29 October 2011

Papa fishes mouth brooding babies at Semakau

Cardinalfishes are mouth brooders. Usually it is papa fish who keeps eggs in his mouth until they hatch. This fish has a mouth bulging with eggs that seem about to hatch, see the little eyes!
We were back at Magnificent heaven on Pulau Semakau and also saw all kinds of other reef animals!

These little fishes are Chequered cardinalfishes (Apogon margaritophorus) which are commonly seen on our shores. There were other carnidalfishes with little orange eggs in their mouths.
I'm not sure if this is a papa that has just released his little babies? Although there were also lots of tiny transparent shrimps in the water, these little things look very much like fishes to me. How exciting! There's so much to discover if we take a closer look at our marine life!
Once again, we dodged the rain clouds that dumped rain on the mainland and enjoyed a brilliant blue sky over Pulau Semakau. On this trip, we headed for the reefs that have grown outside the area of replanted mangroves. On the seawall surrounding the replanted area, all kinds of mangrove seedlings are taking root!
This shore has the largest number of Magnificent anemones (Heteractis magnifica) that I've seen!
I came across this lovely expanded Fire anemone (Actinodendron sp.) AND a pretty swimming crab that I don't recall seeing recently. Rob says its a Charybdis!
Some parts of the shore have corals, soft corals and hard corals. Most of the corals looked healthy, and there seems to be a good representation of the usual kinds.
This large colony of Ridged plate coral (Merulina sp.) was overturned. I was glad I turned it back to the correct position as most of the colony seemed to still be alive.
There were many colourful Favid corals (Family Faviidae), the species most commonly encountered on our reefs. The next most abundant species I saw on this trip was Anemone coral (Goniopora sp.). There were also many Pore corals (Porites sp.) and some Galaxy corals (Galaxea sp.) and Cauliflower corals (Pocillopora sp.). As well as some branching Montipora corals (Montipora sp.) on the higher shore.
There were also some special corals including Pebble coral (Astreopora sp.), Brain corals (Family Mussidae), Lettuce corals (Pavona sp.) and Carnation coral (Pectinia sp.).
The number of hard corals on this shore seem rather low. Perhaps not all the corals survived the coral bleaching last year? Here's a view of the many white and bleaching corals on this shore from Terumbu Semakau in June 2010 at the height of coral bleaching. At first I thought this was just another strangely coloured coral. A closer look and I realise it is covered thickly with lots of tiny brown Acoel worms.
Here's a closer look at the worms. They're so thickly clustered over the coral polyps! Do they affect the coral? I don't know.
I also came across a nice large Persian carpet flatworm (Pseudobiceros bedfordi) swimming in the water! I don't often see this beautiful animal.
I'm fascinated by the Xenia soft corals (Xenia sp.) found here. I haven't come across these animals on our other reefs yet, aside from those I saw at Terumbu Bayan which has since been reclaimed. I noticed on this trip, that the Xenia colonies actually have a body column, as shown by these droopy ones left hanging at low tide. A very close look at the colony and I realise there are tiny flower-like things at the base of the polyps. Are they a different kind of polyp? Or retracted polyps? Wah, so much more to find out!
There were many Asparagus flowery soft corals (Family Nephtheidae). Most of them seemed healthy although some were rather yellowish. In one of them, I noticed little orange brittlestars! The last time I saw these was when Chay Hoon found some on Cyrene Reef in 2008.
Marcus found lots of Crown sea stars (Asterina coronata)!
As usual for this shore, I saw many Durian sea cucumbers (Stichopus horrens). I also saw one large fat White-rumped sea cucumber (Actinopyga lecanora).
I have no idea what this is. It seems to have tentacles on the end. And it burrowed away rapidly when I tried to have a closer look at it. Some kind of sea anemone? Or sea cucumbers? Yet another mystery to ponder.
In pools of water left behind by the tide, there were all kinds of small colourful fishes. Many gobies, baby damselfishes.
Other interesting fishes included some damselfishes, cardinalfishes and a tiny little Razorfish (Family Centriscidae). In deeper waters in the dark, there was constant splashing. Large fishes hunting?
A Bartail flathead (Platycephalus indicus) with the typical colourful tail! I don't see this fish too often.
Although it's hard to explore the reefs safely during a bloom of Sargassum seaweeds, these seaweeds provide shelter and food for all kinds of animals. Here's a Variable fang-blenny (Petroscrites variabilis) and an Ornate leaf slug (Elysia ornata)!
The only nudibranchs I saw was one Glossodoris atromarginata and a very large Discodoris boholiensis. Marcus saw a Discodoris lilacina, my first time having this for Semakau.
After sunset, the octopuses came out to hunt! I also saw one squid (Family Loliginidae) and many many little Pygmy squids (Idiosepius sp.).
Another predator that is more active at night is the Dog-faced water snake (Cerberus rynchops). These snakes are common in mangroves and have bulbous eyes that stick out of the head. Thus allowing them to peek out above the surface of the water while keeping the rest of the body submerged. Alas, we didn't encounter a snake feeding frenzy as we did when we last visited this shore at night in 2009. But Marcus saw a pair of Banded file snakes (Acrocordus granulatus) mating!
As the tide turned, I noticed that the cerianthids (Order Ceriantharia) started to emerge in pools on the higher shore.
This shore lies just across from the refineries on Pulau Bukom. It has just been reported that the refineries will "return to full capacity in December" following the shutdown due to the recent fire there.
We don't visit this special part of Semakau often enough. Hopefully, it will remain well.

Posts by others on this trip


  1. The swimming crab near the fire anemone is Charybdis feriata.

  2. Thanks Swee Hee! It was a pretty crab!



Related Posts with Thumbnails