New Species Named After Hong Kong

Introducing Hoilungia hongkongensis a Placozoan. What’s a placozoan? Literally it means “flat animal” and these animals represent one of the simplest multicellular life forms known. And up until this year the entire phylum (major branch of the tree of life) of Placozoans had only 1 species: Trichoplax adharens! That would be like saying that the sum of all known vertebrates was just one species.

But a team of scientists have now added Hoilungia hongkongensis making it 2!

Hoilungia – meaning sea dragon – was isolated from HK and therefore honoured with the species name hongkongensis. Don’t rush to go looking for this 1 mm across flattish blob though. Placozoans are utterly featureless and have only 5-6 different cell types – one of which is the epithelial cell which has little beating hairs that propel the animal across the sediment (slooowly) where it feeds like an amoeba by engulfing detritus. Like other featureless or cryptic species this one was identified and separated from others by genetic analysis alone. Basically there is nothing to look at.

Featured image: Bernd Schierwater (cc by 4.0)

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Three Green Turtles Returned to Sea

The AFCD released three green turtles (Chelonia mydas) in the southern waters of Hong Kong on July 27.

One of the turtles was seized by the AFCD in an operation, while the other two were rescued in the waters near Sha Tau Kok and Siu Sai Wan, respectively. The three green turtles were accommodated temporarily at Ocean Park where they were assessed by veterinarians and kept under constant monitoring and veterinary care.

Photo shows one of the green turtles, earlier rescued in the waters near Siu Sai Wan, being released to the sea. (Photo from the AFCD Press Release)
Photo shows one of the green turtles, confiscated by the AFCD in an enforcement operation earlier, being released to the sea. (Photo from the AFCD Press Release)
Photo shows one of the green turtles, earlier rescued in the waters near Sha Tau Kok, being released to the sea. (Photo from the AFCD Press Release)

The three turtles released weighed 10 kg, 11 kg and 93kg respectively, and their shell lengths were 43 cm, 45 cm and 92 cm. All of them were assessed by veterinarians as being in good condition and ready to be returned to the sea.

Before the green turtles were released to the sea, the AFCD tagged each of them with a microchip and tags for future identification. Satellite transmitters were also attached to their shells. By tracking the movement and feeding grounds of green turtles in the sea, the AFCD will collect data for formulating appropriate conservation measures and share its findings with other conservation authorities for the better conservation of green turtles through concerted efforts.

If you see any sea turtles or suspected irregularities involving sea turtles you should call the AFCD via 1823.

The Starfish of Hong Kong, Part 6

Bordered Seastar (Craspidaster hesperus)

via WikiCommons (cc-by-sa-2.0)

Described as the new species Pseudarchaster spatuliger in 1934, it was later revised to an already known species. The diameter with arms is about 10 cm. It is a flat starfish with tapered arms. The edges of the body are bordered with large, wide plates giving it its english name. The tube feet are pointy and not tipped with suckers like other starfish. Occurs from the Bay of Bengal to China and southern Japan.

Sand-sifting Starfish (Astropecten polyacanthus)

via WikiCommons, cc-by-sa 3.0

The sand sifting starfish or comb sea star is a widespread species, found throughout the Indo-Pacific region in shallow tropical and sub-tropical seas (from the Red Sea and Zanzibar to Hawaii, and from Japan to Australia and New Zealand). The diameter including arms is up to 20 cm. The upper surface is dark purplish in colour and the underside is orange. Little pillars with flattened top on the upper surface are cream, grey or brown, sometimes making chevron patterns. Along the edges of the arms are long, sharp spines, with brown bases and pale tips. It spends its time buried in silty seabeds feeding on detritus and small invertebrates. Sometimes it also engulfs pebbles and digests the biofilm (bacterial and algal films) and small invertebrates adhering to the surface. It contains the potent neurotoxin, tetrodotoxin, also known as TTX which has no known antidote. In a case of paralytic poisoning in Japan it was found that the victim had eaten a trumpet shell, Charonia lampas, which had acquired the toxin through its food chain, thus implicating Astropecten polyacanthus.

The Starfish of Hong Kong, Part 5

Pentaceraster chinensis (no English common name)

Pentaceraster regulus – a relative of P. chinensis. Image by Bernard Dupont cc-by-4.0

A tropical starfish know from several locations including Hainan.

Luzon Sea Star (Echinaster luzonicus)

Echinaster luzonicus from Pulau Tioman (Malaysia)
Author Ron Yeo, cc-by-nc-sa.

The Luzon sea star is prone to shed its arms, which then regenerate into new individuals. It is normally six-armed but often quite asymmetrical in appearance, because of it has a habit of shedding arms. Its colouring ranges from red to dark brown. It is found in the tropical and sub-tropical western Indo-Pacific region, ranging from Madagascar and the east coast of Africa to Northern Australia, Indonesia and the Philippines. It is found on both reef crests and in the intertidal zone where it feeds on bacterial and algal films that it extracts from the sediment. By shedding its arms for regeneration the species can reproduce asexually. The shed arm regenerates, growing a new disc and further arms.  Up to 65 cm in diameter.

The Starfish of Hong Kong, Part 4

Eight-armed Luidia sea star (Luidia maculata)

Luidia maculata (Seven armed starfish) taken in Ras Sedr,Egypt in 2012 by لا روسا (cc-by-sa 4.0).

The diameter with arms is 12 – 20cm and it has  5 – 9, but normally 8 arms. The arms are long, rounded and tapered to a sharp tip. The tips bear small sharp spines on the sides. The underside is pale and the grooves along the arms bear large tube feet with club-like, pointy tips. The colours and patterns on the top side are variable from greyish blue, to brown and beige, but normally have a darker star-shaped pattern in the middle, and dark irregular bars running along the arms. It ranges from SE Arabian Sea, Persian Gulf, Maldive area, Ceylon, Bay of Bengal, East Indies, north Australia, Philippine, China and south Japan. Occurs inshore at depth from 0-134 m. Observations in Hong Kong include near Kau Sai Chai in Sai Kung and near Port island. It burrows in soft sediments and eats small invertebrates including other starfish.

Astropecten monacanthus

image directly linked from the website: Echinoderms of the Gulf of Eilat (Aqaba)

Distributed in SE Arabia, Maldive area, Ceylon, Bay of Bengal, East Indies, norh Australia, Philippine, China and south Japan. Lives inshore in tropical, Indo-west Pacific Ocean waters at depths from 0 – 50 m. Observed in Hong Kong from Tai Long Sai Wan, in sand substrate.

Dolphins & Porpoise Found Dead During Lunar New Year

A dolphin concern group published on its social media page that one chinese white dolphin (Sousa chinensis) and four finless porpoises (Neophocaena phocaenoides) were found stranded between Saturday the 17th and Monday the 19th of February. Autopsy scans found food remains in the dolphins, showing they were not starved to death. However, they showed multiple fractures. It is feared they were hit by motorboats as they had injuries on their heads and necks.

One finless porpoise was almost cut in half by what is thought to have been a boat propeller.

The adult Chinese white dolphin was found stranded at Mo To Chau. It was a 2.5-meter female, at least 10 years old, and with signs of choking, bone fractures and serious bone dislocation. The death of an adult female is a great loss to the species’ population growth, with numbers in Hong Kong down from over 120 some years ago to 47 at present.

In the past three years there have only been 3-4 stranded cetaceans in tyhe months of January and February. This year, more than 10 dead cetaceans have been discovered in the same period.

High-speed boats are always a big threat to dolphins and some might be hit by propellers and never be discovered. The Dolphin Conservation Society of Hong Kong (HKDCS) has urged the government to launch a speed restrictions on boats around dolphin and porpoise habitats or even ban them from entering these areas.

According to the HKDCS only one new-born Chinese white dolphin was recorded last year. With the loss of another adult female dolphin, there is a dwindling chance of recovery of the local population.

Trawling Ban Enforced – Man Given Suspended Jail Sentence for Trawling 

A man who illegally used trawling gear for fishing on January 17th 2018 has been convicted and sentenced to two months’ imprisonment suspended for two years and a fine of $4,000 at Kwun Tong Magistrates’ Court on January 18th 2018.

The Agriculture, Fisheries and Conservation Department (AFCD) and the Marine Police mounted an anti-illegal fishing operation in the eastern waters of Hong Kong yesterday, and found a mainland shrimp trawler suspected to be trawling at Ninepin Islands. The vessel was inspected and gear used for trawling was seized on board the vessel. Upon investigation by the AFCD, a male master on the vessel was charged for contravening the Fisheries Protection Regulations by using prohibited fishing gear. He was convicted and sentenced.

The ban on trawling came into force on December 31st, 2012. All electricity transmitting devices used for fishing are also prohibited. Under the Fisheries Protection Ordinance, any person who contravenes the ban is liable to a maximum penalty of a fine of $200,000 and imprisonment for six months.

Trawling is a non-selective fishing method which severely damages the seabed, especially trawling with electricity which kills all marine life around the trawl net and causes serious damage to the marine ecosystem.

Photo credit AFCD.