Blog Log: 31 January 2010

February 3, 2010

An intense month of diving at Hantu culminated last Sunday with some brilliant finds! The tiny cuttlefish above appears red in the photograph because of the white light of the flash that’s been cast upon it. With the naked eye however, this intelligent mollusc blends perfectly with the silty substrate upon which it rests. Note how it has distorted the texture of its skin to mimic the cluster of tiny hydroids that surround it.

This side profile of the small cuttlefish gives us a better view of its W-shaped pupils. Their eyes, said to be amongst the most developed in the animal kingdom, are not able to detect colour but can perceive polarised light that enhances their perception of contrast. Less than one inch in length, this cuttlefish did not flee despite us approaching it quite closely, and was committed to relying on its superb camouflage capabilities.

A fish we’ve not seen in awhile is the Carpet eel blenny (above). Despite its name, it’s neither an eel nor a blenny. Rather, it is from the dottyback family, similar to sea bass and wrasses. They are distinguished from other families by the presence of three or less spines in the dorsal fin and an incomplete lateral line organ. This fish spends most of its time squirming into interstices among rubble, or among rocks and benthic debris. They can be quite skittish and have to be carefully approached.

A new encounter on the reef this weekend was with the above sea slug that’s yet to be properly identified. My closest and only guess is that it might be from the genus Philinopsis. It was moving very briskly on the reef. If you’ve got a better, more accurate guess, email me.

Another unknown critter was this nudibranch.

There were also encounters with some more common critters like this Gymnodoris rubropapulosa, with its mouthparts clearly visible.

The False clown anemonefish is one of three anemonefish known to occur in the waters around Pulau Hantu. This particular anemone was full of little anemonefishes, but they were difficult to photograph because they constantly darted into and under the anemone.

A great personal find was this young Winged pipefish. Just look at those amazing appendages on its head!

I spotted another individual close to the first one, which appeared to have a swollen brood pouch. These delicate-looking critters are related to seahorses. They are weak swimmers, hence they sick close to the reef at all times.

We didn’t spot too many critters on whip corals this weekend, but there was this commensal shrimp camouflaged on a while-coloured whip.

Above water, there were several Climber crabs (above) and isopods (below) clinging onto and scuttling about the wooden and rusty beams close to the jetty.

For more pictures from this dive, visit the Hantu Blog Gallery.

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