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.

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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.

Rare Marine Bio Job Offer Posting

Jobs in Marine Biology are rare and even more so in Hong Kong. So when I saw this one posted, I had to share:

Company: ERM Hong Kong LTD.

Responsibilities:Conduct marine mammal observation/monitoring on construction vessels/ land-base in infrastructure projects

Working Hours: From 7 am to 5:30 pm

Working Location: Lantau Island & Tuen Mun

Training will be provided before the commencement of work

Requirements:

Form 5 graduate or above

Patient, responsible, positive and passionate about ocean

Willing to work outdoor, on shifts and during weekends and public holidays

Experience in observing dolphins is preferred but not a must

Immediately available is preferred

Fresh graduates will also be considered

The minimum of working days for the full-time position will be 18 days per month. For the part-time position, the working days will be 5 to 7 days per month.

Original Ad posted here at CP Jobs.

New Species of Tree-Climbing Crab Discovered in HK

Haberma tingkok that’s the name given to a new species of mangrove crab that climbs in trees along the eastern coast of Hong Kong. It was collected from branches between five and six feet high.

It has a dark brown upper shell, or carapace, long, thin legs that are light brown, and its claws, or chelipeds, are a brownish orange.

Mangrove crabs are quite small. The collected specimens measured between 8 and 9 millimeters in length, less than a third of an inch.

Scientists from the University of Hong Kong and the National University of Singapore described the new species in the journal ZooKeys.

The genus Haberma now contains three species. Peter Ng, a marine biologist at NUS and co-author of the latest study, established the genus 15 years ago and helped discover all three species (the other two are H. nanum and H. kamora).

H. tingkok was named after the Ting Kok mangrove stand, in Tolo Harbour, where it was found in the mid intertidal area. The area is the largest mangrove stand on the eastern coast of Hong Kong.

Hong Kong’s mangroves and the species they shelter are under threat from pollution and land reclamation projects.

Image credit: Dr Peter Ng