Don’t let the web bugs bite

by Piter Kehoma Boll

If you think spiders are scary creatures, today you will learn that they are scared too. But what could scary a spider? Well, a web bug!

We usually think of spider webs as an astonishing evolutionary achievement of this group of arachnids and a very efficient way to capture prey without having to pursue them. Webs are sticky, resistant, and only spiders themselves can move freely through them. The only problem is that this is not true.

emesaya_feeding

A thread-legged assassin bug (Emesaya sp.) feeding on a spider after invading the spider’s web in the Western Ghats, India. Photo by Vipin Baliga.*

A group of bugs that conquered the spider world are the so-called thread-legged assassin bugs, which comprise the subfamily Emesinae of the assassin bugs (family Reduviidae). As the name implies, the assassin bugs are a group of true bugs (suborder Heteroptera) that are expert killers of other creatures.

During their evolution, the thread-legged assassin bugs seem to have acquired a special taste for spiders and throughout the world they are usually associated with this eight-legged predators. In many cases, such as the one seen in the picture above, the bugs prey on the spiders, having developed the ability to move through the webs. They usually produce vibrations on the web that attract the spiders. Those, thinking that they caught a prey, are lured directly to their death in the legs and proboscis of the terrible bug.

Some thread-legged assassin bugs have, however, found another way to harass spiders: by stealing their food. In the latter scenario, the bugs usually wait close to or on the spider’s web and, when an insect is caught, they steal it from the spider by ripping it off the web. This kind of behavior is called kleptoparasitism, which means “parasitism by stealing”.

But how can spiders avoid this bug nightmare?

Until recently, it was thought that spiders were safe inside caves. Although emesinid bugs do occurr in caves, their association with spiders seemed to be weaker or non-existent there. But new findings are revealing that they pursue our arachnid fellows even to the deepest abysses of Earth.

The earliest cave-dwelling thread-legged assassin bug known to prey on spiders is Bagauda cavernicola, from India. Its spider-eating habits are known since the first decades of the 20th century.

The second species, Phasmatocoris labyrinthicus, was found almost a century later, in 2013, in Arizona, USA. More than only preying on spiders, such as the species Eidmanella pallida that lives in the same cave, P. labyrinthicus seem to have developed the ability to manipulate abandoned spiderwebs and use them to detect and capture prey for their own consumption. Only a single instance of such a behavior has been recorded and the species’s behavior needs further studies.

phasmatocoris_labyrinthicus_eating

Phasmatocoris labyrinthicus feeding on the spider Eidmanella pallida in the Kartchner Caverns, Arizona, USA. Photo extracted from Bape, 2013.

Now, only 3 years later, there are new evidences of more thread-legged assassin bugs molesting spiders in caves. And this time the observations were made in Minas Gerais, Brazil. One individual of the bug species Emesa mourei was seen standing on the web of a recluse spider (Loxosceles similis) while the spider was at the web’s edge. Another specimen of E. mourei was seen feeding on a fly near the web of a pholcid (cellar spider). The fly and the legs of the bug had vestiges of silk, indicating that the bug stole the fly from the spider. Another bug species, Phasmatocoris sp., was observed on a web of the cellar spider Mesabolivar aff. tandilicus. If this species of Phasmatocoris manipulates spider webs the same way that P. labyrinthicus seems to do is something yet to be investigated.

emesa_mourei_eating

Nymph of Emesa mourei feeding on a fly that it apparently stole from a pholcid spider in the cave Lapa Arco da Lapa, Minas Gerais, Brazil. Photo by Leonardo P. A. Resende, extracted from Resende et al., 2016.

With three different and very distant records of thread-legged assassin bugs associated with spiders in caves, it is clear that the poor arachnids cannot get rid of those bugs even if they run down into the bowels of the Earth.

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ResearchBlogging.orgReferences:

PAPE, R. (2013). Description and Ecology of A New Cavernicolous, Arachnophilous Thread-legged Bug (Hemiptera: Reduviidae: Emesini) from Kartchner Caverns, Cochise County, Arizona Zootaxa, 3670 (2) DOI: 10.11646/zootaxa.3670.2.2

Resende, L., Zepon, T., Bichuette, M., Pape, R., & Gil-Santana, H. (2016). Associations between Emesinae heteropterans and spiders in limestone caves of Minas Gerais, southeastern Brazil Neotropical Biology and Conservation, 11 (3) DOI: 10.4013/nbc.2016.113.01

Wignall, A., & Taylor, P. (2010). Predatory behaviour of an araneophagic assassin bug Journal of Ethology, 28 (3), 437-445 DOI: 10.1007/s10164-009-0202-8

Wygodzinsky, P. W. 1966. A monograph of the Emesinae (Reduviidae, Hemiptera). Bulletin of the American Museum of Natural History, 133:1-614.

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Filed under Behavior, Conservation, Entomology, Spiders, Zoology

New Species: January 11 to 20, 2017

by Piter Kehoma Boll

Here is a list of species described from January 11 to January 20. It certainly does not include all described species. Most information comes from the journals Mycokeys, Phytokeys, Zookeys, Phytotaxa, Zootaxa, International Journal of Systematic and Evolutionary Microbiology, and Systematic and Applied Microbiology, as well as journals restricted to certain taxa.

polypaguropsis_mollymullerae

Polypaguropsis mollymullerae is a new hermit crabs described in the past 10 days that has a moray as a friend.

Archaeans

Bacteria

SARs

Plants

Fungi

Sponges

Flatworms

Annelids

Arachnids

Crustaceans

Insects

Ray-finned fishes

Lissamphibians

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Friday Fellow: Giant Kelp

by Piter Kehoma Boll

This week we’ll stay in the sea and meet on of the most impressive algae, the giant kelp, Macrocystis pyrifera. It is called giant for a good reason, since it can grow up to 50 m in length and form real forests in the sea. Being able to grow 60 cm in a single day, it has the fastest linear growth of any organism on Earth.

The giant kelp is a brown algae, so it is not related (at least not closely) to green or red algae, but it is a relative of the tiny diatoms that cover the ocean. It grows in cold waters along the Pacific Coast of the Americas and close to the coast of the countries near Antarctica, such as Chile, Argentina, South Africa, Australia, and New Zealand.

macrocystis_pyrifera

It’s a really beautiful alga, isn’t it? Photo by California Academy of Sciences.*

This amazing organism is composed by a thallus that branches at the base and then continues as a single and very long stalk from which blades develop at regular intervals on only one side. At the base of each blade, there is a gas  bladder that helps the whole organism to stand in a more or less upright position.

The huge kelp forests in the oceans are an important ecosystem and many species depend on them to survive, including other algae. Humans also use the giant kelp either as a direct food source or as a source of dietary supplements, since the alga is rich in many minerals, especially iodine and potassium, as well as several vitamines.

macrocystis_pyrifera2

The kelp forests sustain a huge diversity of lifeforms in the oceans. Photo by Stef Maruch.**

In the last decades, the kelp populations are decreasing rapidly. This is most likely caused by climatic changes, as this alga cannot develop in temperatures above 21°C. The giant kelp is, thus, just one more victim of global warming. And if it goes extinct, a whole ecosystem will be gone with it.

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ResearchBlogging.orgReferences:

Foster, M. (1975). Algal succession in a Macrocystis pyrifera forest Marine Biology, 32 (4), 313-329 DOI: 10.1007/BF00388989

Wikipedia. Macrocystis pyrifera. Available at . Access on January 19, 2007.

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**Creative Commons License
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Friday Fellow: Branching Vase Sponge

by Piter Kehoma Boll

A fascinating group of animals that has not yet joined the Friday Fellows are the sponges. Different from all other animals, sponges have a unique body structure that behaves more like a plant or fungus. They grow in irregular or radial ways and are usually branched. More than that, they have thousands of small mouths along their bodies, called pores, that suck water from the environment in order to filter food from it.

But let’s talk about our species. Living in the Caribbean Sea, its name is Callyspongia vaginalis, commonly known as branching vase sponge. Its usual shape is that of a tube or set of tubes, sometimes branched, that may reach several centimeters in length and usually abour 3 cm in diameter. The color may vary from pink or lavender to duller colors, such as brown or gray.

callyspongia_vaginalis

A lavender pipe of Callyspongia vaginalis. Photo by Mark Rosenstein*.

As most sponges, the branching vase sponge feeds on small particles and microorganisms that it filters from water. As the concentration of particles in the water increases with depth, organisms growing deeper usually grow faster due to the higher food availability.

The main predators of the branching vase sponge are fishes. They actually act more like herbivores eating plants, as they don’t eat the whole sponge and usually do not kill it, but bite its surface, taking off pieces.

callyspongia_vaginalis2

A large and branched individual of the branching vase sponge. Photo by Paul Asman and Jil Lenoble.**

Bristlestars, especially of the genus Ophiothrix, such as Ophiothrix lineata, are frequently found living inside the main cavity of the sponge. There, these animals find shelter from predators and, at night, when the environment is safer, they extend their arms outside and clean the sponge from large organic particles, feeding on them. It’s a mutually benefitial association.

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ResearchBlogging.orgReferences:

EOL – Encyclopedia of Life. Callyspongia vaginalis. Available at <http://eol.org/pages/1163688/overview&gt;. Access on January 12, 2017.

Hendler, G. (1984). The Association of Ophiothrix lineata and Callyspongia vaginalis: A Brittlestar-Sponge Cleaning Symbiosis? Marine Ecology, 5 (1), 9-27 DOI: 10.1111/j.1439-0485.1984.tb00304.x

Hoppe, W. (1988). Growth, regeneration and predation in three species of large coral reef sponges Marine Ecology Progress Series, 50, 117-125 DOI: 10.3354/meps050117

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*Creative Commons License
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**Creative Commons License
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You can help biological research from home

by Piter Kehoma Boll

There are a lot of people around the world that, although not being scientists, are science enthusiasts. I guess many of you reading this article fit in this category. You may be a housemaid, a lawyer, a taxi driver, or simply a young student, but you have a big interest in science.

Well, what if you could help science from home? That’s actually possible in several ways. There are plenty of programs, applications or websites in which you can help to do research on several different areas. Here, I’ll focus on biological research, since biology is the subject of this blog.

So, let’s start! See below how you can help.

1. Take photographs of wildlife and make them available online

A lot of people love to take photographs of wildlife. Some websites, such as flickr, are crowded with amazing images of all kinds of lifeforms. Unfortunately, most people protect their work under copyright laws that prevent the photographs to be used without direct permission from the author or by buying it.

But you can be more generous and distribute your work under a creative commons license. This makes sure that you have to be mentioned as the author of the work while still allowing others to use it. There are several different creative commons licenses. Choose the one that suits you! The important thing is to allow your works to be used on other websites, on books, scientific articles, etc, and thus helping to spread scientific knowledge.

You can upload your photographs on flickr, Wikimedia Commons, or even on your own website, as long as you indicate the right creative commons license. Be generous!

wikimediacommonsplanarians

I’ve uploaded many of my photos of land planarians on Wikimedia Commons.

2. Record the lifeforms you see

More than only sharing your pictures, you can record the location where you found the species. Thus, you will help the scientific community to improve the knowledge on species distribution around the world. A wonderful place to do that is the website iNaturalist.org. Even if you don’t know the identity of the species you found, you may upload your records there and someone will eventually identify the species for you. Likewise, you may help identify records from other users.

inaturalist

I’ve uploaded many records on iNaturalist.org

3. Share your bibliographic research on Wikipedia and EOL

If you are an undergraduate or graduate student, an academic researcher, or simply someone who loves science, and you read a lot of scientific articles, books, encyclopedias, etc, do not lock your knowledge within yourself. Make it available to others! And a wonderful way to do that is by editing Wikipedia.

I guess everyone knows Wikipedia, the free encyclopedia that anyone can edit. If you have been reading about the sexual behavior of earthworms, or the use of a plant extract in the tratment of cervical cancer, just check the Wikipedia’s article on the subject and, if the information is not there already, do not hesitate and add it and, of course, cite the source! Wikipedia may be a little confusing to handle at first, but once you understand it and get excited, no one can stop you!

Furthermore, if you information on a subject that does not have an article on Wikipedia yet, simply start a new article!

wikipediarsp

The article Reproductive system of planarians is one of my contributions to Wikipedia.

Another project that you can help is the EOL (Encyclopedia of Life), a website that aims to gather information on all lifeforms and let them available in a single place. After you have registered, you will have some limited freedom to add new content, but eventually you may ask for a higher position that will give you access to a greater number of features.

Do you know other ways to help biological research from home? Let a comment to share it with us!

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New Species: January 1 to 10, 2017

by Piter Kehoma Bolll

Here is a list of species described from January 1 to January 10. It certainly does not include all described species. Most information comes from the journals Mycokeys, Phytokeys, Zookeys, Phytotaxa, Zootaxa, International Journal of Systematic and Evolutionary Microbiology, and Systematic and Applied Microbiology, as well as journals restricted to certain taxa.

cratera_aureomaculata

Cratera aureomaculata is a new land planarian species described in the past 10 days.

Plants

Fungi

Flatworms

Annelids

Horsehair worms

Nematodes

Arachnids

Crustaceans

Insects

Ray-finned fishes

Lissamphibians

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Friday Fellow: Conan the Bacterium

ResearchBlogging.orgby Piter Kehoma Boll

Most people would agree that 2016 was a hard year. So let’s try to make 2017 better by starting this year with a tough Friday Fellow, actually the toughest of them all: Conan the bacterium, or Deinococcus radiodurans.

A relative of Taq, Conan the bacterium is a rather large bacterium, measuring 1.5 to 3.5 µm in diameter and usually forming groups of four organisms sticking together, a formation known as tetrad. It is an extremophilic bacterium, able to resist to very harsh environments. Actually, Conan the bacterium is one of the most radiation-resistant organisms known to date and can also resist extremes of cold, dehydration, vacuum, and acid. Its popular name was based on the character Conan the Barbarian.

deinococcus_radiodurans

A tetrad of Deinococcus radiodurans.

Conan the bacterium was discovered in 1956 during an experiment that tried to sterilize canned food using high doses of radiation. One bacterium survived the high doses of gamma radiation and was identified as a new species.

Later, a group of scientists suggested that the high degree of radioresistence was an adaptation to the Martian environment, so this could be an alien bacterium! But that’s actually bullshit. Conan the bacterium has nothing significantly different from other lifeforms on Earth, but how did such a resistance to radiation evolve? Background radiation on Earth is very weak, so it could not appear by natural selection.

The results of some experiments published in 1996 revealed that strains of D. radiodurans that are susceptible to desiccation are also susceptible to radiation. Thus, the most likely explanation is that the high resistance to radiation is simply a side-effect to the resistance to desiccation, a condition much more common in the bacterium’s environment.

The mechanism that allows Conan the bacterium to withstand radiation is very complex, but includes an ability to rebuild DNA strains from fragments, which is helped by the fact that each cells contains four copies of the bacterial chromosome, so that a partially-damaged strain can serve as a model to repair another partially-damaged strain.

Our tiny fellows are always full of amazing surprises!

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References:

Mattimore, V., & Battista, J. (1996). Radioresistance of Deinococcus radiodurans: functions necessary to survive ionizing radiation are also necessary to survive prolonged desiccation. Journal of Bacteriology, 178 (3), 633-637 DOI: 10.1128/jb.178.3.633-637.1996

Wikipedia. Deinococcus radiodurans. Available at <https://en.wikipedia.org/wiki/Deinococcus_radiodurans&gt;. Access on January 2, 2017.

Zahradka, K., Slade, D., Bailone, A., Sommer, S., Averbeck, D., Petranovic, M., Lindner, A., & Radman, M. (2006). Reassembly of shattered chromosomes in Deinococcus radiodurans Nature DOI: 10.1038/nature05160

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