Lifting the veil over mysterious desert truffles: Terfezia’s ecology and diversity towards cultivation

Developing below the soil surface, desert truffles are hard to find. Recently, researchers of the University of Évora updated the number of known species of the desert truffle genus Terfezia occurring in Portugal from three to ten species. They thoroughly characterized their ecological preferences, adding new knowledge on Terfezia’s cryptic lifestyle. These findings are of major importance, as desert truffles have a high economic value. The study was published in the open-access journal MycoKeys.

In a caring, symbiotic relationship, mycorrhizal fungi live and feed in the roots of specific plants, while providing water and nutrients to their ‘companion’. In arid and semi-arid environments, mycorrhization processes are essential to the survival of both plants and fungi. Moreover, the fungus’ hyphal network, which spreads within the soil connecting several plant individuals, is of utmost importance to enhancing soil quality and fertility.

Researchers of the University of Évora in Portugal, led by biologist Celeste Santos e Silva, worked on Terfezia fungi, the most diverse and species-rich genus among desert truffles. Their study, published in the open-access journal MycoKeys, might prove particularly valuable to rural populations in the Mediterranean basin, where desert truffles, highly valued in local markets, are an important food source. Increasingly turning into an exquisite component of the Mediterranean diet, Terfezia products can also be very profitable. Furthermore, these fungi are essential for soil conservation, preventing erosion and desertification.

Desert truffles.

After 8 years of exhaustive field exploration in search of desert truffles and many hours in the molecular biology lab, the researchers noted some previously unknown trends in the ecology of Terfezia species. They recorded seven species that were new to Portugal, including two that are new to science – Terfezia lusitanica and Terfezia solaris-libera. This brings the number of Terfezia species known to be growing in the country to ten. Particularly important was the discovery of a broader ecological range for many of the studied species (e.g. Terfezia grisea). Adding valuable information about their possible hosts, symbionts and ecological constraints, these findings help open new opportunities for truffle cultivation.

“It is very difficult to identify all specimens given that the Terfezia species look so much alike, and molecular biology was absolutely fundamental here”, explains the researcher. “The technique was essential to update and solve problems about their taxonomy and the relationship between the species in the genus.”

Furthermore, the discoveries are also expected to positively impact the local communities by stimulating agriculture produce, business and even employment. 

Desert truffle production explained. Video by University of Évora

Knowledge gained in this research about the conditions in which different Terfezia species grow is an important step to desert truffle cultivation: the fungi are hard to find in the wild, which is why it would make a big difference – including financially – for local communities if they figure out a way to grow truffles themselves.

Within the project “Mycorrhization of Cistus spp with Terfezia arenaria (Moris) Trappe and its application in the production of desert truffles” (ALT20-03-0145-FEDER-000006), the researchers took a step forward towards achieving mycorrhizal association of desert truffles with perennial plants (rock roses), which would allow their mass production for various sectors such as food, medicine and soil recovery. This new form of production, assures the MED researcher and leader of the project, “will make it possible to create more jobs, reversing the current trend towards desertification in rural areas, while being a great tool for ecosystem recovery and restoration”.

Research article:


Santos-Silva C, Louro R, Natário B, Nobre T (2021) Lack of knowledge on ecological determinants and cryptic lifestyles hinder our understanding of Terfezia diversity. MycoKeys 84: 1-14. https://doi.org/10.3897/mycokeys.84.71372

New family of fungi threatens a UNESCO-listed 8-century-old cathedral in Portugal

The Old Cathedral of Coimbra [right], the Santa Maria chapel [left, top] and the artwork from which the scientists retrieved the studied fungi [left, bottom]. Photo by Miguel Mesquita.
To be listed as UNESCO World Heritage requires special care and protection of valuable cultural monuments and pieces of Art from threats such as biodeterioration caused by microcolonial black fungi. The culprits lodge their branch-like structures (hyphae) deep into the stone forming fissures and cracks and also produce polysaccharides that trigger corrosion.

These fungi are well known for their unique resistance to hostile environmental conditions, including extreme temperatures, high solar and UV radiation, severe droughts and low abundance of nutrients. As a result, they survive in hot and cold deserts, saltpans, acidic and hydrocarbon-contaminated sites and exposed rocks surfaces. All of this makes them a particular challenge to conservationists and biologists who care for historic monuments.

During a multi-disciplinary scientific survey at the 8-century-old cathedral Sé Velha de Coimbra (Old Cathedral of Coimbra), which is the only Romanesque cathedral in Portugal to have survived relatively intact since the Reconquista times, scientists retrieved a peculiar slow-growing microcolonial black fungus.

What João Trovão of the University of Coimbra (Portugal) and his colleagues were looking at turned out to be a species of a whole new family (Aeminiaceae) in the order of the sooty mould fungi. The new species, its new genus and the novel family are described in the open-access journal MycoKeys.

This is a colony of the newly described black fungus species Aeminium ludgeri. Photo by João Trovão.

To define the new group of fungi, the researchers first scraped off samples from a deteriorated limestone artwork in the “Santa Maria” chapel and then conducted an extensive and integrative analysis, based on morphological, physiological, ecological characters and DNA sequences.

As for the origin of the previously unknown fungus, the scientists hypothesise that the species had ‘arrived’ at the Old Cathedral of Coimbra with the limestone used during its construction. Coming from the unique nearby areas of Ançã and Portunhos, such limestone has been used on several of the “Our Ladies of the O” statues, as well as in the portal of the Royal Hospital in Santiago de Compostela (Spain). Currently, these fungi are considered endemic to the limestone quarries in the Iberian Peninsula.

“Regarding stone monuments exposed to the environment, microcolonial black fungi are considered one of the main culprits for the phenomenon of stone biodeterioration, being responsible for severe aesthetic, biochemical and biophysical alterations,” comment the scientists.

“It is, therefore, crucial to gather deeper knowledge regarding their biodiversity and their biological, ecological and physiological unique characteristics, in order to span our knowledge regarding these fungi and, at the same time, allow the development and improvement of tools to protect stone monuments from their deteriorative effects.”

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Original source:

Trovão J, Tiago I, Soares F, Paiva DS, Mesquita N, Coelho C, Catarino L, Gil F, Portugal A (2019) Description of Aeminiaceae fam. nov., Aeminium gen. nov. and Aeminium ludgeri sp. nov. (Capnodiales), isolated from a biodeteriorated art-piece in the Old Cathedral of Coimbra, Portugal. MycoKeys 45: 57-73. https://doi.org/10.3897/mycokeys.45.31799

The first case of a Portuguese beetle living exclusively in groundwater

New to science, the species was named after Pluto, the ruler of the underworld in Greek mythology

A diving beetle demonstrating various adaptations to the life underground, including depigmentation and evolutionary loss of eyes, was discovered at the bottom of a clay pound in the cave Soprador do Carvalho, Portugal. The species turned out to be the very first in the whole order of beetles (Coleoptera) to be known exclusively from the underground waters of the country.

The Soprador do Carvalho cave (Portugal) is the type locality of the newly described species Iberoporus pluto. Photo by Ignacio Ribera.

Despite not being able to find any other specimens during their study – save for the single female, the team of Dr Ignacio Ribera, Institute of Evolutionary Biology (Spain) and Prof Ana Sofia P. S. Reboleira, University of Copenhagen (Denmark) identified the beetle as new to science, thanks to its unambiguous morphology in combination with molecular data.

Profile view of the newly described species Iberoporus pluto. Photo by Ignacio Ribera.

Aptly named Iberoporus pluto in reference to the ruler of the underworld in Greek mythology Pluto, the species was recently described in the open-access journal ZooKeys.

With a uniformly pale orange body measuring 2.8 mm in length and 1.1 mm in its widest part, the beetle is larger than the rest species known in its genus, and its appendages are longer and more slender. While blindness and depigmentation are clear adaptation to life away from sunlight, the elongated limbs and antennae reflect poor swimming abilities needed in a subterranean habitat. Going for 4 km in horizontal direction, Soprador do Carvalho is the largest in the Dueça cave system, located in the north-eastern part of the Sicó karst area in central Portugal. In recent years, the cave is being explored for tourism.

“The knowledge of the subterranean fauna from Portugal has significantly increased over the last decade, with the description of a high number of obligate subterranean species (tripling their number) and the establishment of new biogeographic patterns,” explain the authors of the study. “A high number of these species are stygobiont (i.e. confined to groundwater), mostly from wells in the north of the country, where evapotranspiration is higher.”

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Original source:

Ribera I, Reboleira ASPS (2019) The first stygobiont species of Coleoptera from Portugal, with a molecular phylogeny of the Siettitia group of genera (Dytiscidae, Hydroporinae, Hydroporini, Siettitiina). ZooKeys 813: 21-38. https://doi.org/10.3897/zookeys.813.29765

New moth in Europe: A southern hemisphere species now resident in Portugal

As travelling in the 21st century is easier than ever, so is for species to make their way to new areas, sometimes increasing their distributional range, or even establishing whole new habitats. On the other hand, when they leave their natural predators and competitors behind, and find abundance of suitable resources somewhere else, they are running the risk of becoming invasive.

Nevertheless, such is not the case of a small, darkish brown moth from the southern hemisphere that is now resident in central Portugal. There, the species do not exhibit invasive behaviour, and so far has been only observed in very low numbers. The discovery is published in the open access journal Nota Lepidopterologica by an international research team, led by Martin Corley, CIBIO-InBIO, Portugal.

In 2012, Jorge Rosete, one of the co-authors of the study, spotted a female specimen that he could not identify near his house. When Martin took a look at it, he placed it in the concealer moth family (Oecophoridae), but was unable to recognise neither its species, nor its genus. It did not took long before a few more specimens were found, including males.

Initially, Martin thought the moth might originate from Australia, given the abundance of eucalyptus plantations in the area where it was found, and the fact that there are more concealer moth species in Australia than on any other continent. However, despite their efforts and contacts with other researchers, they failed to find an Australian species to match the Portuguese specimens. As a result, the mystery remained for the next four years, until a molecular study into moth DNA pulled the curtains.

A fragment of DNA, also called DNA barcode, matched three other genetically identical unnamed specimens, originally collected from South Africa, in the DNA database BOLD. Further collaboration with Alexander Lvovsky, Russian Academy of Sciences, allowed the assignation of the specimens to a species name: Borkhausenia intumescens, known from South Africa. However, it did not end there. Further research into museum collections showed that in fact this species had been previously described from Argentina as Borkhausenia crimnodes, and therefore should be named as such.

The origin of the Portuguese specimens remain a mystery, but it is evident that the species is now established in central Portugal. The larvae of other species in the same genus feed on decomposed plants, so this is likely the case with the moth species as well. It might be that it has entered the country through Figueira da Foz port along with imported timber from South America intended for the paper industry.

It is not known if this is a South African species that had first been transported to South America, and then – to Portugal, or if it is originally South American. It is also possible that it is not native in neither of these areas, and instead originates from another country, where it has not even been discovered yet. The moth favours warm temperate zones and potentially might appear anywhere in the world with suitable climate.

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Original source:

Corley MFV, Ferreira S, Lvovsky AL, Rosete J (2017) Borkhausenia crimnodes Meyrick, 1912 (Lepidoptera, Oecophoridae), a southern hemisphere species resident in Portugal. Nota Lepidopterologica 40(1): 15-24. https://doi.org/10.3897/nl.40.10938.

Species conservation profile of a critically endangered endemic for the Azores spider

Subject to continuing population decline due to a number of factors, an exclusively cave-dwelling (troglobitic) spider endemic to the Azores is considered as Critically Endangered according to the IUCN Red List criteria.

To provide a fast output, potentially benefiting the arachnid’s survival, scientists from the IUCN – Spider and Scorpion Specialist Group and the Azorean Biodiversity Group (cE3c) at University of Azores, where the main objective is to perform research that addresses societal challenges in ecology, evolution and the environment, also known as the three E’s from the centre’s name abbreviation, teamed up with colleagues from University of Barcelona, Spain, and the Finnish Museum of Natural History.

Together, they make use of a specialised novel publication type feature, called Species Conservation Profile, created by the open access journal Biodiversity Data Journal, to provide scholarly credit and citation for the IUCN Red List species page, as well as pinpoint the population trends and the reasons behind them.

The studied spider species (scientifically called Turinyphia cavernicola) is a pale creature with long legs, large eyes and a total size of merely 2 mm in length. These spiders never leave their underground habitats, which are strictly humid lava tubes and volcanic pits. There they build sheet webs in small holes and crevices on the walls of the caves.

The volcanic pit Algar do Carvão (Terceira, Azores), the main location of the species Turyniphia cavernicola.Not only is the species restricted to a single island within the Azorean archipelago (Portugal), but it is only found in three caves. Furthermore, out of the three, only one of them is home to a sustainable large population. These caves are under severe threat due to pasture intensification, road construction and tourist activities.

Although there is not much information about the species distribution through the years, with the spider having been discovered as recently as in 2008, the authors make the assumption that originally there have been significantly greater populations. Not only have they studied thoroughly another fifteen caves located on the island without finding any individuals, but they have identified increasing anthropogenic impact on the habitat.

“The species original distribution was potentially very large compared with the current,” the scientists explain. “Relatively intensive searches in and around the current caves where the species occurs have failed to find additional subpopulations.”

“The trend of decline is based on the assumption that this species can occur in all these caves and that the absence is due to anthropogenic disturbance on caves during the last 50 years,” they note.

 

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Original source:

Borges P, Crespo L, Cardoso P (2016) Species conservation profile of the cave spiderTurinyphia cavernicola (Araneae, Linyphiidae) from Terceira Island, Azores, Portugal.Biodiversity Data Journal 4: e10274. doi: 10.3897/BDJ.4.e10274