Science
7/12/2023

Parrotfish: small reef defenders

Who would say that there are small heroes on the reefs that fight marine threats? And one of them is the parrotfish. Its name comes from skairos (which means jumping or hitting).

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Photo credit: Selene Jacobo Cabral
Who would say that there are small heroes on the reefs that fight marine threats? And one of them is the parrotfish. Its name comes from skairos (which means jumping or hitting).
Science
9/26/2024

Parrotfish: small reef defenders

Who would say that there are small heroes on the reefs that fight marine threats? And one of them is the parrotfish. Its name comes from skairos (which means jumping or hitting).

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Healthy Reefs
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Who would say that there are small heroes on the reefs that fight marine threats? And one of them is the parrotfish. Its name comes from skairos (which means jumping or hitting).

This fish is known as "reef gardener"

They feed on macroalgae that grow between rocks and corals. Their importance is that they are herbivores and help to maintain the coral reefs’ health, because they keep them free of algae. "The parrotfish is very important because being a herbivore, it feeds on algae, which makes it a great natural ally to clean the algae that invade the corals, cover them, suffocate them and get sick" - said Mélina Soto, Mexico Coordinator for the Healthy Reefs Initiative (HRI).

Unfortunately, its population has drastically decreased due to fishing and climate change, among others. Despite the danger of the beloved parrotfish, measures have been taken to safeguard its future. In Mexico, at the end of 2019, the Ministry of Environment and Natural Resources (Semarnat) published in the Official Journal of the Federation, a solution and proposal to update the Official Mexican Standard 059, where it includes in the list of protected species 10 species of parrotfish, in which HRI and some of its partners were working for more than 5 years.

According to the 2020 Mesoamerican Reef Health Report Card, parrotfish are now protected throughout the region, except off the coast of Honduras. Continued transboundary protection of species with high ecological value is crucial to ensure vital ecosystem services. The incorporation into all national laws in the 4 MAR countries for their protection is due to the fact that parrotfish are facing serious dangers for the maintenance of their populations. The 2020 Mesoamerican Reef Report Card highlights that since 2006, the biomass of herbivorous fish has increased in all countries except Honduras, which experienced a drastic decrease; despite protection in the Bay Islands. The protection of herbivorous fish has been one of HRI’s main recommendations.

Between 2009 and 2015, Belize, Guatemala and Honduras have had encouraging results and previous to that of Mexico. In Belize, the biomass of parrotfish has increased since its protection and there is already evidence in the reduction of macroalgae. Efforts to protect herbivorous fish, such as the ban on parrotfish fishing in Guatemala, are especially important as more herbivores may be able to increase foraging intensity, reaching levels that can change the balance and reach reefs with more coral abundance.

Thanks to the work of CORAL and its allies, in 2018 the government of Honduras approved a declaration of a new marine protected area: the wildlife refuge of Bahía de Tela, with an extension of 86,259 hectares of reefs and ocean. With these innovative actions, they help safeguard this ecosystem and protect the herbivorous fish of the region.

The parrotfish ban in Guatemala should be extended; and Honduras needs to improve the enforcement of regulations in the Bay Islands and protect herbivores along the coast of Honduras - some recommendations we suggest at HRI.

HRI and its partners have been monitoring reef sites for more than a decade, and in the 99 sites surveyed in 2018 we found the biggest changes in fish biomass. We have initiated three strategies to improve and restore herbivory: reintroduction of king crabs, repopulation of reefs with Diadema urchin and protection of parrotfish. The recovery of coral reefs in the MAR also depends on herbivorous fish, king crabs and sea urchins. These species help to maintain healthy reefs, eating fleshy macroalgae that can grow too much and kill corals, or competing for space, preventing new coral larvae from settling.

"An extensive family of marine heroes"

Also, the parrotfish family has ten species that have managed to be protected in the NOM 059 for Quintana Roo, Mexico and that are also found in other MAR countries. We will show you its unique and unusual particularities:

Rainbow parrotfish

(Scarus guacamaia)

These are so called because their teeth are similar to that of a parrot’s beak and for their distinguished colors. They are considered one of the largest herbivorous fish in the Atlantic Ocean, reaching 1.2 meters. Something exceptional is that these can change sex, females for males.

Redtail parrotfish

(Sparisoma chrysopterum)

Vaguely, its dark spots that impregnate its scales, alluding to a saddle. When sleeping, they change their reddish color, for tones that create a camouflage, avoiding being a prey.

Midnight parrotfish

(Scarus coelestinus)

Its scales are large and smooth, with black and bright blue patterns on the body and head, and the teeth are blue-green causing the memory of bright and dark nights.

Blue parrotfish

(Scarus coeruleus)

Young and adults have very colorful changes: juveniles are pale blue with yellow areas on the head and dorsal fin, while adults are deep blue or blue-green with a broad gray cheek.

Striped parrotfish

(Scarus iseri)

This species at birth are females and become males in adulthood - they are hermaphrodites.

Yellowtail parrotfish

(Sparisoma rubripinne)

They have large, smooth scales. Their body is elongated and somewhat robust.

Princess parrotfish

(Scarus taeniopterus)

Depending on the stage of their life, they change their appearance: the young are dark olive and those in a terminal phase, are bluer. Even, it influences where they usually live: the former prefer areas with greater vegetation and the latter opt for depth.

Queen parrotfish

(Scarus vetula)

Its body is elongated, reaching 51 cm.

Stoplight parrotfish

(Sparisoma viride)

Like striped parrotfish, they are also hermaphrodites, varying their color as well. The dorsal fin has 9 spines and 10 soft rays, the anal fin has 3 spines.

Redband parrotfish

(Sparisoma aurofrenatum)

Its teeth create a beak of rough plates, covered by the lips, and the upper jaw is behind the lower when the mouth is closed - drawing a remarkable stripe.

In our upcoming blogs, you will find more information about other herbivores important for the health of the Mesoamerican Reef.

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