We determined the health status of similar channel catfish (Ictalurus punctatus) ponds in Lincoln and Desha counties of Arkansas, using the nematode soil food web condition as our reference point. Soil nematodes were categorized into colonizer-persister (cp) groups, based on their life course characteristics e.g sensitivity to environmental changes, body size, etc. These cp groups represent different components of the soil food web, which in turn were indicators of soil conditions. Benthic soil samples were collected at four week intervals over a 4-month period, from 6-ponds in each county. The nematodes were extracted according to standard methods and the recovered nematode taxa grouped according to their cp values. The product of each nematode taxon was determined (mean number of individuals x cp value) and the sum of all members of a cp group constituted the biomass produced by that cp group. Nematodes of the cp-3 and cp-4 groups dominated in biomass productivity in ponds for both counties. These groups of nematodes represent structured components of a food web and therefore a healthy ecosystem. Lincoln county ponds had higher cp-3 and cp-4 biomass likely due to slightly less acidic conditions while Desha county ponds had a greater biomass of plant-parasitic nematodes. It was also found that free-living nematodes tolerate more acidic conditions than plant-parasitic nematodes, though this could also be related to more root tissues. Nematode biomass calculations could be useful in determining benthic soil food web conditions, which may provide a simple way of assessing environmental conditions and changes in Arkansas catfish ponds.
Matute, M. M.; Perschbacher, P. W.; and Newell, A.
"Determination of Benthic Soil Conditions Using Nematodes: Nematode FoodWeb Conditions of Fish Ponds in the Lincoln and Desha Counties of Arkansas,"
Journal of the Arkansas Academy of Science: Vol. 63
, Article 16.
Available at: http://scholarworks.uark.edu/jaas/vol63/iss1/16