trophonema

Noun

 * 1) Any of several glandular villi of the uterus of viviparous sharks which supply nutrient to the embryos
 * The trophonema consists of 50–60 trophocytes that maintain contact with <1% of the oocyte surface and forms a circular, bowel-shaped depression on the luminal surface of the gastrodermis as they sink into the mesoglea with the oocyte.