I am a ex-marine biologist now working for a regular job, but I am still passionate about marine biology and oceanography. I studied Marine Science and completed a PhD in deep-sea ecology and biodiversity. I fell in love with HK's rich marine environment when I was a child. This blog is my collection of interesting facts, news and articles that celebrate and educate on HK's diverse marine environment.
The betuline cone (Conus betulinus) is a large predatory and venomous cone snail, related to the textile cone.
It has a heavy shell that grows to up to 17 cm in length, and is distributed across the Indo-Pacific. The snail itself is velvet black and crawls around on a broad foot hunting worms.
In Hong Kong it occurs on sandy bottoms down to 5 m and in 1985 was still regarded common, although I haven’t ever seen a live one locally (yet!)
In contrast to the textile cone, the toxicity of the betuline cone is low. The toxins of cone shells are known collectively as conotoxins and act on the ion-channels regulating cells activities as well as on neurotransmitter functions.
On the 29th of June the government gazetted a proposed plan for artificial reefs to be built inside the Brothers Marine Park, to improve the habitat and boost fish numbers. The artificial reefs will cover around 0.7 hectares inside the 66-hectare marine park off Lantau to the east of the airport.
The works are tentatively scheduled to start at the end of 2018 and should be completed by 2019.
The marine park has been identified as an important habitat for endangered Chinese White Dolphins, and a spawning ground for commercially important fish species.
Dapeng New Area – just across Mirs Bay from Hong Kong – is planning to build a national marine park according to the Shenzhen Daily newspaper. The aim is to “create the first coral-themed marine ecological system in the country”, by which I think is meant the first man-made coral ecosystem in China.
Dapeng will install artificial reefs to connect the coral reef communities in Da’ao Bay with those in the Tung Ping Chau area of Hong Kong, in the hope of providing a good marine ecological environment
Dapeng New Area has commissioned marine protection organizations to install 68 artificial reefs and plant more than 13,000 coral seedlings in the sea area in recent years.
The new area said it will draw on the experience of Hong Kong’s marine parks and adopt tough protective measures to provide a good environment for the reproduction and growth of the coral reefs.
By joining hands with the Hong Kong Underwater Association they want to establish the first diving research base on the mainland to improve awareness of marine environmental protection and encourage NGOs to participate in coral conservation.
Currently there are 39 diving organizations in the new area.
Over the past two years, volunteers have completed 12 cleaning operations and salvaged more than 448 kg of marine waste, including fishing nets, fishing cages and plastic bags.
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)
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.
A tropical starfish know from several locations including Hainan.
Luzon Sea Star (Echinaster luzonicus)
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 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.
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.