Saturday, 30 April 2022

Hynobius owariensis: A new species of Salamander from Japan.

The Yamato Salamander, Hynobius vandenburghi, was originally described from Yamato Province (modern Nara Prefecture) in 1923, and has a modern distribution across Osaka, Nara, Kyoto, Shiga, Mie, Gifu, and Aichi prefectures. Molecular data has suggested that this distribution consists of two monophyletic populations (i.e. each population can be traced back to a separate common ancestor, with little-or-no interbreeding since that time), one comprising the population on the Atsumi Peninsula (a 50 km outcrop of land in southern Aichi Prefecture, separating Mikawa Bay, to the north, from the Philippine Sea, to the south, with Ise Bay lying to its west) and the other all other living Yamato Salamanders. However, this understanding is currently based upon only a very small number of populations, so the true picture is likely to be more complicated, potentially with more distinct lineages within the whole.

In a paper published in the Bulletin of the Kanagawa Prefectural Museum on 29 March 2022, Hirotaka Sugawara of the Faculty of Science and Technology at Kochi University, Takeshi Fujitani of the Higashiyama Zoo & Botanical Gardens, Shota Seguchi and Takuo Sawahata of the Graduate School of Agriculture at Kinki University, and Masahiro Nagano of the Faculty of Science and Technology at Oita University, evaluate the distinctiveness of the two 'Yamato Salamander' groups using morphological, phylogenetic, and evolutionary species concepts, and formally describe the Atsumi Peninsula population as a separate species.

Sugawara et al. took tissue samples from live Salamander specimens collected on private property or in fields from February 2007 to April 2021, from which DNA was extracted, another 55 specimens were anesthetized and measured for morphometric analysis (a tool used by palaeontologists, archaeologists, anthropologists and forensic pathologists to analyse and compare specimens, which involves taking numerous measurements of an object such as a bone or shell, and comparing both these measurements and ratios between measurements to those obtained from other specimens in order to establish relationships between them), with the majority then released back into the wild; three specimens from Atsumi were retained, providing a holotype and two paratypes of the new species. Samples were taken from a total of seven populations.

Two phylogenetic analyses were performed, including the collected samples and including other Hynobius species, and Salamandrella keyserlingii as the outgroup. The analysis based upon posterior probability values supported the concept that all specimens currently assigned to Hynobius vandenburghi form a monophyletic group (i.e. they share a single common ancestor from which they are all descended, with no specimens not assigned to the species being descended from that ancestor), however, an analysis based upon bootstrap values did not support this conclusion. Both the posterior probability and bootstrap analyses supported the conclusion that the two populations were themselves monophyletic groups, exclusive of one-another.

The new species is named Hynobius owariensis, where 'owariensis' means 'from Owari' (an old name for Aichi Prefecture). In this species the males tend to have a mottled pattern on their throats (generally absent or indistinct in Hynobius vandenburghi), but seldom had distinct black dots on the dorsum, distinct white dots on the venter, or distinct white dots on the lateral side of the body (generally present in Hynobius vandenburghi). Nor did they have a distinct and bright yellow line on the dorsal and ventral sides of the tail, something typically seen in Hynobius vandenburghi

Holotype of Hynobius owariensis (TMNHAM-78, adult male, 58.2 mm SVL): (A) dorsal and (B) ventral views. Sugawara et al. (2022).

Sugawara et al.'s study only included specimens from Aichi, Nara and Osaka prefectures, despite Hynobius vandenburghi being much more widely distributed, due to the high level of protection given to the species by Japan's strict conservation laws. This raises the distinct possibility that other, undiscovered cryptic species are hidden within this range, raising further concerns for the future of these Salamanders. As it is, the population of Hynobius owariensis comprises a number of isolated populations, each too small to be realistically viable. Attempts to address this have included at least one case of specimens of Hynobius vandenburghi being introduced to a park in the city of Nagoya-shi. Sugawara et al. therefore recommend that a conservation plan specific to the needs of this species by drawn up as a matter of urgency.

(A) Live holotype of Hynobius owariensis (TMNH-AM-78), and the (B) larva, (C) banana-shaped egg sacs, and (D) type locality of the new species. Sugawara et al. (2022).

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Friday, 29 April 2022

Partial Solar Eclipse to be visible from parts of Antarctica and South America.

A partial Solar Eclipse will occur on Saturday 30 April 2022, which will be visible from parts of Peru and the south Pacific. Part of the eclipse will also be visible from Chile, Argentina, Uraguay and parts of Paraguay, Bolivia, Brazil, and Antarctica, where the Sun will either rise or set part way through the eclipse. The event will occur between 6.45 pm and 10.38 pm, GMT.

The area over which the 30 April 2022 partial Solar Eclipse will be visible. Areas in darker grey will be able to observe the entire eclipse, in the lighter grey areas the eclipse will either begin before sunrise or end after sunset, so only part of the event will be visible. HMNautical Almanac Office.

Eclipses are a product of the way the Earth, Moon and Sun move about one-another. The Moon orbits the Earth every 28 days, while the Earth orbits the Sun every 365 days, and because the two Sun and Moon appear roughly the same size when seen from Earth, it is quite possible for the Moon to block out the light of the Sun. At first sight this would seem likely to happen every month at the New Moon, when the Moon is on the same side of the Earth as the Sun, and therefore invisible (the Moon produced no light of its own, when we see the Moon we are seeing reflected sunlight, but this can only happen when we can see parts of the Moon illuminated by the Sun)


The relative positions of the Sun, Moon and Earth during a Solar eclipse. Starry Night.

However the Moon does not orbit in quite the same plane as the Earth orbits the Sun, so the Eclipses only occur when the two orbital planes cross one-another; this typically happens two or three times a year, and always at the New Moon. During Total Eclipses the Moon entirely blocks the light of the Sun, however most Eclipses are Partial, the Moon only partially blocks the light of the Sun.

How the differing inclinations of the Earth and Moon's orbits prevent us having an eclipse every 28 days. Starry Skies.

Although the light of the Sun is reduced during an Eclipse, it is still extremely dangerous to look directly at the Sun, and an eclipse should always be viewed using appropriate equipment.

Animation showing the shadow of the Moon at five minute intervals on 30 April 2022. Andrew Sinclair/HM Nautical Almanac.

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Wednesday, 27 April 2022

Leopard shot after attacking policeman in northern Iran.

A Leopard has been shot dead after attacking a policeman in the city of Ghaemshahr in Mazandaran Province, northern Iran, on Sunday 24 April 2022. The Animal had broken of the attack and fled the scene before being shot, but there were concerns that it could potentially attack other people. After being shot the Leopard was taken to a local wildlife centre in the hope that it could be saved and released in a sanctuary, but it died of its injuries before this could happen. The policeman is reported to be in a stable condition.

A Persian Leopard in Iran. Future 4 Leopards Foundation.

Persian Leopards, Panthera pardus tulliana, the subspecies found in Iran, and the only Big Cat now found in Iran following the local extinction of the Asiatic Lion and Caspian Tiger, are considered to be Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species, with less than a thousand surviving in the wild. The majority of these are found in Iran, but smaller populations in Turkey, Iraq, Georgia, Armenia, Azerbaijan, Afghanistan, Kazakhstan, Turkmenistan and possibly Pakistan, Historically, this subspecies had a wider range, extending into Syria and part of Russia. The species is threatened by hunting (now illegal across almost al of its range) and habitat loss, which brings it into conflict with Human populations, particularly herders, as its natural wild prey is replaced by domestic Sheep and Goats, which can lead to Leopard attacks on both livestock and Humans, with subsequent, usually lethal, retaliation towards the Leopards. 

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Monday, 25 April 2022

Eruption on Anak Krakatoa produces column of ash 3 km high.

Anak Krakatoa, a volcanic island located in the Sunda Strait between Sumatra and Java, underwent a major eruption on Sunday 24 April 2022, producing a column of ash about 3 km high. The volcano had been erupting intermitantly for several weeks, but this event was significantly larger than previous eruptions in this cycle, and 24 hours after the initial eruption the Anak Krakatoa was still erupting intermitently, producing ash columns between 500 m and 3 km high. The Badan Nasional Penanggulangan Bencana has advised that people living close to the volcano wear dust masks when going outside until the volcano subsides.

An ash column over Anak Krakatoa (at the right of the image) on 24 April 2024. Dziki Oktomauliyadi/AFP.

Anak Krakatau is a volcanic island located in the Sunda Strait between Sumatra and Java. The volcano (then known simply as Krakatoa) famously exploded in 1883, killing over 36 000 people (possibly over 120 000), largely through a series of tsunamis. This explosion more-or-less completely destroyed the island, but since then a new volcano, Anak Krakatau (meaning the 'son of Krakatoa'), has grown in its place. Anak Krakatau is almost never completely quiet, but goes through periods of greater and lesser activity. An eruption on 22 December 2018 triggered a tsunami which tsunami caused over 430 fatalities, injured 14 000 people, and displaced 33 000 more along the Sunda Strait. The tsunami risk of this area is particularly high as the coast is very popular with both locals and tourists and is home to over 20 million people within a 100 km distance from the volcano.

Anak Krakatau is located to the north of the Sunda Trench, along which the Australian Plate is being subducted beneath the Sunda Plate, on which the island sits. As the Australian Plate is subducted it is partially melted by the friction and the heat of the planet's interior. Some of this melted material then rises through the overlying Sunda Plate, fuelling Krakatau and the volcanoes of Sumatra and Java.

The Subduction zone beneath Sumatra. NASA/Earth Observatory.

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Asteroid 2022 HM passes the Earth.

Asteroid 2022 HM passed by the Earth at velocity of 14.61 km per second and a distance of about 245 300 km (0.64 times the average distance between the Earth and the Moon, or 0.16% of the distance between the Earth and the Sun), slightly after 1.40 am GMT on Thursday 21 April 2022. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2022 HM has an estimated equivalent diameter of 6-19 m (i.e. it is estimated that a spherical object with the same volume would be 6-19 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) between 38 and 24 km above the ground, with only fragmentary material reaching the Earth's surface.

The relative positions of 2022 HM and the Earth on at 2.00 am on 21 April 2022. JPL Small Body Database.

2022 HM was discovered on 22 April 2022 (the day after its closest approach to the Earth) by the Piszkés-Tető Mountain Station of the Hungarian Academy of Science's Konkoly Observatory. The designation 2022 HM implies that the asteroid was the 12th object (asteroid M - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 26, A2 = 51, etc., which means that M = 12) discovered in the second half of April 2022 (period 2022 H - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

The orbit and current position of 2022 HM. The Sky Live 3D Solar System Simulator.

2022 HM is calculated to have a 448 day (1.23 year) orbital period, with an elliptical orbit tilted at an angle of 16.7° to the plain of the Solar System which takes in to 0.68 AU from the Sun (68% of the distance at which the Earth orbits the Sun, and slightly inside the orbit of the planet Venus) and out to 1.60 AU (1.60 times the distance at which the Earth orbits the Sun, and lightly more than the distance at which the planet Mars orbits). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that 2022 HM has occasional close encounters with the Earth, with the last thought to have happened in October 2020 and the next predicted in January 2027. 

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