Chek Jawa
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Solitary Ascidian or Tunicate (Class Ascidiacea)
Their name comes from the Greek 'askidion' which means 'leather wine bag'. Hence their other name 'tunicate' from the leathery 'tunic' of their outer skin. Essentially, they are a hollow sack made of tough leathery tissue, with two openings. The creature creates a current through these openings, passing water through an internal filter which traps minute edible titbits. -
Compound Tunicates (Class Ascidiacea)
Some Ascidians form colonies. The individuals in a colony are connected, allowing them to share food. Compound tunicates can some in a bewildering array of shapes. -
Compound Tunicate or Ascidian (Class Ascidiacea)
Colonial tunicates can take strange forms, including this one, which is often encountered at Chek Jawa. Their free-swimming larvae have a primitive spinal chord, so these creatures are placed in the same phylum as humans!! -
Compound Tunicate or Ascidian (Class Ascidiacea)
The pilings under the jetty near House No. 1 are covered in colourful compound tunicates. -
Compound Tunicates (Class Ascidiacea)
Orange, brown and white tunicates form an out-of-this-world scene under the jetty! A sea anemone lies below them in the water. -
Compound Tunicate (Order Ascidiacea) -
Solitary Tunicate (Order Ascidiacea)
These strange orange striped creatures are solitary tunicates. They are often encountered attached to rocks or other hard surfaces. -
Fan Worms (Sabellastarte sp.)
Fan worms or tube worms are segmented worms that have developed feathery tentacles, and secrete a tube to hide in. -
Fan worm (Sabellastarte sp.)
Fan worms build tubes. At the slightest sign of danger, they retract into their tubes for safety. -
Fan worm (Sabellastarte sp.)
Fan worms are quite common in the coral rubble area. They come in various colours and sizes. -
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Fan Worm (Sabellastarte sp.)
Fan worms have feathery tentacles lined with tiny cilia (beating hairs). The tentacles generate a current of water through the fan. The cilia trap edible titbits from this current and move the food particles into the central mouth. -
Fan Worm (Sabellastarte sp.)
Fan worms have separate sexes and reproduce by releasing eggs and sperm simultaneously into the water. -
Fan Worm (Sabellastarte sp.)
Fan worms appear to be more active at night. -
Fan Worm (Sabellastarte sp.) -
Fan Worm (Sabellastarte sp.) -
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Seagrass beds
Seagrass grows thickly in the lagoon that forms behind the sandbars on Chek Jawa. -
Feathery green seaweed (Caulerpa sertularioides)
This seaweed is often mistaken for seagrass. It is quite common on Chek Jawa. -
Ribbon sea grass (Cymodocea rotundata) with grazing snails
Sea grass like other "normal" land plants have veins, roots and bear flowers. They photosynthesise and so are green. Although few animals can digest living seagrass, tiny algae often grow on the seagrasses and this algae is eaten by lots of animals. -
Sea Grapes (Caulerpa racemosa) with Feathery green algae (Caulerpa sertularioides)
Sea grapes are also seaweed. They are edible and cultivated in some places as food for humans as well as livestock. -
Fern seagrass (Halophila spinulosa)
Elegant fronds of this refreshingly green sea grass forms thick meadows on Chek Jawa. Their leaves provide shelter for all kinds of small animals, while their roots stabilise the sediment for burrowing creatures. -
Carpet anemone growing among clumps of seaweed (Caulerpa sp.)