The first drywood termite known to use snapping stick-like mandibles to defend its colony

Tasked to defend the colony from attackers, the specialised soldier caste in some termite species has evolved various impressive mechanisms, including plug-like heads – meant to block intruding ants trying to invade their lairs, and mouthparts designed to bite and pierce.

Still, there are even more spectacular soldiers, such as a recently discovered drywood termite species, whose unique long and slender, stick-like snapping mandibles produce one of the highest acceleration speeds measured in a living organism. Rather than bite, these peculiar ‘jaws’ deliver powerful strikes at enemies bold enough to stand in the way of the soldier termite and its colony.

The scientists describe the new termite’s specialty in detail:

“Roisinitermes employs a unique strategy of snapping, achieved by long and slender mandibles pressed against each other in a defensive encounter. When this potential energy is released, the left mandible springs over the right and the resultant snap is forced onto the opponent if it is in the path of the strike.”

Discovered in Cameroon, this striking species is the first drywood termite found to rely on snapping mandibles as a defense strategy. Given that until now there had been a single subfamily (Termitinae) known to have developed such, the very existence of the new insect poses a whole new set of questions before scientists. Have snapping mandibles evolved independently in two evolutionary lineages? Or, is it that these groups share a distant kin relationship which has gone unnoticed for that long?

The new drywood termite, which is also assigned to a new genus, is named Roisinitermes ebogoensis, and is described in the open access journal ZooKeys by an international team of researchers, led by Dr Rudolf Scheffrahn of the Institute for Food and Agricultural Sciences at University of Florida, Davie, USA. Although this particular species is not thought to be a pest, some drywood termites cause serious damage to wooden structures around the world.

Both colonies studied by the scientists were found near the Ebogo II village, which also stands behind the name of the species. The first unusual colony to draw the attention of the scientists was collected from a forest on an island in the Nyong River, where it lived in a thin (3 cm) and long (over 3 m) broad-leaf tree branch suspended from a canopy. The second one – in a 15-mm thick dead liana branch hanging from a tree in a nearly pristine rainforest.

The team expects that future research will shed more light on the origins and evolution of the newly discovered termite.

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Original source:

Scheffrahn RH, Bourguignon T, Akama PD, Sillam-Dussès D, Šobotník J (2018) Roisinitermes ebogoensis gen. & sp. n., an outstanding drywood termite with snapping soldiers from Cameroon (Isoptera, Kalotermitidae). ZooKeys 787: 91-105. https://doi.org/10.3897/zookeys.787.28195

Twenty-five frogs added to the amphibian fauna of Mount Oku, Cameroon

 

While amphibians all over the world are undergoing a continuous decline, their status in certain regions, such as Central Africa, remains unknown due to incomplete information. New paper, published by two scientists in the open access journal ZooKeys, addresses the knowledge gap by providing an updated list of already 50 amphibian species living on Mount Oku, Cameroon.

Scientists Dr Thomas M. Doherty-Bone, Royal Zoological Society of Scotland, and Dr Václav Gvoždík, affiliated with both the Czech Academy of Sciences and the National Museum in Prague, have spent more than 10 years studying the Cameroonian mountain. As a result of their thorough surveys, literature review, and re-examination of museum specimens, there are now 50 species known from the locality, which doubles previous numbers. In their newly published checklist the researchers have listed 49 species of frogs and toads, as well as one caecilian species – a limbless, snake-like amphibian.

However, the number of threatened species seems to increase quite proportionally. Many of the newly recorded frogs, for instance, appear to be extremely endangered, yet they have not been assessed by the International Union for Conservation of Nature (IUCN). Therefore, the authors have used the IUCN criteria to propose conservation assessments for them. If the suggested statuses are approved, together with the updated declines of previously abundant in the area species, the proportion of the threatened would rise to nearly half (48%) of the Mount Oku’s entire amphibian fauna. Meanwhile, it is 42% of amphibians at risk of extinction globally.

In their study, the scientists also review the research and conservation undertaken at the mountain so far, including the work they have initiated themselves. Although Mount Oku’s forest turned out to be the best managed among the rest in the region, threats such as forest loss, encroachment and degradation are still largely present and increasing. Additional threats, including use of agrochemicals, climate change and diseases, have also been identified. However, conservation actions for the amphibians of Mount Oku are on the rise, considering both the population and the ecosystem-level perspectives.

“Our paper provides a foundation for continuously improving amphibian conservation at Mount Oku, as well as other mountains in Cameroon,” conclude the authors.   

 

Original source:

Doherty-Bone TM, Gvoždík V (2017) The Amphibians of Mount Oku, Cameroon: an updated species inventory and conservation review. ZooKeys 643: 19-139. https://doi.org/10.3897/zookeys.643.9422