Saving Reefs, Building Beaches, Sex Changes And Mosquito Nets – Just A Typical Parrotfish Day
Thankfully many species of parrotfish are common on Phuket reefs and we really need to keep it that way. Heavy fines or even jail time await anybody who take parrotfish from the ocean and for good reason. Read on to find out why.
Keystone Species
A keystone species is an animal that is so important to it’s particular ecosystem that it’s loss or number depletion will have a heavy impact or even cause total breakdown. Parrotfish are one such species, their grazing on algae and seaweed allow corals to flourish. Coral reef restoration can begin by banning fishing of parrotfish as case studies in the Caribbean have shown.
Can’t Somebody else step up?
A fair question, with the myriad different species that we have on Phuket reefs you would think if we lost parrotfish then another organism would be ready to step in and exploit the food source. Apparently not, nobody does it better than the humble parrotfish and that’s why it’s considered a keystone species. Coral reef health significantly decreases in areas where parrotfish are over fished.
The law In Thailand
There have been quite a few high profile cases in Phuket over the last couple of years, tourists have been arrested for catching parrotfish and heavily fined – story here. Restaurants have also been warned about having parrotfish on the menu. The fine is up to THB 100,000, a year in jail or both! for catching any parrotfish species under 50cm in length.
Beach Builders
Apart from the garish colours, the first thing you may notice about parrotfish is the seemingly never ending clouds of pooh that they like dropping in divers faces. They haven’t all got digestive issues it’s just the reef rock and both live and dead coral that they scrape up along with the algae. This will later wash up and form the white sand beaches that we all like to laze around on, some species can produce up to 90kg per year.
Destructive Dentures
To be able to chomp through rock and coral all day everyday takes some seriously strong dentistry and the parrotfishes teeth are amongst the strongest on the planet. Upwards of a thousand tiny teeth meshed together in many rows produce set of teeth that could literally eat through a brick wall. Ever the opportunists, scientists are looking at the design to make stronger materials for us to use and justify their salary.
Lots of Ladies
Most species but not all are protogynous hermaphrodites which means they will start life of as females and turn male when the harem leader meets his demise. It’s possible to have many different colour phases from the same species – juveniles, adolescents, male and female can all be different which makes getting an idea a bit of a challenge. Although the parrot like beak, generally garish colurs, clouds of pooh and locomotion from it’s pectoral fins make the family easy to recognise.
Makes Own Mosquito Net
Lots of species of parrotfish can secrete a mucus from the gill cavity at night that envelops the whole body and offers some protection from blood sucking parasites (Gnathiids). Not only a physical barrier but it also masks the scent cues that attract the parasites. As far as we know it’s the only animal capable of producing it’s own mosquito net, allowing for a peaceful nights sleep.
In the day they will regularly visit cleaning stations to get rid of the tiny vampires, the gills are full of blood and is why you’ll see many fish open up their gill covers to let the cleaner wrasse in and eat the unwanted stowaways.
Please Don’t Eat Them
Not such a common sight in Thailand nowadays because of the law but in other countries you may see parrotfish displayed at seafood restaurants, they’re not that tasty and really only add a bit of colour. Targeting the larger and more colourful males as many fisherman do interrupts breeding cycles therefor reducing populations. So please don’t eat parrotfish.
Where to find?
They’re present on all Phuket dive sites but there has been a small but noticeable drop in numbers over the last few years. Fishing and indiscriminate spearfishing are the main reasons but we can still see a parrotfish or two on every dive.
Come and join Local Dive Thailand to see the beach builders at work. Contact us at info@localdivethailand.com for more information.
By Justin Hartrey
Posted in Rare & Peculiar Critters on .
