The Living Fossils of Hong Kong and Richard Fortey’s Survivors – Part 1

Having briefly worked in the Natural History Museum in London, i had the pleasure of listening to a lecture by Richard Fortey who is known for a whole list of popular science books. One of these books, as ibrecently found out has nearly a whole chapter set in Hong Kong and dealing with some of Hong Kong’s lesser known marine animals.

In “Survivors: the Animals and Plants That Time Has Left Behind”, Richard Fortey visits East Sai Kung Country Park with Professor Paul Shin of City University, to explore some mudflats looking for creatures that are rare survivors of past geological ages millions of years ago.

You may be familiar with this animal:

Credit Citron / CC-BY-SA-

The coelacanth is a lobe-finned fish thought to be the ancestor of all land vertebrates. Having evolved 400 million years ago, it was thought extinct for 66 million years until famously it was discovered living in 1938. That made it the poster boy for living fossils. But few Hongkongers would suspect a living fossil in their city, let alone 4!!!

One of these is Lingula anatina. It consists of two valves forming a clasped shell and a long stalk or pedicle. The pedicle is buried vertically in the sediment to anchor the animal while its valves open to filter tiny edible pieces out of the sea water at the sediment surface. 

Lingula anatina (via Wikicommons)

To an untrained eye this might seem like mussel or clam or other mollusc. But it is in fact a brachiopod, a group of animals that has been around for about 500 million years. To put that into context, the colonisation of land by plants happened 400 million years ago. How a brachiopod differs from a mussel or clam is its internal organs and body structure – but that’s a matter for undergraduate invertebrate textbooks….

Lingula for all its similarity to a mussel, is not a mollusc, but the next living fossil is.  The chiton Acanthopleura japonica is very ancient and primitive mollusc.

A chiton preserved in its rolled up state after becoming detached from its rock surface

The animal is similar to a snail but instead of a shell it has 8 armoured plates which it locks together to form a shield. They use a muscular foot to glide around rocks scraping algae off them. If scared or at low tide they suck themselves onto the rock with their foot and at the same time lift their shell to form a vacuum – so prying them off rocks is not recommended as you will only end up breaking and killing them. If they do get pried off rocks they roll up a bit like a wood louse. Acanthopleura is a common sight around Hong Kong’s rocky shores. And chitons very similar to it started appearing about 450 million years ago…for context, dinosaurs appeared about 200 million years later…and in all that time they really haven’t changed much.

The third living fossil is a type of worm. The Peanut-worm to be precise, so named because it can bunch itself into a peanut-shaped blob. Its proper name is sipunculid worms, and they too have been around for almost 500 million years. As with brachiopod sand mussels, the difference between a sipunculid and a ‘regular’ marine worm is in its internal body structure and organs. Hong Kong actually hosts at least two species of sipunculid worm. One of these is Siphonosoma cumanenses, pictured below. It makes burrows on fine sandy shores.

Live specimen of Siphonosoma cumanenses collected in Fort Pierce, Florida. Photo by Kawauchi, Gisele Y. by myspecies.info licensed under CC BY-NC-SA

The other is Sipunculus nudus, pictured below, which is – not surprisingly – also eaten in Southern China.

A bucket of deliciously-looking purple worms (labeled 即劏北海沙虫 – “‘Sand worms’ from Beihai, at a street vendor in Guangzhou. Photo by Vmenkov via WikiCommons licensed under CC-BY-SA 3.0
Live specimen of Sipunculus nudus (dorsal view) collected in Fort Pierce, Florida. Photo by Kawauchi, Gisele Y. From myspecies.info licensed under CC BY-NC-SA
 
Finally, there are the horseshoe crabs, but that is for Part 2…

Advertisements

Dead Green Turtle Found with Plastic in Stomach

A green turtle (Chelonia mydas) was found dead in Sai Kung over the weekend, apparently after ingesting too much trash.
Click here for the Coastal Watch HK Facebook page with images of the turtle.

On Saturday (24 Oct), the lifeless body of a green turtle was spotted on a beach at Pak Lap village, Ming Pao Daily reported.

The turtle’s body was said to have been dragged by stray dogs and its stomach mauled. An examination revealed that the stomach was full of litter.

The trash found inside the turtle, which was about 40-50 centimeters long, included nylon string and plastic bags.

It was the first time that evidence has been found in Hong Kong of green turtles consuming marine litter the report cited the World Wide Fund for Nature (WWF) as saying.

After looking at the pictures of the turtle’s body, Chong Dee-hwa, the founder of the Hong Kong Ichthyological Society, believes the green turtle was a female aged around 10 years.

Patrick Yeung, project manager of the Coastal Watch Project under the WWF, said the case can be taken as evidence that sea turtles in Hong Kong are eating a lot of trash, which is a worrying situation.

The Agriculture, Fisheries and Conservation Department was quoted as saying that it has been informed about the case and that it will send an officer to look into the matter.

The green turtle is a protected species in Hong Kong. The beach area in Sham Wan on Lamma Island and nearby shallow waters is one of the last nesting sites of the highly endangered green turtles of southern China.

Since 1999, the area was being closed to the public from June to October every year to enable the turtles to carry out their nesting activities.

Whale Shark Spotted off Sai Kung

On Monday morning (20/7/15) at around 9am, a fisherman was out on his 20-foot-long boat off the shores of Tung Lung Chau Island, south of Sai Kung, when he spotted what he thought to be a shark.

It was a gentle whale shark, the largest fish in the ocean which feeds on plankton with the occasional small squid or fish.

Once the fisherman realised that the animal posed him no harm, he observed it and took photos for the next half hour before it swam away, reports Headline News.

Whale sharks can reach up to about 13 metres in length and 21 tons in weight.

The last time a whale shark was sighted in Hong Kong was in 2012.

The president of the Ichthyological Society of Hong Kong believes that the trawling ban has led to healthier fish populations. He predicts that in the future, we’ll be seeing even more sharks in Hong Kong.

HKU Student Identifies Dinosaur-Era Fish in Sai Kung Rocks

A Hong Kong University (HKU) student is said to have identified a Jurassic fish from Lai Chi Chong after studying some fossil collections at the university’s Stephen Hui Geological Museum.

Edison Tse Tze-kei found the specimen by chance as he was doing a research project in his final year of undergraduate study during the 2013-14 academic year, according to an announcement from HKU.

The fish, which is believed to date back to around 147 million years, represents the first dinosaur-era vertebrate specimen identified in Hong Kong, the university said in a statement posted on its website Thursday.

   

 

Tse, a graduate of the class of 2014, completed the research, description and identification under the supervision of three professors, including Michael Pittman, Research Assistant Professor and Head of the Vertebrate Palaeontology Laboratory at HKU.

The research results will now be published in PeerJ, an open access, peer-reviewed, scholarly journal of biological and medical sciences, by the end of this month.

The fossil specimen was found at Lai Chi Chong in Sai Kung, which is within the Hong Kong Geopark area, and was kept at a HKU museum.

The Jurassic fish was an osteoglossoid teleost fish, which is also referred to as Paralycoptera.

 

The preserved skeleton represents the first of such fish species from Hong Kong and the most southerly Paralycoptera identified to date, meaning that the activity area of the fish could be larger than scientists had first estimated.

Matthew Sin, a spokesperson for local NGO Green Power, said some visitors to Lai Chi Chong may have taken away rocks as souvenirs.

He reminded people that taking any sedimentary rocks, fossil, mineral or even sand samples from the Geopark is illegal.

Featured image: Magnified image (inset) of a fossil specimen from a Lai Chi Chong geological collection. Research by a HKU student has led to Hong Kong’s first identified dinosaur-era vertebrate. Credit:10.7717/peerj.865

Hong Kong Pufferfish

I recently discovered the greenbluesea blog by Emilie. She is one of the few people doing underwater photography in HK (mostly) and this is a nice post about the HK pufferfish, which I recommend.

green blue sea ∙ 蔚藍碧海

HK Pufferfish

Juvenile Hong Kong Pufferfishes can be curious. Hello there!


I have picked Takifugu alboplumbeus to feature in this first ‘marine life’ post, because although it is a common species which is not only restricted to Hong Kong, it somehow has come to be commonly known as the Hong Kong Pufferfish. And also, well, would you just look at that little face.

The characteristic of pufferfishes is their ability to inflate their body, increasing their size dramatically. The fish triggers this defence mechanism by drawing water into a chamber near the stomach. Pufferfishes have beak-like teeth and small spines covering much of the body, though you wouldn’t think it from looking at these guys. Also, pufferfishes can be highly toxic if eaten; the notorious Japanese delicacy of ‘fugu’ which requires specialist preparation is in fact a pufferfish. Pufferfishes are omnivorous, feeding on worms, crustaceans, molluscs and algae amongst other things.

HK Pufferfish buried

Those divers can’t spot…

View original post 144 more words

Green Sea Turtle Found at Clear Water Bay Beach

The SCMP reported on Saturday (14/3/15) that a green sea turtle (Chelonia mydas) was discovered on Sheung Sze Wan beach in Clear Water Bay Saturday. The animal appeared to have breathing difficulties.

David Gething, a local vet who helped transport the animal said “It was breathing very, very heavily and had bubbles coming from its nose, which suggests it has fluid in its chest.” 

The reptile was picked up by SPCA staff and taken to Ocean Park.

Green sea turtles are known to have occurred and nested in Hong Kong in the past – as shown by such names as Turtle Cove – but have become very rare with Sham Wan on Lamma Island being one of the last remaining nesting sites.

Sai Kung Sharks Story a Bit Fishy

As reported by Coconuts Hong Kong (November 12, 2014) in blurb headlined “Pair of meter-long sharks spotted in Sai Kung” , HK resident Adri Blumberg spotted what seemed to be a shark in Sheung Sze Wan, Sai Kung on the morning of the 12th November:
“two sharks (or shark-like creatures) have been seen in shallow waters near a beach over the last few days. The sharks, thought to be of the same species, are reported to be about a meter long with blue dorsal fins and black and white stripes.”

Enthusiastic as all tabloids are for a attention-grabbing headline, but also trying to appear as socially responsible, Coconuts goes on to say: “It’s actually a great sign that sharks are back in Hong Kong waters. If there are sharks, there are fish. And if there are fish, it means our seas are doing okay!
Scientists estimate that 100 million sharks are killed by humans every year, and Hong Kong is the world’s biggest trade hub for shark’s fin. If anyone should be scared – it’s the sharks!”

Here is the thing: it’s not sharks, it’s most likely mackerel…
How can this be?
Have a close (zoom in) look at Adri Blumberg’s pictures.

IMG_7852.JPG
Image: Adri Blumberg (Facebook)

Notice the shiny bluish color on the caudal (tail fin). Sharks have sandpaper like skin made up of tiny denticles (horns) that don’t normally shine, let alone iridescent blue. Bony fish with scales however have shiny skin often as in the case of coral reef fish in bright colors.

IMG_7853.JPG
Image: Adri Blumberg (Facebook)

The other thing is the strongly curved dorsal fin that shows hints of Rays and the sickle-shaped upper lobe of the caudal fin. Both are not seen in sharks or only rarely at least.

IMG_7854.JPG
Image: Adri Blumberg (Facebook)

And lastly there a close look shows dark stripes faintly recognisable on the back in front of the dorsal fin. Faint dark stripes point towards a tiger shark, but tigers are very bulky fish and have chunky straight dorsal and caudal fins.

The pictures look a lot like a fish from the Scombridae family that includes mackerel, though. One species recorded from HK is Narrowed-barred Spanish mackerel (Scomberomorus commerson), which commonly grows to 1.2m. I will not claim authority as an ichthyologist (fish biologist) but i am quite sure this is not a shark and very likely a mackerel or close relative.

What’s that? You don’t believe mackerel can be big enough to confuse with sharks? Check out this angling sites photos of the Chinese seerfish (Scomberomorus sinensis), a species of mackerel known from China, Japan and Korea.

Here are a few bad (but rights-free) Spanish Mackerel pics cropped to comparable proportions. What do you think?

 

1024px-Narrow-barred_Spanish_Mackerel-ed King_Mackerel-ed Spanish_Mackerel-ed