Muller's pearlsides

Maurolicus muelleri

Fish
IUCN: Least concern

Usual depth56–366 m
Water temperature1–25 °C
Best monthsFebruary and November
How commonCommon

Photo credit: (c) Stan Rullman, some rights reserved (CC BY), uploaded by Stan Rullman · CC BY · iNaturalist

About this species

Maurolicus muelleri, commonly referred to as Mueller's pearlside, Mueller's bristle-mouth fish, or the silvery lightfish, is a marine hatchetfish in the genus Maurolicus, found in deep tropical, subtropical and temperate waters of the Pacific Ocean and the Atlantic Ocean, from the surface to depths of 1,500 metres (4,900 ft). It can grow to a maximum total length of 8 centimetres (3.1 in).

Text from the Wikipedia article “Mueller's pearlside”, licensed CC BY-SA 4.0. Read the article

Where and when

Where it has been recorded

Worldwide

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Best months

Worldwide (open data)

January: 916 records
February: 2,272 records
March: 608 records
April: 286 records
May: 638 records
June: 325 records
July: 679 records
August: 590 records
September: 892 records
October: 564 records
November: 1,375 records
December: 272 records

Depth and water temperature

Depth

Mostly recorded at 56–366 m · Deepest record: 3,516 m

0–10 m: 63 records
10–20 m: 29 records
20–30 m: 54 records
30–40 m: 168 records
40–50 m: 318 records
50–60 m: 836 records
60–70 m: 828 records
70–80 m: 504 records
80–90 m: 361 records
90–100 m: 301 records
100–110 m: 433 records
110+ m: 7,568 records

Water temperature

Recorded in surface water of 1–25 °C

0–2 °C: 2 records
2–4 °C: 3 records
4–6 °C: 19 records
6–8 °C: 71 records
8–10 °C: 109 records
10–12 °C: 417 records
12–14 °C: 112 records
14–16 °C: 40 records
16–18 °C: 68 records
18–20 °C: 38 records
20–22 °C: 9 records
22–24 °C: 1 records
24–26 °C: 3 records

Photos

Names and classification

English: Muller's pearlsides, Pearl-side, Pearlsides, Pearlsides argentine, Sheppy argentine, Daisy Pearlside, Hatchetfish, Mueller's Bristle-mouth Fish, Mueller's pearlside, Muller's Bristlemouth Fish, Muller's Pearsides, Pearlfish, pearl-side, Pearlside, pearlsides, pearlsides argentine, sheppy argentine, Silvery Lightfish, Silvery lightfish, Pearlsides

Names in 4 more languages

German: Lachsherring
Spanish: Anchoa de Fondo, Luciérnaga Perlada, Pez Hacha, Yoalaakaci
French: Brossé améthyste, Brossé améthyste, Maurolique de Müller, Maurolique de miller, maurolique de Müller
Simplified Chinese: 斧魚, 海洋斧魚, 穆氏暗光魚, 銀斧

Other scientific names: Argentina pennanti, Benthosema muelleri, Maurolicus mülleri, Maurolicus pennanti, Mauroluccius mulleri, Salmo muelleri, Scopelus borealis, Scopelus humboldtii, Scopelus maurolici

Similar species

Pennant Lantern-fish
Maurolicus australis
North Pacific lightfish
Maurolicus japonicus
Javan Pearlside
Maurolicus javanicus
Half-naked hatchet fish
Argyropelecus hemigymnus
Atlantic silver hatchetfish
Argyropelecus aculeatus
Pacific hatchet fish
Argyropelecus affinis

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).
18,625 open-data records from 1789 to 2024.
Species data updated November 4, 2026.

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