Divewerkz would like to give you an overview about commonly encountered marine life in South-East Asia to make your future dives even more rewarding.
Why ID fish?
To many divers identifying fish may be an overwhelming task. But, believe
it or not, with the right approach, it’s fun and easy.
Better dives
When you are
able to recognize fishes you have a mental description of the dive. Remember
those times when you get frustrated describing a fish and nobody seems to
understand what you are talking about? Knowing the names of fishes helps
communications with other divers and you get more out of the dive.
Aid navigation
Certain fishes
are territorial and when you recognize them they become the landmarks for
your course of travel. Fishes such as clownfish and damselfishes live and
often feed within a certain area.
Safer diving
Knowing which
fish is dangerous is obviously important. Scraps with fishes such as surgeonfish,
stonefish or scorpionfish can leave you with serious injuries.
How to ID fish?
Shapes
The first step
to identifying fish is to put them into their family group. Classifying
with shape and general features is the easiest way to identify the family
they belong to.
Size and special markings
Within the same family, some fishes look incredibly identical. If this is
the case, take note of the size and confirm it with the size in fish ID
books. Also take note of specific features and/or markings on the fish.
To do this it helps to learn the parts of the fish (see below) and jot down
the markings observed on a slate.
Depth and habitats
Fishes
have distinct habitats. Some fishes favour deep waters whilst others stay
within 20 metres from the surface. Some are primarily coral dwellers such
as anthias, whereas fishes such as goatfish and gobies stay mainly on sandy
bottoms.
Below we offer you some brief explanations about fish
groups along with their typical outlines to help you identify them more
easily. Click on the fish outline (they are not to scale) to be directed to a website with
a lot of pictures of the respective species.
Batfish: Highly exaggerated dorsal, anal and pelvic fins.
Young fish occur singly or in small groups and stay near reefs.
In Asia, the Pinnate and Teira Batfish are commonly sighted.
The juveniles have very long fins that become proportionally
shorter as it grows. |
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Butterflyfish: Round and small and have concave foreheads.
They often have snouts for feeding from crevices and corals.
Butterfly fishes are renowed for their striking colours and
graceful swimming patterns. Most are active during the day and
stay within 20m depth. Many feed on corals and small invertebrates.
They are often seen in pairs. |
|
Bannerfish: The bannerfish belongs to the butterflyfish
family. They have unusually long dorsal fins and are usually
not more than 20cm long. At places like Sipadan and Layang Layang, the
schooling bannerfish form a beautiful picture against the bluewater
backdrop. |
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Angelfish: They have long dorsal fins and rounded foreheads.
Most angelfish are found in boulders, caves and large crevices.
Most stay within a certain territory and they are one of rare
species that feed on sponges among other things like algae,
zooantharians, tunicates, gorgonians, hydroids and seagrasses.
During their growth from juvenile to adult, they take on the
most dramatic transformation. |
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Surgeonfish: Somewhat horse-shaped or sloping face with spines
sticking out from each side of their tail base. Most surgeonfish
are docile and travel in schools. They feed on algae and seaweed. |
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Jacks:
Also called trevallies, usually silver or blueish in colour,
seen in open water at reef’s edge. The most frequently sighted
jacks are the big-eyed, golden, black and blue-finned trevally.
The largest trevally, the Giant Trevally is an awesome sight
and can grow up to 1.7m and weigh up to 170 kg. In places such
as Sipadan and Layang
Layang you can often see trailing
sharks under a group of hunting travellies hoping to feed of
the scrapes of the hunt. |
|
Barracudas: Long cylindrical and silver with faint markings.
Large mouths with visible teeth. Large barracuda tend to travel
alone, but smaller species may gather in groups. Schooling barracudas
can number to a thousand and are a spectacular sight! |
|
Snappers: Long tapered bodies and heads that slope towards
the mouth. Common commercial fish. Most snappers are brightly
coloured and active predators of smaller fishes, crabs shrimps,
gastropods, cephalopods and planktonic organisms. |
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Sweetlips: Look quite similar to snappers, their most distince feature is their lips which seem to be swollen. Often found hovering under coral tables or just above reefs. |
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Damselfish: Small, oval fish that dart in and out of crevices
on the reef. Algae feeding damselfishes are very territorial
of their food turf. Damselfishes make up one the most abundant
groups of coral reef fishes. Most are small, and are not bigger
than 15cm. It is believed that the drape coloured species feed
on algae and their brightly colour counterparts feed on plankton. |
|
Groupers: They have bigger and rounder bodies with
large mouths and lips. Commonly in brown, black or reddish colour
with splotchy markings. Mostly solitary and stay in shadows
of sloping reefs. |
|
Fairy Basslets: Also know as Anthias. Very tiny and colourful
fish that brighten the reefs as a rainbow does. They often stay
in large aggregations and swim in tandem against the current
above corals. |
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Parrotfish: Beak-like teethplates and rainbow colours, much
like parrots. They swim with their pectorals fins, and often
scrape algae off hard surfaces. Like wrasses, parrotfish undergo
female to male sex change according to growth stage. The colours
between the sexes can be so different that they have long been
regarded as different species! |
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Wrasses: Generally smaller than parrotfish, usually foraging
through sand and the reefs. Wrasses make up the second largest
group of reef fishes after the gobies. They are very active
and are constantly foraging for small crabs, shrimps, worms,
and other small bottom dwelling invertebrates. |
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Squirrelfish: Pronounced rear dorsal fin that sticks out like
a squirrel and very large glassy eyes. Hidden in crevices and
under ledges. Squirrelfishes are nocturnal and during the day,
they are found hidden inside caves or under large crevices.
They come out to hunt shortly after sunset. They feed primarily
on night animals such as crustaceans and echinoderms. |
|
Bigeye:
Bigger eyes than squirrelfish, with continuous dorsal fin and
they appear less scaly. Like squirrelfishes, they are nocturnal
and feeds on cephalopods, crustaceans and fishes. |
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Cardinalfish: Small and reddish, with short snouts and 2 separate
dorsal fins. They are small reef dwelling fishes and crustaceans.
Some species, form large shoals over entire coral formations. |
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Blennies and Gobies: Long bodies and generally perched on their pectoral
fins. Most blennies are less than 15cm long, and are bottom
dwellers, feeding on small invertebrates, algae and bottom detritus.
Several species such as the False Cleanerfish have large teeth
of the lower jaw that is used mainly for defense. |
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Flounders: also know as Flatfish, are amazing bottom-dwelling
creatures, masters of camouflage. They change colour to blend
into the bottom colours. Both their eyes are on the same side
and they move independently. |
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Scorpionfish: Stocky and rough bodies, with spiny dorsal
fins that carry venom. Still and pretends to be a piece of rock.
Scorpionfishes varies from mottled brown colour (for those found
in rocks) to bright red in colour, found in caves and deeper
sections of the reef. |
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Lizardfish: Elongated bodies and large upturned mouths.
Often perched motionless on corals and bottoms. Lizardfish look
somewhat like a cross between a monitor lizard and a chameleon.
They lay like a monitor lizard with their bellies on the coral,
and pretend like they are part of the "furniture". |
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Frogfish: Bulky bodies with large upturned mouth. Blend
well with bottom, and often motionless. Some have appendage
that dangles in front of their mouths, which baits unsuspecting
fish. |
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Filefish: Oval or diamond shaped with rough textured skin.
Elongated pointy dorsal fins. Filefish are the sweetie pies
of the reefs. They move daintily with slow measured movements.
When there isn’t any big fish action to watch, the filefish
can provide amusement and enjoyment. |
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Triggerfish: Oval or diamond shaped bodies with elongated
pointy dorsal fins similar to a gun’s trigger. Most triggerfish
species are solitary in habit, and they use their strong teeth
to crush hard-shelled prey such as crabs and molluscs. Most
triggers are same and harmless such as the pretty Picasso Triggerfish.
In Asia, the larger species such as the Yellowmargin and Blue-finned
triggers should be treated with respect, particularly during
their nesting period. |
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Pufferfish: Round bodies and can inflate their bodies when
threatened or scared. They are strange creatures with bodies
encased in a bony carapace and fins are relatively small. They
are slow swimmers, but capable of short, rapid bursts. The spiky
ones are called Porcupinefish. The non spiky puffer has no scales
and have beady eyes. Under no circumstances should puffers be
eaten. Some carry toxins that may cause serious illness and
death. |
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Trunkfish/Boxfish and Cowfish: Boxy and rectangular bodies. Cowfish have two
‘horns’ on their heads. Common species in Southeast-asian waters
are the Striped trunkfish and Black-saddled Toby. |
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Goatfish: Long cylindrical bodies with two widely seperated
dorsal fins, and a pair of long chin-barbels that are used for
detecting food in the sand. The barbels are also used by males
to attract females during courtship. When they are not used,
you can hardly see them as they are tucked tightly under their
chin. |
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Trumpetfish: Long tube-like bodies with long pouty mouth.
They stalk by handing head down, often near corals to camouflage
themselves. A common species is the Painted Trumpetfish. |
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Eels:
Snake like and often hiding in crevices and holes. Eels
are shy creatures in the day, and at most, peek out of their
crevice. However they transform to another creature as night
falls. Eels have been found free swimming in the night, foraging
for food such as small fishes. With their gaping mouths they
are excellent photographic subjects. |
Fish parts
|
1 barbel |

Lionfish showing off