Japanese codlet

Bregmaceros japonicus

Fish
IUCN: Not evaluated

Usual depth65–929 m
Water temperature12–29 °C
Best monthsJuly
How commonOccasional

All species

Where and when

Where it has been recorded

Worldwide

Loading the map

Best months

Worldwide (open data)

January: 2 records
February: 2 records
March: 3 records
April: 3 records
May: 2 records
June: 6 records
July: 12 records
August: 0 records
September: 3 records
October: 5 records
November: 4 records
December: 5 records

Depth and water temperature

Depth

Mostly recorded at 65–929 m · Deepest record: 1,125 m

20–30 m: 1 records
30–40 m: 1 records
40–50 m: 0 records
50–60 m: 0 records
60–70 m: 2 records
70–80 m: 0 records
80–90 m: 2 records
90–100 m: 0 records
100–110 m: 3 records
110–120 m: 0 records
120–130 m: 1 records
130+ m: 26 records

Water temperature

Recorded in surface water of 12–29 °C

10–12 °C: 1 records
12–14 °C: 0 records
14–16 °C: 4 records
16–18 °C: 3 records
18–20 °C: 3 records
20–22 °C: 8 records
22–24 °C: 7 records
24–26 °C: 8 records
26–28 °C: 13 records
28–30 °C: 7 records

Names and classification

English: Japanese codlet, Japanese Unicorn-fish

Names in 2 more languages

Japanese: Saiuo, サイウオ
Simplified Chinese: 日本海鰗鰍, 日本犀鱈, 海土鰍, 海鰗鰍

Similar species

Spotted codlet
Bregmaceros mcclellandi

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).
215 open-data records from 1938 to 2024.
Species data updated October 26, 2026.

Log what you see on your next dive

The free DiveHive diver app keeps your logbook with every sighting and shows what lives at the site you dive next.

Join the waitlist