The external opening of a nephridium.
- ‘In both there is a single pair of metanephridia and they are anterior with an anterior nephridiopore.’
- ‘These excretory organs open through nephridiopores on the ventral surface of the body wall.’
- ‘Expulsion of resorufin was readily observed from the nephridiopore during observation of the labelled parasites.’
- ‘Then the waste exits out of the nephridiopore as dilute urine, balancing osmotic intake of fresh water surrounding the annelid.’
- ‘Eggs and sperm reach the outside of their body through the nephridiopores.’