Bumphead Parrotfish: the head butting, sand pooping fish with beak-like teeth

One of the largest reef fishes, the Bumphead Parrotfish (Bolbometopon muricatum) is also the largest of the parrotfish species. It can be recognised by its bulbous forehead and powerful beak.

Humphead Parrotfish, Bolbometopon muricatum
The Bumphead Parrotfish can grow up to 1.3 metres in length, weigh over 50 kilogrammes, and is known to live up to 40 years of age. They can be can be found on reefs in the Indian and Pacific Oceans, from the Red Sea east to the Line Islands, north to Taiwan, and south to the Great Barrier Reef and New Caledonia.

Like all parrotfish, Bumphead Parrotfish are born female and live in harems with one dominant male. When the male dies, the largest female will transform into a male.

Male Bumphead Parrotfish use their impressive bumps to battle for female attention, and establish their territory to ward off rivals. The headbutting results in a loud clinking sound, as filmed by researcher Roldan C. Muñoz. (Turn up the volume to hear the clinking sound):

Read more about Muñoz’s findings here.

The sand machine with beak-like teeth

Bumphead Parrotfish use their fused ‘beak like’ teeth (mandibular jaws) to scrape live or dead coral that is encrusted with algae – their main food source. They have a second set of teeth at the back of their throat which crushes the coral into a sludge like a cement mixer. This slurry of organic and inorganic material is passed through their long gut (note: parrotfish do not have a stomach) where nutrients are absorbed. Inorganic material is then excreted as sand, which forms beaches and islands.

By pruning the corals and removing the algae and parasites that compete with these corals, Bumphead Parrotfish play an important role in maintaining healthy coral reef ecosystems.

Live in schools, vulnerable to extinction

Bumphead Parrotfish is a social species that consistently schools to better protect themselves from predators. Each school comprises up to 60 individuals and they can travel about five to 10 kilometres a day while feeding. Juvenile Bumphead Parrotfish are usually found in sheltered lagoonal reefs whereas adults are predominantly found on exposed outer reef environments.
Humphead Parrotfish, Bolbometopon muricatum
The schools frequently sleep at predicable locations in shallow water, making them highly vulnerable to capture by nighttime spearfishers. As such, this species is currently listed as Vulnerable on the IUCN Red list, with widespread population declines throughout its range attribute to overfishing.

But overfishing isn’t the only cause of their population decline.

Climate change and loss of habitat

Destruction of forests for palm oil and furniture result in soil erosion, which increases the amount of sediment entering and destroying the Bumphead Parrotfish’s nursery grounds.

At the same time, climate change has led to warmer seas and more severe storms, which destroy the coral reef habitats that these fish depend on.

Here’s a video on how logging threatens the Bumphead Parrotfish in the Solomon Islands, as explained by Dr Richard Hamilton.

4 things you can do to help the Bumphead Parrotfish

  1. Avoid eating them as they play an important role in coral reefs
  2. Buy timber products that are FSC-certified as sustainable.
  3. Choose products that contain sustainable palm oil.
  4. Choose energy-efficient electrical appliances and switch them off when not in use.

S.E.A. Aquarium is one of the few institutions worldwide to feature the Bumphead Parrotfish. With Spooky Seas happening now till 28 October 2018, there are interactive activities around the aquarium to help everyone, especially the kids, learn more about these amazing fish and other quirky sea creatures. Details here

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