Armless flounder

Neoachiropsetta milfordi

Fish
IUCN: Least concern

Usual depth434–898 m
Water temperature4–17 °C
Best monthsJuly and November
How commonOccasional

Photo credit: (c) Dr Tony Ayling, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist

About this species

Neoachiropsetta milfordi, the armless flounder or finless flounder, is a species of southern flounder, the only member of the genus Neoachiropsetta. It is found in Antarctic and subantarctic waters, in depths of between 100 and 1,000 metres, and grows to a length of 57 centimetres (22 in).

Text from the Wikipedia article “Armless flounder”, 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: 20 records
February: 93 records
March: 8 records
April: 3 records
May: 41 records
June: 17 records
July: 110 records
August: 39 records
September: 42 records
October: 99 records
November: 170 records
December: 32 records

Depth and water temperature

Depth

Mostly recorded at 434–898 m · Deepest record: 1,591.5 m

100–110 m: 1 records
110–120 m: 0 records
120–130 m: 0 records
130–140 m: 2 records
140–150 m: 0 records
150–160 m: 2 records
160–170 m: 0 records
170–180 m: 5 records
180–190 m: 2 records
190–200 m: 0 records
200–210 m: 5 records
210+ m: 2,549 records

Water temperature

Recorded in surface water of 4–17 °C

2–4 °C: 1 records
4–6 °C: 20 records
6–8 °C: 329 records
8–10 °C: 438 records
10–12 °C: 54 records
12–14 °C: 31 records
14–16 °C: 100 records
16–18 °C: 5 records

Names and classification

English: Armless flounder, Armless Deepsea Flounder, armless flounder, Finless Flounder, Finless flounder, Largemouth flounder

Names in 2 more languages

French: Grande Mancopsette
Japanese: ムテカツビラメ

Other scientific names: Apterygopectus avilesi, Apterygopectus milfordi, Mancopsetta milfordi

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).
2,688 open-data records from 1974 to 2022.
Species data updated November 4, 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