Saturday, October 09, 2010

Stonefish Bay Without Stonefish. Phew...

For today's Project Semakau survey, we went to where we called "Stonefish Bay". We had seen stonefish here before, and SK actually saw two (almost stepped onto one) during a trip! As such, I was rather worried and gave a longer than usual safety briefing to ensure that the volunteers note where they step. Fortunately, no stonefish was encountered during the trip, and we had a few good finds too!

Stonefish Bay's marine life were a lot denser compare to the usual intertidal area that we went, and the nicest thing about it must be the Magnificent Anemone (Heteractis magnifica). While the other intertidal area had hundreds of sea stars (knobbly sea stars in some areas), here we got hundreds of these huge sea anemones that come in shades of purple, red or brown.

On this rock, there were 9 of them! Some of them even had clownfish and anemone shrimps living inside them! It is unfortunate that there was a cyanobacteria (blue-green algae) bloom and these dark furry algae covered lots of the other sessile organisms, or this would be an even prettier sight.

Several other sea anemones were spotted, included this unidentified one.

There were several areas which had lots of these Mushroom Anemones (Order Corallimorpharia). Related to sea anemones, these sessile animals are often seen in clusters, sometimes so extensive that they cover huge areas several metres wide like a huge carpet.

Also related are the zoanthids (Order Zoantharia), which exist in colonies with hundreds or even thousands of individuals.

I noticed this shore had a lot more colonies of these bluish furry soft corals compared to the usual side that we visit too.

I came across this rather interesting looking soft coral, which I don't think I have seen before.

Fanworms (Sabellastarte sp.), which are basically segmented worms with the fan-like tentacles on their heads, are rather common here too. These worms live in tubes, which they build using sand and mucus. They use their tentacles to filter plankton or other tiny organic matter from the water.

Marine Spiders (Desis martensi) were seen busy scampering over rocks and corals hunting for small prey with their venomous fangs.

There were lots of Red Swimming Crabs (Thalamita spinimana) among the algae. They are able to swim rather quickly using their paddle-like back legs.

Another rather abundant swimming crab is Thalamita danae. The species name is named after the princess of Argos in the Greek Peloponessos, a daughter of King Akrisios. Those who have seen Clash of the Titans will be familiar with the story. Danae is the mother of Perseus.

I was rather happy when I spotted this Hairy Hermit Crab (Dardanus lagopodes), as I seldom see them. It was living in a dead Noble Volute's shell, and living with it attached to the insides of the shell were a few Slipper Snails (Crepidula walshii, the flat, white and rounded things behind the hermit crab).

And here's a living Noble Volute (Cymbiola nobilis). Its shell was covered with silt and dirt, allowing it to blend rather nicely to the surrounding sandy habitat.

Yet another well-camouflaged snail was this Spider Conch (Lambis lambis), which got its name from the long spines on one side of its shell.

I did not find any echinoderms in my zone, but saw quite a number of brittle stars and sea cucumbers on my way there and back, including this Stonefish Sea Cucumber (Actinopyga lecanora). Note that this is different from the venomous stonefish, which is a fish.

We did not have to survey fishes for this trip, but that didn't stop me from taking photos of some of the more colourful ones, such as this Copperbanded Butterflyfish (Chelmon rostratus).

While we fortunately did not encounter any stonefish, we encountered a few venomous Blue-spotted Fantail Ray (Taeniura lymma). Like most other venomous fishes, if you don't touch them and just observe them, they are not dangerous at all.

The most exiting moment of the day must be the spotting of this Yellow-lipped Sea Krait (Laticauda colubrina)! By the time I saw the snake, its head had already gone under water. A few of the other fortunate volunteers got to see and photograph it though. We often see other snakes like the Dog-faced Water Snake and Banded File Snake here, but none can certainly match seeing this very venomous sea krait! One bite from this snake can kill a human! However, they are generally not aggressive unless provoked, fortunately, and that's also why we could observe rather closely.

The terrain was really tough over this shore, and this was possibly the most tiring Semakau trip I ever made, but it was certainly all worth it, with so many great sightings! :)

No comments: