15 November 2010

Wildfacts updates: fishies, crusties and more!

I haven't updated the wild fact sheets since April! It has been a whirlwind of field trips as we tried to keep up with the double whammy of oil spill impact and coral bleaching, plus relentless explorations of submerged reefs and locations we haven't been to before. Finally, the morning low spring tides ended, and I could catch up with fact sheet updates!
Zebra sole (Zebrias zebra)
Among the fascinating first time sightings is this Zebra sole (Zebrias zebra) that Chay Hoon spotted on Changi!

I didn't actually see the reef-dwelling Eightband butterflyfish (Chaetodon octofasciatus) myself. But they were documented by Chay Hoon at, among others, Sisters and Kusu Island, and also by Kok Sheng at Tanah Merah! I learnt that juveniles are often seen in groups among branching corals such as Acropora corals (Acropora sp.).
I've also finally figured out the other little creatures that we sometimes glimpse living inside branching corals.

The Red coral crab (Trapezia cymodoce) lives only in Cauliflower corals (Pocillopora sp.). The crab feeds on the mucus produced by the coral, gathering these with the minute comb-like structures at the tips of their feet. In turn, it protects the coral from predators such as the Crown-of-Thorns sea star. It discourages the sea star by using its sharp pincers to nip at the sensitive tube feet of the sea star. Sadly, I managed to take better photos of them only because their coral home was bleaching.
Red coral crab (Trapezia cymodoce)
The Face-banded coral crab (Tetralia nigrolineata) lives in Acropora corals (Acropora sp.) and has a bandit-like dark band across its broad face. These little crabs are usually well hidden in their branching homes and are hard to photograph. James and Kok Sheng have much better photos of this little crab.
Another curious little crustie that lives in Acropora corals (Acropora sp.) is the aptly named Machine gun shrimp (Coralliocaris graminea). It has a pair of huge flattened pincers that can be larger than its body. Like the snapping shrimps (Family Alpheidae), the pincer has an enlarged tooth and a special catch. When the catch is released, the tooth makes a loud snapping sound. Unlike the snapping shrimp which only has one such 'snapping' pincer, the Machine gun shrimp has two such pincers, hence its common name!
Sadly, my first time spotting this beautiful Banded mantis shrimp (Lysiosquilla sp.) was on Tanah Merah a day after the oil spill hit the shore. The shrimp seemed to have crawled out of its burrow to die. Its mate was seen a little distance away, also dead. Sigh. But James shared that he had earlier seen a living one on Changi!
Banded mantis shrimp (Lysiosquilla sp.)
We've been seeing this strange colonial animal in many locations. I've tried to find out what it is but failed. I'm making a guess that it's some kind of sea fan because it has a stiff wire-like thing at the core of the leathery branches. If you know what it really is, I'd be grateful for a correction. Thank you!
Unidentified leathery sea fan (Order Gorgonacea)
Kok Sheng has seen this sea cucumber twice so it seems a sign to do a fact sheet on it! He saw the Brown sea cucumber (Bohadschia vitiensis) on Cyrene last year and this year. It tends to remain buried in sand during the day and only emerges at dusk. When disturbed, it releases sticky white cylindrical tubes called Cuvierian tubules.
Chay Hoon spotted this tiny seven-armed sea star twice, at Cyrene and at Pulau Jong. We still don't know what it is exactly, but it sure is cute!
During this period, some unidentified sea creatures also got sorted out!

Thanks to Siyang, Lionel and Kok Sheng, we now know this sea cucumber is Holothuria fuscocinerea. 'Fuscocinerea' suggests 'dark' and 'ashy' and indeed, the sea cucumber does look like it has been rolled in ash with dark blotches and splotches on its generally pale pink to beige body.
Ashy pink sea cucumber (Holothuria fuscocinerea)
More about this sea cucumber in their paper: Teo, S., C. S. L. Ng & K. S. Loh, 2010. New record of a sea cucumber, Holothuria (Stauropora) fuscocinerea Jaeger, 1833 (Holothuroidea: Aspidochirotida: Holothuriidae) in Singapore. Nature in Singapore, 3: 133–137. [PDF, 1.10 MB]

Thanks to Chandran Rethnaraj who kindly emailed me, this strange colonial animal turns out to be a soft coral! The Knobbly soft coral (Carijoa sp.) is often seen growing on hard man-made surfaces.
Knobbly soft coral (Carijoa sp.)
After looking more closely at references especially the awesome new Reef Creature Identification: Tropical Pacific by Paul Humann and Ned Deloach, I'm making a guess that this Spotted sea hare is Aplysia oculifera.
Spotted sea hare (Aplysia oculifera)
I mistook these stick-like fishes for Halfbeaks (Family Hemiramphidae). Until someone, sorry I can't recall whom, suggested they were barracudas. I finally found time to look up the references and indeed, they do seem to be baby barracudas (Family Sphyraenidae)!
Baby barracuda (Family Sphyraenidae)?
Of course besides these, there were many MANY other sightings of other plants and animals by the rest of the team which I've added to the fact sheets. Because of the lapse of months, there were just too many sightings to consolidate in this post. My apologies.

Thanks to those who found the critters, and who took photos and video clips and shared about them. See all the photos in full glory and read about the recent adventures on these blogs:
I'd gladly include your sightings in the wild fact sheets. Just email me, Ria at hello@wildsingapore.com

2 comments:

  1. Hi Ria! That leathery whip bundle might be a soft coral. I asked Jeff before and he commented on my FB about it.

    http://www.facebook.com/photo.php?fbid=232420614451&set=a.152304714451.111186.565034451

    Jeff's comment:
    "Soft coral, maybe from the genus Sinularia, which, according to my book, shows a great diversity in growth forms, including a branching type."

    Hope that helps!

    ReplyDelete
  2. Yes Mei Lin, I remember this exchange. The tricky part is the wire-like thing at the core of the branch.

    I combed through all my references. There are branching gorgonians with leathery tissues and a central support. So my guess is gorgonian for now...

    ReplyDelete

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