Coral reef decline in Hong Kong

This 2015 video is called Hong Kong coral reef thrives despite pollution.

From The University of Hong Kong:

Was Hong Kong once a coral reef paradise?

October 15, 2020

Researchers from The University of Hong Kong’s School of Biological Sciences and The Swire Institute of Marine Science, have for the first time investigated the historical presence of coral communities in the Greater Bay Area, revealing a catastrophic range collapse and loss of diversity that occurred in the last several decades.

The research, published in the journal Science Advances, looks at fossil corals collected from over 11 sites around Hong Kong, and creates the first palaeoecological baseline for coral communities in the Greater Bay Area. Led by PhD candidate and National Geographic Explorer Jonathan CYBULSKI, the team revealed what coral genera were present in the past well before major human impacts, and these include: Acropora, Montipora, Turbinaria, Psammacora, Pavona, Hydnophora, Porites, Platygyra, Goniopora and Faviids.

Every fossil tells a story

“The data we collect helps us to create a sort of fossil time machine,” said Cybulski. “As corals grow naturally, parts of them will break off and fall to seafloor becoming a part of the sediment. Over time, many different layers of these coral skeletons will stack on top of one another. With a bit of effort we can core through the sediments and collect the different layers and reveal what coral communities were like through time,” Cybulski explained. By using this method, the team was able to collect skeletons from over 5,000 years ago, which they determined thanks to radiocarbon dating by collaborator Dr Yusuke YOKOYAMA of the Atmosphere and Ocean Research Institute at The University of Tokyo.

When the team compared their fossil data to a modern-day dataset collected by collaborators at Baptist University — Dr Jian Wen QIU and Dr James XIE, several striking conclusions were revealed. First, there has been about a 40% decrease in the number of different corals living in Southern Hong Kong waters. Second, the greatest loss was of the ecologically important yet highly-sensitive staghorn corals (Acropora), which now only lives in an area about 50% smaller than its historic range. Finally, the greatest impact and losses of corals occurred in waters that are closest to the Pearl River Estuary in the southwest and Tolo Harbor in the Northeast. Based on the data, the teams best guess for the timing of this coral community change is conservatively within the last century, but likely within the past few decades. The overall conclusion: poor water quality driven by increased development and lack of proper treatment is presently the regions greatest threat to the survival of corals.

More hope for corals

“This trend we saw of a diversity decline and the loss of Acropora is consistent with other research in different areas of the world,” Cybulski continues: “It’s particularly bad news for this region, as Acropora represents the only type of coral that is complex, and creates physical space that promotes greater biodiversity. The loss of this coral is similar to losing all the big trees in a forest.” However, similar to trees in a forest, Cybulski continued by saying there is hope for Hong Kong’s corals through conservation efforts.

Indeed, this historical research has already played a critical role in protecting and restoring corals locally. In July earlier this year, PhD Candidate Ms Vriko YU, also of the Baker Lab at HKU, pioneered a coral restoration project in Hoi Ha Wan Marine Park (Note 1). This project aims to restore and better understand what it will take to save Hong Kong corals, and was made possible due to the water quality improvements in the bay by the local government.

Using Cybulski’s historical data to infer the appropriate steps needed, the team is now returning corals such as Acropora that previously thrived in Hoi Ha, back to their proper home. To date, 100% of the reintroduced coral have survived. Furthermore, the team has documented several coral-associated invertebrates at the site, showing that this restored habitat is indeed increasing biodiversity. The team feels this multi-faceted model — historical research that identifies major stress targets for local improvements — can be used by other researchers who hope to give corals their greatest chance for future survival.

Mysterious young sea stars, new research

From the Smithsonian Tropical Research Institute in Panama, 13 October 2020:

Sea star’s ability to clone itself may empower this mystery globetrotter

October 13, 2020

Summary: The identity of wild cloning sea star larvae has been a mystery since they were first documented in the Caribbean. The most commonly collected cloning species was thought to belong to the Oreasteridae, on the basis of similarity with sequences from Oreaster reticulatus and Oreaster clavatus.

For decades, biologists have captured tiny sea star larvae in their nets that did not match the adults of any known species. A Smithsonian team recently discovered what these larvae grow up to be and how a special superpower may help them move around the world. Their results are published online in the Biological Bulletin.

“Thirty years ago, people noticed that these asteroid starfish larvae could clone themselves, and they wondered what the adult form was,” said staff scientist Rachel Collin at the Smithsonian Tropical Research Institute (STRI). “They assumed that because the larvae were in the Caribbean the adults must also be from the Caribbean.”

Scientists monitor larvae because the larvae can be more sensitive to physical conditions than the adults and larval dispersal has a large influence on the distribution of adult fishes and invertebrates. Collin’s team uses a technique called DNA barcoding to identify plankton. They determine the DNA sequence of an organism, then look for matches with a sequence from a known animal in a database.

“This mystery species was one of the most common in our samples from the Caribbean coast of Panama,” Collin said. “We knew from people’s studies that the DNA matched sequences from similar larvae across the Caribbean and it matched unidentified juvenile starfish caught in the Gulf of Mexico — but no one had found a match to any known adult organism in the Caribbean. So we decided to see if the DNA matched anything in the global ‘Barcode of Life’ data base.”

“That’s when we got a match with Valvaster striatus, a starfish that was thought to be found only in the Indo West Pacific,” Collin said. “The is the first-ever report of this species in the Atlantic Ocean. We could not have identifed it if Gustav Paulay from the University of Florida didn’t have DNA sequences from invertebrates on the other side of the world.”

But why are the larvae common in the Caribbean if adult Valvaster starfish have never been found here? Are the adult starfish hidden inside Caribbean reefs, or are the larvae arriving from the other side of the world?

V. striatus is widespread but rare in the western Pacific. The few reports from collectors and the confirmed photos on iNaturalist range from the Indian Ocean to Guam and Hawaii. These starfish live deep in the reef matrix, only coming out at night. So, it is possible that there are adults in the Caribbean that have never been seen. But the other possibility, that the ability to clone themselves may allow them to spread around the world, is also intriguing.

“It’s possible that the ability of the larvae to clone themselves is not just a clever way to stay forever young,” Collin said. “There’s a natural barrier that keeps organisms from the western Pacific and the Indian ocean from crossing the Atlantic to the Caribbean. After they make it around the tip of Africa, they are met by a cold current that presumably kills tropical species.”

“Just how cloning could help them get through the barrier is still not known, but it’s intriguing that another sea star species from the Indo West Pacific that was collected for the first time in the Caribbean in the 1980s also has cloning larvae,” Collin said.

Crabs, ecology and economy in Oman

This February 2019 video is about saving an Omani crab which had got caught in a fishing net.

From the Royal Netherlands Institute for Sea Research:

Crabs are key to ecology and economy in Oman

Importance of crabs should be considered when looking at increasing human pressure on Barr Al Hikman nature reserve

October 8, 2020

The intertidal mudflats of Barr Al Hikman, a nature reserve at the south-east coast of the Sultanate Oman, are crucial nursery grounds for numerous crab species. In return, these crabs are a vital element of the ecology, as well as the regional economy, a new publication in the scientific journal Hydrobiologia shows. ‘These important functions of the crabs should be considered when looking at the increasing human pressure on this nature reserve’, first author and NIOZ-researcher Roeland Bom says.

Blue swimming crab

The mudflats of Barr Al Hikman are home to almost thirty crab species. For his research, Bom, together with colleagues in The Netherlands and at the Sultan Qaboos University in Oman, looked at the ecology of the two most abundant species. Bom: ‘Barr Al Hikman is also home to the blue swimming crab Portunus segnis. That is the species caught by local fishermen. This crab uses the mudflats of Barr Al Hikman as nursery grounds.’

The counts of Bom and his colleagues show, that there are millions and millions of these crabs in Barr Al Hikman. They are food to hundreds of thousands of birds, both migrating species, as well as birds breeding in the area, such as crab plovers. The crabs live in holes in the ground. They forage on the seagrass beds that are still abundant in Barr Al Hikman. ‘Apart from the high primary production (algae) in Barr al Hikman, this reserve is also well suited for crabs because of the vastness of the area’, Bom assumes. ‘The slopes of the mudflats are very gentle, so at low tide, the crabs have an immense area at their disposition.’

Eco value

The value of the crabs is not just ecological, Bom stresses. “Local fishermen that catch the blue swimming crabs, distribute them not only through Oman, but also through the rest of the Arabian Peninsula and even to Japan. At approximately € 2,- per kilo, these crabs represent an important economic pillar, both under the region around Barr Al Hikman, as well as for the whole of Oman.’

Reserve

The protection of the reserve of Barr Al Hikman is limited to national legislation. Efforts to acknowledge this reserve under the international Ramsar-convention were never effectuated. There is, however, increasing human pressure on the mudflats of Barr Al Hikman, the authors describe, that would justify further protection. For example, there are well-developed plans to start shrimp farming around this intertidal area. ‘When looking at the cost and benefits of these activities, it is important to look at the role of this reserve in the local ecology, as well as in the broader ecology of the many migratory birds that use the area’, Bom says. ‘Moreover, our research shows that the unique ecosystem of Barr Al Hikman plays a key role in the economy as well.’

Voorne-Putten island wildlife, four seasons

This 3 October 2020 video is about wildlife of Voorne-Putten island in the Netherlands, all four seasons. Including birds like robin and wren, mating butterflies, etc.

Millipede evolution, new research

This 2016 video says about itself:

My friend Dani sent me two unidentified Millipedes. After a bit of research and investigation they turned out to be European White Legged Snake Millipedes (Tachypodoiulus niger ) so i thought i would show a size comparison to my adult female African Giant Millipede (Archispirostreptus gigas)

From PLOS:

Genomes of two millipede species shed light on their evolution, development and physiology

September 29, 2020

Millipedes, those many-legged denizens of the soil surface throughout the world, don’t always get the recognition they deserve. But a new study by Jerome Hui of Chinese University of Hong Kong and colleagues puts them in the spotlight, sequencing and analyzing complete genomes from two very different millipede species. The study, publishing on September 29th in the open-access journal PLOS Biology, provides important insights into arthropod evolution, and highlights the genetic underpinnings of unique features of millipede physiology.

Millipedes and centipedes together comprise the Myriapoda — arthropods with multi-segmented trunks and many legs. CentipedesHow centipedes walk and swim sport one pair of legs per segment, while millipedes bear two. Despite the apparent numeric implications of their names, different centipede species bear between 30 and 354 legs, and millipedes between 22 and 750. There are about 16,000 species of myriapods, including over 12,000 species of millipedes, but only two myriapod genomes have so far been characterized; a complete genome for the centipede Strigamia maritima, and a rough “draft” sequence of a millipede genome.

The authors of the new study fully sequenced the genomes of two millipede species, the orange rosary millipede Helicorthomorpha holstii, and the rusty millipede Trigoniulus corallinus, from two different orders, each distributed widely throughout the world. They also analyzed the gene transcripts (transcriptomes) at different stages of development, and the proteins (proteomes) of the toxin-producing “ozadene” glands.

The researchers found that two species have genomes of vastly different sizes — the orange rosary’s genome is 182 million base pairs (Mb), while the rusty’s is 449 Mb — which the authors showed was due mainly to the rusty millipede’s genome containing larger non-coding regions (introns) within genes and larger numbers of repetitive “junk” DNA sequences.

Homeobox genes play central roles in body plan formation and segmentation during animal development, and the authors found lineage-specific duplications of common homeobox genes in their two species, which differed as well from those found in the previously published millipede genome. None of the three, however, displayed the massive duplications seen in the homeobox genes in the centipede genome. They made further discoveries about the organization and regulation of the homeobox genes as well.

Many millipedes bear characteristic glands on each segment, called ozadene glands, which synthesize, store, and secrete a variety of toxic and noxious defensive chemicals. The authors identified multiple genes involved in production of these chemicals, including genes for synthesizing cyanide, as well as antibacterial, antifungal, and antiviral compounds, supporting the hypothesis that ozadene gland secretions protect against microbes as well as predators.

The results of this study provide new insights into evolution of the myriapods, and arthropods in general. “The genomic resources we have developed expand the known gene repertoire of myriapods and provide a genetic toolkit for further understanding of their unique adaptations and evolutionary pathways,” Hui said.

Wasps killing cockroaches 25 million years ago

This 2011 video is about the ensign wasp Evania appendigaster.

From Oregon State University in the USA:

Salute the venerable ensign wasp, killing cockroaches for 25 million years

September 28, 2020

An Oregon State University study has identified four new species of parasitic, cockroach-killing ensign wasps that became encased in tree resin 25 million years ago and were preserved as the resin fossilized into amber.

“Some species of ensign wasps have even been used to control cockroaches in buildings,” OSU researcher George Poinar Jr. said. “The wasps sometimes are called the harbingers of cockroaches — if you see ensign wasps you know there are at least a few cockroaches around. Our study shows these wasps were around some 20 or 30 million years ago, with probably the same behavioral patterns regarding cockroaches.”

Ensign wasps, of the Hymenoptera order and scientifically known as Evaniidae, earned their common name because their abdomen resembles a flag; an ensign is a large flag on a ship, usually flown at the stern or rear of the vessel, that indicates the ship’s nationality.

“As the wasps move about, their ‘ensign’ is constantly moving up and down as if they are flag-waving,” said Poinar, professor emeritus in the OSU College of Science and an international expert in using plant and animal life forms trapped in amber to learn more about the biology and ecology of the distant past.

About 400 species of ensign wasps exist today, distributed across 20 genera. The wasps live everywhere except polar regions. They typically measure 5 to 7 millimeters in length and don’t sting or bite but are lethal for unhatched cockroaches.

A female ensign wasp will look for cockroach egg cases, known as ootheca, and lay an egg on or in one of the cockroach eggs inside the case. When the wasp egg hatches, the larva eats the cockroach egg where it was laid.

Successive instars of the larva then consume the other dozen or so eggs inside the cockroach egg case. Mature wasp larvae pupate within the cockroach egg case en route to coming out as adults, and no cockroach offspring emerge from an egg case infiltrated by an ensign wasp.

Analyzing Tertiary period specimens from Dominican amber, Poinar was able to describe three new species of ensign wasps: Evaniella setifera, Evaniella dominicana and Semaeomyia hispaniola. He described a fourth, Hyptia mexicana, from Mexican amber. The Tertiary period began 65 million years ago and lasted for more than 63 million years.

No cockroaches accompanied the wasps in the amber, but three flying termites were found along with an ensign wasp in one of the Dominican amber pieces. It’s likely the termites were sharing a nest with the cockroaches and this attracted the wasp, Poinar said.

Wildlife of Voorne-Putten island

This 17 September 2020 video is about wildlife of Voorne-Putten island in the Netherlands. Including osprey, great crested grebes with chicks, blue butterflies, ruddy shelducks ad more.

Why tarantula spiders are blue or green

This video is called Greenbottle Blue and Sazimai’s Blue Tarantula Comparison.

By Yale-NUS College in the USA:

Scientists discover why tarantulas come in vivid blues and greens

September 24, 2020

Summary: Researchers find support for new hypotheses: that tarantulas‘ vibrant blue colors may be used to communicate between potential mates, while green coloration confers the ability to conceal among foliage. Their research also suggests that tarantulas are not as color-blind as previously believed, and that these arachnids may be able to perceive the bright blue tones on their bodies.

Why are some tarantulas so vividly coloured? Scientists have puzzled over why these large, hairy spiders, active primarily during the evening and at night-time, would sport such vibrant blue and green colouration — especially as they were long thought to be unable to differentiate between colours, let alone possess true colour vision.

In a recent study, researchers from Yale-NUS College and Carnegie Mellon University (CMU) find support for new hypotheses: that these vibrant blue colours may be used to communicate between potential mates, while green colouration confers the ability to conceal among foliage. Their research also suggests that tarantulas are not as colour-blind as previously believed, and that these arachnids may be able to perceive the bright blue tones on their bodies. The study was published in Proceedings of the Royal Society B on 23 September, and is featured on the front cover of the current (30 September 2020) issue.

The research was jointly led by Dr Saoirse Foley from CMU, and Dr Vinod Kumar Saranathan, in collaboration with Dr William Piel, both from the Division of Science at Yale-NUS College. To understand the evolutionary basis of tarantula colouration, they surveyed the bodily expression of various opsins (light-sensitive proteins usually found in animal eyes) in tarantulas. They found, contrary to current assumptions, that most tarantulas have nearly an entire complement of opsins that are normally expressed in day-active spiders with good colour vision, such as the Peacock Spider.

These findings suggest that tarantulas, long thought to be colour-blind, can perceive the bright blue colours of other tarantulas. Using comparative phylogenetic analyses, the team reconstructed the colours of 110 million-year-old tarantula ancestors and found that they were most likely blue. They further found that blue colouration does not correlate with the ability to urticate or stridulate — both common defence mechanisms — suggesting that it did not evolve as a means of deterring predators, but might instead be a means of attracting potential mates.

The team also found that the evolution of green colouration appears to depend on whether the species in question is arboreal (tree-dwelling), suggesting that this colour likely functions in camouflage.

“While the precise function of blueness remains unclear, our results suggest that tarantulas may be able to see these blue displays, so mate choice is a likely potential explanation. We have set an impetus for future projects to include a behavioural element to fully explore these hypotheses, and it is very exciting to consider how further studies will build upon our results,” said Dr Foley.

The team’s survey of the presence of blue and green colouration across tarantulas turned up more interesting results. They found that the blue colouration has been lost more frequently than it is gained across tarantulas. The losses are mainly in species living in the Americas and Oceania, while many of the gains are in the Old World (European, Asian, and African) species. They also found that green colouration has evolved only a few times, but never lost.

“Our finding that blueness was lost multiple times in the New World, while regained in the Old, is very intriguing. This leaves several fascinating avenues for future research, when considering how the ecological pressures in the New and the Old Worlds vary,” said Dr Saranathan. “For instance, one hypothesis would be differences in the light environments of the habitats between the New and the Old World, which can affect how these colours might be perceived, if indeed they can be, as our results suggest.”

World’s oldest, dinosaur age, animal sperm discovery

This 17 September 2020 video says about itself:

100 Million-Year-Old Sperm Is The Oldest Ever Found. And It’s Giant

The oldest known sperm in the world has been discovered, locked in a piece of amber that solidified when behemoths like Spinosaurus dominated the Earth.

From Queen Mary University of London in England:

World’s oldest animal sperm found in tiny crustaceans trapped in Myanmar amber

September 16, 2020

An international collaboration between researchers at Queen Mary University of London and the Chinese Academy of Science in Nanjing has led to the discovery of world’s oldest animal sperm inside a tiny crustacean trapped in amber around 100 million years ago in Myanmar.

The research team, led by Dr He Wang of the Chinese Academy of Science in Nanjing, found the sperm in a new species of crustacean they named Myanmarcypris hui. They predict that the animals had sex just before their entrapment in the piece of amber (tree resin), which formed in the Cretaceous period.

Fossilised sperm are exceptionally rare; previously the oldest known examples were only 17 million years old. Myanmarcypris hui is an ostracod, a kind of crustacean that has existed for 500 million years and lives in all kinds of aquatic environments from deep oceans to lakes and rivers. Their fossil shells are common and abundant but finding specimens preserved in ancient amber with their appendages and internal organs intact provides a rare and exciting opportunity to learn more about their evolution.

Professor Dave Horne, Professor of Micropalaeontology at Queen Mary University of London said: “Analyses of fossil ostracod shells are hugely informative about past environments and climates, as well as shedding light on evolutionary puzzles, but exceptional occurrences of fossilised soft parts like this result in remarkable advances in our understanding.”

During the Cretaceous period in what is now Myanmar, the ostracods were probably living in a coastal lagoon fringed by trees where they became trapped in a blob of tree resin. The Kachin amber of Myanmar has previously yielded outstanding finds including frogs, snakes and a feathered dinosaur tail. Bo Wang, also of the Chinese Academy of Science in Nanjing added: “Hundreds of new species have been described in the past five years, and many of them have made evolutionary biologists re-consider long-standing hypotheses on how certain lineages developed and how ecological relationships evolved.”

The study, published in Royal Society Proceedings B, also has implications for understanding the evolutionary history of an unusual mode of sexual reproduction involving “giant sperm.”

The new ostracod finds may be extremely small but in one sense they are giants. Males of most animals (including humans) typically produce tens of millions of really small sperm in very large quantities, but there are exceptions. Some tiny fruit flies (insects) and ostracods (crustaceans) are famous for investing in quality rather than quantity: relatively small numbers of “giant” sperm that are many times longer than the animal itself, a by-product of evolutionary competition for reproductive success. The new discovery is not only by far the oldest example of fossil sperm ever found but also shows that these ostracods had already evolved giant sperm, and specially-adapted organs to transfer them from male to female, 100 million years ago.

Each ostracod is less than a millimetre long. Using X-ray microscopy the team made computer-aided 3-D reconstructions of the ostracods embedded in the amber, revealing incredible detail. “The results were amazing — not only did we find their tiny appendages to be preserved inside their shells, we could also see their reproductive organs,” added He Wang. “But when we identified the sperm inside the female, and knowing the age of the amber, it was one of those special Eureka-moments in a researcher’s life.”

Wang’s team found adult males and females but it was a female specimen that contained the sperm, indicating that it must have had sex shortly before becoming trapped in the amber. The reconstructions also revealed the distinctive muscular sperm pumps and penises (two of each) that male ostracods use to inseminate the females, who store them in bag-like receptacles until eggs are ready to be fertilised.

Such extensive adaptation raises the question of whether reproduction with giant sperms can be an evolutionarily-stable character. “To show that using giant sperms in reproduction is not an extinction-doomed extravagance of evolution, but a serious long-term advantage for the survival of a species, we need to know when they first appeared” says co-author Dr Renate Matzke-Karasz of Ludwig-Maximilians-University in Munich.

This new evidence of the persistence of reproduction with giant sperm for a hundred million years shows it to be a highly successful reproductive strategy that evolved only once in this group — quite impressive for a trait that demands such a substantial investment from both males and females, especially when you consider that many ostracods can reproduce asexually, without needing males at all. “Sexual reproduction with giant sperm must be very advantageous” says Matzke-Karasz.

New spider species discovered in Colombia

This 21 September 2020 video is called New species of spider discovered – Ocrepeira klamt.

From the Universität Bayreuth in Germany:

A new species of spider

September 16, 2020

During a research stay in the highlands of Colombia conducted as part of her doctorate, Charlotte Hopfe, PhD student under the supervision of Prof. Dr. Thomas Scheibel at the Biomaterials research group at the University of Bayreuth, has discovered and zoologically described a new species of spider. The previously unknown arachnids are native to the central cordillera, not far from the Pacific coast, at an altitude of over 3,500 meters above sea-level. In the magazine PLOS ONE, the scientist from Bayreuth presents the spider she has called Ocrepeira klamt.

“I chose the zoological name Ocrepeira klamt in honour of Ulrike Klamt, my German teacher at high school. The enthusiasm with which she pursues her profession and the interest she shows in her students and in literature are an inspiration to me,” says Charlotte Hopfe.

The cordillera in Colombia is famous for its unusually large variety of species. The habitats of these species are distributed at altitudes with very different climatic conditions, vegetation, and ecosystems. The Bayreuth researcher has collected and zoologically determined specimens of more than 100 species of spider in these habitats. In doing so, she was mainly in a region that has only been accessible to researchers since the end of civil war in Colombia in 2016. She discovered the new spider, which differs from related species in the striking structure of its reproductive organs, at altitudes of over 3,500 meters above sea-level. In the identification of this and many other spider specimens, Hopfe received valuable support from researchers at Universidad del Valle in Cali, Colombia, with which the University of Bayreuth has a research cooperation. Colombia has been identified as a priority country in the internationalization strategy of the University of Bayreuth, which is why it maintains close connections with several Colombian universities.

The study of spiders from regions of such various huge climatic and ecological variety may also offer a chance to find answers to two as yet unexplored questions. It is not yet known whether temperatures, precipitation, or other climatic factors influence the evolution of spiders, or the properties of their silk. For example, is the proportion of species with extremely elastic silk in the lowland rainforest higher than in the semi-desert? And it is also still unclear whether the properties of the silk produced by a species of spider are modified by climatic factors. Would a spider living in the high mountains, such as Ocrepeira klamt, produce the same silk if it were native to a much lower region of the cordillera? The answer to these questions could provide important clues as to the conditions under which unusual spider silks develop.

Along similar lines, it would also be interesting to explore whether there are spider silk proteins which, due to their properties, are even more suitable for certain applications in biomedicine and biotechnology than silk proteins currently known. “The greater the variety of spider silks whose structures and properties we know, the greater the potential to optimize existing biomaterials and to develop new types of biomaterials on the basis of silk proteins,” Hopfe explains.

Charlotte Hopfe’s research was funded by the German Academic Exchange Service and the German Academic Scholarship Foundation.