2 research outputs found
Horizontal transfer of boron by the Formosan subterranean termite (Coptotermes formosanau Shiraki) after feeding on treated wood
The goal of the present study was to determine whether Coptotermes formosanus Shiraki workers exposed to boron-treated wood were capable of transferring quantifiable amounts of boron to non-exposed nestmates. This effect is called horizontal transfer. Borates are not repellent to termites, nor do they cause rapid mortality, making them excellent candidates for the study of horizontal transfer. In the present study, C. formosanus workers were collected from field colonies maintained in Honolulu, Hawaii and dyed with Sudan Red 7B over a 7-day period. These termites then underwent a 3-day exposure period to one of two types of composite board, either an experimental formulation of zinc borate and anhydrous boric acid or an untreated composite board. Treated termites were placed with an equal number of untreated termites for either 5 or 10 days; sham-dyed donors and recipients were used to control for possible effects of the dye. Horizontal transmission of boron and toxic effects were assessed based on termite wet weight, percent survival, and boron content. Horizontal transfer of boron was noted at both 5 and 10 days over those levels reported in untreated, field-caught termites from the same colony (ca. 7 μg boron g termites). After 5 days, boron content was elevated in both dyed donor and recipient termites (ca. 92 and 38 μg boron g dyed termites, respectively), as well as in undyed donors and recipients (ca. 84 and 30 μg boron g undyed termites). The same pattern was observed after 10 days in both dyed donor and recipient termites (ca. 61 and 46 μg boron g , respectively) and undyed donor and recipient termites (59 and 24 μg boron g , respectively). Increased boron content of recipient termites after exposure to donor termites (fed on treated wood) demonstrated horizontal transfer of boron
Profile of cortisol, glycaemia, and blood parameters of American Bullfrog tadpoles Lithobates catesbeianus exposed to density and hypoxia stressors
The aim of this study was to evaluate alterations to the physiological profile (cortisol, glycaemia, and blood parameters) of Lithobates catesbeianus caused by the stressors density and hypoxia. The organisms were in the prometamorphosis stage and exposed to different tadpole densities: 1 tadpole/L (T1), 5 tadpoles/L (T2), and 10 tadpoles/L (T3) for 12 days. The blood was collected through the rupture of the caudal blood vessel and collected under normoxia (immediate collection) and hypoxia (after 15 minutes of air exposure) conditions. Cortisol levels rose on the fourth and eighth days of treatment and returned to basal levels by the end of the experiment. The stressor mechanisms tested did not affect glycaemia. White blood cells (total number of lymphocytes, neutrophils, and eosinophils) showed a significant difference at the twelfth day of the experiment when compared with the start of the experiment. We concluded that, under controlled conditions, a density of up to 10 tadpoles/L and air exposure for 15 minutes did not cause harmful physiological alterations during the experimental period. The answer to these stressors maybe was in another hormonal level (corticosterone)