Biodiversity & Conservation

Light bulb sea squirt - Clavelina lepadiformis - General information

Clavelina lepadiformis

Image Keith Hiscock - Clavelina lepadiformis. Image width ca 5 cm.
Image copyright information

  • #
  • #
  • #
  • #
  • #
  • #
  • #
  • #
Distribution map

Clavelina lepadiformis recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

Why do the maps differ?

Sightings Have you seen Clavelina lepadiformis?
If so please submit your record.

Clavelina lepadiformis is not listed under any importance categories.

General information

Key Icon Researched by: Karen Riley Text page icon Refereed by: Dr Xavier Turon

Taxonomy icon Taxonomy

Phylum Chordata Sea squirts, fish, reptiles, birds and mammals
Class Ascidiacea Sea squirts
Map icon Recorded distribution in Britain and Ireland Clavelina lepadiformis occurs around most coasts of Britain and Ireland.
Habitat information icon Habitat information Clavelina lepadiformis attaches itself to rocks, stones and seaweed in the sublittoral, to a depth of about 50 m.
Text page icon Description Clavelina lepadiformis is a colonial sea squirt that grows up to 20 mm high. Groups of transparent zooids are joined at the base by short stolons. Eggs and larvae vary in colour and are visible in the atrial cavity. In the Mediterranean the eggs and embryos are most often yellowish white and sometime pink (X. Turon, pers. comm.) although in other areas in NW Europe they can also be red (Fish & Fish, 1996). Zooids possess a white ring around the pharynx, and have pale yellow or white longitudinal lines along the endostyle and dorsal lamina, which gives this species its 'light-bulb' appearance. In some areas colonies regress in winter and re-grow in spring although in the Mediterranean this may not be the case. De Caralt et al. (2002) looked at the differences in Clavelina lepadiformis between populations inside and outside of harbours and found that the population inside the harbour remained all year (albeit often at very low abundances). In contrast, the population in a rocky littoral area outside the harbour aestivated (regressed) for up to 7 months over the summer period (De Caralt et al., 2002).

This review can be cited as follows:

Karen Riley 2008. Clavelina lepadiformis. Light bulb sea squirt. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 24/05/2013]. Available from: <http://www.marlin.ac.uk/speciesfullreview.php?speciesID=3009>