Light bulb sesquirt

Clavelina lepadiformis

Other invertebrates
IUCN: Not evaluated

Usual depth5–24 m
Water temperature10–20 °C
Best monthsJune, July, and August
How commonCommon

Photo credit: (c) Georgina Jones, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist

About this species

Clavelina lepadiformis, common name the light-bulb sea squirt, is a colonial sea squirt native to the NE Atlantic Ocean.

Text from the Wikipedia article “Clavelina lepadiformis”, licensed CC BY-SA 4.0. Read the article

Where and when

Where it has been recorded

Worldwide

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Best months

Worldwide (open data)

January: 415 records
February: 234 records
March: 368 records
April: 695 records
May: 1,924 records
June: 3,312 records
July: 3,520 records
August: 2,563 records
September: 935 records
October: 330 records
November: 406 records
December: 218 records

Depth and water temperature

Depth

Mostly recorded at 5–24 m · Deepest record: 79 m

0–10 m: 2,681 records
10–20 m: 3,803 records
20–30 m: 1,646 records
30–40 m: 177 records
40–50 m: 24 records
50–60 m: 3 records
60–70 m: 1 records
70–80 m: 1 records

Water temperature

Recorded in surface water of 10–20 °C

8–10 °C: 43 records
10–12 °C: 451 records
12–14 °C: 300 records
14–16 °C: 60 records
16–18 °C: 11 records
18–20 °C: 2 records

Photos

(c) Donald Davesne, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Rachel Crane, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Kelvin Perrie, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Hannes Dahm, some rights reserved (CC BY) · CC BY · iNaturalist
(c) John Hepburn, some rights reserved (CC BY) · CC BY · iNaturalist
no rights reserved · CC0 1.0 · iNaturalist
no rights reserved · CC0 1.0 · iNaturalist

Names and classification

English: Light bulb sesquirt, Light bulb tunicate, Pin-head squirt, Light-bulb Sea Squirt, Lightbulb Sea Squirt, light bulb sesquirt, light bulb tunicate, Light Bulb Tunicate, pin-head squirt

Names in 3 more languages

German: Keulenseescheide, Keulen-Seescheide
Spanish: ascidia bombilla
French: claveline, Claveline lépadiforme, clochette de cristal, Grande Claveline

Other scientific names: Ascidia lepadiformis, Clavelina pumillo, Clavelina rissoana, Clavelina savigniana

Similar species

Sources and credits

Names and taxonomy: WoRMS (CC BY 4.0) and the GBIF Backbone (CC BY 4.0). Photos: iNaturalist observers, each under the licence shown (CC0, CC BY or CC BY-SA).

Depth, temperature, months and maps: records from OBIS and GBIF under CC0 or CC BY.
Descriptions: Wikipedia, licensed CC BY-SA, each linked to its article.
Conservation status as published by GBIF (IUCN Red List).
16,685 open-data records from 1899 to 2025.
Species data updated November 1, 2026.

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