Lemon shark caught preying on invasive freshwater fish in Fernando de Noronha, Brazil

Unprecedented footage of jaguar cichlid being preyed upon was captured after heavy rains caused the overflow of freshwater into Sueste Bay, the species’ feeding ground.

Fundação de Amparo à Pesquisa do Estado de São Paulo

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Disoriented by the salinity of the water, jaguar cichlids try to escape from a lemon shark in Fernando de Noronha 

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Credit: Mariano Correa

Researchers supported by FAPESP recorded lemon sharks (Negaprion brevirostris) preying on an invasive species, the jaguar cichlid (Parachromis managuensis), for the first time. This observation was made in Sueste Bay in March 2024. Sueste Bay is a well-known shark feeding ground in the Brazilian archipelago of Fernando de Noronha.  

The study was published in the journal Environmental Biology of Fishes. 

The event was considered unlikely because Sueste Bay is a sea inlet with saltwater, while the jaguar cichlid is a freshwater species. However, the bay receives freshwater inflows from a nearby mangrove swamp after heavy rains.

Introduced to Fernando de Noronha probably for producing animal protein, the jaguar cichlid can tolerate a certain degree of salinity but becomes stressed above a certain level. The researchers observed erratic swimming patterns in the fish, making them easier targets for sharks.

In addition to having difficulty swimming, studies by other groups have shown that salinities above 25 practical salinity units (psu) cause an increase in heart rate in jaguar cichlids. In Sueste Bay, salinity can reach 32 psu.

“This is a breeding, nursery, and feeding area for lemon sharks. The night before our observation, there were heavy rains, causing the Xaréu reservoir, where the fish live, to overflow into the mangrove swamp, which in turn also overflowed and created a connection with the bay,” says Bianca Rangel, the first author of the study. Rangel is conducting postdoctoral research at the University of São Paulo’s Institute of Biosciences (IB-USP) with a scholarship from FAPESP.   

Sueste Bay, with its shallow, warm, and murky waters, is also a feeding ground for tiger sharks (Galeocerdo cuvier). Swimming and diving were banned in 2022 after accidents involving tourists.  

The researchers made the observations using drones during shark monitoring. The animals are captured, measured, weighed, tagged with microchips, and have blood samples collected before being returned to the environment.  

Lemon shark pups remain in the bay for up to a year after birth, at depths ranging from one to six meters, before migrating to the open sea. This protects them from adult sharks, which may cannibalize them. Both pups and probable adults were observed eating jaguar cichlids. 

The researchers believe that sharks alone are unlikely to eliminate the invasive species but can help reduce its population by preying on individuals that arrive in Sueste Bay. 

Although there are no studies on the impact of the jaguar cichlid on the archipelago’s biodiversity, it is believed that it may harm local species through competition or predation, as occurs in other aquatic systems when invaders are present (read more at agencia.fapesp.br/51646). 

The research is part of the project “Impact of Anthropogenic Changes on Fauna: Contributions from Conservation Physiology”, which is supported by FAPESP and coordinated by Fernando Ribeiro Gomes, a professor at IB-USP.

Opportunism

The authors believe that the sharks’ behavior is opportunistic because freshwater species are not part of their diet. However, it is unclear whether jaguar cichlids consistently enter Sueste Bay after heavy rains or if this was a one-time occurrence.

“This year there was another overflow, but no one observed this interaction. We don’t know if there were fewer jaguar cichlids or if they simply disappeared. Since there’s no monitoring in the mangrove swamp and the reservoir, we have no way of knowing if the animal is still present,” Rangel reports.

“If freshwater fish entering the bay becomes commonplace, it’s possible that sharks will learn that after the rains, food will be available,” she adds.

There are records of sharks feeding on invasive species, such as lionfish (Pterois spp.). However, there are no records of jaguar cichlid predation, nor has the hunting process been observed, as Rangel and her collaborators did. Continuous monitoring will verify whether this interaction continues and the role that sharks may play in controlling the invaders.

About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

Originally from Central America, jaguar chichlids were introduced to Brazil, including Fernando de Noronha, probably for their meat 

Credit

Bianca Rangel/IB-USP

Journal

Environmental Biology of Fishes

DOI

10.1007/s10641-025-01745-0 

Article Title

Unexpected prey: lemon sharks (Negaprion brevirostris) observed preying on an alien invasive freshwater fish in a remote no-take marine reserve in the Equatorial Atlantic

Article Publication Date

4-Sep-2025

 

Does mental illness have a silver lining? New paper says yes

Research shows certain psychological disorders are associated with greater empathy, creativity, resilience and more

R. D. LAING WOULD AGREE

University of Colorado at Boulder

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An estimated one in five U.S. adults live with mental illnesses, conditions that are almost universally characterized by their negative consequences. But there are also positive attributes associated with psychological disorders— and acknowledging them can reduce stigma, improve care and provide hope to patients and their families.

That’s the case made in a new paper titled Silver Linings in Psychological Disorders: An Agenda for Research and Social Change. 

In it, University of Colorado Boulder psychology professor June Gruber and co-authors at Cornell University point to dozens of studies dating back decades, which associate mental illness with heightened creativity, empathy, resilience and other positive qualities. 

“The prevailing narrative in clinical psychology focuses on mental health from a disease model perspective—we are taught to diagnose what’s wrong and try to fix it,” said Gruber, director of the Positive Emotion and Psychopathology Lab at CU Boulder. “This leaves out the fact that at the same time people struggle with mental health challenges, they may also grow, thrive and even develop unique strengths.” 

Published in Current Directions in Psychological Science, the paper highlights evidence showing that people with mild schizophrenia, hypomania and bipolar disorder tend to score higher on measures of creativity and gravitate toward more creative professions. 

“Some of the most creative minds in our society have also been the minds of people who had mental illness,” said Gruber.

People with a history of depression also tend to show more willingness to cooperate, research from Gruber's lab and others has shown. 

One CU Boulder study of nearly 2,000 college students found that although those on the bipolar spectrum report greater social conflict, they also report significantly larger social networks and feel greater social support. Another study from Gruber’s lab found that while young adults at increased risk for mania tend to perceive even negative situations in an overly positive light, they are also better at detecting emotional shifts in others.

“Together, our findings show that along with well-documented social challenges that come with mood disorders, there may also be meaningful social strengths,” said Gruber.

In the silver linings paper, the authors note that many people in remission from mental illness look back on their darkest struggles as catalysts that helped them build resilience and self-awareness.

Take one 2019 study, led by Cornell Psychology Professor Jonathan Rottenberg, a co-author on the ‘silver linings’ paper. It found that 10 years after being diagnosed with clinical depression, 10% of study participants were “thriving” (meaning they were not only free of depression but had a psychological well-being better than one-quarter of nondepressed adults). 

Gruber and Rottenberg said they do not intend to convey a “Pollyanna,” or “all-will-be-well” approach that glosses over the real suffering that comes with mental illness. But they do want to provide hope, rooted in data, that positive outcomes can occur.

They also stress that the paper is not a call to abandon medication or psychotherapy, which can be lifesaving. Rather, it is a call for a more holistic approach to research and care.

By acknowledging silver linings, Gruber believes her field can reduce stigma and potentially develop treatment plans that seek to preserve the unique traits people like about themselves while keeping the harmful elements of their illness at bay.

“If you have a more holistic understanding of a person, you can do more to support them,” she said. 

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Journal

Current Directions in Psychological Science

DOI

10.1177/09637214251360738 

Method of Research

Literature review

Subject of Research

People

Article Title

Silver Linings in Psychological Disorders: An Agenda for Research and Social Change


LA REVUE GAUCHE - Left Comment: Search results for ANTI-PSYCHIATRY

When schizophrenia meets a personality disorder: why more research is urgently needed

University of Montreal

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A new study by a research team at Université de Montréal highlights a critical lack of knowledge about the cognitive profiles of people living with both schizophrenia and a personality disorder.  

A comprehensive review of scientific literature from the past 24 years, published in Schizophrenia Research: Cognition, reveals that despite the high prevalence of this dual diagnosis (affecting approximately 40 per cent of people diagnosed with schizophrenia) and its association with unfavourable outcomes, the available data are surprisingly limited and fragmented. 

“Our analysis shows a significant blind spot in current knowledge,” said Anouck Chalut, lead author of the study and a Psy. D. in neuropsychology from UdeM. “Little is known about cognition in people living with a personality disorder in addition to schizophrenia.”  

Led by UdeM psychology professor Tania Lecomte—director of L'ESPOIR, a research laboratory in the Department of Psychology dedicated to improving treatments and services for people with severe mental disorders—the researchers combed through hundreds of scientific articles but found only 10 that met their criteria for scientific rigour. 

“We found that the existing research is limited, fragmentary and sometimes contradictory, leaving clinicians with few clear guidelines,” noted Chalut. This gap is consequential because cognition is the strongest predictor of recovery for individuals living with schizophrenia, she said. 

Significant health challenges 

The combination of schizophrenia and a personality disorder presents considerable challenges, including more severe psychotic symptoms, serious functional impairment, reduced compliance with medication, more frequent hospitalization and increased risk of suicide. 

Despite these challenges, people with this dual diagnosis are often excluded from clinical studies or grouped together with patients who have only schizophrenia. 

“Our findings underscore the need to improve our understanding of these individuals and focus on their cognitive profiles to support functional recovery, given that cognition plays a decisive role in that process,” said Chalut. 

The study offers concrete recommendations for both clinicians and researchers, including systematic screening for symptoms of personality disorders in people living with schizophrenia and the use of standardized tools to characterize cognitive profiles in this population. 

The research highlights the need for further investigation into adapting treatments and therapies to the specific needs of these individuals, who are often overlooked in current research, the study team argues. 

Approaches such as cognitive remediation – which aims to mitigate the effects of cognitive deficits and support strategies to strengthen impaired mental abilities, including memory, attention and problem-solving – could prove useful, the researchers believe. 

About this study 

“Cognitive deficits in individuals with comorbid personality disorder and schizophrenia: a scoping review,” by Anouck Chalut et al., was published in the March 2026 issue of Schizophrenia Research: Cognition. 

 

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Journal

Schizophrenia Research

DOI

10.1016/j.scog.2025.100403 

Method of Research

Meta-analysis

Subject of Research

People

Article Title

Cognitive deficits in individuals with comorbid personality disorder and schizophrenia: A scoping review

 

Garden ponds as potential sources of plant invasions

Hun-Ren Ökológiai Kutatóközpont

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Researchers at the Institute of Aquatic Ecology, HUN-REN Centre for Ecological Research in Hungary, launched a citizen science project to uncover the hidden diversity of garden ponds — the MyPond project. Within this initiative, citizens provided information about the presence of invasive plants in their ponds. Out of 560 ponds surveyed, almost half contained at least one of the six targeted invasive plant species. Water hyacinth (Eichhornia crassipes), considered the world’s worst invasive aquatic plant due to its environmental and economic impacts, was frequently reported. Water lettuce (Pistia stratiotes) and submerged species such as Elodea spp., Vallisneria spp., and Myriophyllum aquaticum were also common.

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Credit: Photo: Barbara Barta

As small aquatic habitats disappear at an alarming rate, private garden ponds may help compensate for the loss of natural habitats and support biodiversity in urban areas. However, as these ponds become increasingly popular, the spread of invasive species is emerging as a pressing issue.

Ponds, small (<5 ha) standing waterbodies, are among the most common freshwater habitats worldwide, but they are vanishing rapidly due to agricultural activities, urbanisation, climate change, and other human impacts. At the same time, we are creating new, secondary habitats in the form of garden ponds. These artificial ponds provide a range of ecosystem services, offering refuge for aquatic biodiversity, including protected amphibians, and supporting terrestrial species, especially during dry periods. In some regions, the number of garden ponds even exceeds that of natural waterbodies.

Yet the growing number of garden ponds may pose a new challenge for biodiversity. A wide variety of aquatic plants and animals are available through the ornamental trade, increasing the risk of invasive species introductions. Because these ponds are located on private property, researching and monitoring the species they contain, whether native or invasive, can be difficult. Citizen science, which involves the public in data collection, offers an effective way for researchers to gain access to these otherwise hidden habitats and to document their plant and animal communities.

Researchers at the Institute of Aquatic Ecology, HUN-REN Centre for Ecological Research in Hungary, launched a citizen science project to uncover the hidden diversity of garden ponds — the MyPond project. Within this initiative, citizens provided information about the presence of invasive plants in their ponds. Out of 560 ponds surveyed, almost half contained at least one of the six targeted invasive plant species. Water hyacinth (Eichhornia crassipes), considered the world’s worst invasive aquatic plant due to its environmental and economic impacts, was frequently reported. Water lettuce (Pistia stratiotes) and submerged species such as Elodea spp., Vallisneria spp., and Myriophyllum aquaticum were also common.

Some of these species originate from tropical regions, yet they have already established populations in several European countries. In Hungary, current climatic conditions may still limit their spread, but they can survive in thermal waters, and with climate change, the environment may become increasingly suitable for them. So far, it appears that these plants have primarily spread to natural waterbodies through human activity. However, garden ponds often attract waterbirds, which may also disperse seeds or plant fragments beyond garden boundaries.

“Most of these plants are on the EU’s list of invasive species, meaning it is illegal to keep them. Yet participants willingly reported having them,” said Barbara Barta. “Therefore, the main issue seems to be that the general public is not well informed about the threat posed by invasive species. Many people simply don’t realise that the plants they purchase are banned, and that keeping, growing, or exchanging them is an offence.”

The researchers emphasise the importance of environmental education and of engaging both buyers and sellers of aquatic plants used in garden ponds. “We need to take an active role in helping citizens make better choices for managing their ponds,” they said. “Providing a list of alternative, native plant species would be a good place to start.”

 

 

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Journal

Freshwater Biology

DOI

10.1111/fwb.70145 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Garden Ponds: Hidden Sources for Plant Invasions?

Article Publication Date

3-Dec-2025