Slender argentine

Microstoma microstoma

Fish
IUCN: Least concern

Usual depth0–1,039 m
Water temperature9–30 °C
Best monthsApril and October
How commonRare

About this species

The slender argentine, Microstoma microstoma, is a species of pencil smelt, found around the world in tropical and subtropical areas. This species grows to a length of 21 centimetres (8.3 in) TL.

Text from the Wikipedia article “Slender argentine”, 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: 2 records
February: 2 records
March: 3 records
April: 8 records
May: 4 records
June: 3 records
July: 2 records
August: 4 records
September: 1 records
October: 5 records
November: 3 records
December: 1 records

Depth and water temperature

Depth

Mostly recorded at 0–1,039 m · Deepest record: 2,085 m

0–10 m: 6 records
10–20 m: 0 records
20–30 m: 0 records
30–40 m: 0 records
40–50 m: 1 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: 30 records

Water temperature

Recorded in surface water of 9–30 °C

8–10 °C: 1 records
10–12 °C: 5 records
12–14 °C: 10 records
14–16 °C: 2 records
16–18 °C: 5 records
18–20 °C: 5 records
20–22 °C: 4 records
22–24 °C: 9 records
24–26 °C: 3 records
26–28 °C: 5 records
28–30 °C: 2 records

Names and classification

English: Slender argentine, Dusky Pencilsmelt, slender argentine, Slender Smallmouth

Names in 1 more languages

French: Serpe petite bouche

Other scientific names: Gasteropelecus microstoma, Microstoma argenteum, Microstoma mediterranea, Microstoma rotundata, Serpe microstoma

Similar species

Slender Smallmouth
Microstoma australis
Robust Smallmouth
Nansenia ardesiaca
Longtail Pencilsmelt
Nansenia longicauda
Nansenia macrolepis
Nansenia pelagica

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).
224 open-data records from 1949 to 2024.
Species data updated November 4, 2026.

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