Macrofauna del suelo y condiciones edafoclimáticas en un gradiente altitudinal de zonas cafeteras, Huila, Colombia / Soil macrofauna and edaphoclimatic conditions in an altitude gradient of coffee growing regions, Huila, Colombia

Introducción: La macrofauna del suelo cumple un rol clave en los procesos del suelo, por lo tanto, regula la oferta se servicios ecosistémicos; sin embargo, su nivel de actividad depende en gran parte de las condiciones edafoclimáticas. Objetivo: El presente trabajo evaluó el efecto del gradiente de altitud sobre comunidades de macrofauna del suelo y propiedades edafoclimáticas en zonas cafeteras del Norte del Huila. Métodos: El estudio incluyó 12 lotes de café separados en dos gradientes de altitud: bajo (1 300-1 600 m.s.n.m) y alto (1 600-1 900 m.s.n.m), se recolectó la macrofauna del suelo mediante monolitos (25 x 25 cm a 30 cm de profundidad) y se estudiaron las condiciones edafoclimáticas. Resultados: En total se registró 9 520 individuos m-2 y una riqueza específica de 14 táxones. Las condiciones edafoclimáticas con mayor diferencia estadística entre los gradientes de altitud, fue la temperatura ambiente y humedad relativa con diferencias de 4.9 °C y 10.4 %, respectivamente. Conclusiones: La mayor abundancia de Coleoptera, Hemiptera, Isoptera y Lepidoptera se presentó en sitios más cálidos, es decir a un gradiente de altitud entre 1 300-1 600 m.s.n.m, mientras que Chilopoda y Diplopoda se adaptaron mejor a sitios más fríos en el gradiente altitudinal entre 1 600-1 900 m.s.n.m.

Introduction: Soil macrofauna plays a key role in soil processes and therefore regulates the supply of ecosystem services; however, its level of activity depends largely of the edaphoclimatic conditions. Objective: This work evaluated the effect of altitude gradient on soil macrofauna communities and edafoclimatic properties in coffee zones of North Huila. Methods: The study included 12 coffee lots separated in two altitude gradients: low (1 300-1 600 masl) and high (1 600-1 900 masl). Soil macrofauna was collected by means of monoliths (25 x 25 cm with 30 cm depth) and edaphoclimatic conditions were studied. Results: A total of 9 520 individuals m-2 and a specific richness of 14 taxa were registered. The edaphoclimatic conditions with the greatest statistical difference between altitude gradients were the environmental temperature and relative humidity with differences of 4.9 °C and 10.4 %, respectively. Conclusions: The highest abundance of Coleoptera, Hemiptera, Isoptera, Lepidoptera was presented in warmer sites, that is, altitude gradient 1 300-1 600 masl, while Chilopoda and Diplopoda adapted better to colder sites in altitude gradient 1 600-1 900 m.a.s.l.

First record of Dero (Aulophorus) bimagnasetus Harman (Oligochaeta) from Brazil and habitat characteristics / Primeiro registro de Dero (Aulophorus) bimagnasetus Harman (Oligochaeta) do Brasil e notas ecológicas

Annelid worms represent a significant part of freshwater benthic communities worldwide and Oligochaeta is a particularly species-rich group. Dero (A) bimagnasetus (Naididae) previously found and described from a small marsh in Surinam in 1974, has now been found for the first time in Barra Lake, MG, Brazil. Due to the scarce biological data and absence of ecological information in the literature regarding this species we are presenting morphological information on the specimens obtained and the physical and chemical characteristics of the habitat they were found. This species occurred only in the littoral zone of Barra Lake, in muddy, low oxygen, low conductivity and low organic matter sediment. The four individuals collected ranged 3.17-4.15 mm total length; 0.25 - 0.26 mm body width and 0.16-0.21 mm3 total volume. Considering the present anthropic pressures on freshwater biota and fast biodiversity losses worldwide it is now recognized that attention must be paid to low abundance species and the urgency for preservation of their habitats.

Vermes anelídeos representam uma parte significativa das comunidades de água doce em todo o mundo e Oligochaeta é um grupo particularmente rico em espécies. Dero (A) bimagnasetus (Naididae) havia sido encontrado e descrito em um pequeno pântano no Suriname em 1974, e agora também coletado na lagoa Barra, MG, Brasil. Devido ao baixo número de espécimes coletados e à ausência de informações ecológicas sobre esta espécie, estamos apresentando informações sobre a morfometria dos espécimes obtidos e as características físicas e químicas de seu habitat. Esta espécie ocorreu apenas na região litorânea da lagoa da Barra, em sedimento lamacento e com pouca matéria orgânica, baixa concentração de oxigênio e baixa condutividade elétrica na água. Os quatro indivíduos encontrados tiveram 3,17-4,15 mm de comprimento total; 0,25-0,26 mm de largura e 0,16-0,21 mm3 de biovolume. Considerando as atuais pressões antrópicas sobre a biota de água doce e as rápidas perdas de biodiversidade em todo o mundo, é agora reconhecido que muita atenção deve ser dada às espécies pouco abundantes e que é urgentemente necessário preservar seus habitats.

Life history, distribution and abundance of the giant earthworm Rhinodrilus alatus RIGHI 1971: conservation and management implications / História de vida, distribuição e abundância do minhocuçu Rhinodrilus alatus RIGHI 1971: implicações para sua conservação e manejo

Rhinodrilus alatus is an endemic giant earthworm of the Brazilian Cerrado hotspot used as live bait for about 80 years. The goal of this study was to gather ecological data about this species, which will support the establishment of management strategies. The life history, distribution and abundance of R. alatus were investigated in Cerrado, pastures and Eucalyptus plantation areas following the harvesting activities of the local extractors of this species. We found that this earthworm is abundant in all of the sampled areas, showing its resilience to land-use conversion. The Capture Per Unit Effort was 4.4 ± 5 individuals per 100 metres of transect and 5.6 ± 3 individuals per hour. The earthworm's annual cycle is markedly seasonal, with an aestivation period throughout the driest and coldest season of the year. Significant differences in the length and diameter of the body and in the diameter and depth of the aestivation chambers were found between the juveniles and adults. The distribution range of the species was expanded from two to 17 counties. The life history, abundance, distribution and resilience of R. alatus to certain perturbations are key elements to be considered in conservation and management strategies for this species.

Rhinodrilus alatus é um minhocuçu endêmico do hotspot Cerrado, utilizado como isca viva por cerca de 80 anos. O objetivo deste estudo foi obter informações ecológicas sobre essa espécie, as quais servirão para o estabelecimento de estratégias para seu manejo. A história de vida, a distribuição e a abundância de R. alatus foram investigados em áreas de Cerrado, pastagens e plantações de Eucalyptus, acompanhando sua extração pela comunidade local. Rhinodrilus alatus foi abundante em todas as áreas amostradas, mostrando-se resiliente à conversão do Cerrado em outros usos. A Captura por Unidade de Esforço foi de 4.4 ± 5 indivíduos por 100 metros de transecto e 5.6 ± 3 indivíduos por hora. O ciclo anual do minhocuçu é marcadamente sazonal, apresentando estivação no período mais frio e seco do ano. Jovens e adultos diferiram significativamente no comprimento e diâmetro do corpo e no diâmetro e profundidade da câmara de estivação. A distribuição da espécie foi expandida de dois para 17 municípios. A história de vida, a abundância, a distribuição e resiliência de R. alatus por certos distúrbios são elementos chave a serem considerados nas estratégias de conservação e manejo dessa espécie.

Características bio-ecológicas en poblaciones de lombrices (Oligochaeta: Glossoscolecidae) de una sabana natural y una protegida en los llanos centrales de Venezuela / Bioecological characteristics of earthworm populations (Oligochaeta: Glossoscolecidae) in a natural and a protected savanna in the central Llanos of Venezuela

In tropical savannas, the earthworm communities have a predominant role since they regulate the soil structure and dynamics of the organic matter. To study the effect on earthworm populations in two differently managed savannas, we compared the general aspects of the biology and ecology of earthworm populations from a 40 years protected savanna (SP) with no fire or cattle raising at the Estación Biológica de los Llanos, Venezuela (EBLL), and a natural savanna (SNI), under normal burning and cattle raising management conditions. Sampling was carried out at the end of the dry season (April), and at the peak of the wet season (July-August). The main physical properties of soils per system were estimated. In each system, in plots of 90x90m, five fixed sampling units were selected at random; and at each sampling point one soil monolith of 25x25x30cm was collected per unit. Earthworms were extracted using the hand sorting extraction method; and the flotation method was used to estimate the density of cocoons. The earthworms were classified in different ecological categories considering their pigmentation, size and depth profile distribution. As a result of the savanna protection, physical parameters were modified in relation to SNI. The SP soils had higher soil moisture when compared to SNI. Soil moisture varied with depth during the dry season since, after the start of the rainy season, the soil was saturated. Field capacity in the SP was greater than that in the SNI. The surface apparent bulk density of soil was lower in the SP respect SNI, reflecting a lower soil compaction. Total average for the density and biomass of earthworms differed greatly, showing higher values in the SP. The earthworm density average in SP ranged between 25.6-85 individuals/m2 and the average biomass between 6.92-23.23g/m2. While in SNI, earthworms were only found in August, with a mean density of 22.40individuals/m2 and a mean biomass of 5.17g/m2. The vertical distribution pattern was only analyzed for the SP, and as in the SNI, no earthworms were found during the dry season; in the SP, a migration of earthworms to deeper layers during the dry season was observed; while in the rainy season they moved to upper soil layers to feed. The systems were characterized by abundance in juvenile Glossoscolecidae family earthworms which might be included in the endo-anecic ecological category. Results suggest that savanna agricultural management can modify an important fraction of pedofauna, particularly their earthworm communities, by modification of soil properties.

Las lombrices de tierra tienen un papel importante en el ciclado de nutrientes y el mantenimiento de la fertilidad de los suelos. En este estudio se empleo el método de extracción manual para determinar la densidad y la biomasa de las lombrices de tierra en diferentes profundidades y en diferentes estaciones, seleccionando al azar cinco monolitos de 25cm2x30cm, ubicados en un área de 90x90m en una Sabana Protegida (SP) y una Sabana Natural Intervenida (SNI). Adicionalmente, se estimó la densidad de los capullos, se analizaron las clases de etapas de desarrollo y se clasificaron los individuos en categorías ecológicas. Se estimó la humedad del suelo, la capacidad de campo, la temperatura, la densidad aparente y la textura del suelo. La SP presentó mejores condiciones físicas en el suelo que la SNI, mientras que la actividad de las lombrices de tierra estuvo limitada a los meses de lluvia y se observó un patrón de migración estacional en el perfil del suelo. En la SNI sólo se observó presencia de individuos en agosto y no se encontró diferencia significativa en sus biomasas con la SP. Los sistemas estuvieron dominados por individuos jóvenes con una categoría ecológica de tipo endo-anécica pertenecientes a la familia.

Tres nuevas especies de Righiodrilus Zicsi 1995 (Annelida, Oligochaeta: Glossoscolecidae) de la Amazonía colombiana / Três novas espécies de Righiodrilus Zicsi 1995 (Annelida, Oligochaeta: Glossoscolecidae) da Amazônia colombiana / Three new species of RighiodrilusZicsi, 1995

Se describieron tres nuevas especies de Righiodrilus Zicsi, 1995 para la Amazonía: R. andake sp. n., R. inga sp. n. y R. muinanei. Con las nuevas adiciones el género suma 26 especies. Se presenta una clave para las especies y algunos comentarios relacionados con las características y presencia en usos del terreno de Righiodrilus.

Three new species of RighiodrilusZicsi, 1995 from Amazonia were described: R. andake sp. n., R. inga sp. n. y R. muinanei sp. n. With these new additions the genus now contains 26 species. A key for species is provided and some remarks related to characteristics and presence of Righiodrilusland uses are furnished.

Sublethal doses of malathion alter male reproductive parameters of Eisenia foetida / Malathion en dosis subletales altera los parámetros reproductivos masculinos de Eisenia foetida

Malathion es un insecticida organofosforado cuyo efecto agudo principal es la inhibición de la enzima acetilcolinesterasa. Este pesticida es usado ampliamente y se ha informado como dañino para la espermatogénesis de ratones. El objetivo de este trabajo fue evaluar el riesgo tóxico de malathion. Gusano de tierra Eisenia foetida (Annelida, Oligochaeta) se usó como modelo biológico y se analizaron testículos y espermatozoides de animales controles y tratados. Se usaron gusanos de tierra con clitelo desarrollado, los cuales fueron aspersados con dosis sub letales de 0, 80, 150, 300 y 600 mg de malathion por kilogramo de tierra (LD50 = 880 mg/kg de tierra seca). A los grupos controles se les agregó solo agua destilada. Cada grupo se analizó a los 1, 5, 15 y 30 días post tratamiento. Los resultados observados en los animales tratados indican un alza significativa en el número de espermatozoides a los 1 y 5 días después del tratamiento, seguido por una disminución espermática entre los 15 y 30 días. El uso de naranja de acridina mostró un aumento significativo de espermatozoides metacromáticos anormales en animales tratados (fluorescencia roja). La histología testicular en animales tratados mostró desorganización del tejido y vacuolización, con la presencia de núcleos pequeños e hipercromáticos, indicativo de posible apoptosis. Además, malathion causó contracción corporal caracterizada por la cola enrollada. Se concluye que malathion provoca una alteración significativa en el recuento y en la calidad espermática, en la histología testicular y en la morfología corporal de Eisenia foetida. Este modelo biológico resulta ser excelente para supervisar el daño citotóxico de pesticidas organofosaforados.

Cocoon production, morphology, hatching pattern and fecundity in seven tropical earthworm species - a laboratory-based investigation.

Data on the reproductive biology of seven Indian species of earthworms, viz. Perionyx excavatus Perrier, Lampito mauritii Kinberg, Polypheretima elongata (Perrier), Pontoscolex corethrurus (Muller), Eutyphoeus gammiei (Beddard), Dichogaster modiglianii (Rosa) and Drawida nepalensis Michaelsen are presented. The peregrine earthworms such as Perionyx excavatus, Pontoscolex corethrurus, Dichogaster modiglianii, and Polypheretima elongata are considered to be continuous breeders with high fecundity. Native Lampito mauritii and Drawida nepalensis are semi-continuous and Eutyphoeus gammiei discrete breeders. There is a dramatic increase in cocoon production by most earthworm species of Tripura in the summer and monsoon with a corresponding peak during April and July. Cocoon production decreased or ceased during winter. Temperature affected the incubation period of cocoons. With increase in temperature, incubation period increased in the endogeic worms, Pontoscolex corethrurus, Polypheretima elongata and Drawida nepalensis and decreased in the epigeic worms, Perionyx excavatus and Dichogaster modiglianii, within a temperature range between 28-32 degrees C under laboratory conditions. There was a significant (P < 0.05) positive correlation between number of hatchlings per cocoon and incubation period in Lampito mauritii. High rate of cocoon production, short development time with high hatching success, as well as continuous breeding strategies in the epigeic species Perionyx excavatus and Dichogaster modiglianii and the top soil endogeic species, Pontoscolex corethrurus, Drawida nepalensis and Lampito mauritii, indicate their possible usefulness in vermiculture. The giant anecic worm, Eutyphoeus gammiei, which has a very long cocoon development time, discrete breeding strategy and very low rate of cocoon production, is not a suitable species for vermiculture.