Friday Fellow: Deathstalker

by Piter Kehoma Boll

The name of today’s fellow may sound intimidating, and it is for a good reason. Scientifically known as Leiurus quinquestriatus, the deathstalker, which is also known as the Omdurman scorpion, Naqab desert scorpion, Palestine scorpion or Israeli scorpion, is considered one of the most venomous scorpions in the world.

800px-deathstalker_28leiurus_quinquestriatus29_6

A deathstalker in Israel. Photo by Wikimedia user מינוזיג.*

The deathstalker is found in arid regions of North Africa and the Middle East. There are two subspecies, L. quinquestriatus quinquestriatus found in Africa from Algeria and Niger to Somalia and Sudan, and L. q. hebraeus found from Turkey to Iran and Yemen. They are relatively large, measuring up to 11 cm in length.

The venom of the deathstalker has been shown to contain a variety of different neurotoxins, including several inhibitors of potassium and chloride channels, which affect the transmission of nervous impulses through the nervous system. Although very painful, the sting of a single scorpion would hardly kill a healthy adult human, but immediate medical treatment with antivenom is always required to avoid any unpleastant consequences. Children, elderly people, or adult people with heart problems or allergies, however, can easily be killed.

One of the toxins, chlorotoxins, which affects chloride channels, has shown potential to be used in the treatment of brain tumors.

Despite its danger, the deathstalker is often raised as a pet. Why? Because humans…

– – –

Likes us on Facebook!

Follow us on Twitter!

– – –

References:

Castle, N. A.; Strong, P. N. (1986) Identification of two toxins from scorpion (Leiurus quinquestriatus) venom which block distinct classes of calcium-activated potassium channel. FEBS Letters 209(1): 117–121. DOI: 10.1016/0014-5793(86)81095-X

EOL – Encyclopedia of Life. Leiurus quinquestriatus. Available at < http://eol.org/pages/10208954/overview >. Access on January 7, 2018.

Garcia, M. L.; Garcia-Calvo, M.; Hidalgo, P.; Lee, A.; McKinnon, R. (1994) Purification and Characterization of Three Inhibitors of Voltage-Dependent K+ Channels from Leiurus quinquestriatus var. hebraeus Venom. Biochemistry 33(22): 6834–6839. DOI: 10.1021/bi00188a012

Gueron, M.; Ilia, R.; Shahak, E.; Sofer, S. (1992) Renin and aldosterone levels and hypertension following envenomation in humans by the yellow scorpion Leiurus quinquestriatusToxicon 30(7): 765–767. DOI: 10.1016/0041-0101(92)90010-3

Lyons, S. A.; O’Neal, J.; Sontheimer, H. (2002) Chlorotoxin, a scorpion-derived peptide, specifically binds to gliomas and tumors of neuroectodermal origin. GLIA 39(2): 162–173. DOI: 10.1002/glia.10083

Sofer, S.; Gueron, M. (1988) Respiratory failure in children following envenomation by the scorpion Leiurus quinquestriatus: Hemodynamic and neurological aspects. Toxicon 26(10): 931–939. DOI: 10.1016/0041-0101(88)90258-9

– – –

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

Advertisements

Leave a comment

Filed under Friday Fellow, Zoology, Arachnids

Friday Fellow: Pink Miniacina

by Piter Kehoma Boll

It’s time  for the next foraminifer, which is always a problematic time, but I managed to find a suitable fellow for this Friday. Called Miniacina miniacea in the scientific community, it obviously lacks a common name, so I decided to call it the pink miniacina.

Differently from the previously introduced foraminifers, the pink miniacina is a sessile and colonial species. It usually grows attached to other lifeforms, especially algae and corals. Due to its colonial nature, added to the already bigger-than-average size of foramnifers when compared to other unicellular organisms, the pink miniacina is easily visible to the naked eye and can be seen as a series of small branched organisms with an intense pink color. It is particulary common in the Mediterranean Sea, although it can be found in other places as well.

miniacina_miniacea_30-09-06_dscf3288

Several pink colonies of Miniacina miniacea growing in the Mediterranean Sea. Photo by Stefano Guerrieri.

Due to its habit of living on the surface of other sessile organisms, the pink miniacina competes with many other organisms that have the same behavior. As a result, its abundance tends to increase in deeper water, where many of such organisms find the conditions too unsuitable to live. In a few areas, the abundance of the pink miniacina may be high enough to create a “pink sand” from the shells of dead specimens.

– – –

Like us on Facebook!

– – –

References:

Di Camillo, C.; Bo, M.; Lavorato, A.; Morigi, C.; Reinach, M. S.; Puce, S.; Bavestrello, G. (2008) Foraminifers epibiontic on Eudendrium (Cnidaria: Hydrozoa) from the Mediterranean Sea. Journal of the Marine Biological Association of the United Kingdom88(3): 485–489. https://doi.org/10.1017/S0025315408001045

Milliman, J. D.(1976) Miniacina miniacea: modern foraminiferal sands on the Outer Moroccan shelf. Sedimentology23: 415–419. https://doi.org/10.1111/j.1365-3091.1976.tb00059.x

Leave a comment

Filed under Friday Fellow, protists

Cat-handedness: can cats be left- or right-handed?

by Piter Kehoma Boll

In humans, as you may know, there is usually a preference for using one side of the body to perform a task, a thing called laterality. And we have a strong tendency to be right-handed, with about 90% of humans using their right side to perform most unilateral tasks. Several studies revealed that many other animals, at least among vertebrates, display laterality as well.

A recent study investigated laterality in the domestic cat during spontaneous behaviors in contrast with the more common experiments using forced behaviors, such as making the cat try to reach food. They looked for a side preference in cats during the behaviors of lying side, stepping down and stepping over.

400px-fiumi_28805948955029

Photo by Juan Eduardo de Cristófaro.*

The result indicated that about one third of the cats is left-pawed, one third is right-pawed and one third is ambidextrous while moving up and down, but there is no clear preference for lying on their right or left side. Thus, we can see that, differently from humans, there is no strong bias to use one side of the body in cats, at least not when looking at cats in general.

When we consider sex, though, there was a significant difference: male cats tend to be left-pawed, while female cats are usually right-pawed. That would be very useful if cats danced the waltz.

– – –

Like us on Faceebok!

Follow us on Twitter!

– – –

References:

McDowell, L. J.; Wells, D. L.; Hepper, P. G. (2018) Lateralization of spontaneous behaviours in the domestic cat, Felis silvestris. Animal Behavior135: 37–43. https://doi.org/10.1016/j.anbehav.2017.11.002

– – –

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

Leave a comment

Filed under Behavior, mammals

Friday Fellow: Reishi Mushroom

by Piter Kehoma Boll

The first Friday Fellow of 2018 is here, and it is a beloved parasite from the Far East. This lovely mushroom is scientifically known as Ganoderma lucidum and has no native common name in English, being usually called the reishi mushroom, from its Japanese name 霊芝 (reishi), or lingzhi mushroom, from its Chinese name 靈芝 (língzhī).

800px-lingzhi_1

The beautiful and shiny kidney-shaped reishi. Photo by Wikimedia user Mokkie.*

The reishi mushroom, as other species in the genus Ganoderma and in the order Polyporales, grows on tree trunks, usually parasitizing live trees and continuing to grow on them after they die. The mature fruiting body is kidney-shaped and may or may not have a stalk, which is displaced to the side, below the concave side of the cap. The cap has a red-varnished color with a lighter rim. It is easily mistaken for some of its closest relatives, such as Ganoderma tsugae and G. lingzhi.

Traditionally used in Chinese medicine, the reishi mushroom was considered the “mushroom of immortality” and said to improve the heart and the mind. Recently, it has demonstrated, in laboratory studies, to have many potential uses for the treatment of different illnesses. For example, their fruiting bodies release polysaccharides that showed the ability to increase the cytokine production of human white blood cells, which increase anti-tumor activities. Other studies have identified compounds with potential anti-HIV activity and the ability to reduce the levels of blood sugar.

– – –

Like us on Facebook!

– – –

References:

El-Mekkawy, S.; Meselhy, M. R.; Nakamura, N.; Tezuka, Y.; Hattori, M.; Kakiuchib, N.; Shimotohnob, K.; Kawahatac, T.; Otakec, T. (1998) Anti-HIV-1 and anti-HIV-1-protease substances from Ganoderma Lucidum. Phytochemistry49(6): 1651–1647. https://doi.org/10.1016/S0031-9422(98)00254-4

Wang, S.-Y.; Hsu, M.-L.; Hsu, H.-C., Lee, S.-S.; Shiao, M.-S.; Ho, C.-K. (1997) The anti-tumor effect of Ganoderma Lucidum is mediated by cytokines released from activated macrophages and T lymphocytes. International Journal of Cancer70(6): 699–705. Doi: 10.1002/(SICI)1097-0215(19970317)70:6<699::AID-IJC12>3.0.CO;2-5

Wang, Y.-Y.; Khoo, K.-H.; Chen, S.-T.; Lin, C.-C.; Wong, C.-H.; Lin, C.-H. (2002) Studies on the immuno-Modulating and antitumor activities of Ganoderma lucidum (Reishi) polysaccharides: functional and proteomic analyses of a fucose-Containing glycoprotein fraction responsible for the activities. Bioorganic & Medicinal Chemistry, 10(4): 1057–1062. https://doi.org/10.1016/S0968-0896(01)00377-7

Wikipedia. Lingzhi mushrom. Available at: < https://en.wikipedia.org/wiki/Lingzhi_mushroom >. Access on December 31, 2017.

– – –

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

Leave a comment

Filed under Friday Fellow, Fungi

Hundreds of lionfish were released in the Atlantic out of pity

by Piter Kehoma Boll

The red lionfish, Pterois volitans, is a beautiful and venomou coral fish native from the Indo-Pacific region. Due to its great beauty, it is a very popular in fish tanks all around the world.

799px-red_lionfish_near_gilli_banta_island

A red lionfish in its natural and native habitat in Indonesia. Photo by Alexander Vasenin.*

Since the 1980s, the lionfish started to be found in the waters of the Atlantic ocean around Florida. How did they get there? Certainly humans had something to do with it, but the exact way is yet unknow. Originally a small population, the species spread quickly by the beginning of the 21th century and in 2010 had colonized the Caribbean and the Gulf of Mexico.

Some original studies on the genetic diversity of the Atlantic population estimated that the minimum number of introduced specimens was around 10. If that was true, the established population may have been the result of an accident, like, for example, the fish of a single aquarium accidentally ending up in the sea.

800px-caribbean_lionfish3f_28519689049529

A red lionfish photographed in Curaçao, Caribbean. Photo by Laszlo Ilyes.**

A recently published study (see reference), however, reestimated this number using new models and additional data. The conclusions are that the number of fish that colonized the Atlantic was much bigger, around 272 individuals. Such a large introduction would unlikely occur by accident. Introductions by fish being transported from the Indo-Pacific region in the ballast water of ships is unlikely, as they would hardly survive the transport. The most likely answer is that these fish were introduced through several small releases that happened in Miami. How and why? Well, many people like to have fish in beautiful fish tanks at home, and when they get tired of managing the animals or cannot afford continuing to have them, they decide to simply release them in the ocean out of pity, because the alternative would be to kill them.

Now can you see what are the consequences of thinking this way? You care too much for a single specimen, has no ecological knowledge, and simply decide to release them in the wild. Years later, they have depleted whole ecosystems and caused a large-scale disaster. That’s what humans do. As they say, the road to hell is paved with good intentions.

– – –

Like us on Facebook!

Follow us on Twitter!

– – –

References:

Selwyn JD, Johnson JE, Downey-Wall AM, Bynum AM, Hamner RM, Hogan JD, Bird CE. (2017Simulations indicate that scores of lionfish (Pterois volitans) colonized the Atlantic OceanPeerJ 5:e3996 https://doi.org/10.7717/peerj.3996

– – –

*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 2.0 Generic License.

Leave a comment

Filed under Conservation, Fish, Zoology

Friday Fellow: Tulip Cone

by Piter Kehoma Boll

The year has almost ended, but if you would touch today’s Friday Fellow, it would end for you right now, and without a new year coming.

Living along the coasts of the Indian Ocean, including East Africa, Madagascar,  India, West Australia and several archipelagos such as Mascarene Islands and the Philippines, our fellow, Conus tulipa, is popularly known as tulip cone. Despite its beautiful name, however, it is not a nice species to have nearby.

800px-conus_tulipa

A live Conus tulipa in La Réunion, Mascarene Islands. Photo by Philippe Bourjon.*

The tulip cone is a species of the genus Conus, predatory sea snails that feed on a variety of animals, such as fish, worms and other mollusks. They capture prey by stinging them with a venomous harpoon that is made of a modified tooth of their radula (tongue). The harpoons are stored in a sack and shot on a nearby prey. Because many species feed on fast moving prey, such as fish, they have a very powerful venom able to kill the target in a few seconds. In some species, including the tulip cone, this powerful venom is strong enough to kill an adult human being.

As with all other venomous species, though, not everything is bad. Several different toxins and other components have been recently isolated from the venom of the tulip cone, many of which may eventually be used to develop new medicines.

– – –

Like us on Facebook!

– – –

References:

Alonso, D.; Khalil, Z.; Satkunanthan, N.; Livett, B. G. (2003) Drugs From the Sea: Conotoxins as Drug Leads for Neuropathic Pain and Other Neurological Conditions. Mini Reviews in Medicinal Chemistry3: 785–787.

Dutertre, S.; Croker, D.; Daly, N. L., Anderson, Å,.; Muttenhaler, M.; Lumsden, N. G.; Craik, D. J.; Alewood, P. F.; Guillon, G.; Lewis, R. J. (2008) Conopressin-T from Conus tulipa reveals an anatagonist switch in vasopressin-like peptides. Journal of Biological Chemistry283, 7100–7108.

Hill, J. M.; Alewood, P. F.; Craik, D. J. (2000) Conotoxin TVIIA, a novel peptide from the venom of Conus tulipa. The FEBS Journal, 267 (15): 4649–4657.

Wikipedia. Conus tulipa. Available at < https://en.wikipedia.org/wiki/Conus_tulipa >. Access on December 28, 2017.

– – –

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

Leave a comment

Filed under Friday Fellow, mollusks

Friday Fellow: Yerba Mate

by Piter Kehoma Boll

Christmas is in a few days and a plant that is always associated to this time of the year in Europe is the holly Ilex aquifolium. I was about to make it today’s Friday Fellow, but then I thought: why not a less popular but much cooler relative?

So let’s welcome Ilex paraguariensis, the yerba mate!

400px-misiones_-_hojas_de_yerba_mate

Detail of a branch of yerba mate (Ilex paraguariensis). Photo by Leandro Kibisz.*

The yerba mate is a shrub or tree that can grow up to 15 meters in height and is found in several forest fosrmations of South America, especially along the Paraguay and Paraná rivers. The leaves are oval and have a dark green color and a slightly serrated margin. The flowers are mall and lack petals and the fruits are red as in its European cousin.

The leaves of yerba mate are used for the preparation of a traditional beverage called mate in both Spanish and Portuguese, and also as chimarrão in Portuguese. It is traditionally consumed in Paraguay, Argentina, Uruguay and Southern Brazil, as well as in some areas of Bolivia and Chile. The consumption of mate started with the guarani people and later  spread to the Tupi and to the European colonizers and is currently associated with the gaucho culture in South America.

800px-salam_g

A man drinking mate. Photo by Aslam Singh.**

The leaves of yerba mate are rich in caffeine and polyphenols, thus having stimulant, diuretic and antioxidant properties. The beverage seems to be able to help in weight loss by reducing the absorption of lipids and can also reduz the risk os several types of cancer. However, there are some evidence connecting the consumption of mate with increased risk of some cancers as well, such as oral and esophageal cancer. This risk, however, may be more related to the temperature of the beverage than the plant itself, so try not to drink it too hot!

– – –

Like us on Facebook!

– – –

References:

Heck, C. I.; De Mejia, E. G. Yerba Mate Tea (Ilex paraguariensis): A Comprehensive Review on Chemistry, Health Implications, and Technological Considerations. Journal of Food Science, 72(9):R138–R151. DOI: 10.1111/j.1750-3841.2007.00535.x

Wikipedia. Yerba mate. Available at < https://en.wikipedia.org/wiki/Yerba_mate >. Access on December 17, 2017.

– – –

*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-ShareAlike 3.0 Unported License.

Leave a comment

Filed under Botany, Friday Fellow