Nemo on Anemone @ Little Sisters Island 03Jan2010

nemo2010 from BeachBum on Vimeo.

The rising tide enabled the anemone to show it's true form. At the lowest tide, the anemone was almost out of water and the resident false clownfish (Amphiprion ocellaris) was nowhere to be seen...possibly hiding below the anemone's folds. This is the same anemone pictured in an earlier clip glowing in the dark when a bluish light was cast upon it.

Once the incoming tide floated the anemone's disc, the very active false clownfish appeared. It was about 4cm long and constantly kept moving about amongst the anemone's stinging tentacles. Any other fish would have been stung by the numerous stinging tentacles. Human skin is supposedly too thick for the stinging cells to penetrate effectively but one can usually feel a little numb around the contact points after prolonged contact.

Interesting fact : 'all clownfish are born male'

There may have been smaller clownfish hiding below the anemone. The largest nemo on an anemone is typically female whilst all the smaller ones are male. When the dominant female dies, the next largest nemo switches from being a male to be a female.

Read more about clownfish trans-sexuality here :
Ask a Geneticist : http://www.thetech.org/genetics/ask.php?id=28
FAQs on Clownfish : http://www.chehaliscoral.com/page.php?id=10
Redefining Nemo : http://www.flmnh.ufl.edu/fish/InNews/nemo2006.html
Smithsonian Zoogoer : http://nationalzoo.si.edu/Publications/ZooGoer/2004/2/wildersideofsex.cfm

For general info about the false clownfish :
http://www.wildsingapore.com/wildfacts/vertebrates/fish/pomacentridae/ocellaris.htm
and it's host anemone : http://www.wildsingapore.com/wildfacts/cnidaria/actiniaria/gigantea.htm

More links :
http://www.fishbase.org/Summary/speciesSummary.php?ID=6509
http://www.flmnh.ufl.edu/fish/innews/clownfish2003.html
http://en.wikipedia.org/wiki/Clownfish

bioluminescent anemone @ little sisters island 03Jan2010

bioluminescent anemone from BeachBum on Vimeo.

I was curious to see if the anemone did give off or reflect certain wavelengths of light. It does seem to react to the blue LED light from my torch. The tips of the tentacles were bright blue-green for a few moments. You can see the difference as compared to when the xenon bulb was used towards the end of the clip.

Various other organisms like some corals and zooanthids also exihbited a similar reaction. This will make for interesting experimentation on future biodiversity exploration trips.

Find out more about this anemone here :
http://www.wildsingapore.com/wildfacts/cnidaria/actiniaria/gigantea.htm
http://en.wikipedia.org/wiki/Stichodactyla_gigantea

Cute Cute Cephalopod

cute cute squid from BeachBum on Vimeo.

There were a good many squid which started appearing when the tide turned shortly after dusk. They kept close to the cover of sargassum seaweed. The squid adopted various poses for the camera but interestingly enough did not try to propel away in a cloud of ink. This could have been because the animals were waiting for small fish to swim by...fishing.
Watch closely and you will see the chromatophores pulsating. Some parts of the cuttlefish, especially near the eyes seemed to have a iridiscent glow. However, these pencil squids did not exhibit the level skin colour changes like that seen in the octopuses and cuttlefish seen on Singapore's other shores. Those were visibly much more dynamic compared to the display showed by these pencil squids.

time of night : about 7.30pm
depth : about 10 to 15 cm
average length : about 7cm

I did have some confusing moments as to whether to describe the cephalopod as a squid or as a cuttlefish. I initially thought they were cuttlefish but later changed my mind because of the pencil like shape of this particular species. Cuttlefish apparently tend to be broader laterally. Well, they are cephalopods anyway!

Read more about them and other information about cephalopods here :
http://en.wikipedia.org/wiki/Squid
http://www.wildsingapore.com/wildfacts/mollusca/cephalopoda/squid.htm
http://www.wildsingapore.com/wildfacts/mollusca/cephalopoda/loliginidae.htm
http://www.ucmp.berkeley.edu/taxa/inverts/mollusca/cephalopoda.php
http://news.nationalgeographic.com/news/2004/01/0108_040108_squidflashlight.html
http://www.cephbase.utmb.edu/
http://www.weichtiere.at/Mollusks/Kopffuesser/haupt.html


Question : how does one differentiate between a squid and a cuttlefish?
See one answer here http://www.cephbase.utmb.edu/TCP/faq/TCPfaq2b.cfm?ID=5

Another question : why are cuttlefish called cuttlefish?
Click here for the answer!!!

tiny spotted horned slug 04Dec2009

tiny spotted horned slug from BeachBum on Vimeo.
This little slug, Plakobranchus ocellatus, was about 1.5cm long. It could contract and expand it's body at will. It was found rummaging on a muddy shore near a mangrove. There were quite a few of them around on the same part of the shore. It was difficult to notice the spotted pattern until one gets really close. The clip seems to show that the slug was moving fast ... relative to itself. It also had the ability to produce a copious amount of mucous to facilitate gliding over the substrate.
Although it looked largely sand brown coloured from a distance, parts of it were slightly greenish(chloroplasts?), brown-pink and grey. It does looks as if the upper part of the slug was being covered inwards by two parapodial flaps one on either side. However, they were not observed to open similar to how the geographica sea hare 'flies' through the water.

Read more about this slug here : http://www.seaslugforum.net/placocel.htm (CH, thank you for the link!)
Here is another interesting link : http://www.seaslugforum.net/factsheet/solarpow

upside-down jelly@04Dec2009

upside-down jelly 04Dec2009 - Southern Islands ~ Siingapore from BeachBum on Vimeo.

These upside-down jelly(fish) are commonly seen around mangrove mudflats and beaches around Singapore. They turn themselves upside down and rest on the bottom substrate pulsating along all the time to enable the symbiotic algae in their body tissues to receive sunlight from above. These symbiotic algae use the sunlight to make food...some of which benefits the jelly. When upside down, the jellies are frequently mistaken for anemones.

The jelly also uses it's stinging tentacles to catch plankton for food.

Crabs sometimes use the upside down jellies (and some types of anemones as well) to protect themselves by carrying them on their shells.

Size : about 6cm across.

Find out more about this and other types of jellyfish here :
WildSingapore's WildFacts on Cassiopea

Wikipedia on Cassiopea
Jellyfish Facts on Cassiopea
Monterey Bay Aquarium's link on the Cassiopea
Interesting Facts about Jellyfish
The largest jellyfish
The most poisonous jellyfish
What do Jellyfish eat?
Jellyfish species

Elysia ornata Leaf Slugs@Tanah Merah 06Dec2009

Elysia ornata @ Tanah Merah 06Dec2009 from BeachBum on Vimeo.

Came across these Ornate leaf slugs cruising on the sandy bottom at Tanah Merah.
Usually difficult to spot amongst seagrass and seaweed as they are rather small at about 6cm long and greenish. However, this time they were easily noticeable as they were on bare sand. There was very little seaweed around too. Strangely, the slugs were rumaging on the sandy bottom instead of feeding on the Bryopsis seaweed which they are commonly seen on. There was not much Bryopsis in the lagoon. Note the continuous slime carpet maintained between the lower body and the sand whilst the slugs went about 'hoovering' the sand.

Depth (Intertidal) : 10 cm of water. Tide was about 0.3 m.
Location : Tanah Merah, Singapore
Length : about 6 cm
Time : about 7 pm.
Date : 06Dec2009

Read more about the slugs here :
http://www.wildsingapore.com/wildfacts/mollusca/slugs/sacoglossa/ornata.htm
http://www.seaslugforum.net/factsheet.cfm?base=elysorna
http://seaslugsofhawaii.com/species/Elysia-ornata-a.html

Click here for a nice picture of this beautiful slug.