Chek Jawa
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Leatherjacket fish (Family Monacanthidae)
These fish are named after their tough, rough skin. They are sometimes also called Filefishes. Juveniles, like this one, may be hardly bigger than a seagrass leaf. -
Grouper (Family Serranidae)
This one was trapped in a pool in the middle of the seagrass lagoon. It kept very still and was hard to spot. We left it alone to avoid stressing it. -
Three red Swimming Crabs
Crabs are important scavengers and an important food source for sea creatures, both as a larvae and adult. They are also eaten by land creatures like birds and mammals. Humans, of course, relish crabs as a delicacy. -
Spider crab (Family Majidae)
They are called Spider crabs because of their spider-like legs. These tiny well camouflaged crabs are often overlooked. -
Mud Crab (Scylla sp.)
A common, popular food crab, they feed on any animals they can find, preferring shelled molluscs which they crush with their powerful claws. Their last pair of legs are paddle-shaped, but these are used to burrow rather than swim. They can stay out of water for a long time. -
Elbow Crab (Family Parthenopidae)
A tiny crab with distinctive long pincers, it is usually found near seagrasses. It feeds on small creatures that wander within reach of its unusually long pincers. Because it is so well-camouflaged and slow moving, it is rarely spotted. -
Myriad tiny crabs are found among the seagrass and algae. -
A crab with a well camouflaged body, but brightly coloured appendages. -
Swimming Crab (Thalamita sp.)
These bright red crabs swim well with their paddle-shaped last legs. Very aggressive crabs, they even wave their vicious-looking pincers at people. But they rarely actually pinch anyone. -
Swimming Crabs (Thalamita sp. or Charybdis sp.)
In crabs, mating occurs when the female has just moulted and her new shell is not yet hard. Thus males may protect a female just before she moults, so he can have first access when she is able to mate, and may continue to protect her until her shell hardens. -
Flower Crab (Portunus pelagicus)
A common popular food crab, they are more active at night, hunting small fish and other animals, swimming quickly with their last paddle-shaped pair of legs. -
Flower crab (Portunus pelagicus)
The males are blue with long pincers and colourful markings, while the females are duller brown or green. During the day, they hide in sand, mud or sea grass. Their empty shells are often seen on Chek Jawa, but these are mostly moults. -
Mating Flower Crabs (Portunus pelagicus)
The bright blue male is on top of the duller coloured female. -
Purple Climbing Crab (Metapograpsus sp.)
These colourful crabs squeeze into the tiniest crevices. They use their pincers to scrape off algae which is their main food. But they will eat anything else they can get hold of and manage. -
Volute (Voluta nobilis)
We often come across this shell, but usually, hermit crabs have taken over. Volutes are carnivorous. They prey on bivalves, enveloping the victim completely with their foot forcing the bivalve to finally open from exhaustion and lack of oxygen. They can grow to more than 20cm and used to be common. The local name is 'kilah' and they are sometimes eaten. -
Spiral melongena (Pugilina cochlidium) laying its eggs
This snail lays its eggs in rows on hard surfaces. Each "petal" is an egg capsule. -
Venus clam (Family Veneridae)
Venerid shells are strong burrowers, digging in vertically by violently rocking themselves. This particular species are edible and often collected for food. This one has its siphon extended to feed. -
Venus clam (Family Veneridae)
This Venus clam has pretty lines. Although clams are among the favourite seafood of people everywhere, they are among the sea creatures that are affected by red tide. During a red tide, there is a bloom of harmful micro-organisms that do not kill the clam but is toxic to humans that eat the clam. -
Whelk (Nassarius sp.)
This tiny whelk has an even tinier passenger: a sea anemone on its shell. These scavenging snails are commonly seen. They can move rapidly especially when they detect the aroma of the recent dead! -
Olive whelk (Nassarius olivaceus)
This whelk is much larger than the other more commonly seen whelk species. -
Fan Shell (Family Pinnidae)
Burying themselves in sand with only their widest parts protruding out of the sand, these shells can grow to more than 10cm. Their edges are sharp and can cut unprotected feet. -
Fan Shell (Family Pinnidae)
This large living Fan shell was found above the sand. We left it in the water after taking a photo of it. Fan shells were once common on the sandy beaches of Singapore. They are now rare elsewhere in Singapore. -
Green mussels (Perna viridis)
These large bivalves attach to hard surfaces by byssus threads. They are adapted to water with a high silt content. Also called 'kupang', they are edible and eaten locally. -
Button Shells (Umbonium vestiarum)
So beautiful that we have dubbed them "the Jewels of Chek Jawa", hundreds of these tiny snails are found in the northern arm of the sand bar. They are preyed upon by the moon shell. -
Onyx cowrie (Cypraea onyx)
The Onyx cowrie is not seen as often as the Ovum cowrie. It has a handsome black body which covers the glossy shell when the snail is alive..