Batfishes
Also known as the Longfin Spadefish, these curious fishes are often seen accompanying divers on their dive's descend and ascend. There are 5 species in the Indo-Pacific region. Another favourite amongst marine aquarists, the Batfish looks magnificent in the reefs' clear water . They travel in synchronised movements on outer reaches of the reef or around shipwrecks and easily recognisable from a distance from the compressed, disk-shaped body. It has a tiny mouth with a set of small, brush-like teeth that is useful in scraping off algae and scooping small invertebrates from the seabed.
Its juveniles have exaggerated dorsal, anal and pelvic fins. The fins may measure 1½ times the length of the oval shaped body mass from anal fin tip to dorsal fin tip. As they grow into adults, the fins reduce proportionately until it resumes its adult disk-shape.
The Boersiis Spadefish (Platax boersii) is another Batfish specie that is found in the Malaysian waters. The Silver Batfish or Silver Moony (Monodactylus aregenteus) feeds on plankton and detritus are usually found in estuaries and can live in rivers but sometimes it ventures out into silty coastal reefs.
Trumpetfish
This solitary, odd-looking fish is found throughout the Indo-Pacific region. The Trumpetfish family consists of only 3 species and all are piscivores, which means that their diet is based mainly on fish. It eats all kinds of fishes including wrasses, gobies, damselfishes, cardinalfishes, blennies, goatfishes, and sometimes shrimps. One may not be able to envisage how a fish with such long, tubular snout can fit in its prey.
The Trumpetfish, in fact has expandable jaws that enables it to suck in prey that is larger than its normal jaw opening. This method is rather similar to that of snakes. Like snakes, the Trumpetfish does not have teeth for tearing of flesh, hence it swallows its victims whole. In order to do that, the Trumpetfish shadow stalks its prey where they swim close to another large nonpredatory fish like the surgeonfish or parrotfish to get closer to an unsuspecting victim. Once close enough, it swiftly attacks its prey.
Since Trumpetfishes hunt only in the day, they need a lot of camouflaging to pull off this act of shadow stalking. Special colour cells in the body, called chromatophores, enables the Trumpetfish to change colour to blend in at will. The Trumpetfish is able to blend in with the coral surroundings and sometimes with other fishes as well. It can change from red or brown to blue or bright yellow to match its shield.
This sneaky piscivores has been seen poking around at cleaning stations. This is one place where by unanimous agreement that all predatory activities are put aside, sort of a 'time out' . Here, all interest is focussed on cleaning activities only. But not the Trumpetfish. Here they take advantage of the situation to prey on the smaller fishes such as the damselfishes and certain wrasses, busy cleaning its customers. Trumpetfishes also take advantage of the fading sunlight during sunset to surprise unsuspecting victims but as night falls all hunting activities cease and the Trumpetfishes retire for the night. Although solitary in the day, at night divers may find groups of Trumpetfishes sleeping together, hanging snout down amongst long weeds and sea grass in shallow waters. This safety in numbers grouping is a form of defence from other night predators such as snappers and groupers that may feed on them.
Squirrelfish or Soldierfish
Snorkellers and novice divers seldom see Squirrelfishes as they are usually hidden in caves and holes, sleeping off the daylight hours. Squirrelfishes are in fact, nocturnal which means that they come out during the night to search for food. As the diurnal fishes retreat into their hiding places as the sunsets, the nocturnal fishes begin to emerge from theirs. Usually, the Cardinalfishes would be the first to leave their holes, staying close to the bottom. The next to appear is the Squirrelfishes. These tiny fishes are exceptionally noisy, emitting a series of staccato calls, sounding like, "click, click" believed to be a form of communication amongst family members. They also emit a series of rhythmic grunts when threatened by intruders or when attempting to chase away other fishes.
Squirrelfishes feed on invertebrates such as shrimps and other small crustaceans. As there are different types of fishes plying the reefs between day and night, there are also different types of food available during the day and at night. Even the plankton changes. At night, shrimps and other tiny invertebrates leave their day hideouts on the sandy bottoms for the open water to feed on the microplankton. This makes them easy targets for nocturnal fishes. Other crustaceans, starfishes, sea urchins, worms and molluscs leave their safe crevices to scour the sandy bottom for food. The smaller 'items' are snapped up by the smaller species combing the area, such as squirrelfishes and cardinalfishes. The larger ones are food for bigger predators like the stingrays. The squirrelfishes have adapted well to their conditions through thousands of years of evolution, and instead of competing for food with other predators during the day, it has coped with hunting at night.
This fish as with many types of Squirrelfishes, have red coloration, large scales and large eyes. The majority of Squirrelfish species are benthic, or bottom feeders. We know, as we descend deeper into the ocean, illumination gets poorer and poorer. How does the fish especially a nocturnal one see in such darkness? The fish must have very large eyes to capture as much light as possible. The Squirrelfish has massive eyes that protrude from the body. With this, the fish has a much wider field of vision and because the eyes protrude means that this enables to see a large area without having to turn their body.
The pinkish red colour helps them blend into the darkness. There are at least 30species of Squirrelfishes in South East Asia. During the day, some Squirrelfish species can be spotted quite easily sleeping in holes and some can be seen huddled in groups, suspended in coral valleys or over holes. Try not to handle these fishes as they have sharp spikes on the fine and head, which can cause a nasty wound.
Catfish
Divers will have frequent encounters with these fishes in the Malaysian coral reefs. It is often thought that catfishes are only found in freshwaters. Most are confined to estuaries and brackish coastal waters but there are a few that are found on reefs. Catfishes are easy to recognise from the barbels or feelers that are seen around the mouth. The juveniles are most often seen and form large groups when they swim up and down the reefs. The group sometimes made up of several hundred individuals, move in synchronised motion. This helps as the mass formed often fool predators into thinking that the aggregation is a much larger animal.
The adult Catfishes have venomous fin spines and should not be approached at any time. It can inflict painful wounds.
Illustrations provided by Dennis Ho: Underwater photography by Moti Uttam
Corals & Fishes in Malaysia
| Corals - Hard & Soft Corals | Eels | Sharks | Rays | Octopus | Squids and Cuttlefish | Nautilus | Nudibranchs | Clams | Starfish | Brittlestars | Featherstars | Sea Urchins | Sea Cucumbers | Worms | Sponges | Jellyfish | Damselfish | Butterflyfish | Angelfish | Surgeonfish | Parrotfish | Wrasse | Triggerfish | Batfish | Trumpetfish | Squirrelfish | Catfish | Grouper | Athias | Sweetlips | Fusiliers | Puffers | Filefish | Trevally | Snappers | Scorpionfish | Cardinalfish | Goby | Barracuda | Rainbow Runner | Pompano | Bream | Goatfish |
