Abstract: | FMRFamide-like immunoreactivity has been demonstrated in the digenean trematode Echinostoma liei. The functions of FMRFamide-like substances appear to be many and varied within the invertebrates, where they are involved in neurotransmission, cardiovascular regulation, muscular contraction and/or relaxation, and in co-ordination of growth and maturation. It is clearly indicated that FMRFamide-like substances function as neurotransmitter/neuromodulator in E. liei by the abundance of positively stained nerve fibres and perikarya seen throughout the CNS and PNS. A single endocrine-like cell also showing FMRFamide-like immunoreactivity is situated within the muscular cirrus pouch. |