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Crayfish on antidepressants act weirdly

When crayfish are on antidepressants they become bolder and more outgoing – although that may not be a good thing, according to a new study.

Okay, so the crayfish weren’t actually on antidepressants, but they were exposed to them to mimic what could happen when their water gets contaminated.

Crayfish in Lindsey Reisinger’s lab at the University of Florida. Credit: Brianne Lehan/University of Florida

“Low levels of antidepressants are found in many water bodies,” said A.J. Reisinger of the University of Florida, lead author of the study, which was published in Freshwater Ecology, “Because they live in the water, animals like crayfish are regularly exposed to trace amounts of these drugs. We wanted to know how that might be affecting them.”

Crayfish eat algae and dead plants from the bottom of ponds, and the antidepressant boldness make them spend more time out getting food.

“Crayfish exposed to the antidepressant came out into the open, emerging from their shelter, more quickly than crayfish not exposed to the antidepressant. This change in behaviour could put them at greater risk of being eaten by a predator,” said Lindsey Reisinger, a co-author of the study.

Childfree by choice and still happy

Around a quarter of adults choose to be childfree and are perfectly happy about it, according to a recent study by University of Michigan researchers, published in PLOS ONE.

“Most studies haven’t asked the questions necessary to distinguish ‘child-free’ individuals – those who choose not to have children – from other types of non-parents,” says Jennifer Watling Neal, a co-author of the paper.

“Non-parents can also include the ‘not-yet-parents’ who are planning to have kids, and ‘childless’ people who couldn’t have kids due to infertility or circumstance. Previous studies simply lumped all non-parents into a single category.”

The researchers separated these groups to compare life satisfaction.

“After controlling for demographic characteristics, we found no differences in life satisfaction and limited differences in personality traits between child-free individuals and parents, not-yet-parents, or childless individuals,” says co-author Zachary Neal.

“We also found that child-free individuals were more liberal than parents, and that people who aren’t child-free felt substantially less warm toward child-free individuals.”

Interestingly, there were many more childfree people than originally thought.

“We were most surprised by how many child-free people there are,” says Watling Neal. “We found that more than one in four people in Michigan identified as child-free, which is much higher than the estimated prevalence rate in previous studies that relied on fertility to identify child-free individuals.

“These previous studies placed the rate at only 2% to 9%. We think our improved measurement may have been able to better capture individuals who identify as child-free.”

Really really old Coelacanths

The coelacanth, once thought to be extinct, and now hailed as a living fossil, might be able to live up to a century, suggests a new study, published in Current Biology. Previously, they were thought to live only to 20.

“Our most important finding is that the coelacanth’s age was underestimated by a factor of five,” says Kélig Mahé of IFREMER Channel and North Sea Fisheries Research Unit in Boulogne-sur-mer, France.

“Our new age estimation allowed us to re-appraise the coelacanth’s body growth, which happens to be one of the slowest among marine fish of similar size, as well as other life-history traits, showing that the coelacanth’s life history is actually one of the slowest of all fish.”

Ther researchers found the two-metre-long fish may reach sexual maturity at 55 years and be pregnant for up to five years!

“Long-lived species characterised by slow life history and relatively low fecundity are known to be extremely vulnerable to perturbations of a natural or anthropic nature due to their very low replacement rate,” Mahé says.

“Our results thus suggest that it may be even more threatened than expected due to its peculiar life history. Consequently, these new pieces of information on coelacanths’ biology and life history are essential to the conservation and management of this species.”

Could AI help prevent relapse of mental illness?

New AI software developed at Flinders University shows promise for getting timely support for people with severe mental illness, before a relapse.

The AI² software recognised that 10% of patients were at increased risk of not adhering to treatment plans, such as not taking a medication or not participating with health services. The AI notified support clinicians who could intervene.

“AI² delivers important data in real time, providing clinicians with an effective digital alternative to monitoring patients,” says Niranjan Bidargaddi, who led the project.

“The two clinician monitors spend about two hours per week monitoring the dashboard, reviewing case notes and speaking with case managers,” he says.

“Feedback from the clinicians at this stage suggests they actually saved time on routine calls, as they would only contact the GP when necessary – such as if the software had detected a missed prescription refill.”

The report was published in The Australian and New Zealand Journal of Psychiatry.

New defence against superbugs

Another Flinders study, published in mBio, has confirmed a link between the role of fish oil to stop ‘superbugs’ from becoming resistant to antibodies.

The study found that the antimicrobial powers of fish oil fatty acids could be a safe and simple dietary supplement to help fight infections against so big bad bugs.

“We know Acinetobacter baumannii is one of the world’s most notorious multidrug resistant pathogens, yet how it responds to host-mediated stress is poorly understood,” says co-author Felise Adams, from Flinders University.

“With the rise of superbugs, we have now been able to show this greedy bacterium cannot distinguish between ‘good and bad’ host fatty acids and will consume all of these during an infection,” she adds.

“Our research showed that fish oil fatty acids become part of the bacteria membrane and thus make the invading bacteria membrane more permeable and susceptible to the antibiotics being used to attack it.”