Tag: Annelida

The Western Ghats of India revealed two new primitive species of earthworm

The Western Ghats mountains lie at the southwestern continental margin of Peninsular India and extend all the way from Gujarat to Kerala. The massif has earned its place amongst the eight ‘hottest’ biodiversity hotspots in the world.

There is a great variety of vegetation types which, coupled with the high rainfall and the moderate yearly temperature in the Western Ghats, provide many different habitats. Therefore, the mountains an area rich in earthworm, as well as amphibian and reptile diversity.

The two new species, named Drawida polydiverticulata and Drawida thomasi, have been discovered in the Western Ghats mountain ranges in Kerala by scientists Dr. S. Prasanth Narayanan, Mr. S. Sathrumithra, Dr. G. Christopher, all affiliated with Mahatma Gandhi University and Dr. J.M. Julka of the Shoolini University, India. They belong to the primitive family Moniligastridae. The species are described in the open access journal ZooKeys.

The new earthworms are distinguished by a set of characters. For one of them – Drawida polydiverticulata – there were peculiar features which determined its species name (polydiverticulata). It turned out that its multiple lobes, also called diverticulums, an organ located in the front of its body, are unique amongst the members of the genus. This species was found to be widespread in the protected shola grasslands of the Munnar region, including Eravikulam National Park, Pampadun Shola National Park and Chinnar Wildlife Sanctuary.

The second new earthworm, Drawida thomasi, was collected at the Kozhippara Waterfalls near Kakkadampoyil, at the border between Malappuram and Kozhikode. The species name (thomasi) is a tribute to Prof. (Dr.) A.P. Thomas, the Director of the Advanced Centre of Environmental Studies and Sustainable Development (ACESSD), Mahatma Gandhi University, “who initiated the taxonomical studies on the earthworms in Kerala after being at a standstill for almost a century.”

In addition to the new species, the scientists also report the occurrence of five species of the same genus that have not previously been recorded from the state.

To date, there are 73 species of the genus Drawida confirmed to be living in the Indian subcontinent. However, the greatest concentration (43 species) is found in the Western Ghats. The genus has an important centre of speciation in the southernmost state of Kerala.

Prior to this study, there had been sixteen Drawida species known from the state with ten of them being unique. The present discovery of two new species and five new local records further contributes to the vast species richness of the genus in the state.

At present, there are about 200 species known in the genus Drawida. Their habitats are spread across India throughout the Indochina region to southeastern Asia and up to the north in Japan.

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Original source:

Narayanan SP, Sathrumithra S, Christopher G, Julka JM (2017) New species and new records of earthworms of the genus Drawida from Kerala part of the Western Ghats biodiversity hotspot, India (Oligochaeta, Moniligastridae). ZooKeys 691: 1-18. https://doi.org/10.3897/zookeys.691.13174

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

It’s a girl! Tweaking the names of a pest fanworm group

The largest group of fanworm species with rigid chalky (calcareous) tubes belong to the Hydroides genus, and are easily recognised thanks to the shape of their beautifully ornate tube plugs. Hydroides is economically important as its members have the potential to cover immersed marine structures with massive nuisance settlements of chalky biofouling. The best-known example is Hydroides elegans, which settles on boat hulls so readily that colonies of it are perpetually in transit around the world, hitch-hiking to new places.

Latin names of animals mostly do not change over the decades because they are kept stable by a code book of naming rules. However, a mistake has recently been discovered regarding Hydroides. It turns out that it is a feminine genus rather than masculine, thus requiring each of the 107 Hydroides species names, described since 1768, to be re-examined so that the appropriate spelling, determined by the derivation of each name, can be used consistently by all biologists in future.

Scientists Geoffrey Read, National Institute of Water and Atmospheric Research, New Zealand, Harry ten Hove, Naturalis Biodiversity Center, the Netherlands, Yanan Sun and Elena Kupriyanova, Australian Museum, have carefully compiled the data on original Hydroides names, and published a checklist paper in the open access journal ZooKeys.

‘Detective’ work has often been required to get the details, as early biologists have been remarkably vague about the names they created and where their worms had come from. Fortunately, the Biodiversity Heritage Library has digitised many of the legacy taxonomic works required and it was possible to find out some unexpected information such as that species H. floridana actually did not come from Florida, although its name suggests it did.

Some Hydroides names have a descriptive basis that fits how the worms look, such as H. bulbosa, H. elegantula and H. longispinosa, others are named after people or places, for example, H. dafnii (after its collector, Yaacob Dafni) and H. sanctaecrucis (after Saint Croix Island). Yet, there are others, whose names are of quite tricky origin. It turns out that H. dianthus was actually named after a group of popular garden flowers, and H. euplaeana and H. stoichadon commemorate the long-forgotten names of tiny Mediterranean islands.

A few 19th century Hydroides descriptions are so bad that taxonomists have given up on using the names. However, one of these discarded names was revived last century by American biologists and was then used in often-cited research on sperm biology. Now, we can only guess what the actual species was.

Hydroides itself is a very old name, but it arose in a somewhat accidental and misleading way (in a letter to Linnaeus), because the worms have absolutely no connection to true hydroids, the well-known group of colonial animals related to corals.

The Hydroides species original descriptions are mostly accessible via the checklist because one third of the reports cited in the checklist are linked to the open access Biodiversity Heritage Library, and a large proportion are matched to an online source. While in the past one could only expect to find recorded the geolocations (the latitudes and longitudes) of worms collected during ship voyages, now the original localities of all the Hydroides are finally mapped. Further information on the taxonomy of all Hydroides, including many now regarded as synonyms, is available via links to the World Register of Marine Species Polychaeta web pages.

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Original source:

Read GB, ten Hove HA, Yanan Sun Y, Kupriyanova EK (2017) Hydroides Gunnerus, 1768 (Annelida, Serpulidae) is feminine: a nomenclatural checklist of updated names. ZooKeys 642: 1-52. https://doi.org/10.3897/zookeys.642.10443

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

Old specimens establish a new bamboo worm genus and species

Bamboo worms (family Maldanidae) comprise an easily recognizable family of bristle worms (class Polychaeta). Their common name they receive because of their elongated segments, ending with an appendage, which gives them the joint appearance of slender bamboo-shoots. These often fragile marine inhabitants can be found in mud-walled tubes in shelf sediments.

However, bamboo worms are tough to identify from each other. The problem is that to safely recognize them, a researcher needs both anterior and posterior ends from the same specimen. Nevertheless, now PhD student Wang Yueyun and Dr Li Xinzheng from the Marine Biological Museum, Institute of Oceanology, Chinese Academy of Sciences have discovered two new species and a new genus (Paramaldane). The new bamboo worms are described in the open access journal ZooKeys.

Several specimens of the new genus were found during re-examination of specimens collected from South China Sea between 1959 to 1962. The new genus is characterized by the collar-like glandular band on the sixth chaetiger. This is the first discovery of a collar-like structure in the subfamily of Maldaninae. Moreover, there is only one species in this genus till now.

Another discovery, published in the present study, is the second new species, called Maldane adunca, which belongs to another genus within the family. It is similar to the cosmopolitan species Maldane sarsi, yet the differences are clear. The shape of its nuchal grooves, a kind of sense organ, is much more curved, thus resembling hooks. Therefore, it is called adunca, meaning ‘hooked’ in Latin.

Both new species are only found in mud sediment of offshore waters of Hainan Island.

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Original source:

Wang Y, Li X (2016) A new Maldane species and a new Maldaninae genus and species (Maldanidae, Annelida) from coastal waters of China. ZooKeys 603: 1-16. doi: 10.3897/zookeys.603.9125