Monthly Archives: June 2017

Friday Fellow: Bubble Globigerina

by Piter Kehoma Boll

A little more than a year ago I introduced the first foraminifer here, the tepid ammonia. Now it is time to bring the second one, this time a planctonic species that is rather famous and whose scientific name is Globigerina bulloides, or the bubble globigerina as I call it.

Globigerina_bulloides

A live specimen of Globigerina bulloides. Photo extracted from Words in mOcean.

This species can be found throughout the world, but it’s more common in cold subantarctic waters and a little less common in subarctic waters. The most common areas are the North and South Atlantic and the Indian Oceans, but the tropical records are most likely a misidentification of other closely related species.

The bubble globigerina usually lives in the upper 60 m of the water column, at least while reproducing, and feeds on other planktonic organisms, especially microscopic algae. In oder to maximize the ability of their gametes to meet in the vast extension of the ocean, the bubble globigerina synchronizes its sexual cycle with the moon cycle, reproducing during the first week after the new moon. It is, therefore, a kind of biological calendar.

– – –

ResearchBlogging.orgReferences:

Bé, A. W. H.; Tolderlund, D. S. 1972. Distribution and ecology of living planktonic Foraminifera in surface waters of the Atlantic and Indian Oceans. In: Funnell, B. M.; Riedel, R. (Eds.) The Micropaleontology of Oceans, Cambridge University Press, pp. 105–150.

Schiebel, R., Bijma, J., & Hemleben, C. (1997). Population dynamics of the planktic foraminifer Globigerina bulloides from the eastern North Atlantic Deep Sea Research Part I: Oceanographic Research Papers, 44 (9-10), 1701-1713 DOI: 10.1016/S0967-0637(97)00036-8

Advertisements

Leave a comment

Filed under Friday Fellow, protists

Greek Gods as genus names

by Piter Kehoma Boll

Although I’m not much of a taxonomist, I really love taxonomy and the way it can be used to add some sort of literary art to biology. So here I am going to present a list of genera named after some Greek gods. I hope you enjoy it!

Zeus_faber

The genus of fish Zeus is named after the king of the Greek gods. The photo shows the species Zeus faber. Photo by Wikimedia user Kleines.Opossum.*

Zeus_olympius

The genus of fungi Zeus is also named after the king of the Greek gods. The photo shows the species Zeus olympius. Photo by Rossen Aleksov.*

Lineus_ruber

Named after the Greek god of the sea, Poseidon used to be a genus of ribbon worms (nemerteans), but this name is currently a synonym of Lineus. The photo shows a specimen of Lineus ruber, formerly known as Poseidon ruber. Photo by Eduardo Zattara.**

Hades_noctula

The name of the god of the underworld, Hades, was given to a genus of butterflies. Here you can see an individual of the species Hades noctula. Photo by Dan Wade.

OLYMPUS DIGITAL CAMERA

The plant genus Hestia, with a single species, Hestia longifolia, was named after the Greek goddess of the hearth. Photo by Michael Lo.

800px-aphrodita_aculeata_28sea_mouse29

The sea mouse genus Aphrodita was so named after Aphrodite, the Greek goddess of love, sex and beauty. The photo shows the species Aphrodita aculeata. Photo by Michael Maggs.*

hetul_u0

The fish genus Hephaestus, including the species Hephaestus tulliensis seen above, is named after the Greek god of fire and forgery. Photo by Glynn Aland.

OLYMPUS DIGITAL CAMERA

The greek goddess of wisdom, Athena, was honored in the owl genus Athene, which includes the borrowing owl Athene cunicularia seen above. Photo by flickr user travelwayoflife.***

Ares_mexicoensis

Ares, named after the Greek god of war, is a genus of fossil radiolarians that includes the species Ares mexicoensis shown above. Photo extracted from Whalen & Carter, 2002.

800px-dosinia_coerulea_003

Artemis, the greek Goddess of hunt, used to be the name of a genus of clams, but currently it is a synonym of Dosinia. The species seen above, Dosinia coerulea, used to be in the genus Artemis.

399px-nussatella1

The Greek god of travelers and messenger of the gods, Hermes, was honored in a genus of sea snails. Currently, it is regarded as a subgenus of the genus Conus and includes the species Conus (Hermes) nussatella seen above. Photo by Nick Zantop.*

 

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

**Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License.

***Creative Commons License
This work is licensed under a Creative Commons Attribution-Share Alike 2.0 Generic License.

Leave a comment

Filed under taxonomy

Friday Fellow: Spiked Pepper

by Piter Kehoma Boll

A relative of the famous black pepper from India that is used as a spice worldwide, today’s fellow, the spiked pepper Piper aduncum, comes from South America, where it is also called by other names such as matico and higuillo de hoja menuda.

Growing as a small tree or shrub, the spiked pepper is widespread throughout the continent, being found in both the Atlantic and the Amazonian forests. Having a peppery odor as other peppers, it can be used as a substitute of them while preparing food, but its main uses are medicinal.

Piper_aduncum

Close up of a branch of Piper aduncum showing the inflorescences. Photo by João Medeiros.*

It is classically used by local populations as an antiseptic applied directly on open wounds and also as an infusion or paste to treat gastrointestinal disorders and problems of the genital organs. Laboratory studies using extracts from the plant concluded that it has antibacterial and moluscidal properties, thus having the potential to be used as both an antiseptic and a pesticide against mollusks.

Outside of South America, the spiked pepper became a problematic invasive species in several islands of the Pacific, such as New Guinea and Fiji. In Papua-New Guinea, it has become so common that it was incorporated in the culture of local people, who use it as a wood source and as a medicine and pesticide.

– – –

References:

Maia, J., Zohhbi, M., Andrade, E., Santos, A., da Silva, M., Luz, A., & Bastos, C. (1998). Constituents of the essential oil ofPiper aduncum L. growing wild in the Amazon region Flavour and Fragrance Journal, 13 (4), 269-272 DOI: 10.1002/(SICI)1099-1026(1998070)13:43.0.CO;2-A

Orjala, J., Wright, A., Behrends, H., Folkers, G., Sticher, O., Rüegger, H., & Rali, T. (1994). Cytotoxic and Antibacterial Dihydrochalcones from Piper aduncum Journal of Natural Products, 57 (1), 18-26 DOI: 10.1021/np50103a003

Potzernheim, M., Bizzo, H., Silva, J., & Vieira, R. (2012). Chemical characterization of essential oil constituents of four populations of Piper aduncum L. from Distrito Federal, Brazil Biochemical Systematics and Ecology, 42, 25-31 DOI: 10.1016/j.bse.2011.12.025

Siges, T., Hartemink, A., Hebinck, P., & Allen, B. (2005). The Invasive Shrub Piper aduncum and Rural Livelihoods in the Finschhafen Area of Papua New Guinea Human Ecology, 33 (6), 875-893 DOI: 10.1007/s10745-005-8214-7

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution 2.0 Generic License.

Leave a comment

Filed under Botany, Friday Fellow

Friday Fellow: Downy Mildew

by Piter Kehoma Boll

Last week I introduced a serious plant pathogen, the gray mold, that attacks many crops and has a special role as either a bad or a good guy in wine grapes. But a plant that is never happy with an infection by the gray mold is certainly the lettuce. And in this case our juicy vegetable has an enemy that makes it susceptible to the mold, and I’m bringing it to you today.

Named Bremia lactucae, this organism is a oomycete, thus belonging to a group of organisms that was formerly classified as a fungus, but that currently is known to be more closely related to brown and golden algae. This species attacks lettuces and closely related plants, causing a disease called downy mildew.

Bremia_lactucae

A lettuce leaf with downy mildew. Photo by Gerald Holmes.*

The downy mildew is the most important disease affecting lettuce worldwide. The disease itself is not the main problem, although it decreases the quality of the crop. Its main problem is that it makes the vegetable more vulnerable to other infections, such as those by the gray mold, and also increases the risk of contamination by human pathogens, such as intestinal parasites.

Bremia_lactucae1

A branch of the downy mildew under the microscope. Photo by Bruce Watt.*

The usual forms of controling the spread of the downy mildew is by using fungicides and developing mildew-resistant lettuces by hybridization with wild and naturally resistant varieties. However, as usual, the downy mildew eventually adapts to this, giving rise to fungicide-resistant strains, as well as strains able to neutralize the resistance of lettuce lineages. It’s one more evolutionary arms race.

– – –

ResearchBlogging.orgReferences:

Beharav, A., Ochoa, O., & Michelmore, R. (2013). Resistance in natural populations of three wild Lactuca species from Israel to highly virulent Californian isolates of Bremia lactucae Genetic Resources and Crop Evolution, 61 (3), 603-609 DOI: 10.1007/s10722-013-0062-5

Parra, L., Maisonneuve, B., Lebeda, A., Schut, J., Christopoulou, M., Jeuken, M., McHale, L., Truco, M., Crute, I., & Michelmore, R. (2016). Rationalization of genes for resistance to Bremia lactucae in lettuce Euphytica, 210 (3), 309-326 DOI: 10.1007/s10681-016-1687-1

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.

1 Comment

Filed under Disease, Friday Fellow, protists

Friday Fellow: Gray Mold

by Piter Kehoma Boll

Today’s Friday Fellow will show you how beauty is only a matter of perspective. Being an ascomycete fungus, it is commonly known as gray mold and is usually found growing on decaying vegetables, especially fruits such as the strawberry in the photo below:

Botrytis_cinerea1

Gray mold growing on a strawberry. Most people would not see it as a beautiful image. Photo by Wikimedia user Rasbak.*

The gray mold has a controversial biological nomenclature, as many other fungi. The most common name is Botrytis cinerea used for its asexual stage (anamorph), which is the most common. Its sexual stage (teleomorph) is known as Botryotina fuckeliana. I guess this issue, which was common in naming fungi with rare or unknown occurrences of sexual stage, has already been settled, but as I’m not a taxonomist of fungus, I cannot speak much on the subject.

More than only having a controversial name, this fungus has also a controversial interaction with humans. It is a notable pest in wine grapes and may lead to two different infections on them. One of those is called “grey rot” and happens under wet conditions, leading to the loss of the grapes. The other is called “noble rot” and is a beneficial form of the infection that happens when the wet condition is followed by a dry one and produce a fine and sweet vine due to the concentration of sugars in the grape.

Out of the vine world, however, the gray mold is not something that you want growing on your crops. As as it attacks more than 200 species, many of them being important food crops, there is a big interest in developing strategies to reduce the damage it causes. And these strategies include the use of pesticides, plant essential oils or even other organisms that may parasitize the gray mold.

But one cannot deny that if you look closer, even the gray mold is beautiful:

Botrytis_cinerea

A beautiful tiny forest of gray mold on a strawberry. Photo by Macroscopic Solutions.**

– – –

ResearchBlogging.orgReferences:

Wikipedia. Botrytis cinerea. Available at <https://en.wikipedia.org/wiki/Botrytis_cinerea&gt;. Access on June 2, 2017.

WILLIAMSON, B., TUDZYNSKI, B., TUDZYNSKI, P., & VAN KAN, J. (2007). Botrytis cinerea: the cause of grey mould disease Molecular Plant Pathology, 8 (5), 561-580 DOI: 10.1111/j.1364-3703.2007.00417.x

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

**Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommerical 2.0 Generic License.

Leave a comment

Filed under Friday Fellow, Fungi

Going a long way with your mouth open to new tastes

by Piter Kehoma Boll

Everybody knows that human activities have driven our environment toward an unfortunate situation. The most popular forms of human impact include pollution, deforestation and overexploitation of natural resources, but certainly an important factor in remodeling ecosystems is the invasion of species.

While humans move around the world, they carry many species with them, either intentionally or not, an some of them establish successfully in the new environment, while others do not. But what makes some species become successful invaders while other are unable to do so?

It is clear for some time that having a broad niche, i.e., a broad tolerance in environmental conditions and a broad use of resources is very important to succeed in invading a new habitat. Food niche breadth, i.e., the amount of different food types one can ingest, is among the most important dimensions of the niche influencing the spread of a species.

I myself studied the food niche breadth of six Neotropical land planarians in my master’s thesis (see references below) and it was clear that the species with the broader niche are more likely to become invasive. Actually, the one with the broadest food niche, Obama nungara, is already an invader in Europe, as I already discussed here.

obama_marmorata_7

A specimen of Obama nungara from Southern Brazil that I used in my research. Photo by myself, Piter Kehoma Boll.*

But O. nungara has a broad food niche in its native range, which includes southern Brazil, and likely reflected this breadth in Europe. But could a species that has a narrow food niche in its native range broaden it in a new environment?

A recent study by Courant et al. (see references) investigated the diet of the African clawed frog, Xenopus laevis, that is an invasive species in many parts of the world. They compared its diet in its native range in South Africa whith that in several populations in other countries (United States, Wales, Chile, Portugal and France).

Xenopus_laevis

The African clawed frog Xenopus laevis. Photo by Brian Gratwicke.**

The results indicated that X. laevis has a considerable broad niche in both its native and non-native ranges, but the diet in Portugal showed a greater shift compared to that in other areas, which indicates a great ability to adapt to new situations. In fact, the population from Portugal lives in running water, while in all other places this species prefers still water.

We can conclude that part of the success of the African clawed frog when invading new habitats is linked to its ability to try new tastes, broadening its food niche beyond that from its original populations. The situation in Portugal, including a different environment and a different diet, may also be the result of an increased selective pressure and perhaps the chances are that this population will change into a new species sooner than the others.

– – –

References:
Boll PK & Leal-Zanchet AM (2016). Preference for different prey allows the coexistence of several land planarians in areas of the Atlantic Forest. Zoology 119: 162–168.

Courant J, Vogt S, Marques R, Measey J, Secondi J, Rebelo R, Villiers AD, Ihlow F, Busschere CD, Backeljau T, Rödder D, & Herrel A (2017). Are invasive populations characterized by a broader diet than native populations? PeerJ 5: e3250.

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

**Creative Commons License
This work is licensed under a Creative Commons Attribution 2.0 Generic License.

Leave a comment

Filed under Conservation, Ecology, Evolution, Extinction

Friday Fellow: Field Hornwort

by Piter Kehoma Boll

Three weeks ago our Friday Fellow was a moss, being the third non-vascular plant to be introduced. And before going back to vascular plants, let’s take a look at another non-vascular fellow from the only non-vascular division that was not yet introduced here, the hornworts.

The species I chose to start the participation of hornworts is the field hornwort, Anthoceros agrestis.

Anthoceros_agrestis

A piece of soil with the field hornwort growing on the top. Photo by Wikimedia user BerndH.*

As with other hornworts, the field hornwort has a dominant gametophyte phase which appears as a small flattened plant growing very close to the soil. The sporophyte grows over it and has the form of an elongate vertical horn, hence the name hornwort.

Found in Europe and North America, the field hornwort usually grows in wet places and is often surrounded by  mosses. Its gametophyte has some internal cavities filled with muscilage that are a favorite place for species of cyanobacteria of the genus Nostoc to grow. This association is what makes hornworts acquire their slight bluish tinge.

The field hornwort has the smallest genome of all non-vascular plants studied until the present and because of that it has been cultivated to serve as an interesting model organism.

– – –

ResearchBlogging.orgReferences:

EOL – Encyclopedia of life. Field Hornwort. Available at <http://eol.org/pages/399515/overview&gt;. Access on May 18, 2017.

Szövényi, P., Frangedakis, E., Ricca, M., Quandt, D., Wicke, S., & Langdale, J. (2015). Establishment of Anthoceros agrestis as a model species for studying the biology of hornworts BMC Plant Biology, 15 (1) DOI: 10.1186/s12870-015-0481-x

– – –

*Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

Leave a comment

Filed under Botany, Friday Fellow