Wednesday, 25 May 2016

Dramatic rise in Cephalopod populations across the globe.

In the past few decades marine biologists have become aware of many dramatic changes in the world's oceans, including dramatic falls in many commercially exploited Fish species, rising temperatures and widespread pollution and marine litter. During this time several studies have shown that as Fish populations have fallen in many areas, they have been replaced by rising Cephalopod numbers, leading some experts to wonder if this might be a global trend, though to date the data has not been examined to test this hypothesis.

In a paper published in the journal Current Biology on 23 May 2016, Zoë Doubleday and Thomas Prowse of the School of Biological Sciences and The Environment Institute at the University of Adelaide, Alexander Arkhipkin of the Fisheries Department of the Falkland Islands, Graham Pierce of the Oceanlab at the University of Aberdeen, Jayson Semmens of the Institute for Marine and Antarctic Studies at the University of Tasmania, Michael Steer of the South Australian Research and Development Institute, Stephen Leporati of the Department of Fisheries Western Australia, Sílvia Lourenço of the Instituto Português do Mar e Atmosfera, Antoni Quetglas of the Centre Oceanogràfic de les Balears of the Instituto Español de Oceanografía, Warwick Sauer of the Department of Ichthyology and Fisheries Science at Rhodes University and Bronwyn Gillanders, also of the School of Biological Sciences and The Environment Institute at the University of Adelaide, present a detailed analysis of Cephalopod population statistics from around the globe since 1953.

A Caribbean Reef Squid, Sepioteuthis sepioidea, on Bari Reef in the Caribbean Netherlands. Betty Wills/Wikimedia Commons.

Doubleday & Prowse et al. examined records from all major oceanographic regions in both hemispheres from 1953 to 2013, examining all key taxonomic groups (Squid, Octopus and Cuttlefish) and life history groups: demersal (living close to the bottom), benthopelagic (living on the bottom, but also swimming higher into the water column at times), and pelagic (living in the water column away from the bottom).

 A Two-spot Octopus, Octopus bimaculoides. Monterey Bay Aquarium.

In all cases Cephalopod numbers were found to have grown over the period examined. Doubleday & Prowse et al. suggest several possible explanations for this. Cephalopods are highly adaptable and intelligent, enabling them to colonise new areas and exploit novel resources, and have shorter life-cycles than comparably sized fish. In addition almost all Cephalopods, regardless of adult lifestyle, have a planktonic larval phase enabling them to reach suitable new habitats quickly. In addition recent studies have shown that rising temperatures tend to reduce generation times in Cephalopods (i.e. they reach maturity and reproduce more quickly). Furthermore many such larval Cephalopods are subject to predation by Fish species that have undergone dramatic population declines in recent years, potentially enabling more larval Cephalopods to survive to adulthood and reproduce.

Broadclub Cuttlefish, Sepia latimanus. Nick Hobgood/Wikipedia.

Doubleday & Prowse et al. note that such a rise in Caphalopod numbers is likely to have knock-on effects, most notably a rise in predation on species targeted by Cephalopods and an increase in food supply to species targeting Cephalopods (including many Humans). However they also observe that the current rise in Caphalopod numbers does not necessarily imply that in future Cephalopod populations will continue to rise, noting that the group are potentially vulnerable to future threats, such as rising ocean acidification and increased targeting by Human predation as Fish populations decline.

See also...

http://sciencythoughts.blogspot.co.uk/2015/12/determining-environments-favored-by.htmlDetermining the environments favored by Late Cretaceous Ammonites.              Ammonites are almost ubiquitous fossils in Mesozoic Marine deposits, and as such have been used extensively in interpreting and dating these deposits. They were free-swimming Cephalopods, related...

http://sciencythoughts.blogspot.co.uk/2014/08/brooding-behaviour-in-deep-sea-octopus.htmlBrooding behaviour in a Deep-sea Octopus.  Most Octopus reproduce only once in their life cycle, with the female undertaking an extended period of brooding in which she tends her eggs, keeping them clean and oxygenated and protected from predators, expiring at the end of this period. In most species the female does not feed at all during this...

http://sciencythoughts.blogspot.co.uk/2014/05/egg-masses-of-diamond-shaped-squid-in.htmlEgg masses of the Diamond-shaped Squid in the Canary Islands.                                       The Diamond-shaped Squid, Thysanoteuthis rhombus, is a large (up to 100-130 cm, excluding tentacles) ocean-going Squid found in tropical and...

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Tuesday, 24 May 2016

Truncospora wisconsinensis: A new species of Bracket Fungus from Wisconsin.

Bracket Fungi, Polyporales, are Basidiomycote Fungi that predominantly grow on dead, rotting, wood, though some species are significant pathogens of trees and woody plants. They produce distinctive fruiting bodies on the outside of the wood, which are shelf or bracket shaped with the spore-producing basidia on the underside. Bracket fungi found in commercial woodlands and those which attack structural timber have been well studied, but the group is know to be much more diverse in old-growth woodland, where it has been little studied.

In a paper published in the journal Phytotaxa on 14 April 2016, Chang-Lin Zhao, Feng Xu and Donald Pfister of the Farlow Herbarium of Cryptogamic Botany at Harvard University describe a new species of Bracket Fungus from Lakeshore Nature Reserve in Dane County, Wisconsin.

The new species is placed in the genus Truncospora and given the specific name wisconsinensis, meaning 'from Wisconsin'. The Fungus was found growing on fallen Oak trees, where it produces white fruiting bodies. A genomic phylogenetic analyses suggests that this species is closely related to two other North American Bracket Fungi, Truncospora ohiensis and Truncospora arizonica.

Fruiting body of Truncospora wisconsinensis. Scale bar is 1 cm. Zhao et al. (2016).

See also...

http://sciencythoughts.blogspot.co.uk/2016/05/penicillium-excelsum-new-species-of_6.htmlPenicillium excelsum: A new species of Fungi from the Brazil Nut Tree Ecosystem in the Amazon Basin.                                           Fungi of the genus Penicillium are considered to be highly important both ecologically and economically. They act as major biodegrading agents in many ecosystems, helping to recycle a wide range of biological material, but this also makes them spoiling agents capable of rotting food and man made...
http://sciencythoughts.blogspot.co.uk/2016/03/jahnula-purpurea-new-species-of.htmlJahnula purpurea: A new species of Ascomycote Fungo from Martinique. Ascomycote Fungi of the order Jahnulales are aquatic wood decomposing Fungi found almost exclusively in freshwater environments (one species is known from Mangroves). Members of the genus Jahnula, from which the family gets its name, are primarily tropical...
http://sciencythoughts.blogspot.co.uk/2014/11/two-new-species-of-coral-fungi-from.htmlTwo new species of Coral Fungi from the Ozark region of Arkansas.                                      Coral Fungi of the genus Ramariahave been extensively studied in the temperate rainforests of the American Pacific Northwest, and to a lesser extent in the forests of America’s Eastern Seaboard, but are...
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Monday, 23 May 2016

Decapod Crustaceans from the Tarioba Shell Mound.

Shell mounds are archaeological sites common in coastal areas around the world. In Brazil there are hundreds of such mounds, mostly dating to between 8000 and 1000 years ago, with the greatest abundance being found in Espírito Santo and Santa Catarina States. The Tarioba Shell Mound is located in Rio das Ostras Muncipality in eastern Rio de General State. It was discovered in 1967, but not excavated until 1998-1999, when the site was completely excavated, with the material being relocated to a museum, with the site subsequently being developed. The site had five layers, dated to between 3620 and 3440 years ago, though the site shows signs of overturning with the oldest layer at the top. A total of 47 Mollusc species have been described from the site, as which also yielded numerous Decapod Crustacean specimens, predominantly chelae (claws).

In a paper published in the journal Check List on 28 March 2016, Felipe Barta Rodrigues, Michelle Rezende Duarte and Rosa Cristina Corrêa Luz de Souza of the Laboratório de Genética Marinha e Evolução at the Universidade Federal Fluminense, Abílio Soares‑Gomes of the Laboratório de Ecologia de Sedimentos Marinhos, also at the Universidade Federal Fluminense and Edson Pereira Silva, again of the Laboratório de Genética Marinha e Evolução at the Universidade Federal Fluminense, analyze and describe the Crustacean material from the Tarioba Shell Mound.

Rodrigues et al. describe nine species of Decapod from five layers, these being Callinectes danae, a type of Swimming Crab, Callinectes sapidus, the Atlantic Blue Crab (another type of Swimming Crab and a species still widely eaten and considered economically important in the United States), Cardisoma guanhumi, the Blue Land Crab, Goniopsis cruentata, the Mangrive Root Crab, Menippe nodifrons, the Cuban Stone Crab, Mithrax hispidus, the Shaggy Climbing Crab, Ocypode quadrata, the Atlantic Ghost Crab, Ucides cordatus, the Atlantic Mangrove Crab and Panopeus austrobesus, the South American Mud Crab.

Voucher specimens, with morphological characters used for identification. (A) Callinectes danae (elongated dactyl format. Teeth arranged in a single row, with two small followed by a larger one pattern. More pointed teeth than the Callinectes sapidus); (B) Callinectes sapidus (elongated dactyl format, teeth arranged in a single row, with two small followed by a larger one pattern); (C) Cardisoma guanhumi (rounded tubers, arranged in a row, the largest tuber near to the palm); (D) Goniopsis cruentata (curved dactyl format, with teeth distributed in four rows); (E) Menippe nodifrons (large tuber at the base, followed by other smaller tubers); (F) Mithrax hispidus (curved dactyl format, teeth arranged in a single row, with the largest tooth near to the palm); (G) Ocypode quadrata (small tubers arranged in four rows, it has small thorns arranged in a single row); (H) Ucides cordatus (tubers arranged in three rows with other dispersed, it has thorns records); (I) Panopeus austrobesus (curved dactyl format, with a large basal tooth). Scale bars are 5 mm. Rodrigues et al. (2016).

The most biodiverse layer was the uppermost (oldest), in which all the species were present, with the other layers each having eight species. The presence of more species in the oldest layer could be taken as indication of loss of biodiversity due to consumption over the time the site was occupiedm however Rodrigues et al. do not consider the loss of diversity to be significant given the overall low number of samples.

See also...

http://sciencythoughts.blogspot.co.uk/2015/11/genotyping-500-year-old-inca-child-mummy.htmlGenotyping a 500-year-old Inca child mummy.                                                         In recent years the development of methods for sequencing ancient DNA has led to a greater understanding of how many ancient peoples are related to modern populations, particularly in Europe. However the method has been little used...
http://sciencythoughts.blogspot.co.uk/2014/04/bone-infection-in-pre-columbian-skull.htmlBone infection in a Pre-Columbian skull from south Jamaica.                                               The Taíno people are thought to have colonized the Caribbean Islands by island hopping from northern South America from about 500 BC onwards, reaching Jamaica by around 645-898 AD. They were skilled agriculturalists, introducing crops such as Cassava and Maize from South America and...
http://sciencythoughts.blogspot.co.uk/2012/02/pleistocene-rock-carving-from-brazil.htmlPleistocene rock carving from Brazil; possibly the oldest art in the Americas.                      The earliest people arrived in the Americas some time between 12 000 and 13 500 years ago. They are known from burials and tools scattered (albeit thinly) across both North and South America. Art made by...
...
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Callionymus alisae: A new species of Dragonet from New Ireland.

Dragnets, Callionymidae, are benthic, sublittoral (dwelling between the low tide livel and the edge of the continental shelves), Perciform Fish found throughout the world's temperate, subtroipical and tropical seas (and occasionaly esturine or even freshwater environments), but most abundant and diverse in the western Indo-Pacific region. They have elongate, slightly flattened bodies with two dorsal fins and spines on their gill-coverings, which is venemous in some species.

In a paper published in the journal FishTaxa on 9 April 2016, Ronald Fricke of the Staatliches Museum für Naturkunde Stuttgart describes a new species of Dragonet from New Ireland Province, Papua New Guinea.

The new species is named Callionymus alisae, in reference to the French research vessel RV Alis, which collected the specimen from which the species is described. The species is describd from a single male specimen, caught to the southeast of Bauddisson Island at a depth of between 90 and 228 m. The specimen, yellowish in colour, darker towards the rear and white on the underside, with dark blue eyes and greyish spots.

Callionymus alisae, holotype, male, 32.1 mm SL, Papua New Guinea, New Ireland Province, Kavieng District. Lateral view, left side (scale indicates 15 mm). Fricke (2016).

See also...

http://sciencythoughts.blogspot.co.uk/2015/10/symphysanodon-andersoni-second-specimen.htmlSymphysanodon andersoni: A second specimen of the Bucktoothed Slopefish from the south coast of Oman.                       Slopefish, Symphysanodontidae, are deepwate Perciform...
http://sciencythoughts.blogspot.co.uk/2015/04/philometrid-nematodes-from-perciform.htmlPhilometrid Nematodes from Perciform Fish off the north Australian coast.                   Philometrids are large Nematodes parasitizing Fish . They show a high degree of sexual dimorphism, with males typically only a few mm in length, while...


http://sciencythoughts.blogspot.co.uk/2015/02/a-new-species-of-serranineperchlet-from.htmlA new species of Serranine Perchlet from the Philippines.                                                   The Philippines form a major component of the...


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Pyroclastic flow kills at least seven on Mount Sinabung, North Sumatra.

Seven people have been confirmed dead and an unknown number are still missing following a pyroclastic flow (avalanche of hot rock, ash and gas) that swept through farms and villages on the slopes of Mount Sinabung in North Sumatra on Sunday 22 May 2016. A number of other people are being treated for extensive burns following the event, with rescue teams still scouring the mountain.

Rescue workers searching a ash-covered village near Mount Sinabung, North Sumatra. Dedi Sinuhaji/EPA.

Mount Sinabung, a 2460 m stratovolcano (cone shaped volcano made up of layers of ash and lava) in the Karo Regency; it is potentially a very dangerous volcano, as a large number of people live in its immediate vicinity. The last major eruption prior to the twenty-first century happened in about 1600, with small eruptions occurring in 1889 and 1912. However the volcano returned to life in late August 2010, erupting throughout September and causing about 12 000 people to flee their homes.
 
 The location of Mount Sinabung. Google Maps.
 
The Indo-Australian Plate, which underlies the Indian Ocean to the west of Sumatra, is being subducted beneath the Sunda Plate, a breakaway part of the Eurasian Plate which underlies Sumatra and neighboring Java, along the Sunda Trench, passing under Sumatra, where friction between the two plates can cause Earthquakes. As the Indo-Australian Plate sinks further into the Earth it is partially melted and some of the melted material rises through the overlying Sunda Plate as magma, fueling the volcanoes of Sumatra.
 
 The Subduction zone beneath Sumatra. NASA/Earth Observatory.
 
The two plates are not directly impacting one-another, as occurs in the subduction zones along the western margins of North and South America, but at a steeply oblique angle. This means that as well as the subduction of the Indo-Australian plate beneath the Sunda, the two plates are also moving past one-another. This causes rifting within the plates, as parts of each plate become stuck to the other, and are dragged along in the opposing plate's direction. The most obvious example of this is the Sumatran Fault, which runs the length of Sumatra, with the two halves of the island moving independently of one-another. This fault is the cause of most of the quakes on the island, and most of the island's volcanoes lie on it.

The movement of the tectonic plates around Sumatra. NASA/Earth Observatory.

See also...
 
http://sciencythoughts.blogspot.co.uk/2016/05/seventeen-students-confirmed-dead-after.htmlSeventeen students confirmed dead after flash flood and landslide at popular Sumatran tourist spot.                                          Seventeen students have been confirmed dead and another...
http://sciencythoughts.blogspot.co.uk/2016/03/magnitude-78-earthquake-to-southwest-of.htmlMagnitude 7.8 Earthquake to the southwest of Sumatra triggers small tsunami.              The United States Geological Survey recorded a Magnitude 7.8 Earthquake at a depth of 10 km...
http://sciencythoughts.blogspot.co.uk/2016/02/eruption-on-mount-sinabung.htmlEruption on Mount Sinabung.                 Residents of villages close to Mount Sinabung on North Sumatra have been forced to evacuate their homes following two eruptions on the volcano on Thursday 25 February 2016. The first eruption...

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Laelaspis natanziensis: A new species of Laelapid Mite from Isfahan Province, Iran.

Laelapid Mites are a large and diverse group, including free-living carnivorous forms as well as both obligate and facultative parasites (species that feed only parasitically and species that are sometimes parasitic but can feed in other ways). Members of the group are also found in a variety of environments, including soil and leaf litter and the nests of vertebrate and invertebrate animals. The family takes its name from the genus Laelaspis, which is found in the nests of Ants, though exactly how members of this genus feed is unknown, with suggestions having been made that they feed on substances secreted by the Ants, smaller invertebrates living in the nests or even the eggs of the Ants.

In a paper published in the Persian Journal of Acarology on 15 January 2016, Elham Masoomi of the Department of Entomology at the Islamic Azad University, Omid Joharchi of the Young Researchers and Elite Club, also at the Islamic Azad University and Alireza Jalalizand, again of the Department of Entomology at the Islamic Azad University, describe a new species of Laelaspis from Natanz County in Isfahan Province, Iran.

The new species is named Laelaspis natanziensis, meaning 'from Natanz'. The Mites were extracted from soil associated with the nests of Ants of the genus Tetramorium. Females range from 532 to 545 μm in length and from 437 to 451μm in width, the single male discovered measured 413 by 312 μm.

 Laelaspis natanziensis (female) Left: Dorsal view of idiosoma. Right: Ventral view of idiosoma. Masoomi et al. (2016).

See also...

http://sciencythoughts.blogspot.co.uk/2014/03/a-new-species-of-gall-mite-from-tripura.htmlA new species of Gall Mite from Tripura State, northeast India.                                   Gall Mites (Eriophyidae) are small Archnids related to Spider Mites and Scrub Itch Mites. They are exclusively parasitic, targetting higher plants. Gall Mites have only two pairs of legs, and an...
http://sciencythoughts.blogspot.co.uk/2013/12/a-new-species-of-feather-mite-from.htmlA new species of Feather Mite from Saudi Arabia.                                                        Mites (Acari) are small Arachnids related to Microwhip Scorpions (Palpigradi) and Sea Spiders (Pycnogonida). They are one of the...
  

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Sunday, 22 May 2016

Flooding and landslides kill at least seventy three in Sri Lanka.

Seventy three people have been confirmed dead and hundreds more are still missing after the heaviest rains in over twenty years have brought widespread flooding and numerous landslides. The worst hit area is in the Kegalle District in the central part of the country, where a series of huge landslides have engulfed at least three villages, and driven back repeated rescue missions by the Sri Lankan military. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall. Other areas of the country, including the capital, Colombo, have suffered extensive flooding, with close to a quater of a million people in temporary shelters.

The aftermath of a landslide in Kegalle District, Sri Lanka, on Wednesday 18 May 2016. Eranga Jayawardina/AP.

The rains are associated with the onset of the Sri Lankan summer monsoon, which lasts from May to October, typically brining around 400 mm of rain to many parts of the country in an average year. Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate. 

 Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

See also...

http://sciencythoughts.blogspot.co.uk/2015/12/heavy-rains-bring-further-flooding-to.htmlHeavy rains bring further flooding to Chennai, Tamil Nadu.                                                 Heavy rains have brought further flooding to the city of Chennai in Tamil Nadu, India, with about 8 cm of rain falling on the morning of Tuesday 1 December...
http://sciencythoughts.blogspot.co.uk/2014/12/at-least-six-dead-following-landslide.htmlAt least six dead following landslide in Badulla District, Sri Lanka.                             At least six people are known to have died following a landslide at Rilpola in the Badulla District of Uva...
http://sciencythoughts.blogspot.co.uk/2013/08/a-least-five-dead-following-landslide.html 
At least five dead following landslide in Kerala State, India.                                      Five people are known to have died and another fifteen, including two foreign tourists, are believed to still be buried in their vehicles following a...


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