| Main Ref. | Koli, L., 1990 |
| Mode | dioecism |
| Fertilization | external |
| Mating type | polyandry |
| Spawning frequency | once in a lifetime |
| Spawning aggregation | Yes. Ref. SCRFA, Science and Conservation of Fish Aggregations, 2018 |
| Batch spawner | Ref. Renaud, C.B., 2011 |
| Reproductive guild |
guarders nesters |
| Parental Care | |
| Description of life cycle and mating behavior | Adults migrate from the sea to the rivers to spawn (Ref. 51442), ascending rivers at night, anytime between autumn and spring but this movement ceases when water temperature drops (Ref. 59043). During the early stages of its spawning migration, the river lamprey has been shown to be attracted to chemical odours given off by ammocoetes (Ref. 88188). Males reach the spawning grounds first and build nests at depths between 50-100 cm, which have a diameter of 20-40 cm and a height of 10 cm (Ref. 12285, 51442, 59043, 88186). The river lamprey forms spawning aggregations, often during sunny days, when water temperature rises above 9 °C (Ref. 59043). Females may spawn with up to 6 males on separate occasions. One nest is usually utilized by a single mating pair (Ref. 59043). Adults spawn only once in their lifetime and usually die within 2 weeks after spawning (Ref. 12285, 51442). Eggs hatch in 15-30 days (Ref. 88184). The ammocoetes live in the calm zones of the river until metamorphosis at about 13 cm length before migrating to the sea (Ref. 51442). |
| Search for more references on reproduction | Scirus |