Vitality of mycobionts and photobionts after passing through the digestive tract of Constrictotermes cyphergaster (Isoptera) workers

Vitalidade de micobiontes e fotobiontes após passagem pelo trato digestivo de operários de Constrictotermes cyphergaster (Isoptera)

Abstract

Termites are among the insects that consume lichens and may be potential dispersers of these symbionts. This study evaluated the vitality of photobionts and mycobionts after passing through the digestive tract of Constrictotermes cyphergaster. The percentage of live and dead algae was verified throughout the alimentary canal of 450 workers, originating from five sampled colonies in the Caatinga Dry Forest, NE, Brazil. A progressive growth in algae mortality was observed in the crop, paunch and rectum, however more than 40% of the algae found in faeces presented signs of vitality. Photobiont morphology was different between cells extracted from thallus in natura and algae present in termite faeces. The photobiont cells presented more shrunken cytoplasms after passing through the alimentary canal of C. cyphergaster. There was also an increase between the cell wall space and the cytoplasm membrane of algae found in the termite faecal pellets. Only four broken spores were found in the intestine, which made the vitality analysis unfeasible for these cells. The record of photobiont vitality in termite faecal pellets is indicative of endozoochoric dispersal, suggesting that this relationship between insects and lichens extends beyond a trophic interaction.

Keywords:
caatinga; endozoochory; dispersive mutualism; neotropical region; termites