The Mary River Turtle has been named recently as one of the species on the brink of extinction. That is according to the Evolutionary Distinct and Globally Endangered (EDGE) Reptiles list of Zoological Society of London. Some would probably shrug it off with a gibbering murmur that the rule of the game is, by the way, the “survival of the fittest”. However, this meek creature would probably not deserve a slot in the list had it not been struggling against hunters that put a tag on it. Why is the Mary River turtle endangered is due to the threat looming its survival as grim as losing it — with all its fascinating biological features and ecological significance — forever.
Mary River turtle and its rare biological traits
The Mary River turtle (Elusor macrurus) has been a popular exotic pet since 1960s and 1970s. A reptile biologist at Zoological Society London, Rikki Gumbs, explained that the turtle was popular because of its uncanny biological traits.1 It is one of the few animals that ”breathe” oxygen via their cloaca. Its cloaca serves as both the genitals and the anus. Thus, aside from the obvious biological functions (i.e. for excretion and mating), its cloaca is also specialized for respiration. While the turtle regularly comes to the surface to breathe air via its nostrils, it also “breathes” while underwater. The gill-like organs within its cloaca absorb oxygen enabling the turtle to stay submerged for three days.2 Because of its ability to stay underwater for that long, it is not unusual to find one that forms a symbiosis with algae. Strands of algae grow atop its head and shell. Sporting a “fancy mohawked hairdo”, the Mary River turtle is also called the “green-haired turtle”. Another distinctive feature of the Mary River turtle is its tail. Males, in particular, can grow a tail to almost two-thirds of the carapace length and adorned with hemal arches. This turtle also has remarkably long barbels (a pair of slender tactile organs) under the chin.
Mary River turtle – why it is endangered
Why the Mary River turtle is endangered is due to their currently small population. The Mary River turtle was already in the pet trade during the 1960s and 1970s before it was first described formally as a species in the 1990s. Thus, their numbers dwindled over time as a lot of them had been lost by nest pillaging and pet trade before the cognizance of the risk of it being endangered. Another unfortunate fact was the conservation efforts of endangered reptiles were raised only of late. Gumbs was quoted, “Reptiles often receive the short end of the stick in conservation terms, compared with the likes of birds and mammals.”2 In the recent list of Top 100 EDGE Reptiles, the Mary River turtle came at no. 29. 3 Conservation strategies are hoisted to help boost their population. However, one of the factors that made the species vulnerable to extinction is the exceptionally long time it takes for them to become sexually mature, i.e. about 25 to 30 years.1
Saving “Mary River turtle” and other endangered reptiles
The endangered reptiles are apparently overlooked compared with the other groups of endangered animals. They had not received the same gravity of attention and popularity as the endangered mammals and birds had. The reptiles were often overlooked, perhaps, because of their far-from-cuddly looks that made them seem less appealing. The list released this year by the Zoological Society of London’s EDGE now includes reptiles. At the top of the list is the critically endangered Madagascar big-headed turtle (Erymnochelys madagascariensis).3 So, why did the Mary River turtle got more attention past the other more-critically-endangered reptiles on the list? Apart from its captivating punky look, the species is the only member of its genus and became evolutionary distinct 40 million years ago. 3 However, despite being evolutionary distinct for that long, the Mary River turtle became vulnerable to extinction largely due to human intrusions. Now, the species is protected by Australian government laws and more conservation efforts are underway.
The awareness of the need for more concerted efforts to conserve seemingly sturdy, robust reptiles is crucial for their survival. Failure to notice early on the need for conservation efforts accentuated the odds of the species’ extinction. The Mary River turtles are able to thrive and live for many million years, and yet, in a relatively short span of time of human interventions and exploitations, they are now on the dreaded list together with the rest of the endangered reptiles that would one day bid farewell for good – unless effective conservation strategies are implemented on time.
— written by Maria Victoria Gonzaga
1Mahmood, Z. (2018). Australian ‘genital-breathing’ turtle faces extinction, group says. Retrieved from https://edition.cnn.com/2018/04/12/asia/mary-river-turtle-endangered-intl/index.html
2 Graham, B. (2018). Punk rocker Mary River turtle now one of the most endangered reptile species on the planet. Retrieved from http://www.news.com.au/technology/science/animals/punk-rocker-mary-river-turtle-now-one-of-the-most-endangered-reptile-species-on-the-planet/news-story/44e0f028840e40dac3c46f884ca7c967
3“TOP 100 EDGE REPTILES”. (2018). Retrieved from https://www.edgeofexistence.org/species/species-category/reptiles/
Nicotinamide riboside gained traction as a recent study conducted by a team of scientists from University of Colorado Boulder reported the first clinical trial research. The results implicate potential health benefits of nicotinamide riboside supplementation, especially among middle-aged and older adults. One of its major benefits is it boosts nicotinamide adenine dinucleotide (NAD+), which, in turn, is beneficial for healthy aging and in extending lifespan.
The biology of nicotinamide riboside
Nicotinamide riboside is one of the many forms of vitamin B3. Similar to other forms of vitamin B3, nicotinamide riboside is capable of boosting NAD+ in the body. Based on a pre-clinical study conducted by Trammel et al1, it appears that it is the most effective among the other forms in terms of increasing NAD+ levels. The study was also able to point out that nicotinamide riboside is the most effective in promoting sirtuins. A sirtuin is an enzyme involved in mitochondrial biogenesis and in the regulation of circadian clocks. It is also credited for its beneficial effects on calorie restriction. NAD+ precursors, such as nicotinamide riboside, are effective sirtuin activators. Nicotinamide riboside, therefore, has a role in the stimulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)-dependent mitochondriogenic pathway. It is also involved in promoting mitochondrial gene transcription and augmenting respiratory chain activity.2
Nicotinamide riboside for healthy aging
A recent study by Christopher Martens et al. presented proof that nicotinamide riboside supplementation led to an increase in NAD+ metabolism in healthy middle-aged and older adults. This was observed in a six-week randomized, double-blind, placebo-controlled crossover clinical trial of healthy individuals, aged 55 to 79. Half of them were given placebo while the other half, a 500mg-dose of nicotinamide riboside chloride twice daily, followed by a placebo. Based on the results from blood tests and physiological measures post-treatment, the supplement increased the levels of NAD+ by 60%.3 Increasing NAD+ in older adults is beneficial in terms of promoting healthy aging since NAD+ levels tend to decline with age. NAD+ is involved in a myriad of metabolic pathways, serving as a coenzyme in various redox reactions. It shuttles energy within the cell, particularly during cellular respiration. It is also a vital activator of sirtuins. Apart from NAD+ boost, nicotinamide riboside was also found to be associated with reduced blood pressure and arterial stiffness.3
Other nicotinamide riboside effects
Nicotinamide riboside as a form of vitamin B3 and a precursor to NAD+ may prove essential as a supplement that protects against DNA damage and oxidative damage, and therefore, it may also help avert cancer. It may also be useful in improving general health and in lowering the risk of cardiovascular diseases. At present, there are no ample reports on its side effects. Niacin (another form of vitamin B3) has been found to cause mild flushing (i.e. red, warm, itchy or tingling sensation). The flushing though is generally harmless and subsides within an hour or two. Nonetheless, no flushing has been reported with nicotinamide riboside supplementation. More studies, therefore, are vital in order to identify and delineate potentially undesirable effects of nicotinamide riboside.
Future of nicotinamide riboside supplementation
The recent study raised the benefits of nicotinamide riboside supplementation especially among older adults. It also suggested its potential use in modulating hypertension. However, Martens et al. pointed out that their results served as initial insight into the potential benefits. More studies in the form of clinical trials are warranted to establish the efficacy and the safety of long-term supplementation of nicotinamide riboside in humans.
— Written by Maria Victoria Gonzaga
1Trammell, S.A., et al. (2016). Nicotinamide riboside is uniquely and orally bioavailable in mice and humans. Nat. Commun. 7: (12948).
2Zeviani, M. (n.d.). Novel Therapies: Activation Of Biogenesis. Retrieved from [http://www.mrc-mbu.cam.ac.uk/projects/58/novel-therapies-activation-biogenesis].
3Martens, C.R., Denman, B.A., Mazzo, M. R., Armstrong, M. L., Reisdorph, N., Mcqueen, M.B., Chonchol, M., & Seals, D. R. (2018). Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD in healthy middle-aged and older adults. Nature Communications 9(1286 ). DOI: 10.1038/s41467-018-03421-7
As I mentioned in my last blog, the study of aeroallergens depends highly on having data. In order to have data, we need to obtain samples of outdoor air, and analyze them to identify and quantify each type of pollen and fungal spore particle collected. We need to do this on a continuous basis, at set intervals, at multiple locations, for many years, to obtain a data set large enough to be able to study aeroallergen seasonal behaviour. (more…)