Tag: biogeography

Black wattle’s new biogeographic distribution threatens flight safety in China

Black wattle, flowering trees also known as the Australian acacia, have been observed to rapidly spread around local airports in Yunnan province, southwestern China. According to the ecologists, this alien species and its extraordinary pace of invasion are to lead to new threats for both flight safety and local biodiversity. The five Chinese scientists, led by Min Liu, PhD student at Yunnan University, have their findings and suggestions for immediate measures published in the open-access journal Neobiota.

The phenomenon was investigated by the ecologists and botanists, affiliated with Yunnan University and Kunming University of Science and Technology, at Kunming’s Changshui International Airport.

The black wattle is listed as being among the ”Top 100 of the world’s worst invasive alien species” by the World Conservation Union (IUCN). Native to Australia, the species has been settled across the globe for more than 150 years owing to its multiple uses. However, its distribution and expansion are generally overlooked in China.

It is an evergreen fast growing flowering tree species, which is strongly dependent on sunlight and contributes to nitrogen fixation. This means that due to bacteria in its root system, the tree produces nitrogen compounds that help the plant grow and compete with other plants. Once dead, it would release these compounds to fertilise the soil.

During their investigation, the scientists observed a total seedling spread of 1800 m in 2013, with its peak growth taking place between June and November. Other population features such as number, density, height and ground diameter, also showed that the species had a very high invasion rate.

The authors conclude that black wattle has a strong potential to change the local vegetation structure and increase the risk of bird strikes. It is of urgent need that the situation is further assessed and the potential invasion threat at other airports around China and other parts of the world – evaluated.

“I have never found such a rapid expansion like the one of the black wattle trees at this airport in my career,” said the Head of Bird Strike Prevention Office of Changshui Airport. “These trees grow very fast and provide good shelters for local birds, which eventually increases the probability of bird strikes at our airport. So, they must be controlled.”

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Original source:

Liu M, Yang M, Song D, Zhang Z, Ou X (2016) Invasive Acacia mearnsii De Wilde in Kunming, Yunnan Province, China: a new biogeographic distribution that Threatens Airport Safety.NeoBiota 29: 53-62. doi: 10.3897/neobiota.29.7230

How to catch a small squid? First records for the Gulf of California and southwest Mexico

Often avoiding sampling gear with their capability to detect movements and swim their way out of the nets fast enough, the small squids living in the open-ocean zone have so long gone under-researched. The present study, conducted by Dr. Michel Hendrickx, Universidad Nacional Autonoma de Mexico, and his team, seems to provide new and first distributional records of five such species for the Gulf of California and in southwestern Mexico. It also significantly expands the currently known southernmost limit of localities of some of these squids in the eastern Pacific. The research is available in the open-access journal ZooKeys.

The researched five squid species belong to two genera, Abraliopsis and Pterygioteuthis, which although abundant and diverse, have long been shrouded by taxonomic and distributional controversies. To solve them, the researchers used specimens, collected over the span of thirteen years, comprising eight cruises across 113 locations in the Gulf of California and off the southwestern coast of Mexico.

As a result, the scientists concluded a significantly wider distributional range of the species they found. For instance, squids of the Abraliopsis genus were surprisingly found in water deeper than 600 m during the day.

The studied small squids are of high ecological value due to their vital position in the food web. Members of Abraliopsis are important preys for many fishes and mammals, such as the peruvian hake, the Indo-Pacific sailfish, the common dolphinfish and the local sharks. Meanwhile, the representatives of the other researched genus, Pterygioteuthis, are often consumed by larger cephalopods, sea-birds and fur seals. However, their abundance is strongly dependent on temperature, especially when there are fast and significant changes.

The scientists suggest that additional samplings with more adequate equipment, like faster large-sized mid-water trawls, could further bridge the knowledge gaps about these elusive marine inhabitants.

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Original source:

Hendrickx ME, Urbano B, Zamorano P (2015) Distribution of pelagic squids Abraliopsis Joubin, 1896 (Enoploteuthidae) and Pterygioteuthis P. Fischer, 1896 (Pyroteuthidae) (Cephalopoda, Decapodiformes, Oegopsida) in the Mexican Pacific. ZooKeys 537: 51-64. doi: 10.3897/zookeys.537.6023.

A centipede from hell

An international team of scientists has discovered the deepest underground dwelling centipede. The animal was found by members of the Croatian Biospeleological Society in three caves in Velebit Mts, Croatia. Recorded as deep as -1100 m the new species was named Geophilus hadesi, after Hades, the God of the Underworld in the Greek Mythology. The research was published in the open access journal ZooKeys.

Lurking in the dark vaults of some of the world’s deepest caves, the Hades centipede has also had its name picked to pair another underground-dwelling relative named after Persephone, the queen of the underworld.

Centipedes are carnivores that feed on other invertebrate animals. They are common cave inhabitants but members of this particular order, called geophilomorphs, usually find shelter there only occasionally. Species with an entire life cycle confined to cave environments are exceptionally rare in the group.

In fact, so far the Hades and Persephone centipedes are the only two geophilomorphs that have adapted to live exclusively in caves, thus rightfully bearing the titles of a queen and king of the underworld.

Like most cave-dwellers, the newly discovered centipede shows unusual traits, some of which commonly found in cave-dwelling arthropods, including much elongated antennae, trunk segments and leg claws. Equipped with powerful jaws bearing poison glands and long curved claws allowing to grasp and tightly hold its prey, the Hades centipede is among the top predators crawling in the darkness of the cave.

The new species is yet another addition to the astonishing cave critters that live in the Velebit, a mountain that stretches over 145 km in the Croatian Dinaric Karst, which is as a whole considered a hot spot of subterranean diversity. The deepest record comes from the Lukina jama – Trojama cave system, which is 1431 meters deep and is currently ranked the 15th deepest cave in the world.

Just like Hades who ruled over the kingdom of shadows, the new centipede dwells among an extraordinary number of pallid cavernicolous animals, some known to science and many yet to be discovered.

“When I first saw the animal and its striking appearance, I immediately realized that this is a new, hitherto unnamed and highly adapted to cave environment species. This finding comes to prove once again how little we know about the life in caves, where even in the best prospected areas, one can still find incredible animals” says the lead author Pavel Stoev, Pensoft Publishers and National Museum of Natural History, Sofia.

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Original Source:

Stoev P, Akkari N, Komerički A, Edgecombe GD, Bonato L (2015) At the end of the rope:Geophilus hadesi sp. n. – the world’s deepest cave-dwelling centipede (Chilopoda, Geophilomorpha, Geophilidae). In: Tuf IH, Tajovský K (Eds) Proceedings of the 16th International Congress of Myriapodology, Olomouc, Czech Republic. ZooKeys 510: 95-114. doi: 10.3897/zookeys.510.9614