Coral reefs occupy less than 1% of the surface area of the world oceans, but still they provide a home for 25% of all marine fish species. According to FishBase, 34,300 species have been described as of 2020, and as many as 8,500 species dwelling within coral reef ecosystems of the world's oceans. Over 400 species have been recorded across the reefs around Aride island.
Angelfish (Pomacanthidae) resemble butterflyfishes and share their perfectly splendid colours, brush-like teeth, and small scales. The only characteristic that distinguishes angelfish from the butterflyfish is a small spine in front of their gill and below the eye. Occur across a large geographic range, spanning the tropical Atlantic, Indian and western Pacific Oceans. There are about 86 species found worldwide, of which 6 are found around Aride. Active during the day, and they like to eat sponges, algae, jellyfish and small fish. These species are hermaphrodites, and all begin life as females and switch sex only when required. DID YOU KNOW? Bright coloured body provides camouflage in the coral reefs and plays important role in communication.
Roundface Batfish Platax teira
Batfish (genus Platax). The common Roundface Batfish Platax teira (illustrated) can be recognised by the dark blotch below the pectoral fin, and a second elongated dark mark above the origin of the anal fin. They are omnivores, feeding on plankton, anemones, coral and algae, and can grow up to 60cm. The species occurs through much of the tropical Indo-Pacific. Two species of batfish are recorded from Aride waters. They are curious fish, often schooling with other species and approaching divers to present a fantastic photo opportunity.
DID YOU KNOW? Juveniles do not look much like their adult counterparts, but are masters of mimicry, pretending to be leaves or even flatworms to hide from predators (Richard Ling, CC BY-SA 2.0, via Wikimedia Commons).
Yellow Boxfish Ostracion cubicus
Boxfish (Ostraciidae) are small to medium-sized (to 40 cm) fishes with a body almost completely encased in a bony shell. Out of the 26 species in the Ostraciidae family, 5 have been recorded at Aride. Fish in the family are known variously as boxfishes, cofferfishes, cowfishes and trunkfishes. Members of this family occur in a variety of different colours, and are notable for the hexagonal or "honeycomb" patterns on their skin. They swim in a rowing manner and feed on benthic invertebrates.
DID YOU KNOW? Several species are considered delicacies in southern Japan, although some species are reported to have toxic flesh and are also able to secrete a substance when distressed that is highly toxic, both to other fishes and themselves. For example, the Yellow Boxfish that is found around Aride, releases the neurotoxin tetrodoxin (TTX) from its skin when stressed or injured that may prove lethal to the fish in the surrounding waters. The bright yellow colour and black spots are a form of warning colouration to any potential predators (Norbert Potensky, CC BY-SA 3.0, via Wikimedia Commons).
Butterflyfish (Chaetodontidae) are among the most colourful and conspicuous of coral reef fishes. There are about 129 species found worldwide, of which 20 are found around Aride. Most species are small (between 12 and 30cm), often have disk-shaped bodies, some yellow-colouration, and a long terminal mouth with highly modified brush-like teeth. They are mostly diurnal and home ranging. At night they rest and seek protection among corals. Many are generalists that feed on a combination of coral polyps, small invertebrates, fish eggs and filamentous algae. Others are specialists. Corallivores are territorial and restricted to areas near their food corals, while Planktivores occur typically in the mid-water column.
DID YOU KNOW? Butterflyfish have a fascinating relationship between sexual behaviour and food. Invertivores tend to be polygamous (they form mating pairs, but may change partners with each mating). Corallivores tend to be monogamous (they remain with the same mate for life). Planktivores are promiscuous (randomly mate with any member of the opposite sex within the aggregation).
Skunk Clownfish Amphiprion akallopisos
Seychelles Clownfish Amphiprion fuscocaudatus
Clownfish live in the warm waters of sheltered reefs and shallow seas in the Pacific and Indian Oceans. There are around 30 known species of clownfish worldwide. Aride hosts healthy populations of Seychelles Clownfish Amphiprion fuscocaudatus (above right) and Skunk Clownfish A. akallopsis (above left: Dao Nguyen y James Hardcastle, CC BY 3.0, via Wikimedia Commons. They form symbiotic mutualisms with sea anemones and are unaffected by the stinging tentacles of the host anemone. Clownfish are omnivores. They eat dead anemone tentacles, leftovers from the anemone, plankton, mollusc, zooplankton, phytoplankton, small crustaceans and various algae. They catch prey by swimming onto the reef, attracting larger fish, and luring them back to the anemone. The anemone will sting and eat the larger fish, leaving the remains for the clownfish.
DID YOU KNOW? All clownfish are born male. When the dominant female dies, the dominant male will turn itself into a female. Male clownfish are dedicated fathers. They will prepare the nest for the female, guard the eggs, and clean the nest.
Lionfish (Scorpaenidae) have elongated pectoral fins that resemble the mane of a lion when fanned out. In addition to a number of soft fins, lionfish also have 18 needle-like venomous fins on their backs and undersides, which are used for predator defence. Lionfish have conspicuous aposematic warning colouration to alert predators of their venomous nature, exhibiting contrasting red, white, cream, brown or black stripes. There are about 12 species found worldwide, of which at least 3 are found around Aride. They are generalists and feed on a variety of prey types including small fish, molluscs and invertebrates such as shrimp.
DID YOU KNOW? Lionfish have evolved to be both very efficient predators and dangerous prey. These traits have allowed them to become aggressively invasive species in Western Atlantic Ocean and Gulf of Mexico outside of their native range. Due to their large appetites and generalist diets, invasive lionfish have decimated native fish populations in their introduced range, causing prey fish biomass in the Bahamas to fall by 65 – 95% in the 30 years since their invasion.
Moorish IdolZanclus cornutus is the only fish in the Zanclidae family. Closely related to surgeonfish but lacks a caudal blade. Grows to about 24cm in length, has an elongate snout and very long thin dorsal (upper) fin that trails behind when it swims. Vertical black, yellow and white bars across the body are distinguishing marks. Feeds mostly on sponges, but bryozoans, small molluscs, small crustaceans, hydroids, and tunicates are also on the menu.
DID YOU KNOW? The genus name Zanclus comes from the Greek word for "sickle" and refers to the sickle-shaped dorsal fin. The species name cornutus is from the Latin word for "horn", and presumably refers to the bumps over the eyes of adults (Brocken Inaglory, CC BY-SA 3.0, via Wikimedia Commons).
Moray Eel (Muraenidae) are distinguished by their snake-like body, massive heads, pharyngeal jaws (second set of teeth in the back of the throat that can lunge forward to grasp prey), and striking colouration. There are about 200 species found worldwide, of which 9 are found around at Aride. While some species have adapted to hunt a specific prey, many moray species are generalists and will capture fish, crustaceans, and the occasional squid or octopus. Moray eels are mostly active at night and have very poor vision. However, they rely on chemoreception, a physiological response to chemical stimuli, to catch their food.
DID YOU KNOW? Believe it or not – moray eels will team up with other fish to hunt the reef. This cooperative hunting behaviour is seen in a few different animals, but morays and groupers are commonly recorded. After giving each other a polite head nod, the two hunters take off through the reef. The moray can move easily through the inside of the reef, driving scared fish right into the grouper. At the same time, fish focused on avoiding the grouper make easy prey for the moray.
Parrotfish (Scaridae) are grazers, so named due to their parrot-like beaks and often vivid body colouration. There are about 95 species found worldwide, of which 20 are found around Aride. They all generally live up to 7 years and grow between 30-120cm. During the day, they spend most of their time grazing algae off the reef which helps keep the corals healthy. At night, parrotfish hide from predators by wrapping themselves in a mucus cocoon or finding a hiding place in the reef.
DID YOU KNOW? Parrotfish graze on algae that grows on or within hard surfaces (i.e. symbiotic algae or “zooxanthellae” in corals). Their mouthparts are designed to scrape or bite off chunks of substrate, grinding them between plates in the back of their throats and finally extracting the plant material in their intestines. This bioerosion process helps control algal populations, provides new surfaces for corals to settle and grow, and contributes to sand production.
Aride Marine Protected Area provides an important refuge for Endangered species such as the largest parrotfish – Humphead Parrotfish Bolbometopon muricatum (illustrated), which frequents its reefs in large numbers.
Rays and their close relatives, the sharks, comprise the subclass Elasmobranchii. Rays are the largest group of cartilaginous fishes, with well over 600 species in 26 families. Rays are distinguished by their flattened bodies, enlarged pectoral fins that are fused to the head, and gill slits that are placed on their ventral surfaces. Up to 12 species of ray have been recorded at Aride. Most rays have developed heavy, rounded teeth for crushing the shells of bottom-dwelling species such as snails, clams, oysters, crustaceans, and some fish, depending on the species. The majestic Manta Ray feed on plankton and can sometimes be seen feeding within the Aride Marine Protected Area.
DID YOU KNOW? There are around 60 species of stingrays. They usually have long tails with a spine and venom to protect them from predators. In fact, Greek dentists once used the venom as anaesthetic.
Convict Surgeonfish Acanthurus triostegus
Powder-blue Surgeonfish Acanthurus leucosternon
Surgeonfish(Acanthuridae) are oval to elongate compressed fishes with a small terminal mouth adapted for grazing on algae. There are about 86 species found worldwide, of which 28 are found around Aride. Most species are fairly small, with a maximum length of 15–40 cm. They have long-larval stages resulting in wide distributions for most species.
DID YOU KNOW? The distinctive characteristic of the family is that they have one or more pairs of scalpel-like blades at the base of the tail, which may be used offensively or defensively against other competitors, inflicting deep and painful wounds.
Indian Ocean Oriental Sweetlips Plectorhinchus vittatus
Sweetlips (Plectorhinchus) have big, fleshy lips and tend to live on coral reefs in the Indo-Pacific in small groups or pairs. There are about 31 species found worldwide, of which 5 are found around Aride. They are usually seen in clusters in nooks and crannies or under overhangs. At nightfall, they venture from their shelters to seek out their bottom-dwelling invertebrate prey, such as bristleworms, shrimps, and small crabs. Sweetlips colouring and patterning changes throughout their lives.
DID YOU KNOW? Juvenile sweetlips generally look quite different from the adults, and often live solitary lives on shallower reef sections. Juveniles may be banded or spotted and are usually a completely different colour from the adults of their species. Small juveniles have an undulating swimming pattern, possibly mimicking poisonous flatworms as a means of predator avoidance. Oriental Sweetlips P. orientalis is illustrated.
Trevally (Carangidae) are moderate- to large-sized (50cm-170cm), deep-bodied, silvery to grey coloured fishes. The genus Caranx is one of 30 currently recognised genera of fish Carangidae family. There are about 18 recognised species in the Caranx genus, of which 14 are found around Aride. These carnivorous fishes may form schools or aggregations and occupy a wide range of habitats including estuaries, bays, reefs, and the open sea. All species are powerful predators, taking a variety of fish, crustaceans and cephalopods, while they in turn are prey to larger pelagic fishes and sharks. A number of fish in the genus have a reputation as powerful gamefish and are highly sought by anglers.
DID YOU KNOW? Some species will hunt opportunistically and strategically by trailing other carnivores as they forage including eels, sharks, rays, and marine mammals.
Chinese Trumpetfish Aulostomus chinensis
Trumpetfish (Aulostomus chinensis) is a medium-sized fish which grows up to 80 cm in length. Its body is elongated and compressed laterally, with a long, tubular snout which has a small barbel at the end. The protrusible mouth can be extended forward to catch prey. The body coloration can be uniform or mottled in a range of grey, brown, or dark green. Some fish are uniformly bright yellow. The rear part of the body is normally black with white dots. Two black spots are present on the tail.
DID YOU KNOW? It is a clever stealth hunter with two techniques to catch its prey. The first is the ambush, consisting of lying in wait for a potential prey close to coral. The second is the discrete tracking, where the trumpetfish stays close to some big fishes (groupers, carangids) or even hawksbill sea turtles Eretmochelys imbricata until it has the opportunity to approach unsuspecting prey. The Chinese Trumpetfish (illustrated) feeds on small fishes and crustaceans (Karelj, Public domain, via Wikimedia Commons).