Big mouth shark

Megachasma pelagios

Sharks and rays
IUCN: Least concern

Usual depth23–165 m
Water temperature17–29 °C
Best monthsAugust and November
How commonRare

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

About this species

The megamouth shark is a species of deepwater shark. Rarely seen by humans, it measures around 4–5.5 m (13–18 ft) long and is the smallest of the three extant filter-feeding sharks alongside the much larger whale shark and basking shark. According to Sharkman's World Organization, a total of 296 specimens have been observed or caught since its discovery in 1976. Like the other two planktivorous sharks, it swims with its mouth wide open, filtering water for plankton and jellyfish. The diet of megamouth sharks mainly consists of zooplanktonic organisms like krill, jellyfish, shrimp larvae, squat lobsters, and crab larvae. It is recognizable from its large head with rubbery lips. The megamouth is so unlike any other type of shark that it is usually considered to be the sole extant species in the family Megachasmidae, though some scientists have suggested it may belong in the family Cetorhinidae.

Text from the Wikipedia article “Megamouth shark”, 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: 1 records
February: 1 records
March: 2 records
April: 2 records
May: 1 records
June: 1 records
July: 1 records
August: 6 records
September: 2 records
October: 2 records
November: 6 records
December: 0 records

Depth and water temperature

Depth

Mostly recorded at 23–165 m · Deepest record: 165 m

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

Water temperature

Recorded in surface water of 17–29 °C

16–18 °C: 3 records
18–20 °C: 2 records
20–22 °C: 5 records
22–24 °C: 1 records
24–26 °C: 6 records
26–28 °C: 0 records
28–30 °C: 4 records

Photos

Names and classification

English: Big mouth shark, Megamouth shark, big mouth shark, megamouth shark

Names in 7 more languages

German: Riesenmaulhai
Spanish: tiburón bocón, tiburón bocudo, Tiburón bocudo
French: Requin grande guele, requin grande gueule, Requin grande-gueule
Indonesian: Hiu bermulut besar
Japanese: Megamausuzame, メガマウス, メガマウスザメ
Thai: ปลาฉลามปากกว้าง, ปลาฉลามเมกาเมาท์
Simplified Chinese: 大口鯊, 大沙, 巨口鮫, 巨口鯊

Other scientific names: Megachasma plagios

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).
35 open-data records from 1976 to 2004.
Species data updated November 4, 2026.

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