Differential Time Course of Restoration of Experimentally Depleted Coelomocytes and Fluorophores in the Earthworm Eisenia Andrei.

Stressed earthworms expel coelomic fluid containing several vital cellular and soluble components, thus their post-stress recovery has adaptive value. The present manuscript describes the recovery rates of coelomocytes (amoebocytes and eleocytes) and two fluorophores (riboflavin and 4-methylumbelliferyl β-D-glucuronide, MUG) after experimental extrusion by electrostimulation. Analyses were conducted at time points (from 0.5 hour to 7 weeks) by a combination of cell counts, spectrofluorimetric measurements of riboflavin and MUG, and fluorescence microscopy. Coelomic fluid retrieved 30 minutes after extrusion contained <10% of the baseline levels of amoebocytes, eleocytes and riboflavin; the depleted levels of these variables were fully restored after 3, 5, and 7 weeks post-extrusion, respectively. Restored eleocytes were richer in riboflavin than the eleocytes of worms electrostimulated at t0. MUG was less severely depleted (to 49% of baseline) than riboflavin, and was restored to the initial level within 1 week post-extrusion. This indicates that MUG, unlike riboflavin, resides mainly within non-coelomocyte cellular location(s); moreover, this fluorophore may be a useful molecular marker for distinguishing even immunologically-compromised E. andrei from closely related composting species.