My first time seeing this delightful little snail! It belongs to the Family Cassidae which are merciless predators of sea urchins and sand dollars. One way this snail gets at its prey is to squirts neurotoxic saliva to paralyse the spines. Then the snail sticks its snout through the prey's unprotected anus to eat it. Eeks.
Japanese bonnet snail (Semicassis bisulcatum) which has been seen before on Cyrene Reef by others on the team. I love the way the siphon stick out on the side of the shell so it can snorkel in the sand.
We saw lots of other fascinating molluscs on Changi too!
Another marvellous mollusc encounter, the Baler volute (Melo melo). We saw several today! This handsome snail is listed as 'Endangered' in the Red List of threatened animals of Singapore due to habitat loss. We had in the past encountered this snail being harvested at Changi for the cooking pot. So it's good to know this snail is still seen on Changi. So far, I've only seen this snail also on Chek Jawa and at Beting Bronok.
Watering Pot shell (Verpa penis). It is actually a bivalve! You can see the tiny pair of bumps on it, all that is left of the 'valves'. This animal is listed as "Presumed Nationally Extinct" on the Red List of threatened animals of Singapore. But a paper in Nature in Singapore (pdf) found that recent sightings suggest this animal is alive and well on our shores.
Olive snails (Family Olividae)! These snails are also burrowing predators.
Ball moon snail (Polinices didyma), a few Tiger moon snails (Natica tigrina). James saw a Noble volute (Cymbiola nobilis) and Kok Sheng saw what seems to be a Naked moon snail (Sinum sp.).
Today, there were many MANY Window pane shells (Placuna sp.) of all sizes. From huge ones the size of small dinner plates, to little coin sized ones and very very tiny ones hardly bigger than a pinkie finger nail! I took a closer look at the living animal, and it seems to have short tentacles around the valve opening.
Hammer oyster (Malleus sp.), and lots and lots of Fan clams (Family Pinnidae), many of them seem rather young. When submerged, these clams open their valves very slightly revealing a curtain of lips. Live fan clams are homes to all kinds of encrusting animals. When dead, they shelter animals like fishes and crabs, and also provide a safe place to lay eggs.
Pink sand dollars (Peronella lesueuri) were incredibly plentiful! I have no idea why we have started seeing so many of them on this shore recently. Kok Sheng remarks this seemed to have happened after the oil spill in May 2010...hmmm. These pink sand dollars now seem to outnumber the Cake sand dollars (Arachnoides placenta) on this shore.
Biscuit sea stars (Goniodiscaster scaber), tiny to small, and some Plain sand stars (Astropecten sp.). Kok Sheng also found an orange Cake star (Anthenea aspera). But this shore is not as 'starry' as the other stretch we visited yesterday.
Knobbly sea stars (Protoreaster nodosus) on this shore! There was one that looked like a miniature version of the adult, and Mei Lin found another that was green.
White sea urchins (Salmacis sp.) on the shore today. These animals tend to carry all kinds of bits and pieces. But this is the first time I've seen one literally wrapped up in a sand collar! The sand collar is the egg mass produced by a moon snail and contains countless tiny snail eggs. When the eggs hatch, the collar disintegrates.
Thorny sea urchin (Prionocidaris sp.), and two Black sea urchins (Temnopleurus sp.).
Thorny sea cucumbers (Colochirus quadrangularis) on the shore today. Scattered in the meadows and piled up in clusters on hard surfaces. Also surprisingly common today were the Pink warty sea cucumbers (Cercodemas anceps).
Remarkable sea cucumbers (Holothuria notabilis), one Beige sea cucumber and some See-through sea cucumber (Paracaudina australis). There were plenty of Smooth sea cucumbers and Ball sea cucumbers (Phyllophorus sp.) buried in the sand. We also saw some Orange sea cucumbers, Purple sea cucumbers. Marcus saw one 'Garlic bread' sea cucumber (Holothuria scabra). We didn't see any Polka-dotted sea cucumbers (Holothuria ocellata).
rabbitfishes (Family Siganidae) and filefishes (Family Monacanthidae).
Mangrove whiprays (Himantura walga)! They were so cute. Ivan thinks perhaps they have just been born? Whiprays give birth to live young! Our seagrass meadows are a nursery for many young animals.
Longspined scorpionfishes (Paracentropogon longispinis). I love the thorny flap that this fish has above its mouth. It's hard to take a photo of the fish with this flappy bit expanded.
Commerson's sole (Synaptura commersonnii) and Marcus found a funny flounder. But alas, we looked and looked and didn't find any Estuarine seahorse (Hippocampus kuda) here. Oh dear. I hope they are just well camouflaged or have moved to deeper water for this low spring tide.
It's also a very crabby shore. I saw lots of swimming crabs (Family Portunidae) of various kinds. Among the crabs that I paid attention to were these small crabs. It seems to have 'elbow pads'! Hmmm....parasites?
Spotted box crab (Calappa philgarius) on the high shore! The pincers of box crabs are specialised for cracking open snail shells. The snail is gripped in the left pincer which has pointed claws. With the right pincer, which is stronger, the crab cuts pieces of the shell from the shell opening. Once the gap is big enough, the crab can enjoy its snail meal!
Striped hermit crabs (Clibanarius sp.) had settled into a broken shell so that I could clearly see its abdomen and the tiny little legs on the abdomen that hold on the shell. Something we usually can't see!
Haddon's carpet anemones (Stichodactyla haddoni) on this shore. Some of them had a pair of Five-spot anemone shrimps (Periclimenes brevicarpalis). But this shore didn't have very many kinds of anemones. Although there were a lot of large Swimming anemones (Boloceroides mcmurrichi), I only saw one Peachia anemone (Peachia sp.) and a few Tiger anemones. I saw only a few cerianthids (Order Ceriantharia).
flowery sea pens (Family Veretillidae) and Spiky sea pens (Scytalium sp.), each occupied by a pair of Painted porcelain crabs (Porcellanella picta).
Sea pencils in the sand bars and among the seagrasses. Sea pencils are a kind of sea pen that I don't see in large numbers on other shores. Sea pens are a colony of tiny polyps.
Geographic sea hare (Syphonota geographica), and James found the Spotted sea hare (Aplysia oculifera).
cuttlefishes or octopus. Although there were lots of empty shells on the shore, I couldn't find any living Button snails (Umbonium vestiarum).
Although the seagrass meadows were generally lush, there were large patches of Fern seagrasses (Halophila spinulosa) which have lost their leaflets, leaving only bare stems. Abundant on the shore were Spoon seagrasses (Halophila ovalis) with large fresh green leaves and lots of Needle seagrass (Halodule sp.).
Tumu berau (Bruguiera sexangula)! Wow! Facing the Johor River mouth and Pulau Ubin and Pulau Tekong (which has lots of mangroves), all kinds of interesting mangrove propagules land on Changi with the tides.
October 2010. It seems to be still very much alive!
In a few hours, ANOTHER early wake up call for another trip to another great shore! This time with TeamSeagrass for monitoring at Pulau Semakau.
Other posts about the trip to Changi