BIOTIC

BIOTIC Species Information for Helcion pellucidum

Researched by

Dr Harvey Tyler-Walters

Data supplied by

MarLIN

Refereed by

Dr David McGrath

Reproduction/Life History

Reproductive type

Gonochoristic

Developmental mechanism

Planktotrophic

Reproductive Season

All year with a peak in spring

Reproductive Location

As adult

Reproductive frequency

Annual protracted

Regeneration potential

Life span

1-2 years

Age at reproductive maturity

<1 year

Generation time

<1 year

Fecundity

Insufficient information

Egg/propagule size

Ca 0.16 mm diameter

Fertilization type

External

Larvae/Juveniles
Larval/Juvenile dispersal potential	10-100m	Larval settlement period	Insufficient information
Duration of larval stage	11-30 days

Reproduction Preferences Additional Information

Few individuals survive into their second years. Most specimens >1 year old are found in holdfasts as the laevis form. Breeding occurs throughout the year with a peak in spring. Fertilization is external and eggs are shed singly. The eggs are greenish, ca 0.16 mm across and covered with a gelatinous coat giving an overall diameter of ca 0.32 mm (Fretter & Graham, 1976; Lebour, 1937). Eggs hatch into a 200 micrometer tall trochophore that develops into a 160-180 micrometer veliger larva (Lebour, 1937). Fretter & Graham (1947) state that planktonic life is 'a few weeks'. There is little information on dispersal range, however, 10-100m is assumed given the depth of adult distribution and its settlement on lower shore at least. McGrath (1992) examined recruitment in south east Ireland and reported that newly settled spat have a preference for lower shore Lithothamnia (encrusting corallines). As they grow juveniles (up to 1.8 mm) migrate to Mastocarpus stellatus. The juveniles recruit to Laminarians at about 1.8 mm but are found mainly at the tips of the fronds. Juveniles up to 3 mm may also be found on the receptacles of Himanthalia elongata. McGrath (1992) suggested that larvae settle on Lithothamina and migrate to Mastocarpus stellatus as they grow and finally to Laminaria sp. via Himanthalia elongata.

Reproduction References

Fish & Fish, 1996, Fretter & Graham, 1976, Graham & Fretter, 1947, McGrath, 1992, Fretter & Graham, 1994, Lebour, 1937,