Pacific transparent sea squirt

Ciona savignyi

Other invertebrates
IUCN: Not evaluated

Usual depth1–31 m
Water temperature8–29 °C
Best monthsAugust, September, and October
How commonOccasional

Photo credit: no rights reserved · CC0 1.0 · iNaturalist

About this species

Ciona savignyi is a marine animal sometimes known as the Pacific transparent sea squirt or solitary sea squirt. It is a species of tunicates in the family Cionidae. It is found in shallow waters around Japan and has spread to the west coast of North America where it is regarded as an invasive species.

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

Where and when

Where it has been recorded

Worldwide

Loading the map

Best months

Worldwide (open data)

January: 82 records
February: 111 records
March: 90 records
April: 103 records
May: 108 records
June: 112 records
July: 111 records
August: 190 records
September: 229 records
October: 173 records
November: 115 records
December: 71 records

Depth and water temperature

Depth

Mostly recorded at 1–31 m · Deepest record: 558.4 m

0–10 m: 229 records
10–20 m: 83 records
20–30 m: 178 records
30–40 m: 66 records
40–50 m: 6 records
50–60 m: 0 records
60–70 m: 0 records
70–80 m: 0 records
80–90 m: 0 records
90–100 m: 0 records
100–110 m: 0 records
110+ m: 3 records

Water temperature

Recorded in surface water of 8–29 °C

8–10 °C: 14 records
10–12 °C: 200 records
12–14 °C: 315 records
14–16 °C: 14 records
16–18 °C: 56 records
18–20 °C: 28 records
20–22 °C: 63 records
22–24 °C: 0 records
24–26 °C: 4 records
26–28 °C: 64 records
28–30 °C: 3 records

Photos

(c) Brianna Tracy-Sawdey, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Nathan, some rights reserved (CC BY) · CC BY · iNaturalist
no rights reserved · CC0 1.0 · iNaturalist
(c) Javier, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Javier, some rights reserved (CC BY) · CC BY · iNaturalist
(c) J Yager, some rights reserved (CC BY) · CC BY · iNaturalist
no rights reserved · CC0 1.0 · iNaturalist

Names and classification

English: Pacific transparent sea squirt, Transparent tunicate, Tunicate

Names in 1 more languages

Japanese: ユウレイボヤ

Other scientific names: Ciona aspera

Similar species

Sea vase
Ciona intestinalis

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).
1,288 open-data records from 1982 to 2025.
Species data updated November 1, 2026.

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