Author Archives: Piter Keo

About Piter Keo

PhD in Biology working with ecology, behavior and taxonomy of land planarians. I love biology, astronomy, languages and mythology, among other things.

Friday Fellow: Red Bogmoss

by Piter Kehoma Boll

Among the many different ecosystems found on Earth, bogs are particularly interesting. These peculiar wetlands are basically a large amount of water-soaked plant matter, either dead or alive. Usually very acidic, bogs have very low decomposition rates, so plant matter tends to accumulate more and more, sometimes reaching several meters in depth.

The main organisms responsible for the formation of bogs are mosses of the genus Sphagnum, commonly known as bogmosses or peatmosses (peat being the plant material that forms the bogs). Found all around the world, bogmosses have the ability to absorb huge amounts of water, just like a sponge, and in dry conditions they can release this water into the surrounding areas, helping them stay humid.

Red bogmoss in Canada. Credits to iNaturalist user maddieology.*

One bogmoss species, the red bogmoss, Sphagnum capillifolium, is found in the northern half of North America and Europe, being an important and genetically diverse species. In fact, it is likely that the red bogmoss is actually a complex of many very similar species. Its scientific name, capillifolium, meaning “hair-leaf”, refers to the peculiar shape of the plant, which grows in straight and densely packed branches that bent outwards at the top, resembling tresses.

Greener specimens in the USA. Photo by Joe Walewski.*

Although most bogmoss species are green like any regular plant, the red bogmoss and closely related species can have a reddish color. However, this color is not caused by pigments in their plastids but by a pigment, sphagnorubin, found in their cell walls. The presence or not of sphagnorubin seems to be determined by certain combinations of temperature, light and hormones. The exact function of sphagnorubin is unknown, but there have been suggestions that it may help protect the plant from herbivory. It i also possible that this reddish color works as a sunscreen, protecting the plant’s chloroplasts from intense radiation since sphagnorubin absorbs UV and blue light.

A very red and water-soaked mass in Scotland. Credits to Andrew Melton.*

Bogmosses in general are not attractive to herbivores because they contain high amounts of phenolic compounds, such as tannins, which gave them an adstringent and bitter taste. These phenolic compounds are also the main reason why peat takes such a long time to decompose. As a result, bogs function as huge carbon reservoirs, and about 10 to 15% of all carbon stock on the planet is in the form of Sphagnum. In fact, the amount of carbon fixed by all other photosynthetic lifeforms on Earth every year is lower than the amount held in bogs.

Some slightly red ones in England. Photo by Jeremy Barker*.

Sphagnum is, thus, an essential genus to keep the levels of carbon dioxide in the atmosphere low and the red bogmoss is even more important because it seems to be a very tolerant species that can survive in both shaded and sunny environments, as well as conditions with low and high levels of nitrogen and may, therefore, resist human interference better than other bogmosses.

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References:

Bonnett SAF, Ostle N, Freeman C (2009) Short-term effect of deep shade and enhanced nitrogen supply on Sphagnum capillifolium morphophysiology. Plant Ecology 207: 347–358. https://doi.org/10.1007/s11258-009-9678-0

Gerdol R, Bonora A, Marchesini R, Gualandri R, Pancaldi S (1998) Growth Response of Sphagnum capillifolium to Nighttime Temperature and Nutrient Level: Mechanisms and Implications for Global Change. Arctic and Alpine Research 30(4): 288–395. https://doi.org/10.1080/00040851.1998.12002914

Verhoeven JTA, Liefveld WM (1997) The ecological significance of organochemical compounds in Sphagnum. Acta botanica neerlandica 46(2): 117–130. http://natuurtijdschriften.nl/record/541086

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Friday Fellow: Brown’s Dagger Nematode

by Piter Kehoma Boll

Nematodes are famous because of their parasitic members, which do not only parasitize animals but also plants. People that deal with gardening or agriculture may know that sometimes a plant becomes sick because of “nematodes”.

A genus of nematodes that is commonly associated with grapevines is Xiphinema, whose species are known as dagger nematodes. The two most widely studied species are Xiphinema americanum, the American dagger nematode, and Xiphinema index, the California dagger nematode, but during the last decades it became clear that those species are actually a complex of very similar species and new ones are constantly been described. One of them, described in 2016, is Xiphinema browni, which I decided to call Brown’s dagger nematode. It was named after the nematologist Derek J. F. Brown.

Brown’s dagger nematode was found associated with the roots of grapevines and apple trees in Slovakia and the Czech Republic. Among 86 identified females there was only one male, indicating a huge disparity in sex ratios and the probability that females are parthenogenetic, i.e., they can lay fertile eggs without being fertilized by a male. Females measure up to 2.5 mm in length and the only known male measured 1.8 mm.

Female (left) and male (right) of Xiphinema browni. Modified from Lazarova et al. (2020).*

Since Brown’s dagger nematode was found associated with grapevines, its life cycle is likely similar to that of most other dagger nematodes. Adults are external parasites of grapevine roots and eventually of other woody plants. They live on the root surface and use their long odontostyles (a needle-like proboscis) to perforate the roots and suck the content of their vascular tissue. As a reaction, the plant produces swollen club-like galls on the root tips. The root then branches behind the swollen tip, only to be attacked again, developing another gall and having to branch again. This starts to weaken the plant, which can compromise grape production.

Anterior end of a female with the odontostyle slightly exposed. Modified from Lazarova et al. (2020).*

Females lay their eggs scattered through the soil, not forming clusters, and juveniles pass through about 4 stages in the soil before turning to the parasitic mode.

As another grapevine-feeding dagger nematode, Brown’s dagger nematode is probably also a vector of the grapevine fanleaf virus, which is transmitted to grapevines by the California dagger nematode. This happens when the nematode feeds on an infected plant and then moves to a healthy plant, carrying the virus with it. Grapevine fanleaf causes chlorosis (loss of chlorophyll) and distorts the leaves, making them look like fans, hence the name. As you can imagine, the poor plant becomes even weaker than it already was due to the nematodes sucking it. This can be a nightmare to vineyard owners.

The grapevine fanleaf virus can be a devastating disease for grapevines but in the nematode’s body it seems to have benefitial effects, increasing the survival of these small roundworms. Perhaps this stimulates the dagger nematodes to spread it further, in a sort of “evil coalition”.

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You may also like:

Tospovirus and thrips: an alliance that terrifies plants

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References:

Lazarova S, Peneva V, Kumari S (2016) Morphological and molecular characterisation, and phylogenetic position of X. browni sp. n., X. penevi sp. n. and two known species of Xiphinema americanum-group (Nematoda, Longidoridae). ZooKeys 574:1–42. https://doi.org/10.3897/zookeys.574.8037

van Zyl S, Vivier MA, Walker MA (2012) Xiphinema index and its Relationship to Grapevines: A review. South African Journal of Enology and Viticulture 33(1):21–32.

Wikipedia. Xiphinema. Available at <https://en.wikipedia.org/wiki/Xiphinema>. Access on 29 June 2020.

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New Species: June 2020

by Piter Kehoma Boll

Here is a list of species described this month. It certainly does not include all described species. You can see the list of Journals used in the survey of new species here.

Terrilactibacillus tamarindi is a new lactic acid bacteria isolated from the bark of tamarind trees in Thailand. Credits to Kingkaew et al. (2020).*
Phytoactinopolyspora mesophila is a new actinobacterium isolated from a saline-alkaline soil in China. Credits to Feng et al. (2020).*

Bacteria

Cupriavidus agavae is a new proteobacterium isolated from the rhizosphere of agave plants in Mexico. Credits to Arroyo-Herrera et al. (2020).*

Archaeans

Halobacterium bonnevillei (a), Halobaculum saliterrae (b) and Halovenus carboxidivorans (c) are three new archaeans from saline crusts and soils. Credits to Myers and King (2020).*

SARs

Actinostachys minuta is a new grass fern from the Philippines, Credits to Amoroso et al. (2020).*

Plants

Argyreia pseudosolanum is a convolvulacean from Thailand whose flowers resemble a species of Solanum. Credits to Traiperm & Suddee (2020).*
Senecio festucoides is a new composite from Chile. Credits to Calvo & Moreira-Muñoz (2020).*

Amoebozoans

Curvularia paraverruculosa is a new Pleosporalean isolated from soil samples in Mexico. Credits to Iturrieta-González et al. (2020).*

Fungi

Hygrophorus fuscopapillatus is a new mushroom from Southern China. Credits to Wang et al. (2020).*

Poriferans

Cnidarians

Flatworms

Dugesia umbonata is a new planarian from China. Credits to Song et al. (2020).*

Mollusks

Annelids

Bryozoans

Nematomorphs

Gordius chiashanus is a new millipede-parasitizing horsehair worm from Taiwan. Credits to Chiu et al. (2020).*

Nematodes

Chelicerates

Myriapods

Plusioglyphiulus biserratus (top) and Plusioglyphiulus khmer (bottom) are two new millipedes from Cambodia. Credits to Likhitrakarn et al. (2020).*
Fredius ibiapaba is a new freshwater crab from northeastern Brazil. Credits to Chávez et al. (2020).*

Crustaceans

Cycladiacampa irakleiae is a new cave-dwelling dipluran from Irakleia Island, Cyclades Islands. Credits to Sendra et al. (2020).*
Tachycines trapezialis is a new cave cricket from China. Credits to Zhou & Yang (2020) .*

Hexapods

Dolichomitus mariajosae is a new parasitoid wasp from Colombia, Credits to Araujo et al. (2020).*
Oromia orahan is a new subterranean beetle from La Gomera, Canary Islands. Credits to García et al. (2020).*

Echinoderms

Chondrichthyans

Actinopterygians

Plectranthias hinano is a new perchlet from the Pacific. Credits to Shepherd et al. (2020).*

Amphibians

Dendropsophus bilobatus is a new tree frog from the Amazon Forest in Brazil. Credits to Ferrão et al. (2020).*
Platypelis laetus is a new narrow-mouthed frog from Madagascar. Credits to Rakotoarison et al. (2020).*

Reptiles

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Friday Fellow: Peach Leaf-Curl Fungus

by Piter Kehoma Boll

Fungi are essential for the maintenance of life on Earth, but some of them are also a pain in the leaf, such as Taphrina deformans, which causes the disease known as peach leaf curl.

As you can imagine, peach leaf curl is a disease that affects peach trees (as well as nectarines, which are nothing but a variety of peach) and eventually can occur on almond trees too. The hyphae grow between the leaf cells and secrete enzymes that degrade cellulose, as well as indole-3-acetic acid, a type of auxin, i.e., a plant hormone that induces cell growth and division. As a result, infected leaves start to curl inward and downward and turn from green to pale yellow and eventually red.

Taphrina deformans causing leaf curl on a peach tree in Portugal. Credits to Duarte Frade.*

When the peach leaf-curl fungus is mature, it produces vertical hyphae that grow toward the surface of the leaf, spread just below the cuticle, and form asci, sac-like cells filled by ascospores, the sexual spores. The asci break through the leaf’s surface and cause a whitish aspect. The ascospores produce conidia, the asexual spores, and those are released in the environment, where they wait for the ideal conditions to germinate.

Conidia often remain attached to the branches of the tree and grow in a yeast-like fashion. They infect new leaves as soon as they start to grow. In order to germinate and infect leaves, conidia require about 3 mm of rainfall followed by 12 days with enough humidity and temperatures below 19 °C. As a result, infections are much more common in temperate regions and do not occur every year, as sometimes the requirements are not met. Fungicide is often efficient to stop the infections, but if humidity is too high and the fungus has spread too much, the treatment may not be efficient enough.

A very curly leaf with the whitish surface cased by the asci. Photo by Jerzy Opioła.**

Infected leaves fail to make photosynthesis effectively and die earlier. As a result, the plant becomes weak and produces few or no fruits, which may cause total yield loss.

The genome of the peach leaf-curl fungus has been sequenced and showed to be considerably small compared to other fungal pathogens. Nevertheless, about 5% of its genes are only found in other fungal pathogens, including, for example, enzymes that are able to break the cuticle of plants, which is necessary for infection to occur.

Genes capable of producing plant hormones, such as the auxin mentioned above, appear to be absent in closely related species. Although the idea that they may have been acquired from the plants themselves via horizontal gene transfer has been raised, a deeper analysis suggest that they are formed by very different pathways and probably evolved independently.

When something works, nature invents it more than once, although sometimes the second invention serves as a way to cheat the first one.

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References:

Cissé OH, Almeida JMGCF, Fonseca A, Kumar AA, Salojärvi J, Overmyer K, Hauser PM, Pagni M (2013) Genome Sequencing of the Plant Pathogen Taphrina deformans, the Causal Agent of Peach Leaf Curl. mBio 4(3):e00055-13. https://doi.org/10.1128/mBio.00055-13

Martin EM (1940) The morphology and cytology of Taphrina deformans. American Journal of Botany 27(9):743–751. https://doi.org/10.2307/2436901

Wikipedia. Taphrina deformans. Available at <https://en.wikipedia.org/wiki/Taphrina_deformans>. Access on 25 June 2020.

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**Creative Commons License This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

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Friday Fellow: Tulip Tree

by Piter Kehoma Boll

When people reach a new locality and find new species, they have to think of a way to name them, which can happen by borrowing a name from a local language or make up a new name from one’s own language. When the first Europeans reached North America, they discovered a beautiful tree growing in what is now eastern United States. The Miami people called it oonseentia, but we all know how Europeans treated native Americans back then. So, instead of borrowing this word, they made up a new and completely misleading name: tulip tree.

Cultivated tulip tree in Belgium. Photo by Jean-Pol Grandmont,**

Linnaeus gave this tree its currently accepted binomial name: Liriodendron tulipifera, literally meaning “lily tree that carries tulips”. However, this species has nothing to do with lilies and tulips, being actually closely related to magnolias.

Reaching up to 50 m in height, and rarely becoming even taller, the tulip tree has a brown and furrowed bark and smooth and lustrous branches. The leaves have four large lobes that, if you make a lot of effort, may look a little bit like a violin, which makes it have an additional common name: fiddletree.

Typical “violin”-shaped leaf from a tree in Virginia, USA. Credits to Wikimedia user PumpkinSky.*

The flowers of the tulip tree appear in summer and very superficially resemble a tulip, although their structure is quite different. They have three green sepals and six petals that are arranged in a spiral that continues inward to form the stamens and then the pistils, which form a central cone. This arrangement is considered primitive within angiosperms and kind of look as something between a gymnosperm cone and a true angiosperm flower.

Flowers on a tree in New Jersey, USA. Photo by Wikimedia user Famartin.*

The mature seeds, called samaras, are dispersed by wind. They develop in autumn and are stored in a type of cone-like fruit. As a typical temperate species, the tulip tree is deciuous, shedding its leaves in winter.

Frosted fruits in winter in Virginia, USA. Photo by Jörg Peter.

The tulip tree is considered a species that dominates the first century of a forest since its establishment. It is a shade-intolerant species, so when other trees start to grow among them and block much of the sunlight, they tend to perish.

Due to its beauty, the tulip tree has become an ornamental plant and several cultivars have been developed. Its wood is also used for construction, and Native Americans used to build canoes from its trunks. Due to its wood, the tulip tree has also received the common name “yellow poplar” although it is not closely related to the true poplars, such as the black and white poplar. In fact, their wood is not that similar, with the tulip tree or “yellow poplar” wood being of much higher quality. In other words, the name “yellow poplar” is as misleading as the name “tulip tree”.

Big and old tulip trees in the Joyce Kilmer Memorial Forest, North Carolina, USA. Photo by Wikimedia user Notneb82 .**

The orange part of the petals contain nectar that, when collected by bees, creates a special and strong honey that is usually considered unsuitable for table honey but highly regarded by bakers.

Native Americans and early European settlers used the tulip tree to treat malaria, and modern studies have confirmed that some of its constituents show antiplasmodial activity, as well as antioxidant, antimicrobial and cytotoxic properties, having the potential to help the development of new antibiotics and anticancer drugs.

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References:

Quassinti L, Maggi F, Ortolani F, Lupidi G, Petrelli D, Vitali LA, Miano A, Bramucci M (2019) Exploring new applications of tulip tree (Liriodendron tulipifera L.): leaf essential oil as apoptotic agent for human glioblastoma. Environmental Science and Pollution Research 26:30485–30497. https://doi.org/10.1007/s11356-019-06217-4

Wikipedia. Liriodendron tulipifera. Available at: <https://en.wikipedia.org/wiki/Liriodendron_tulipifera>. Access on June 18, 2020.

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Fighting Aedes mosquitoes with carnivorous plants

by Piter Kehoma Boll

Two mosquitoes of the genus Aedes, Aedes aegypti and Aedes albopictus, are invasive species in tropical and subtropical regions worldwide. While A. aegypti is native from Africa, A. albopictus is originally from southeast Asia, but both species have been spread by humans and continue to increase their range.

Both species are known as vectors of several diseases that affect humans, especially those caused by Flavoviruses, which include the Yellow fever, Dengue fever and Zika fever. Chikungunya, caused by a species of Alphavirus is also transmitted to humans by them. Moreover, they can also transmit some nematodes, such as the heartworm that infects the heart of dogs and other carnivores.

Aedes aegypti biting a human and having a delicious bloody meal. Photo by James Gathany.

Because A. aegypti and A. albopictus pose such a huge threat to public health, getting rid of them is top priority. Here in Brazil, there is a massive national campaign to reduce the ability of Aedes to reproduce by avoiding containers with still water in the open, such as flower vases, buckets, uncovered barrels, discarded tires and virtually everything that can retain water long enough for the larvae to develop. I have to say, though, that this all seems to be useless. The mosquitoes continue to spread and the cases of dengue fever continue to grow. The fact is that the mosquitoes will find a place to lay their eggs. If they don’t find it in your backyard, they will find it in the forest or any vacant lot.

Instead of forcing them to lay their eggs where we cannot see, we should stimulate them to lay their eggs around us and then kill the larvae. Several aquatic predators have been tested as potential allies, including larvivorous fish, dragonfly nymphs, copepods, planarians and even other mosquitoes whoses larvae eat the larvae of Aedes! The use of these predators showed mixed results. Larvivorous fish are difficult to maintain in water tanks at home and dragonfly nymphs are too generalist as predators.

Now a new predator has been suggested: a plant! Yes, a carnivorous plant of the genus Utricularia, which includes species known as bladderworts. These aquatic plants have little bladder-like structures that function as traps to capture small animals. The bladder is hollow and has an internal negative pressure in relation to the environment surrounding it. This negative pressure is created by water being constanly pumped out of the bladder through its walls via active transport. The bladder’s opening is covered by a small lid that avoids water to fill it again when the trap is set. Surrounding the lid, there is a group of bristle-like protuberances. When an animal is moving through the water and moves one of those bristles, they slightly deform the lid, breaking the seal and allowing water to enter the bladder. The negative pressure then sucks water quickly into the bladder, dragging the small animal with it. Then it is only a matter of time for the poor animal to be digested.

Watch the plant in action.

A group of researchers at the University of Rhode Island, USA, tested whether Utricularia macrorhiza, the common North American bladderworth, could be an effective predator of mosquito larvae. By adding U. macrorhiza to containers with larvae of A. aegypti and A. albopictus, they were able to kill 95 to 100% of the larvae in only five days. That’s an amazing result, don’t you think?

Bladderwort with several Aedes larvae (marked with asterisks) in its traps. Credits to Couret et al. (2020).*

Since bladderworts are much easier to raise in tanks and other containers in your backyard than animal predators such as fish and dragonflies, they are a promising new alternative to control the populations of this disease-carrying insects.

So, are you eager to raise some aquatic carnivorous plants to help fight these heinous mosquitoes?

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References:

Couret J, Notarangelo M, Veera S, LeClaire-Conway N, Ginsberg HS, LeBrun RL (2020) Biological control of Aedes mosquito larvae with carnivorous aquatic plant, Utricularia macrorhizaParasites Vectors 13, 208. https://doi.org/10.1186/s13071-020-04084-4

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*Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.

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Friday Fellow: Common Horse Tapeworm

by Piter Kehoma Boll

Flatworms are the fourth largest animal phylum after arthropods, mollusks and chordates and most species known to date belong to the clade Neodermata, which includes parasitic species such as flukes and tapeworms, some of which infect humans. Among tapeworms, the species that infect humans and belong to the genus Taenia are certainly the most popular, but it is expected that all vertebrates can have at least one tapeworm parasite, so that it is only a matter of time and opportunity for us to discover them all.

Among the species known to parasitize horses, the most widespread is Anoplocephala perfoliata, which I decided to call the common horse tapeworm. As tapeworms in general, the adult common horse tapeworm lives in the intestine of its definitive host, in this case a horse.

Different from species of Taenia, which can grow up to several meters in length, species of Anoplocephala are much smaller. The whole body of adult specimens measures about 5 to 8 cm in length and 1 to 2 cm in width and is divided into the same parts seen in other tapeworms. The anteriormost part of the body includes the scolex, which has 4 large suckers. Although the scolex of most tapeworms measures less than 1 mm, in the common horse tapeworm it reaches up to 3 mm.

A preserved specimen. Photo extracted from alchetron.com

After the scolex there is a small neck of undifferentiated tissue that grows constantly to build new proglottids, which form the rest of the body. Proglottids are connected to each other in a chain fashion and the posteriormost ones are continuouly lost and released into the environment. Each proglotid contains male and female sexual organs and is released when it contains mature eggs.

Mature proglottids are released in the environment through the horse’s feces and release their eggs on the ground and the vegetation. The eggs can survive outside a host for as long as 9 months. During this time, they hope to be accidentally ingested by oribatid mites that live in pastures. If this happens, the egg hatches inside the mite due to the mechanical action of the mite’s mouth parts and releases the first-stage larva called the oncosphere.

An egg of Anoplocephala perfoliata. The small 20-µm-diamter sphere is the oncosphere waiting to be released. Photo by Martin K. Nielsen, extracted from msdvetmanual.com

When the oncosphere reaches the mite’s gut, it is activated, probably via ions present in this environment, and uses a group of hooks to penetrate the mite’s tissues. After about 8 to 20 weeks, the oncosphere develops into a cysticercoid. This stage looks like an inverted miniaturized tapeworm inside a bladder-like vesicle, having already a protoscolex inside it.

While horses are grazing, they always ingest some invertebrates together with the grass. It they happen to ingest an infected mite, the cysticercoids are released during digestion, evert the protoscolex and attach to the intestinal walls of the horse. There, the tapeworm develops into an adult, restarting the cycle.

Attached to the intestine of their hosts, tapeworms do not feed on blood or other tissues as many parasites do. Instead of that, they collect nutrients directly from the host’s gut by absorbing them via the worm’s body surface.

For a long time its has been thought that the common horse tapeworm was a harmless parasite since most horses did not seem to have any symptom and the tapeworms were often only discovered during dissection after the horse’s death by other causes. The preferred area for the common horse tapeworm to attach is the caecum and the ileocaecal junction but in heavily infected animals some individuals can be found in suboptimal sites throughout the small and large intestines. In such heavily infected horses, the tapeworms can cause colics and even intestinal obstruction.

Large number of adult tapeworms in a heavily infected horse. Credits to Tomczuk et al. (2014).*

The common horse tapeworm can infect other equids as well, such as donkeys and zebras. Ironically, domesticated horses seem to be the most infected individuals exactly because horse owners treat them with anthelmintics. Most modern anthelmintics do not affect tapeworms and only remove other parasites, such as roundworms, which reduces competition and allows tapeworms to thrive.

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More parasitic flatworms:

Friday Fellow: Green-banded broodsac (on 09 March, 2018)

Friday Fellow: Salmon Fluke (on 11 January, 2019)

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References:

Gasser RB, Williamson RMC, Beveridge I (2005) Anoplocephala perfoliata of horses – significant scope for further research, improved diagnosis and control. Parasitology 131(1): 1–13. https://doi.org/10.1017/S0031182004007127

Tomczuk K, Kostro K, Szczepaniak KO, Grzybek M, Studzińska M, Demkowska-Kutrzepa M, Roczeń-Karczmarz M (2014) Comparison of the sensitivity of coprological methods in detecting Anoplocephala perfoliata invasions. Parasitology Research 113(6): 2401–2406. doi: 10.1007/s00436-014-3919-4

Wikipedia. Anoplocephala perfoliata. Available at < https://en.wikipedia.org/wiki/Anoplocephala_perfoliata >. Access on 11 June 2020.

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Friday Fellow: Common Cockroach Bacterium

by Piter Kehoma Boll

Bacteria are found almost everywhere across our planet and they are essential for the survival of every other lifeform, including the fascinating, and for some disgusting, cockroaches. One special cockroach-friendly genus of bacteria has the adequate name Blattabacterium, whose best-known species is Blattabacterium cuenoti, which I decided to call the “common cockroach bacterium”.

This interesting species, like all species of Blattabacterium, is an obligate endosymbiont of cockroaches, meaning that it can only exists inside cockroach cells. More specifically, the common cockroach bacterium lives inside the cells of the fat bodies of cockroaches, i.e., their adipose tissue. It was found living inside all cockroach species examined to date with the exception of the genus Nocticola. It is also found inside the termite Mastotermes darwinensis because, if you did not know yet, termites are nothing more than highly specialized cockroaches. Thus, it is thought that this bacterium first “infected” the ancestor of all modern cockroaches about 140 million years ago and has only been lost in two lineages, the one from Nocticola and the one from termites.

Blattabacterium cuenoti cells shown in red (above) and gray (below). The cyan areas in the bottom image represent the nucleus of the cockroach cells. Extracted from Sabree et al. (2009).

Although many cockroaches are generalist feeders, being able to feed on almost everything, the main diet of all species is decaying plant material, and this is a relatively nitrogen-poor food. In order to increase their nitrogen intake, cockroaches store uric acid, a common product of protein metabolism. Most animals, including humans, excrete uric acid in their urine, but cockroaches store it in their adipose tissue. Thus, it was originally thought that the cockroach bacteria, by living close to uric acid reserves in the adipose tissue, could use uric acid directly as a food source, but studies have found this is not the case.

When necessary, cockroaches release this uric acid and it is broken down into urea or ammonia by bacteria living in their guts. After that, the common cockroach bacteria can use those compounds to synthesize glutamate, essential amino acids and vitamins for the cockroach.

Since they cannot use uric acid directly, it is a mystery why the common cockroach bacteria lives so close to the place where this substance is stored. One suggestion is that it was originally able to use uric acid but lost this ability by genome reduction.

The functional gene categories of Blattobacterium are very similar to those of Blochmannia, an endosymbiotic bacterium from carpenter ants, which also feed on plant material. However, Blochmannia is very distantly related to Blattobacterium, suggesting that their similar genomes are the result of convergent evolution caused by similar lifestyles.

When something works, nature invents it more than once.

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More on Bacteria:

Friday Fellow: Taq (on 22 January 2016)

Friday Fellow: Witch’s Jelly (on 14 October 2016)

Friday Fellow: Conan the Bacterium (on 6 January 2017)

Friday Fellow: H. pylori (on 8 September 2017)

Friday Fellow: Hay Bacillus (on 14 December 2017)

Friday Fellow: Alder Root Bacterium (on 16 March 2018)

Friday Fellow: Bt (on 1 February 2019)

Badass bacteria are thriving in your washing machine

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References:

López-Sanchez MJ, Neef A, Peretó J, Patiño-Navarrete R, Pignatelli M, Latorre A, Moya A (2009) Evolutionary Convergence and Nitrogen Metabolism in Blattabacterium strain Bge, Primary Endosymbiont of the Cockroach Blattella germanica. PLoS Genetics 5(11): e1000721. 10.1371/journal.pgen.1000721

Patiño-Navarrete R, Moya A, Latorre A, Peretó J (2013) Comparative Genomics of Blattabacterium cuenoti: The Frozen Legacy of an Ancient Endosymbiont Genome. Genome Biology and Evolution 5(2): 351–361. https://doi.org/10.1093/gbe/evt011

Sabree ZL, Kambhapati S, Moran NA (2009) Nitrogen recycling and nutritional provisioning by Blattabacterium, the cockroach endosymbiont. PNAS 106(46): 19521–19256. https://doi.org/10.1073/pnas.0907504106

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Filed under Bacteria, Evolution, Friday Fellow

New Species: May 2020

by Piter Kehoma Boll

Here is a list of species described this month. It certainly does not include all described species. You can see the list of Journals used in the survey of new species here.

Bacteria

Archaeans

Hacrobes

SARs

Athyrium bipinnatum is a new fern from Japan. Credits to Hori (2020).*

Plants

Rhododendron pudingense is a new azalea from China. Credits to Dai et al. (2020).*
Jasminum parceflorum is a new jasmine from China. Credits to Zhang et al. (2020).*

Amoebozoans

Fungi

 Retiboletus sinogriseus is a new mushroom from China. Credits to Liu et al. (2020).*

Poriferans

The spicules of the new sponge Haliclona (Flagellia) xenomorpha have a strange (xenos) shape (morphe) that resembles the derelict spacecraft from the 1979 film Alien in which the xenomorphs were found. Extracted from Dinn (2020).

Ctenophorans

Cnidarians

Rotifers

Flatworms

Bryozoans

Mollusks

Pincerna vallis is a new snail from China. Credits to Chen & Wu (2020).*

Annelids

Peinaleopolynoe orphanae (A), Peinaleopolynoe elvisi (B), Peinaleopolynoe goffrediae (C) and Peinaleopolynoe mineoi (D) are four new scale worms from the Pacific Ocean. Credits to Hatch et al. (2020).*

Nematodes

Tardigrades

Arachnids

Myriapods

Pereinotus tinggiensis is a new amphipod from Malaysia. Credits to Feirulsha & Rahim (2020).*

Crustaceans

Hendersonida parvirostris is a new lobster from Papua New Guinea. Credits to Rodríguez-Flores et al. (2020).*
Acheroxemylla lipsae is a new springtail from Peru. Credits to Palacios-Vargas (2020).*

Hexapods

Podonychus gyobu is a new beetle from Japan. Credits to Yoshitomi & Hayashi (2020).*

Echinoderms

A new sponge-associated starfish was named Astrolirus patricki and I think the reason for that name is evident enough, right? Credits to Zhang et al. (2020).*

Tunicates

Actinopterygians

Epinephelus tankahkeei is a new grouper from the South China Sea. Credits to Wu et al. (2020).*
Hippocampus nalu is a new seahorse from South Africa. Credits to Short et al. (2020).*

Amphibians

Stumpffia froschaueri is a new frog from Madagascar. Credits to Crottini et al. (2020).*
Tylototriton sparreboomi is a new salamander from Vietnam. Credits to Bernardes et al. (2020).*

Reptiles

Cnemaspis lineatubercularis is a new gecko from Thailand. Credits to Ampai et al. (2020).*
Acanthosaura aurantiacrista is a new lizard from Thailand. Credits to Trivalairat et al. (2020).*

Mammals

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*Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.

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Filed under Systematics, taxonomy

Friday Fellow: Red Globe Thistle

by Piter Kehoma Boll

The family Asteraceae (or Compositae), sometimes called “the daisy family”, is the largest family of plants, with more than 30 thousand currently accepted species. This family is characterized by a typical inflorescence called capitulum (or head in English), which is formed by several small flowers arranged in a compact form so that the whole structure resembles a single flower. One of its subfamilies, Carduoideae, include species known as thistles and, among them, one genus, Echinops is quite unusual among the whole family.

The heads of Echinops, different from most Asteraceae, contains a single flower, and these single-flowered heads are arranged in secondary inflorescences that form a globose structure, Thus, species of Echinops are named ‘globe thistles’. Most species of globe thistle have blue or white flowers but one species, Echinops amplexicaulis, has a dark red color. Although not having a common name in English as far as I know, I think that ‘red globe thistle’ is an excellent name.

Red globe thistle in Ethiopia. Photo by Alberto Vascon, extracted from centralafricanplants.senckenberg.de

Found in dry grasslands and dry forests in Central Africa, the red globe thistle reaches a height of about 1 to 1.5 m and has a vertical, usually unbranched stem with hardened leafs whose margin is dentate and the lobes have a terminal spine, as typical of thistles.

Specimen in the Democratic Republic of the Congo. Photo by Mathias D’haen.*

The roots of the red globe thistle are traditionally used in Uganda and Ethiopia to treat a series of conditions, including AIDS, trypanosomiasis, ulcerative lymphagitis, hydrocele, tuberculosis and stomachache. Laboratory studies have identified anti-tuberculosis activity of the root extract in vitro against several strains of Mycobacterium, including strains resistant to the currently common drugs used to treat the infection.

Apparently there is no study addressing the other alleged effects of the plant. There are also no studies on the ecology or life cycle of this species. In other words, that’s all I can tell about this lovely and peculiar globe thistle.

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References:

Bitew H, Hymete A (2019) The Genus Echinops: Phytochemistry and Biological Activities: A Review. Frontiers in Pharmacology 10: 1234. https://doi.org/10.3389/fphar.2019.01234

Kevin K, Kateregga J, Carolyn N, Derrick S, Lubega A (2018) In Vitro Anti-tuberculosis Activity of Total Crude Extract of Echinops amplexicaulis against Multi-drug Resistant Mycobacterium tuberculosis. Journal of Health Science 6: 296–303. https://doi.org/10.17265/2328-7136/2018.04.008

Tadesse M (1997) A revision of the genus Echinops (Compositae-Carduae) in Tropical Africa. Kew Bulletin 52(4):879–901. https://doi.org/10.2307/4117817

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*Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

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Filed under Botany, Friday Fellow