BIOTIC

BIOTIC Species Information for Hydrobia ulvae

Researched by

Lizzie Tyler

Data supplied by

University of Sheffield

Refereed by

This information is not refereed.

Reproduction/Life History

Reproductive type

Gonochoristic

Developmental mechanism

Planktotrophic
Lecithotrophic

Reproductive Season

March to October

Reproductive Location

Insufficient information

Reproductive frequency

Annual protracted

Regeneration potential

Life span

1-2 years

Age at reproductive maturity

<1 year

Generation time

Insufficient information

Fecundity

26.5

Egg/propagule size

Fertilization type

Internal

Larvae/Juveniles
Larval/Juvenile dispersal potential	>10km	Larval settlement period	Insufficient information
Duration of larval stage	11-30 days

Reproduction Preferences Additional Information

The longevity of this species is debatable. Hydrobia ulvae may live up to five years in aquaria and over four years in the arctic. Various studies have suggested that it lives from just over 1 year up to 2.5 years. Individuals hatching from eggs laid in spring can breed in autumn, whereas those hatching in autumn over-winter before breeding in spring. The species is gonochoristic and sperm transfer occurs by copulation. Minimum egg hatching time has been recorded as five days. There is considerable conflicting evidence over the developmental mechanism of the larvae of this species. Some workers (Fish & Fish, 1977) have found the planktonic stage to last up to four weeks and development to be entirely planktotrophic. Others (Pilkington, 1971) have found the planktonic stage to be completely absent with a nonfeeding benthic larva that metamorphoses after just two days. Snails producing planktotrophic forms have several (7-22) smaller eggs that hatch into veliger larvae at around 150 microns. Snails producing lecithotrophic forms lay fewer (3-7) larger eggs. Maximum number of eggs recorded from one mass is 50. The timing of the breeding season varies with latitude. In the north of Scotland there is a short spawning period in Spring. In populations further south the spawning period is more protracted and is split into two peaks (spring and autumn). Age at maturity Eggs are laid preferentially on the shells of live individuals of this species but also on empty shells and grains of sand. The egg mass acquires a protective layer of sand grains.

Reproduction References

Fretter & Graham, 1994, Barnes, 1988, Clay, 1960, Barnes, 1990, Fish & Fish, 1974, Anderson, 1971, Sola, 1996, Pilkington, 1971, Eckert, 2003, Julie Bremner, unpub data,