---
title: Bumphead Sunfish (Mola alexandrini)
scientific_name: Mola alexandrini
common_name: Bumphead Sunfish
taxon: Ocean Sunfishes
published: 2024-11-25T14:26:52.781Z
updated: 2026-08-23T10:59:59.805Z
tags: Bumphead Sunfish, Mola alexandrini, Ocean Sunfishes, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/ocean-sunfishes/bumphead-sunfish
---

# Bumphead Sunfish (*Mola alexandrini*)

## Quick facts

- **Group:** Ocean Sunfishes (*Molidae*)
- **Size:** up to 3.3 m
- **Weight:** 2,744 Kg
- **Depth:** 1-480 m
- **Diet:** Planktivore
- **Activity:** Diurnal
- **Rarity:** Very Rare
- **Habitat:** Open water, from the surface down to several hundred meters
- **Reproduction:** Egg layer

## How to recognise it

- enormous disc of a body ending abruptly, with no true tail
- bump on the forehead and a bulge on the chin in adults
- dorsal and anal fins long and paddle-like, sculled together
- up to 3.3 m and over two tonnes

This is the heaviest bony fish in the world. The record individual weighed two thousand seven hundred and forty-four kilograms, about the same as a large car, and it was this species rather than the common mola that turned out to hold the title once the two were properly separated in 2017.

Everything about the body is unusual. There is no tail: the rear of the fish ends in a stiff rudder-like structure formed from the back ends of the dorsal and anal fin rays, and propulsion comes from those two fins beating together like wings. The skeleton is largely cartilage, the skin is several centimeters of tough collagen, and adults carry a bump on the forehead and another on the chin.

It eats gelatinous plankton, mostly salps and jellyfish, which is thin food, and it covers a lot of water and a lot of depth to get enough, diving to several hundred meters and returning to the surface to warm up.

Here it is a genuine rarity. The first photograph of this species in the Red Sea was taken in 2004 at Small Brother, which for an animal three meters across says something about how much open water goes unwatched.

## Also known as

- **English:** Ramsay's Ocean Sunfish, Short Ocean Sunfish, Southern Ocean Sunfish
- **Arabic:** سمكة الشمس ناتئة الرأس, سمكة الشمش المحيطة الجنوبي, سمكة الشمس القصيرة
- **Hebrew:** דג שמש דרומי
- **French:** Poisson-lune à bosse
- **Italian:** Pesce luna meridionale
- **Spanish:** Pez Luna meridional, Pez luna gigante
- **Portuguese:** Peixe-lua, Peixe-lua-de-Ramsay, Peixe-lua-do-sul
- **Japanese:** ウシマンボウ, Ushimambo
- **Chinese:** 拉氏翻車魨, 花紋翻車魨
- **Russian:** Короткая луна-рыба
- **CA:** Peix lluna meridional
- **KO:** 혹개복치
- **NO:** kjempemånefisk

## Scientific synonyms

- *Mola ramsayi* (Giglioli, 1883)
- *Orthagoriscus eurypterus* Philippi, 1892
- *Orthragoriscus alexandrini* Ranzani, 1839
- *Orthragoriscus eurypterus* Philippi, 1892
- *Orthragoriscus ramsayi* Giglioli, 1883

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/ocean-sunfishes/bumphead-sunfish)*
*Updated: August 23, 2026*