The ship-timber beetle's fungal partner: more than just a food source

How a symbiotic fungus helps a beetle survive in dead wood

Max Planck Institute for Chemical Ecology

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Maximilian Lehenberger with a culture of the ambrosia fungus Alloascoidea hylecoeti on an artificial medium.

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Credit: Angela Overmeyer, Max Planck Institute for Chemical Ecology

The ship-timber beetle (Elateroides dermestoides) is a species of ambrosia beetle. Unlike many of its relatives, which are social insects that live in colonies, it is solitary and does not live with other members of its species. While ambrosia beetles usually have generation times of less than a year, the next generation of ship-timber beetles does not hatch for up to two years. It is also one of the largest European ambrosia beetles, reaching lengths of up to 18 millimetres. Despite its solitary lifestyle, the ship-timber beetle does not live alone; it lives in a symbiotic relationship with the ambrosia fungus Alloascoidea hylecoeti, which provides it with nutrients.

First evidence of nutrient symbiosis with the ambrosia fungus

A team led by Maximilian Lehenberger from the Max Planck Institute for Chemical Ecology in Jena investigated this beetle-fungus symbiosis in more detail. To achieve this, the researchers first analyzed the nutrients accumulated by the fungus in its mycelium — the network of thread-like structures that make up its vegetative body. 'Until now, it was only assumed that ambrosia fungi were nutrient-rich. However, there was hardly any useful data to support this. In our study, we were able to demonstrate for the first time that Alloascoidea hylecoeti, in particular, is extremely nutrient-rich. This fungus accumulates many nutrients — significantly more than other fungi, both symbiotic and non-symbiotic — including sugars, amino acids, ergosterol, fatty acids, and the essential elements phosphorus and nitrogen,' says Maximilian Lehenberger, head of the Forest Pathogen Chemical Ecology (FoPaC) project group in the Department of Biochemistry. This probably also explains why the ship-timber beetle can live in nutrient-poor wood for so long and grow so large.

Surviving in a highly competitive environment

The larvae of the ship-timber beetle spend a relatively long time living in the wood of recently deceased trees. This environment is challenging for the offspring of the beetles, which can grow up to two centimeters long, because dead wood is very poor in nutrients and teeming with competition. In social ambrosia beetle systems, individuals can support each other by keeping harmful fungi at bay. This is not the case with solitary beetles. The research team therefore hypothesized that the symbiotic fungus has developed its own strategies to protect itself from competing species. They found that the fungal symbiont Alloascoidea hylecoeti uses various phenolic substances obtained from the surrounding wood. The fungus accumulates these substances to such an extent in its environment that it inhibits the growth of many other fungi. It uses its ability to grow into wood to access further resources. “Unlike many other fungi, the symbiotic fungus is neither broken down nor inhibited by plant defense compounds. Furthermore, it produces many substances that inhibit other fungi,” explains Maximilian Lehenberger.

A fungus that lowers the pH and grows even better in overly acidic environments

The scientists were particularly surprised by the production of acetic acid, which they detected in fungal cultures and samples from beetle nests using nuclear magnetic resonance (NMR) analysis. Experiments with fungal cultures revealed that the ambrosia fungus outcompetes other fungi by 'acidifying' its environment and lowering the pH to as low as 3.5. Remarkably, Alloascoidea hylecoeti not only copes with a very high concentration of acetic acid, but actually thrives at a pH level that is extremely low for fungi. "To date, acetic acid has not been detected in any other ambrosia beetle system. Since we were also able to identify acetic acid in the nests, this is clear evidence that it must play a role in nature too. The fungus utilizes not only acetic acid, but also a variety of other substances to inhibit competing fungi. These include monoterpenes such as linalool, terpineol and citronellol,' says Jonathan Gershenzon, Head of the Department of Biochemistry. Citronellol is responsible for the lemon-like smell of this fungus.

The impact of a highly acidic habitat on the larvae of the ship-timber beetle is unclear, as is the effect of the defensive substances that accumulate in the fungal biomass of their food source.  Could this make them less attractive to predators? Could symbiotic bacteria in the beetles' guts help break down high concentrations of phenolic compounds? The research team plans to address these questions and others in future experiments.

Maximilian Lehenberger and Jonathan Gershenzon performing mass spectrometric analysis of substances.

Credit

Angela Overmeyer, Max Planck Institute for Chemical Ecology

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Journal

The ISME Journal

DOI

10.1093/ismejo/wraf258 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Fungal symbiont of an ambrosia beetle possesses high nutrient content and suppresses competing fungi with antimicrobial compounds

 

Case reporting practices in forensic anthropology are largely not standardized

Boston University School of Medicine

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(Boston)—Forensic anthropological (the study of skeletonized remains in medico-legal settings) analyses and reports include diverse information that may help in establishing identifications, cause or manner of death determinations, taphonomic (post-death decay, destruction, or burial)  alterations, or other circumstances involving decedents. However, within forensic anthropology in the U.S., there remains no unifying standardization for analyzing cases or writing reports that can be used independent of work environment, education or case circumstance, which may compromise forensic anthropological expertise in courtroom testimony.  

 

A new study from researchers at Boston University Chobanian & Avedisian School of Medicine has found that while some areas of forensic anthropology appear to have tacit agreement on standardized methods and citations, there are many areas where forensic anthropologists are divided and lack standardization. The researchers believe these areas of division and disagreement-for example, thoughts on the objectivity of practitioners and education and training requirements, demonstrate the need for a robust and enforceable standardization that applies to all forensic anthropologists.

 

“Now having evidence of dramatic opposing viewpoints (nearly fifty-fifty splits in some questions) further pushes for an open discussion on this topic and the beginning of change. Further, because many forensic anthropologists are sole practitioners (32.4%) and consult on forensic anthropology cases without access to standard operating procedures or peer review, universal standards are important,” explains corresponding author Sean Tallman, PhD, associate professor of anatomy & neurobiology.

 

In order to explore whether a lack of standardization is problematic, the researchers conducted a survey to explore reporting practices, followed standards and personal experiences regarding overall practices that lead to case reports. The survey was distributed to individuals in an email list associated with professional forensic anthropologists and the social media platform X, targeting forensic anthropologists who have experience creating case reports.
 

Most of the survey respondents (71.3%) agreed that standardization is important; however, respondents expressed concerns that the diverse areas of employment for forensic anthropologists (academia, humanitarian settings, government labs and medical examiner/coroner offices) may prevent universal standards. Presently, the “best practice” standards for forensic anthropology lack specificity regarding which methods to use or whether peer review should be conducted and how.

According to the researchers, the findings also suggest suggests that the overall lack of standardization in forensic anthropological practice may originate from the varied educational pathways to become a forensic anthropologist, as there are no specific training requirements that are universally accepted and overseen by governing or credentialing bodies. “Education and training are arguably two of the least standardized aspects of this field. While it is not expected that every person has the same qualifications, as different experiences are available to different individuals, there is an overall lack of minimum expectations beyond osteology training. This results in forensic anthropologists working today being faced with types of analyses they have not previously experienced, such as postmortem interval estimation and comparison of antemortem and postmortem x-rays for positive identification” adds Tallman.

 

These findings appear online in the journal Forensic Sciences.

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Journal

Forensic Sciences

DOI

10.3390/forensicsci5040071 

Method of Research

Survey

Subject of Research

People

Article Title

The Need for Standardization of Forensic Anthropological Case Reporting Practices in the United States

Article Publication Date

1-Dec-2025

 

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