#of the intermediate snail host in habitats

[ajaegerpilot]

*ribeiroia

This photograph shows a Pacific tree frog infected by parasites from the genus Rebeiroia. They can cause extra limbs - or no limbs - to grow. This typically makes them easier prey for birds which completes the parasites life cycle.

[medicalgreensandcritters]

Scientific name: Schistosoma japonicum

Common name: Blood fluke

Local name: Unknown; “Bulate” for worms collectively

Medical importance: Causes schistosomiasis

Schistosomiasis, one of the many neglected tropical diseases, is endemic in the Philippines. 10 of 16 regions in the country have reported cases of clinical schistosomiasis, with 6.7 million people living in the endemic areas [1].

Infection occurs when the person comes into contact with contaminated freshwater, in which Oncomelania snails, a host for the worms, reside. The parasites that multiplied inside the snail leave the intermediate host, enter the water and penetrate a person’s skin. For several weeks, the larvae develop inside the human host and become adult worms. Some mate and produce eggs. Schistosomisis symptoms occur because of the body’s reaction to the eggs being deposited in the intestine or bladder.     

Habitat & geographical distribution: China, Philippines, Indonesia, Japan

Animal description:

Eggs: 5-85µm by 40-60 µm; large, round and non-operculate; transparent shell with a rudimentary lateral spine or knob

Miracidium: Ovoid, ciliated

Cercariae: Elongated; with tapering head and forked tail

Adult: yellow or yellow brown; male - 12mm by 0.5mm, female - 20mm by 0.4mm; strong sucker around the mouth; tegument coated with tiny spines

Treatment: Praziquantel

References: 

[1] Gordon, C. A., Acosta, L. P., Gray, D. J., Olveda, R. M., Jarilla, B., Gobert, G. N., … McManus, D. P. (2012). High Prevalence of Schistosoma japonicumInfection in Carabao from Samar Province, the Philippines: Implications for Transmission and Control. PLoS Neglected Tropical Diseases, 6(9), e1778. doi:10.1371/journal.pntd.0001778 

[2] Center for Disease Control & Prevention. Schistosomiasis. https://www.cdc.gov/parasites/schistosomiasis/

[adelaideattractions]

Mystery parasite in gecko man death

Queensland father David Dowell who died 10 days after swallowing a gecko may have died from a parasitic tapeworm common in Asian house geckos rather than salmonella poisoning. Doctors have told news.com.au Mr Dowells symptoms a distended stomach, black urine and green bile are more extreme than salmonella and evidence of an abdominal obstruction and liver failure. And a taxonomist and ecologist who is an expert in Asian house gecko parasites says a tapeworm called Spirometra could be the culprit. Ten days is a very short time for a larval parasite inside the gecko to get into the intestine, attach and grow, Diane Barton told news.com.au. But it would certainly be an Asian house gecko if hes from Queensland. If it was full of parasites, most likely the gecko would have been relatively easy to catch. If you have a broom, you can knock them off the wall and then catch them as they fall. It would have to have been packed with larval stages (of parasites), which might have been why it was so easy to catch. Mr Dowell died in absolute agony at the age of 34 in Brisbanes Mater Hospital last December after eating a gecko as a dare at a pre-Christmas party.

media_cameraDavid Dowell (above) left behind his partner of 15 years Allira (right) and their three daughters.

media_cameraMr Dowell is believed to have swallowed an Asian house gecko, which are endemic in Queensland and warm parts of Australia.

media_cameraSpirometra tapeworm is just one parasite inside Asian house geckos that Mr Dowell probably ate. After feeling like he was hung over for days after the party, Mr Dowell was taken to hospital where he began vomiting green bile, his urine turned black, and his stomach was so bloated he looked six months pregnant. RELATED: Queensland dad David Dowell dared to eat gecko at a party dies 10 days later His lungs had also started to fill with fluid, fluid leaked from his stomach, and his testicles were swollen up to grapefruits and there was fluid leaking from them. A doctor told news.com.au Mr Dowell had all the symptoms of a stomach obstruction coupled with fluid in his interabdominal cavity and scrotal oedema. The doctor said the other symptoms were of liver failure, and they sounded extreme for salmonella poisoning. Mr Dowell died in surgery, leaving behind his partner Allira and three daughters. Dr Barton said while reptiles commonly carried salmonella, geckos were also host to other parasites. Asian house geckos carry the larval stage of various things, pentastomes which go into the lungs of snakes, nematodes or roundworms and the larval tapeworms that go into cats, she said. Spirometra is in snakes, frogs and geckos and go into mammals like cats and quolls and attack and grow. Heavy infections of parasites can cause abdominal blockage or something got into the liver and blocked a duct, but that fast?

media_cameraMr Dowell (above), with his partner Allira in 2011, died in agony 10 days after swallowing the gecko.

media_cameraMr Dowell died at Brisbane's Mater Hospital in an operating theatre.

media_cameraLife cycle of the Spirometra tapeworm common in reptiles, including geckos, that can enter the human system. That rapid a response, the gecko would have to have been packed with larval stages, which might have been why it was so easy to catch. When an adult Spirometra tapeworm is present in the small intestine of cats and dogs, it may grow as long as 1.5m. Cases of human infection by the Spirometra have been reported, with a 26-month-old baby having a 42cm worm in the lung and a 70-year-old man with a 20cm larva in his stomach, both in Vietnam. Despite Australia being home to 200 different species of native geckos, the Asian house gecko is the most invasive species of lizard on earth. Since the 1960s, the Asian house gecko has become resident in homes in Queensland and warm parts of Australia where some householders complain about it leaving droppings and making a noise. Spirometra tapeworm, or zipper worm, also known as the gecko tapeworm, is more common in cats than dogs, with pets becoming infected by ingesting intermediate hosts such as geckos, other lizards, mice, rats or frogs. Dr Bartons 2015 study Helminth parasites of the introduced Asian House Gecko was the first report of helminths, or gastrointestinal parasitic worms, infecting the invasive Asian house gecko in Australia. Dr Barton told news.com.au the other recent death of an Australian man who had ingested a garden slug as a dare was another example of why it was a bad idea to ingest creatures. Sam Ballard swallowed the slug as a 19-year-old taking up a drinking game dare and became infected with the parasite Angiostrongylus cantonensis, known as rat lungworm. He contracted eosinophilic meningo-encephalitis and became a non-verbal quadriplegic. Last November, he died. Dr Barton cited the case of a toddler who died from the same disease several decades ago. Dont eat things you are not meant to," she said.

media_cameraGecko parasite expert Di Barton said a heavily infected gecko would have been easy to catch, but 10 days was a rapid rate for a tapeworm to block the gut in Mr Dowell (above).

media_cameraSam Ballard was a normal teenager when in 2010 he swallowed a garden slug as a dare while drinking with friends.

media_cameraSam with his mother Katie after rat lungworm from the slug caused meningitis and left him severely disabled. There was a little boy in Brisbane who went out to get the milk bottles. A snail had left a larval parasite in its slime trail and the boy got rat lungworm and died. These particular parasites are a problem. In their life cycle, they wander through the host, go through the tissues and get lost as they try to find their way to the lungs and end up in the meninges (the protective layers of the brain and spinal cord). The Australian Reptile Parks head keeper, Dan Rumsey, told news.com.au while Asian house geckos chase and eat moths and insects in homes, it was best to wash your hands after touching them. Typically, they are about 8cm long and are highly invasive. They like urban habitats, he said. Reptiles carry salmonella, its just a bacteria they can harbour on their skin. In the US a few years ago there were cases of salmonella poisoning from turtles. You should always wash your hands after handling any animal.

media_cameraThe Queensland coroner has ruled out an inquest into Mr Dowells death. But I dont know why you would eat a gecko you shouldnt be putting them in your mouth. But we love geckos, they are beautiful animals. Following Mr Dowells death on December 11 last year, his family said he suffered mass organ failure and basically rotted from the inside out. More than six months later, Mr Dowells family are still searching for answers, but no inquest into his death will be held. The Queensland Coroners Court said in a statement, After consideration of the hospital records, the coronial registrar finalised the investigation by authorising the cause of death certificate to issue without coronial autopsy. Brisbanes Mater Hospital offered Mr Dowells family its sympathy but would not comment due to patient confidentiality. candace.sutton@news.com.au Originally published as Mystery parasite in gecko man death https://www.adelaidenow.com.au/lifestyle/health/man-who-swallowed-gecko-may-have-died-from-parasite/news-story/5dc31b89126b7bf48363607c5aff72d9?from=htc_rss

[evoldir]

Graduate position: GhentU.EvolutionGastropods

PhD position_Ghent University_snail parasites. Topic: Unravelling the role of Bulinus gastropods as intermediate hosts in Schistosoma disease transmission with state-of-the-art molecular techniques Duration: 3 years with a possible extension Start: October 2017 Vacancy description: We are pleased to announce a PhD fellowship for a highly motivated, enthusiastic and independent person with a keen interest in evolutionary parasitology and the ecological context of snail-parasite-human disease transmission in aquatic habitats in Africa. The project is conceptualized in molecular ecology with a focus on the intermediate snail host rather than in a biomedical context. Experience with molecular biology and bio-informatics, and enthusiasm to participate in fieldwork at transmission sites in Africa are plus-points. Project background: Snail-borne diseases affect more than 300 million people worldwide but also lead to economic losses and mortality in livestock. Especially developing countries are affected but due to globalization and climate change the distribution of snail-borne diseases is changing. Because the distribution of the intermediate snail host species determines where snail-borne diseases occur, updated information on snail distribution and their role in parasite transmission is highly needed. Acquiring these insights is however hampered by taxonomic confusion in the group of host snails and lack of associated ecological and parasitological data. The aim of this PhD project is to develop an efficient, sensitive and robust monitoring tool based on next-generation DNA-sequencing technology that will simultaneously detect the snail and associated parasite DNA. Applied to new and existing museum collections this will allow to 1) accurately define the complete helminth fauna of each snail species and their role in disease transmission; 2) combine genetics with morphology to improve snail identification in the field; and 3) use snail and parasite genetic data for comparative phylogeography. Setting and requirements: The project is funded by the Federal Science Policy of Belgium and will be developed in an inter-institutional collaboration between the Royal Museum for Central Africa (Tervuren, Belgium; Dr. Tine Huyse), Ghent University (Ghent, Belgium; Limnology Unit, Prof. D. Verschuren, Dr. Bert Van Bocxlaer), and the Justus-Liebig University (Giessen, Germany; Prof. Christian Albrecht). Ghent University is the diploma-granting institution for this PhD project. Training in the doctoral school will take place at Ghent University, whereas project-related tasks will be primarily developed at the Royal Museum for Central Africa (Tervuren); language is English and Dutch. Applicants should hold a master degree in biology, bio-engineering or biotechnology to be allowed into the PhD program at Ghent University. Master students who are graduating during the summer of 2017 are also welcome to apply. More information on studying at Ghent University and living in Ghent can be found on the Ghent University webpage: (http://bit.ly/2u0qyWr; http://bit.ly/2thzrxL). Interested? To apply for this position, please send the following information to tine.huyse@africamuseum.be: 1) a complete CV, including grades of the last completed year; 2) a short description of past research accomplishments and motivation to take on this project; and 3) the names and e-mail addresses of at least 2 references. To receive full consideration, please send your application by the 10^thof August. (Late applications will be considered until the vacancy is filled.) Interviews will take place in the week of the 4^th of September 2017. More information: Informal inquiries can be sent to tine.huyse@africamuseum.be (http://bit.ly/2tZVXbI) or Bert.VanBocxlaer@UGent.be (http://bit.ly/2thXLj6) Tine Huyse Royal Museum for Central Africa Department of Biology Leuvensesteenweg 13 3080 Tervuren- BELGIUM TEL: 0032 (0)2 769 53 72 EMAIL: tine.huyse@africamuseum.be http://bit.ly/2tZVXIK Tine Huyse via Gmail

[ladystylestores]

Can gender-bending Israeli superprawns help feed the world? 

Enlarge / This is actually a male shrimp according to the image info, which we don’t need for this.

Enzootic Ltd

Can a shrimp smile? It’s tough to say whether the gangly, blue-legged crustaceans lurking within the massive aquaculture tanks are actually happy, but they certainly appear to be content. Perhaps it’s because they are well-fed and blissfully unaware of what lies just outside the laboratory: the harsh, dry environment of Israel’s Negev Desert, which is not a natural habitat for any form of aquatic life. It may also be because the tank contains an all-female population, devoid of males, which tend to be territorial, aggressive, and create stressful conditions that don’t promote optimal growth.

Regardless of their state of mind, these placid crustaceans are the products of a unique gender-bending technique that promises to make them a delicious link toward a sustainable global food chain. Or, the technique could be the latest in a long line of developments that force us to take a careful look at the benefits and costs of achieving sustainability by intruding into the basic biology of the food we end up eating.

Gender-bending giants

In truth, the creatures in question are not shrimp; rather, they’re a species of freshwater prawns, known to biologists as Macrobrachium rosenbergii. Commonly known as giant river prawns, they are a beloved staple of traditional Southeast Asian cuisine. Their flavor and amenability to simple aquaculture techniques made them a traditional cash crop for Thai, Malaysian, and Vietnamese farmers, who raise them in large outdoor ponds.

Despite their ability to quickly and efficiently convert feedstock into body mass, their adoption in other regions has been hampered by the jungle-bred prawns’ narrow comfort zone. Because they don’t do well in waters cooler than 26ºC (79ºF) or warmer than 30ºC (86ºF), attempts to cultivate them in most other regions have not gone well. The critters also need relatively spacious quarters to reduce growth-inhibiting interactions with aggressive territorial males, a requirement that makes raising them in the warm but more restricted confines of high-tech aquaculture systems less cost-effective.

Enlarge / Giant freshwater prawns have been a beloved delicacy throughout Southeast Asia, but, until recently, their need for a tropical environment has limited their cultivation in most other parts of the world.

Wikipedia

Now, however, freshwater prawns may be able to enjoy wider commercial success, thanks to a new breeding technique developed by Enzootic, an Israeli agro-biotech venture founded in 2012 by Dr. Assaf Shechter and Professor Amir Sagi. One of the company’s first initiatives was to develop and commercialize a technology for manipulating the gender of freshwater prawns in collaboration with Israel’s Ben-Gurion University of the Negev. This collaboration led to the creation of a one-time, non-chemical, non-genetic gender-bending treatment that allows freshwater hatcheries to produce crops of all-female prawns.

Breaking a different gender barrier

Single-sex populations may seem boring to us, but for the aquaculturist, they offer several advantages. For example, all-female freshwater prawn populations are very uniform in size and less aggressive, making it feasible to raise them in the more densely packed environments needed to make indoor aquaculture profitable. Shechter says that this and several other developments make it possible to raise freshwater prawns in highly productive commercial aquaculture systems that are far less polluting and require less space, energy, and water than today’s operations. (All-male populations offer other advantages that improve productivity and profits in other types of production systems.)

While it is possible to hand-sort prawns for gender, the process is time-consuming and can only be done so far down the production cycle that it’s not really practical. Enzootic’s gender-bending process solves that problem by going upstream to the breeding process and making alterations in breeding females that cause them to produce broods of single-sex all-female offspring.

The prawns used in this process determine their sex in a manner somewhat analogous to how it works in humans: there’s a chromosomal signal (think X/Y chromosomes) that is interpreted by an organ that makes hormones that control male and female development. But, unlike in humans, the mother can also influence the sexual development of the next generation.

Enzootics’ process takes advantage of these features. It starts by surgically extracting the hormone-producing organ from “donor” males, which are then broken down into individual cells. When the cells are injected into young females, the hormones they produce cause the females to develop as males, despite their chromosomes. Just like natural male prawns, they can mate normally with other females, but some of their offspring possess a unique trait. Known as “super females,” they produce offspring that will develop as females regardless of the chromosomes they carry.

Enzootic has set up the genetics of its shrimp so that these super females are relatively easy to identify, and they can be used to quickly produce large populations of nothing but females. “Our goal was to take advantage of this natural and remarkable sexual plasticity to accomplish production of all-female populations without any kind of genetic modifications,” says Shechter, Enzootic’s co-founder.

Enlarge / Lab workers looking for the superfemale prawns.

Enzootic

Amir Sagi at Ben Gurion University of the Negev used many of the same insights on the factors that control sex differentiation of prawns enabled to develop a parallel technology for creating breeder prawns capable of producing only male offspring, a process that dramatically boosts the productivity of outdoor aquaculture operations. While all-female prawn populations are less aggressive and do better in the cramped confines of indoor tanks, males offer big advantages for operators using more spacious outdoor ponds.

The absence of females in outdoor ponds eliminates competition between males for mates that would normally result in injuries, deaths, and slower growth rates. Taking away the stimulus for aggressive behavior also reduces stress, allowing the prawns to direct even more of the calories they receive into growth. This can improve production by as much as 45 percent which, when combined with the Asian market’s strong preference for the large prawns, could mean a 50- to 60-percent bump in a prawn farmer’s income.

Both processes leave the prawns’ natural genetic material untouched. In principle, this could avoid any potential real or imagined concerns about introducing “franken-prawns” into the food chain. The process, however, does involve some significant manipulation of the prawns’ biology, so the product might not be viewed as “natural” by people concerned about how their food is produced.

Beyond the consumer applications, Professor Sagi has also been involved in research on using the prawns to combat schistosomiasis, a debilitating waterborne disease that affects around 200 million people worldwide, primarily in impoverished areas. Also known as Snail Fever, the disease is caused by parasitic flatworms called schistosomes, which use aquatic snails as an intermediate host. Anyone swimming in, or drinking water inhabited by, these snails is likely to contract the disease, which can eventually lead to liver damage, kidney failure, infertility, or bladder cancer. In children, it may also inhibit growth and mental development.

Since the prawns are voracious predators of water snails, trials are underway to determine how commercial aquaculture operations can be most effectively configured for a parallel role as snail control centers. In a recent paper, Sagi and other proponents argue that the prawns could significantly reduce the number of infected people and the cost of the drugs required to treat them, plus the prawn ponds would provide permanent sources of food and income.

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