Tropical Ecology and Conservation [Monteverde Institute]



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Publication Date

March 2003


I investigated the effects of pollution and elevation on the population density of freshwater crabs as well as their age structure and sex ratio. This study gives insight into freshwater crabs as bioindicator of water quality as well as provides basic demographic information. Water quality was tested and crabs were collected at three different elevations, 1350 m, 1500 m, and 1650 m, at six different streams. Using a Kruskal-Wallis statistical analysis on the total crabs, the average male size, the average female size, the number of males, and the number of females were analyzed in relation to elevational change (table 2). There was a strong correlation between the total numbers of male and female crabs with a change in elevation (figure 3). The data on the total crab abundance suggests a pattern of crabs being most densely populated in higher elevations around 1650 m above sea level. Investigué los efectos de la contaminación y la elevación en la densidad de población de cangrejos de agua dulce así como su estructura de edad y proporción de sexo. Este estudio da la penetración en cangrejos de agua dulce como bioindicator de la calidad de agua así como proporciona información demográfica básica. El agua se probó y los cangrejos se reunieron en tres elevaciones diferentes, 1350 M, 1500 M, y 1650 M, en seis corrientes diferentes. Utilizar un análisis estadístico de Kruskal Walis en los cangrejos totales, el tamaño masculino mediano, el tamaño mediano de hembra, el número de males, y del número de hembras se analizaron con relación al cambio de elevational (pospone 2). Había una correlación fuerte entre los números totales de cangrejos masculinos y femeninos con un cambio en la elevación (la figura 3). Los datos en la abundancia total del cangrejo sugieren una pauta de cangrejos es la mayoría del densamente poblado en elevaciones más altas alrededor de 1650 M sobre el nivel del mar.


Student affiliation: Department of Continuing Studies, Indiana University Digitized by MVI



Holding Location

Monteverde Institute MVI



Freshwater crab density and demography in relation to water quality and elevation



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