Friday Fellow: Brown-gutted Mud Roundworm

by Piter Kehoma Boll

If you have your face buried in the mud at the bottom of a European lake, you may end up finding some of those tiny little roundworms known as Monhystera stagnalis. As usual, there is no common name for this species, but I decided to call it brown-gutted mud roundworm. Why? Because it lives in the mud and has a reddish-brown gut.

monhystera_stagnalis

An individual of Monhystera stagnalis. Photo by Marco Spiller.*

The brown-gutted mud roundworm is a widely distributed roundworm species, being common especially throughout Europe. It inhabits the fine sediments at the bottom of freshwater bodies, both stagnant and flowing, where it feeds on the organic material deposit in this medium, having a special taste for bacteria. It is able to survive in moderate organic pollution, but is sensitive to low oxygen levels.

It is one of the most common nematode species in its environment and it is very small, measuring around 1 mm in length, females being slightly longer than males. They are found in all depths of the sediment and seem to have a preference for staying closer to the surface during winter and deeper in the mud during summer.

Females are ovoviviparous, meaning that they retain the egg inside their bodies until they hatch, so they are pregnant with eggs. Although we are used to think that invertebrates produce hundreds or thousands of eggs at once, this is not the case with the brown-gutted mud roundworm. Females are usually pregnant of a single egg, sometimes with two or three. They are modest worms.

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ResearchBlogging.orgReferences:

Pehofer, H. (1989). Spatial Distribution of the Nematode Fauna and Production of Three Nematodes (Tobrilus gracilis, Monhystera stagnalis, Ethmolaimus pratensis) in the Profundal of Piburger See (Austria, 913 m a.s.l) Internationale Revue der gesamten Hydrobiologie und Hydrographie, 74 (2), 135-168 DOI: 10.1002/iroh.19890740203

Traunspurger, W. (1996). Autecology of Monhystera paludicola De Man, 1880 – Seasonal, Bathymetric and Vertical Distribution of a Free-living Nematode in an Oligotrophic Lake Internationale Revue der gesamten Hydrobiologie und Hydrographie, 81 (2), 199-211 DOI: 10.1002/iroh.19960810205

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New Species: February 1 to 10, 2017

by Piter Kehoma Boll

Here is a list of species described from February 1 to February 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.

heliconia_berguidoi

Heliconia berguidoi is a new plant species from Panama. Photos by R. Flores and C. Black, seen in the lower picture beside one specimen. (License CC BY 4.0)

Archaeans

Bacteria

SARs

Plants

Fungi

Cnidarians

Flatworms

Annelids

Nematodes

Arachnids

Myriapoda

Crustaceans

Insects

Ray-finned fishes

Reptiles

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Friday Fellow: Paraná pine

by Piter Kehoma Boll

As the first conifer Friday Fellow, I decided to choose one of my beloved ones, the Paraná pine, Araucaria angustifolia, also known as Brazilian pine or candelabra tree.

The Paraná pine can reach up to 50 m in height, although most trees are smaller than that. They have a very particular shape and are easily distinguished from the surrounding forest where they occur, the so-called Mixed Ombrophilous Forest or Araucaria Moist Forest, in southern Brazil. The trees have a cylindrical trunk with a dark and thin bark that detaches in large and flexible pieces, being gray on the outer surface and reddish on the inner one. The crown changes its appearance during the development, being conical in young trees and with a candelabrum-like shape in mature specimens. Mature trees usually stand with their crowns above the forest canopy, which gives the Araucaria moist forest its particular look. The leaves grow in a spiral pattern around the stem and are very hard with a sharp point that can easily pierce through the human skin.

araucaria_angustifolia

A group of Paraná pines in Campos de Jordão, Brazil, close to the northernmost distribution of the species. Photo by Vinícius Ribeiro.*

The species current distribution is almost restricted to Brazil, from northern Rio Grande do Sul to southern São Paulo, with some small populations occurring in neighboring areas of Argentina and Paraguay. Once an abundant species, its population has been drastically reduced due to the heavy logging until the middle of the 20th century and the exploitation for the use of its seeds, called pinhão in Portuguese. As a result, it is currently considered as Critically Endangered by IUCN.

araucaria_angustifolia2

An adult tree in the municipality of Colombo, Paraná, Brazil. Photo by Mauro Guanandi.*

The paraná pine is a dioecious species, i.e., males and females are separate plants. As most conifers, it is pollinated by the wind. The large cones, which take two years to become ripe, contain a number of large and edible seeds used as food by many animals, as well as by humans. Pinhões cooked in salty water is a typical dish in southern Brazil during winter. One of the main seed dispersers of the Paraná pine is the azure jay, Cyanocorax caeruleus, which buries the seeds for future use.

araucaria_angustifolia3

A cone and lose seeds of Araucaria angustifolia in a market. Photo by Marcelo Träsel.**

As most (if not all) conifers, the Paraná pine forms mutualist associations with fungi, such as the glomeromycete Glomus clarum. Thus, in order to preserve this amazing tree, it is also necessary to guarantee the preservation of all its partner species, such as mycorrhizal fungi and seed dispersers.

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ResearchBlogging.orgReferences:

Angeli, A. (2003). Araucaria angustifolia (Araucaria). Departamento de Ciências Florestais – ESALQ/USP. Available at: <http://www.ipef.br/identificacao/araucaria.angustifolia.asp&gt;. Access on January 26, 2017.

IUCN (2016). Araucaria angustifolia The IUCN Red List of Threatened Species DOI: 10.2305/IUCN.UK.2013-1.RLTS.T32975A2829141.en

Soares, T. S. (2004). Araucária – o pinheiro brasileiro. Revista Científica Eletrônica de Engenharia Florestal, 2 (3).

SOUZA, A. (2007). Ecological interpretation of multiple population size structures in trees: The case of Araucaria angustifolia in South America Austral Ecology, 32 (5), 524-533 DOI: 10.1111/j.1442-9993.2007.01724.x

Zandavalli, R., Dillenburg, L., & de Souza, P. (2004). Growth responses of Araucaria angustifolia (Araucariaceae) to inoculation with the mycorrhizal fungus Glomus clarum. Applied Soil Ecology, 25 (3), 245-255 DOI: 10.1016/j.apsoil.2003.09.009

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Friday Fellow: Northern Plaited Radiolarian

by Piter Kehoma Boll

Some weeks ago I introduced a diatom here and mentioned that, despite the fact that they are a very abundant group, little information on species is available. Today our species is a radiolarian and, just as with the diatoms, they are abundant but little known.

I struggled to find an extant species that also had a good and available photo to share. And the winner was a species known as Cleveiplegma boreale, or Rhizoplegma boreale perhaps. I’m not sure what is the currently accepted name. Anyway, it does not have a common name, but I decided to create one, so let’s call it “northern plaited radiolarian”.

Radiolarians are unicelular organism that have an intricate mineral skeleton that contains a central capsule that typically divides the cell into two portions: an inner one and an outer one. Our fellow today looks like this:

cleveiplegma_boreale

A living specimen of the northern plaited radiolarian. Photo by John Dolan.*

The northern plaited radiolarian has from 6 to 10 spines growing out of it and there is a complex plaited pattern of the skeleton that surrounds them and the inner shell. Measuring anout 20µm in diameter, it is a rather large radiolarian.

Although it is known from fossils along the Quaternary, from at least 10 thousand years before present, the northern plaited radiolarian is still a living species. Currently it is known to occur in the Nordic Seas, around Scandinavia, Iceland and Greenland, in the North Pacific, including the Bering Sea, and in the Southern Ocean, around Antarctica. We can see, therefore, that this species likes cold waters.

Ah, and they feed on diatoms… I guess.

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ResearchBlogging.orgReferences:

Dolven, J., & Bjørklund, K. (2001). An early Holocene peak occurrence and recent distribution of Rhizoplegma boreale (Radiolaria): a biomarker in the Norwegian Sea Marine Micropaleontology, 42 (1-2), 25-44 DOI: 10.1016/S0377-8398(01)00011-1

Dumitrica, P. (2013). Cleveiplegma nov. gen., a new generic name for the radiolarian species Rhizoplegma boreale (Cleve, 1899) Revue de Micropaléontologie, 56 (1), 21-25 DOI: 10.1016/j.revmic.2013.01.001

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New Species: January 21 to 31, 2017

by Piter Kehoma Boll

Here is a list of species described from January 21 to January 31. 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.

strigula

Strigula acuticonidiarum (left) and Strigula guangxiensis (right) are two new lichens described in the past 11 days.

Bacteria

SARs

Plants

Fungi and allies

Sponges

Mollusks

Annelids

Bryozoans

Nematodes

Arachnids

Myriapods

Crustaceans

Insects

Cartilaginous fishes

Ray-finned fishes

Reptiles

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Friday Fellow: Black Bread Mold

by Piter Kehoma Boll

Today’s Friday Fellow lives in our houses and our gardens, among our food and our crops. And every time we notice it, we get upset, because it means that something we were supposed to eat is now spoiled. Its name is Rhizopus stolonifer, or black bread mold.

rhizopus_stolonifer

The black bread mold growing on a peach. Photo by University of Georgia Plant Pathology Archive.*

Having a worldwide distribution, the black bread mold is mainly saprotrophic, growing on decaying fruits and bread. During its reproductive phase, it can be noticed as a black and hairy mold, as in the photo above. Eventually, this species can also cause an infection in human face and oropharynx, but most commonly it can be a pathogen of many plant species, thus being of economic concern.

rhizopus_stolonifer2

A closer look at the sporangia of Rhizopus stolonifer. Photo by Stanislav Krejčík.*

The black bread mold is a fungus of the order Mucorales, known as pin molds because their sporangia (the structures that contain the asexual spores) remember a pin. These sporangia, which are black, are what one usually notice growing on decaying food. When the sporangia are mature, they release spores of two kinds that germinate and originate two kinds of hyphae (known as + and -) and when two hyphae of opposite type come into contact, they fuse and create a zygospore, which then grows to originate new sporangia.

Due to its importance as an economic pest, there are many studies trying to find ways to get rid of it and very few studies trying to understand the fascinating things that it hides. What a pity.

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ResearchBlogging.orgReferences:

EOL – Encyclopedia of Life: Rhizopus stolonifer. Available at <http://eol.org/pages/2944808/overview >. Access on January 14, 2107.

Hernández-Lauzardo, A., Bautista-Baños, S., Velázquez-del Valle, M., Méndez-Montealvo, M., Sánchez-Rivera, M., & Bello-Pérez, L. (2008). Antifungal effects of chitosan with different molecular weights on in vitro development of Rhizopus stolonifer (Ehrenb.:Fr.) Vuill Carbohydrate Polymers, 73 (4), 541-547 DOI: 10.1016/j.carbpol.2007.12.020

Wikipedia. Black bread mold. Available at <https://en.wikipedia.org/wiki/Black_bread_mold >. Access on January 14, 2017.

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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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