Saving coral reefs

This video says about itself:

Reef Life of the Andaman (full marine biology documentary)

31 October 2012

“Reef Life of the Andaman” is a documentary of the marine life of Thailand and Burma (Myanmar).

Scuba diving more than 1000 times from the coral reefs and underwater pinnacles of Thailand‘s Similan Islands, Phuket, Phi Phi Island and Hin Daeng, to Myanmar’s Mergui Archipelago and Burma Banks, I encountered everything from manta rays to seahorses, whale sharks to shipwrecks. The 116-minute film features descriptions of 213 different marine species including more than 100 tropical fish, along with sharks, rays, moray eels, crabs, lobsters, shrimps, sea slugs, cuttlefish, squid, octopus, turtles, sea snakes, starfish, sea cucumbers, corals, worms etc..

This marine biology documentary provides an overview of Indian Ocean aquatic life.

From Science News:

Reef rehab could help threatened corals make a comeback

Solutions for threatened reefs vary by location and damage done

By Amy McDermott

5:30am, October 18, 2016

Coral reefs are bustling cities beneath tropical, sunlit waves. Thousands of colorful creatures click, dash and dart, as loud and fast-paced as citizens of any metropolis.

Built up in tissue-thin layers over millennia, corals are the high-rise apartments of underwater Gotham. Calcium carbonate skeletons represent generations of tiny invertebrate animals, covered in a living layer of colorful coral polyps. Their structures offer shelter, and for about 114 species of fish and 51 species of invertebrates, those coral skyscrapers are lunch.

Important as they are, corals are in jeopardy. Warming oceans are causing more and more corals to bleach white and become vulnerable to destruction. A prolonged spike in temperatures, just 1 to 2 degrees Celsius, is enough to kill the marine animals. Greenhouse gas emissions also acidify the water, dissolving the calcium skeletons. In some countries, fishermen use dynamite to catch fish, leaving behind coral rubble. Today, more than 60 percent of the world’s reefs are at risk of disappearing.

Threats to reefs have “dramatically escalated in the last few decades,” says marine scientist Peter Harrison of Southern Cross University in Lismore, Australia. He has studied corals for three decades. “In my time as a reef researcher,” Harrison says, “I’ve seen it get worse, firsthand.”

Thirty years ago, massive coral bleachings were unheard of. Today, reefs are suffering through a third global bleaching event since 1998. With high ocean temperatures dragging on since 2014, this summer marked the longest and most widespread episode of worldwide coral bleaching on record (SN: 7/23/16, p. 5). Australia has been hit especially hard. More than 80 percent of the northern part of the Great Barrier Reef is bleached and close to half of those corals have died, according to a report in April from Australia’s National Coral Bleaching Taskforce.

As reefs take a nose dive, scientists from Hawaii to the Philippines and the Caribbean are scrambling to save corals. Approaches that were once considered radical are “now seen as necessary in some places,” says coral biologist Ruth Gates of the Hawaii Institute of Marine Biology on Oahu.

In Florida, researchers are restoring reefs with tiny coral fragments. In Hawaii, Gates is scouring the water for stress-tolerant corals and experimenting in the lab to breed the hardiest individuals. At the 13th International Coral Reef Symposium in Honolulu in June, Harrison’s team reported early promising results of its effort to flood damaged reefs in the Philippines with tiny coral larvae.

What works on one reef won’t necessarily save another. So researchers are testing an arsenal of options to rescue a diversity of underwater communities.

Crabs, lobsters, shrimp and books

Mantis shrimps

This picture is a cell phone photo, like the others in this blog post. It depicts various mantis shrimp species. As depicted on a slide, part of a lecture on 16 October 2016 in the Lakenhal museum in Leiden in the Netherlands. That was after the lecture by Ms Arita Baaijens in the same hall.

The lecture was about malacostracans: crabs, lobsters, crayfish, shrimp, krill, woodlice and many other related crustaceans. It was by Alex Alsemgeest, an expert on books, and Charles Fransen, a biologist of Naturalis museum, specialised in crustaceans.

The title of the book is In krabbengang door kreeftenboeken, ‘Going like a crab through books about lobsters’. The book was on the shortlist of five books for the Jan Wolkers Prize; though it did not win.

It is about the work of Leiden university professor and Naturalis museum collector Lipke B. Holthuis (1921-2008).

Holthuis was of Frisian ancestry. The name Lipke means ‘northern lapwing‘ in Frisian.

Malacostracans are an important group of animals. On the morning of the lecture, diver Ms Aaf Verkade had caught several of them in the Oude Vest canal next to the Lakenhal. All invasive species: two North American crayfish species, and a Chinese mitten crab.

According to Charles Fransen, there are 70,000 malacostracan species; including 20% of all marine animals.

Isopods, 16 October 2016

This photo shows a slide about isopods, another malacostracan group.

Holthuis was recognized all over the world as an expert on this group. He described and named many newly discovered species. Eg, 279 new shrimp species.

Other species were named after him.

During the second world war, Holthuis hid from the German nazi occupiers between animal skeletons and biology magazines in the old building of the natural history museum (now: Naturalis, in a new building). During the last winter of the war, hunger caused Holthuis to get edema. He then moved to his sister’s home; where also Jews hid from the nazis.

Holthuis kept working on crabs and lobsters until two weeks before his death in 2008. He published about 12,000 pages about them. During that time, he collected about eight thousand books, and many pictures and objects (eg, porcelain depicting crabs) about these animals. These are now part of the Naturalis museum collection.

Some of the books are very old; like the 16th century De Aquatibus, by Pierre Belon.

Crab with barnacles

Holthuis also collected art depicting his favourite animals. Like this picture of a crab with barnacles (its distant relatives) on it.

Madonna with child in landscape

And this engraving by Aegidius Sadeler. ‘Madonna and child in landscape’; depicting the Virgin Mary, baby Jesus, and in the lower right corner, a crab.

Sowerby and Leach

One of the fine books collected by Holthuis is Malacostraca Podophthalmata Brittaniae. It is by British illustrator James Sowerby (1757-1822), misspelled as ‘Sowersy’ in the slide, and British naturalist William Elford Leach (1790-1836).

Lamotius, 16 October 2016

This slide is about Holthuis’ last book, published in 2006. It is about Isaac Johannes Lamotius, 17th century Dutch colonial governor of Mauritius, and interested in marine animals.

Holthuis memorial volume, 16 October 2016

After Holthuis’ death, this book was published: Studies on Malacostraca: Lipke Bijdeley Holthuis Memorial Volume.

Spiders hear better than expected, new research

This video says about itself:

13 October 2016

In a test of hearing airborne noises, a small dark jumping spider stops moving abruptly (red pointer appears) when researchers broadcast a tone similar to the scary droning of the wings of a predatory wasp.

Video: G. Menda, Hoy Lab at Cornell

From Science News:

Be careful what you say around jumping spiders

Arachnids hear airborne sounds over greater distances than thought

By Susan Milius

8:00am, October 15, 2016

Accidental chair squeaks in a lab have tipped off researchers to a new world of eavesdroppers.

Spiders don’t have eardrums, though their exquisitely sensitive leg hairs pick up vibrations humming through solids like web silk and leaves. Biologists thought that any airborne sounds more than a few centimeters away would be inaudible. But the first recordings of auditory nerve cells firing inside a spider brain suggest that the tiny Phidippus audax jumping spider can pick up airborne sounds from at least three meters away, says Ronald Hoy of Cornell University.

During early sessions of brain recordings, Hoy’s colleagues saw bursts of nerve cell, or neuron, activity when a chair moved. Systematic experiments then showed that from several meters away, spiders were able to detect relatively quiet tones at levels comparable to human conversation. In a hearing test based on behavior, the spiders also clearly noticed when researchers broadcast a low droning like the wing sound of an approaching predatory wasp. In an instant, the spiders hunkered down motionless, the researchers report online October 13 in Current Biology.

Jumping spiders have brains about the size of a poppy seed, and Hoy credits the success of probing even tinier spots inside these (anesthetized) brains to Cornell coauthor Gil Menda and his rock-steady hands. “I close my eyes,” Menda says. He listens his way along, one slight nudge of the probe at a time toward the auditory regions, as the probe monitor’s faint popping sounds grow louder.

When Menda first realized the spider brain reacted to a chair squeak, he and Paul Shamble, a study coauthor now at Harvard University, started clapping hands, backing away from the spider and clapping again. The claps didn’t seem earthshaking, but the spider’s brain registered clapping even when they had backed out into the hallway, laughing with surprise.

Clapping or other test sounds in theory might confound the experiment by sending vibrations not just through the air but through equipment holding the spider. So the researchers did their Cornell neuron observations on a table protected from vibrations. They even took the setup for the scary wasp trials on a trip to the lab of coauthor Ronald Miles at State University of New York at Binghamton. There, they could conduct vibration testing in a highly controlled, echo-dampened chamber. Soundwise, Hoy says, “it’s really eerie.”

Neuron tests in the hushed chamber and at Cornell revealed a relatively narrow, low-pitched range of sensitivity for these spiders, Hoy says. That lets the spiders pick up rumbly tones pitched around 70 to 200 hertz; in comparison, he says, people hear best between 500 and 1,000 Hz and can detect tones from 50 Hz to 15 kilohertz.

Spiders may hear low rumbles much as they do web vibes: with specialized leg hairs, Hoy and his colleagues propose. They found that making a hair twitch could cause a sound-responsive neuron to fire.

“There seems to be no physical reason why a hair could not listen,” says Jérôme Casas of the University of Tours in France. When monitoring nerve response from hairs on cricket legs, he’s tracked airplanes flying overhead. Hoy’s team calculates that an 80 Hz tone the spiders responded to would cause air velocities of only 0.13 millimeters a second if broadcast at 65 decibels three meters away. That’s hardly a sigh of a breeze. Yet it’s above the threshold for leg hair response, says Friedrich Barth of the University of Vienna, who studies spider senses.

An evolutionary pressure favoring such sensitivity might have been eons of attacks from wasps, such as those that carry off jumping spiders and immobilize them with venom, Hoy says. A mother wasp then tucks an inert, still-alive spider into each cell of her nest where a wasp egg will eventually hatch to feed on fresh spider flesh. Wasps are major predators of many kinds of spiders, says Ximena Nelson of the University of Canterbury in Christchurch, New Zealand. If detecting their wing drone turns out to have been important in the evolution of hearing, other spiders might do long-distance eavesdropping, too.

Little dinosaur, belemnites, dukes in Pomeranian State Museum

This March 2016 video is about the Pommersches Landesmuseum, the Pomeranian State Museum in Greifswald town in Germany.

This 2015 video is about the Pommersches Landesmuseum as well.

As this blog has mentioned, we arrived there on 1 October 2016.

Not far from the museum entrance was the paleontology room.

There, the fossil, discovered in 1963, of Emausaurus ernstii. An ornithischian young dinosaur … well, by now about 190 million years old, so from the early Jurassic. The name refers to the Ernst Moritz Arndt University. This ornithischian, herbivorous dinosaur was about one meter in size.

Later in the Jurassic, the land of what is now Pomerania became sea; and remained so during the Cretaceous.

In the museum were fossils of Cretaceous cephalopods, belemnites, of the Belemnella genus.

Belemnella lanceolata

This picture shows a Belemnella lanceolata.

A bit further in the museum, amber, about forty million years old.

Still further, humans in the prehistory and history of Pomerania.

In the early Middle Ages, its inhabitants were Slavic tribes, practicing a polytheist religion. However, the Christian German empire attacked them. In the twelfth century, the Slavic dukes of Pomerania could only keep their dukedom by converting to Christianity, recognizing the German emperors as their overlords, and destroying the pagan temples.

In the sixteenth century, another conversion for the dukes and people of Pomerania: from Roman Catholicism to Protestantism. This is documented by an important item in the museum: the Croy Tapestry from 1544.

Croy Tapestry

In the seventeenth century, the ducal dynasty became extinct, and the kings of Sweden became the rulers. The harsh serfdom for the peasants in Pomerania became a model for the oppression of the peasantry in Sweden proper.

Stay tuned! As soon as the photos will be sorted out, there will be more blog posts here on the German Baltic Sea region, especially its birdlife.

Intelligent bumblebees can learn to pull strings

This video says about itself:

Social learning and cultural transmission in bees

Footage shows a pair of bees (the seeded demonstrator and an observer) tested with the string pulling task in Colony 8. The red dot indicates the seeded demonstrator. The observer has not learned string pulling yet but has already been tested three times in paired foraging bouts. The demonstrator lands at the edge of the table, repositions herself in front of the string, and starts pulling immediately.

The observer is first attracted to the blue flower and lands on top of the table. The observer subsequently flies to the demonstrator, lands at her side, and walks to the nearby flower and string. She walks along the protruding string, reaches the table edge, and moves sideways. She notices the demonstrator and walks to her side, moving around her whilst the demonstrator is pulling, always in close contact.

The observer touches the string a few times but does not grasp it. The demonstrator eventually extracts the blue disk and steps onto it. The observer copies the demonstrator. They both slide the flower from under the table and obtain the reward.

Once the first pulled flower is depleted, the demonstrator moves to the nearest flower and pulls the string. The observer stays on the extracted flower for a short period, circling, probing the emptied inverted cap before noticing the demonstrator drinking from a second flower and joining her. In a similar way, once the second pulled flower is emptied, the demonstrator moves and pulls a third flower and the observer joins her. Her crop filled up, the demonstrator flies back to the colony.

From PLOS Biology:

Associative Mechanisms Allow for Social Learning and Cultural Transmission of String Pulling in an Insect

October 4, 2016


Social insects make elaborate use of simple mechanisms to achieve seemingly complex behavior and may thus provide a unique resource to discover the basic cognitive elements required for culture, i.e., group-specific behaviors that spread from “innovators” to others in the group via social learning. We first explored whether bumblebees can learn a nonnatural object manipulation task by using string pulling to access a reward that was presented out of reach. Only a small minority “innovated” and solved the task spontaneously, but most bees were able to learn to pull a string when trained in a stepwise manner.

In addition, naïve bees learnt the task by observing a trained demonstrator from a distance. Learning the behavior relied on a combination of simple associative mechanisms and trial-and-error learning and did not require “insight”: naïve bees failed a “coiled-string experiment,” in which they did not receive instant visual feedback of the target moving closer when tugging on the string.

In cultural diffusion experiments, the skill spread rapidly from a single knowledgeable individual to the majority of a colony’s foragers. We observed that there were several sequential sets (“generations”) of learners, so that previously naïve observers could first acquire the technique by interacting with skilled individuals and, subsequently, themselves become demonstrators for the next “generation” of learners, so that the longevity of the skill in the population could outlast the lives of informed foragers. This suggests that, so long as animals have a basic toolkit of associative and motor learning processes, the key ingredients for the cultural spread of unusual skills are already in place and do not require sophisticated cognition.

Author Summary

Social insects make use of simple mechanisms to achieve many seemingly complex behaviors and thus may be able to provide a unique resource for uncovering the basic cognitive elements required for culture. Here, we first show that bumblebees can be trained to pull a string to access a reward, but most could not learn on their own. Naïve bees learned how to pull strings by observing trained demonstrators from a distance.

Learning the behavior through observation relied on bees paying attention to both the string and the position of the trained demonstrator bee while pulling the string. We then tested whether bees could pass this information to others during a semi-natural situation involving several colonies. We found that once one bee knew how to string pull, over time, most of the foraging bees learned from the initially trained bee or from bees who had learned from the trained bee, even after the initial demonstrator was no longer available. These results suggest that learning a nonnatural task in bumblebees can spread culturally through populations.

These bumblebees were Bombus terrestris, large earth bumblebees.

Primitive signs of emotions spotted in sugar-buzzed bumblebees. After a treat, insects appeared to have rosier outlooks. By Emily Underwood, 2:00pm, September 29, 2016: here.

Sea cucumber biology, video

This video says about itself:

30 September 2016

In this entertaining short video, Jonathan explains the basic biology of sea cucumbers. A sea cucumber is a relative of starfish and sea urchins contained within the phylum Echinodermata.