The Brook Lamprey
The Brook Lamprey is quite common in Latvia, however, you may spot it only in the beginning of summer when they gather at spawning areas. Brook Lamprey presence indicates water quality as they do not live in polluted water. There are still enough clean water bodies in Latvia, while in West Europe this species is rare and specially protected.
The Brook Lamprey is the smallest of all three lamprey species found in Latvia (it rarely reaches 20 cm) and is different from River Lamprey and Sea Lamprey. Brook Lamprey is non-parasitic so they do not feed on other fish. It never travels and spends all his 6-7 year long life in one brook. Moreover, Brook Lamprey spends most of his life as ammocoete buried in mud. Here they feed on detritus – remains of plants and animals. The River Lamprey almost never leaves the sandy or sludgy riverbed. Ammocoete doesn’t have eyes so it may be mistaken for a worm. Only in the end of their life they turn into adults, alimentary canal reduces so they stop feeding and put all their strength into the last great event – spawn. It is interesting that ammocoete is always bigger than adult Brook Lamprey. Sometimes they spawn immature and it’s called neothenia. They start spawning at the beginning of summer when water gets warmer. Spawning site is pebbly overfall that is fixed up by male lampreys pulling some stones away making small fossula for spawning. Fertilization happens when male suck up to females head and their bodies intertwine.
People do not use this lamprey subspecies for food as the secretion from gland within its skin is poisonous and the poison does not decompose in high temperatures.