Category: African Invertebrates

New tarantula species from Angola distinct with a one-of-a-kind ‘horn’ on its back

A new to science species of tarantula with a peculiar horn-like protuberance sticking out of its back was recently identified from Angola, a largely underexplored country located at the intersection of several Afrotropical ecoregions.

Collected as part of the National Geographic Okavango Wilderness Project, which aims to uncover the undersampled biodiversity in the entire Okavango catchment of Angola, Namibia and Botswana, thereby paving the way for sustainable conservation in the area, the new arachnid is described in a paper published in the open-access journal African Invertebrates by the team of Drs John Midgley and Ian Engelbrecht.

Although the new spider (Ceratogyrus attonitifer sp.n.) belongs to a group known as horned baboon spiders, the peculiar protuberance is not present in all of these species. Moreover, in the other species – where it is – the structure is completely sclerotised, whereas the Angolan specimens demonstrate a soft and characteristically longer ‘horn’. The function of the curious structure remains unknown.

The new tarantula’s extraordinary morphology has also prompted its species name: C. attonitifer, which is derived from the Latin root attonit– (“astonishment” or “fascination”), and the suffix –fer (“bearer of” or “carrier”). It refers to the astonishment of the authors upon the discovery of the remarkable species.

“No other spider in the world possesses a similar foveal protuberance,” comment the authors of the paper.

*Individual of the newly described species in defensive posture in its natural habitat. Photo by Kostadine Luchansky.*

During a series of surveys between 2015 and 2016, the researchers collected several female specimens from the miombo forests of central Angola. To find them, the team would normally spend the day locating burrows, often hidden among grass tufts, but sometimes found in open sand, and excavate specimens during the night. Interestingly, whenever the researchers placed an object in the burrow, the spiders were quick and eager to attack it.

The indigenous people in the region provided additional information about the biology and lifestyle of the baboon spider. While undescribed and unknown to the experts until very recently, the arachnid has long been going by the name “chandachuly” among the local tribes. Thanks to their reports, information about the animal’s behaviour could also be noted. The tarantula tends to prey on insects and the females can be seen enlarging already existing burrows rather than digging their own. Also, the venom of the newly described species is said to not be dangerous to humans, even though there have been some fatalities caused by infected bites gone untreated due to poor medical access.

In conclusion, the researchers note that the discovery of the novel baboon spider from Angola does not only extend substantially the known distributional range of the genus, but can also serve as further evidence of the hugely unreported endemic fauna of the country:

“The general paucity of biodiversity data for Angola is clearly illustrated by this example with theraphosid spiders, highlighting the importance of collecting specimens in biodiversity frontiers.”

Apart from the described species, the survey produced specimens of two other potentially new to science species and range expansions for other genera. However, the available material is so far insufficient to formally diagnose and describe them.

*The newly described baboon spider species (Ceratogyrus attonitifer), showing the peculiar soft and elongated horn-like protuberance sticking out of its back. Photo by Dr Ian Enelbrecht.*

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Original source:

Midgley JM, Engelbrecht I (2019) New collection records for Theraphosidae (Araneae, Mygalomorphae) in Angola, with the description of a remarkable new species of Ceratogyrus. African Invertebrates 60(1): 1-13. https://doi.org/10.3897/afrinvertebr.60.32141

Conservation and nameless earthworms: Assessors in the dark?

Species that live exclusively in a single region are at a particular risk of extinction. However, for them to be protected, thorough assessments of the environmental impacts need to be performed.

There are more than 100 earthworm species living in the soil and dead wood of KwaZulu-Natal Province, South Africa. Most of them live exclusively in small regions in the province, which makes them extremely vulnerable.

To scientists Dr Adrian J. Armstrong, Ezemvelo KZN Wildlife, and Ms Thembeka Nxele, KwaZulu-Natal Museum, the problem is twofold. Firstly, they note that the expression “out of sight, out of mind” is very suitable for the case of the endemic earthworms in South Africa. Secondly, they point out that the lack of common names for these species is a stumbling block that hinders their inclusion in conservation assessments.

As a result, the researchers try to rectify this situation by assigning standardised English names to the endemic earthworms in KwaZulu-Natal. Their article is published in the open access journal African Invertebrates.

Scientific names are often intractable to non-specialists, and the lack of common names leaves environmental assessors in the dark when they need to figure out which earthworms may occur at a development site. In the meantime, it has been found that about 50% of the native vegetation in KwaZulu-Natal has already been removed as a result of infrastructure construction and the figure is rising.

“The indigenous earthworms generally don’t survive in developed areas,” say the authors.

For instance, the informal use of an English name (green giant wrinkled earthworm) for the species Microchaetus papillatus, has facilitated the inclusion of this species in environmental impact assessments in KwaZulu-Natal.

While the green giant wrinkled earthworm does occur in a relatively large and rapidly developing area in KwaZulu-Natal, other species live in smaller areas that have been urbanised even more.

The extinction of these earthworms is not only undesirable from the point of view of biodiversity advocates – the role of this group of soil organisms is impossible to replace fully with non-native earthworms. For example, some of the large indigenous earthworms (more than 1 m in length) burrow much deeper than the non-native species, thereby enriching and aerating the soil at greater depth.

The authors are hopeful that by giving the indigenous earthworms in KwaZulu-Natal common names, the threatened and endemic species will be conserved through inclusion in environmental impact assessments. Furthermore, they believe that earthworms could draw attention to the areas where they occur whenever a choice for new protected areas is to be made.

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Original source:

Armstrong AJ, Nxele TC (2017) English names of the megadrile earthworms (Oligochaeta) of KwaZulu-Natal. African Invertebrates 58(2): 11-20. https://doi.org/10.3897/AfrInvertebr.58.13226

Assassins on the rise: A new species and a new tribe of endemic South African robber flies

Discovery of a new species of assassin flies led to the redescription of its genus. This group of curious predatory flies live exclusively in South Africa, preferring relatively dry habitats. Following the revisit, authors Drs Jason Londt, KwaZulu-Natal Museum, South Africa, and Torsten Dikow, Smithsonian Institution National Museum of Natural History, USA, publish updated information about all species within the genus, now counting a total of seven species, and also establish a new tribe. Their study is published in the open access journal African Invertebrates.

The family of assassin flies (Asilidae), also known as robber flies, are curious insects, which have received their common name due to their extremely predatory behavior. The assassin flies prey on a great variety of insects, including beetles, moths, butterflies, wasps, other flies, as well as some spiders, as early as their juvenile stage of development. When hunting, they would ambush their prey and catch it in flight. Then, they would pierce the victim with a short and strong proboscis, while injecting venom. Once in the body of the prey, it quickly dissolves the insides, so that the assassin fly can suck them out.

The published study was spawned by the collection of new specimens of previously described assassin flies of the species Trichoura tankwa by the junior author in December 2015. These specimens could not be easily identified and so the authors started to look at all available specimens in natural history museums.

The new species, called Trichoura pardeos, was discovered in Tierberg Nature Reserve by the authors in 2004, a small conservation area located on the north banks of the Gariep River in the Northern Cape province of South Africa. The habitat comprises almost entirely a large rocky hill, where the vegetation is scarce and dominated by drought-resistant plants, such as aloes. The fly is predominantly red-brown in colour, with silvery, white and yellowish markings.

Having noted morphological variation between the species inhabiting areas with differently timed yearly rainfalls, the entomologists suggest that two groups within the studied genus have adapted to these different patterns in western and eastern South Africa. They also expect that species representing Trichoura could be also dwelling in Namibia, Botswana, Mozambique and possibly Zimbabwe.

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Original source:

Londt J, Dikow T (2016) A review of the genus Trichoura Londt, 1994 with the description of a new species from the Northern Cape Province of South Africa and a key to world Willistonininae (Diptera, Asilidae). African Invertebrates 57 (2): 119-135. https://doi.org/10.3897/AfrInvertebr.57.10772

Unfamiliar bloodline: New family for an earthworm genus with exclusive circulatory system

New earthworm family, named Kazimierzidae, has been established for a South African indigenous genus of 21 species. Although the circulatory system in the group has been regarded as exclusive upon their original description in 2006, their raising to a family status have only recently been confirmed by a research team from South Africa.

Scientists Mrs Thembeka Nxele, Dr Danuta Plisko (original discoverer of the genus Kazimierzus, now known as family Kazimierzidae), affiliated with Natal Museum (NMSA), Oliver Tendayi Zishiri, affiliated with University of KwaZulu-Natal, and Dr Taro Mwabvu, University of Mpumalanga, looked into the earthworm collection at the NMSA, as well as the type material and the available literature. Their study is published in the open access journal African Invertebrates.

When compared to the rest of the members in the family Microchaetidae, where the former genus had been placed, the studied earthworms show a number of distinct characters, including an “exclusive” circulatory system. In these species it is a simple single tube stretching along the whole body.

All 21 earthworm species, now members of the newly established family, can only be found in small areas restricted in the western and south-western Atlantic coast of South Africa. These locations have long been known for their endemic invertebrates and diverse flora.

In their paper, the authors note that it is actually the restricted range, and therefore the specific ecological requirements, that might have led these earthworms to become that different from other species. Their distribution and, hence, poor dispersal ability, are also the reason why the newly established group would be particularly vulnerable if the habitat is transformed.

“The species distribution of earthworms in Southern Africa is presently poorly known hence the urgency for extended study on earthworm diversity and their distribution patterns,” point out the scientists. “Extensive earthworm collection in the western Atlantic coast may bring more data on this and other taxa.”

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Original source:

Nxele TC, Plisko JD, Mwabvu T, Zishiri TO (2016) A new family Kazimierzidae for the genus Kazimierzus, earlier recorded to the composite Microchaetidae (Annelida, Oligochaeta). African Invertebrates 57(2): 111-117. doi: 10.3897/AfrInvertebr.57.10042