraciones y el número de mastocitos, que alcanzó su máximo en T4. La presencia de mastocitos evidencia estrés, promoviendo eventos alérgicos, inflamatorios y apoptóticos. La presencia de mastocitos en estas áreas del cerebro puede llevar a alteraciones en la reproducción e integración de la información visual y olfativa entre otros procesos. Estas alteraciones pueden resultar en una disminución de la supervivencia, afectando la conservación de esta especie en su hábitat natural.(AU)

Glyphosate commercial formulation effects on preoptic area and hypothalamus of Cardinal Neon Paracheirodon axelrodi (Characiformes: Characidae)

In Colombia the use of glyphosate commercial formulations (Roundup™) for spraying have left deleterious effects on animals and humans. Much of this spraying takes place at the Orinoco basin, habitat of one of the most exported ornamental fish in Colombia, Cardinal neon. To evaluate the effect of Roundup Activo™ four experimental treatments were carried out with 0 mg/L (T1), 0.1 mg/L (T2), 1 mg/L (T3) and 5 mg/L (T4) during 30 days of exposure. The fishes were processed for high-resolution optical microscopy. The main finding of Roundup Activo™ exposure was an increase in mast cells number in brain blood vessels and some neuronal nuclei of the preoptic and posterior diencephalic areas, including hypothalamus. A correlation between concentrations and mast cells number was observed, with the largest mast cells number in T4 treatment. Mast cells presence is a stress benchmark, suggesting the beginning of allergic, inflammatory and apoptotic events. Presence of mast cells in these brain areas may lead to alterations on reproduction, visual and olfactory information integration among other processes. These alterations may result in diminished survival, affecting the conservation of this species in its natural habitat.(AU)

En Colombia, el uso de formulaciones comerciales de glifosato (Roundup™) para la fumigación ha producido efectos nocivos en animales y humanos. Gran parte de esta fumigación se realiza en la cuenca del Orinoco, hábitat de uno de los peces ornamentales más exportados de Colombia, el Neón Cardenal. Para evaluar el efecto de Roundup Activo™ se realizó un experimento con cuatro tratamientos 0 mg/L (T1), 0,1 mg/L (T2), 1 mg/L (T3) y 5 mg/L (T4) durante 30 días. Los peces fueron procesados para microscopía óptica de alta resolución. El principal hallazgo fue el aumento del número de mastocitos en los vasos sanguíneos cerebrales y algunos núcleos neuronales del área preóptica y diencefálica posterior, incluido el hipotálamo. Identificamos una correlación entre las concentraciones y el número de mastocitos, que alcanzó su máximo en T4. La presencia de mastocitos evidencia estrés, promoviendo eventos alérgicos, inflamatorios y apoptóticos. La presencia de mastocitos en estas áreas del cerebro puede llevar a alteraciones en la reproducción e integración de la información visual y olfativa entre otros procesos. Estas alteraciones pueden resultar en una disminución de la supervivencia, afectando la conservación de esta especie en su hábitat natural.(AU)

Histología y morfometría de piel del pez Eremophilus mutisii (Trychomecteridae, Siluriformes)

Skin histology and morphometry of the fish Eremophilus mutisii (Trychomecteridae, Siluriformes). The tropical freshwater fish Eremophylus mutisii is endemic to the Cundinamarca highland in Colombia. Skin samples (0.5x0.5 cm²) were taken from 11 specimens at six body parts (mandible, dorsal head, dorsal trunk, caudal trunk, medial trunk and abdominal area), fixed in 4% formaldehyde, dehydrated in 95% ethanol and 99% isopropanol, embedded in paraffin and sectioned at 5 µm. The skin is made of two mayor cutaneous layers (epidermis and dermis) and a subcutaneous layer (hypodermis). The epidermis presents three layers with secretory cells, epithelial cells and a few taste buds; the dermis is separated from the epidermis by a basal membrane. We observed fibroblasts, two layers of melanophors and some blood vessels; the hypodermis has vascularized adipose tissue. Skin thickness changes with body area; the dermis is thicker than the epidermis; skin has more club cells than mucous cells. The medial trunk area has the largest number of club and mucous cells. The skin of E. mutissi seems to mainly have a protective function. Rev. Biol. Trop. 56 (2): 885-893. Epub 2008 June 30.

Se estudió la piel del pez dulceacuícola endémico de Colombia Eremophylus mutissi. Se tomaron muestras de piel (0.5x0.5 cm²) de 11 especimenes en seis partes del cuerpo (mandíbulas, cabeza dorsal, tronco dorsal, tronco caudal, tronco medial y abdominal). Se fijaron en formaldehído al 4%, con deshidratación en etanol al 95 % e isopropanol al 99%, inclusión en parafina y cortes a 5 µm. La piel está constituida por dos capas cutáneas (epidermis y dermis) y una capa subcutánea (hipodermis): la epidermis tiene tres capas con células secretoras, células epiteliales y pocas células gustativas; la dermis está separada de la epidermis por una membrana basal. Observamos fibroblastos, dos capas de melanóforos y algunos vasos sanguíneos; la hipodermis tiene un tejido adiposo vascularizado. La dermis es más delgada que la epidermis; la piel tiene más células tipo clava que células mucosas. El tronco medio tiene muchas células clava y células mucosas. La piel de E. mutissi parece tener una función principalmente protectora.