Original: Ectosymbiosis , also referred to as exosymbiosis , is any symbiotic relationship in which the symbiont lives on the body surface of the host , including the inner surface of the digestive tract or the ducts of exocrine glands .
Simplified: In ectosymbiosis , the symbiont lives on the body surface of the host , including the inner surface of the digestive tract or the ducts of exocrine glands .