Delicate Ark

Calloarca tenella

Molluscs
IUCN: Not evaluated

Usual depth1–113 m
Water temperature22–30 °C
Best monthsFebruary, June, and August
How commonRare

All species

Photo credit: (c) aross0805, some rights reserved (CC BY) · CC BY · iNaturalist

Where and when

Where it has been recorded

Worldwide

Loading the map

Best months

Worldwide (open data)

January: 5 records
February: 12 records
March: 6 records
April: 2 records
May: 10 records
June: 15 records
July: 6 records
August: 17 records
September: 3 records
October: 10 records
November: 4 records
December: 11 records

Depth and water temperature

Depth

Mostly recorded at 1–113 m · Deepest record: 112.5 m

0–10 m: 1 records
10–20 m: 0 records
20–30 m: 0 records
30–40 m: 2 records
40–50 m: 0 records
50–60 m: 1 records
60–70 m: 0 records
70–80 m: 4 records
80–90 m: 0 records
90–100 m: 0 records
100–110 m: 0 records
110–120 m: 1 records

Water temperature

Recorded in surface water of 22–30 °C

22–24 °C: 7 records
24–26 °C: 33 records
26–28 °C: 21 records
28–30 °C: 44 records

Photos

no rights reserved · CC0 1.0 · iNaturalist

Names and classification

English: Delicate Ark

Names in 1 more languages

Japanese: ハブタエエガイ

Other scientific names: Arca tenella, Barbatia (Barbarca) tenella, Barbatia (Barbatia) tenella, Barbatia (Calloarca) tenella, Barbatia mollis, Barbatia tenella, Calloarca (Barbarca) hua, Calloarca hua, Opularca tenella

Similar species

Divaricated Ark
Acar plicata
Antique ark
Anadara antiquata
Indo-Pacific Ark
Arca navicularis
Burnt-almond ark
Barbatia amygdalumtostum
Truncated Ark
Lamarcka ventricosa
Anadara cornea

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.
Conservation status as published by GBIF (IUCN Red List).
157 open-data records from 1844 to 2012.
Species data updated October 26, 2026.

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