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In freshwater ecosystems, rotifers and cladocerans are ideal prey for fish larvae whereas copepods, due to their purported low growth rate and predatory tendency, are not. We recently isolated the parthenogenetic Elaphoidella grandidieri (Gueme et Richard, 1893) a benthic freshwater harpacticoid, from a fish farm in the State of Morelos, central Mexico and tested its potential as a live prey organism for larval vertebrates. Population growth and life table demography experiments were conducted, in 100 ml recipients with 50 ml of test medium on a diet of Scenedesmus acutus at a density of 1.0 X 10(6) cell ml(-1); the former on live algae alone while the latter on live algae as well as detritus. We also conducted experiments to document the prey preference for this copepod by the larval Ameca splendens (Pisces: Goodeidae) and Ambystoma mexicanum (Amphibia: Ambystomatidae), fed the rotifer Plationus patulus, the ostracod Heterocypris incongruens, and the cladocerans Moina macrocopa and Daphnia pulex. Elaphoidella grandidieri is relatively easy to maintain under laboratory conditions, reaching densities (copepodites and adults) of more than 10,000 l(-1). The generation time ranged between 30-45 days, depending on the diet. The net reproductive rate was as high as 60 nauplii female(-1) day (1). Population growth rates ranged between 0.03 and 0.11 d(-1), live algae being the superior diet compared to detritus. Both predators showed no preference for E. grandidieri, but in the absence of alternate prey they consumed 80% of the harpacticoids offered. The data have been discussed in relation to the potential of E. grandidierias live food for aquaculture.

Objective: to evaluate the role of Epstein-Barr virus (EBV) on the intestinal mucosa in the evolution of inflammatory bowel disease (IBD). The risk factors for EBV infection and the frequency of EBV-associated lymphoproliferative disorders in IBD patients were also investigated.Methods: intestinal biopsies of IBD patients with available EBV status determined by Epstein-Barr-encoding RNA (EBER) in situ hybridization were identified in the Pathology Database of our center. Clinical information, including phenotypic characteristics of IBD, previous treatments, diagnosis of lymphoma and patient outcome were reviewed in all cases.Results: fifty-six patients with IBD (28 Crohn's disease, 27 ulcerative colitis and one unclassified colitis) were included. EBV in intestinal mucosa was positive in 26 patients (46 %) and was associated to a lymphoproliferative syndrome in one case. EBV positivity was associated with severe histological activity (52 % vs 17.2 %; p 0.007), the presence of a lymphoplasmacytic infiltrate (50 % vs 33.3 %; p 0.03) and active steroid treatment (61.5 % vs 33.3 %; p 0.03). Multi-variate analyses only found an association between EBV and lymphoplasmacytosis (p 0.001). Escalation in previous treatment was significantly more frequent in the EBER+ group (53.8 % vs 26.7 %; p 0.038). No cases developed lymphoma during follow-up.Conclusions: EBV on the intestinal mucosa is associated with a poor outcome of IBD and the need for escalation of therapy. Lymphoplasmacytic infiltrate is associated with EBV infection. EBER+ patients used steroids more frequently compared with EBER- patients. No EBER+ patients developed lymphoma during follow-up.