Browsing by Author "Landschoff, Jannes"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Open Access
    Brooding behaviour in Ophioderma wahlbergii, a shallow-water brittle star from South Africa
    (2014) Landschoff, Jannes; Griffiths, Charles L
    The brooding behaviour and brooded young are described for Ophioderma wahlbergii Müller & Troschel 1842, a large, common brittle star from the coastal waters of South Africa. Twenty specimens were collected each month from June 2013 – May 2014 (n = 240). The species was found to be gonochoric.
  • Thumbnail Image
    Item
    Open Access
    Contributions to the taxonomy of South African hermit crabs (Crustacea: Decapoda: Paguroidea) – integrating microCT scanning and barcoding
    (2018) Landschoff, Jannes; Griffiths, Charles L
    Hermit crabs form an important component of the marine benthos and globally more than 1,200 species have been described. In the unique bioregion of South Africa, hermit crabs are poorly known, and the last taxonomic revision of the group was that of K. H. Barnard in 1950, who recorded only 32 species. This study combines morphological taxonomy, threedimensional (3D) micro-computed tomography (µCT) visualisations, and molecular barcoding to add to, revise, and provide an updated listing of, the regional fauna. The first section of the thesis comprises four chapters, each giving a detailed account of a species either new to science, or to the region. The pagurid hermit crab Goreopagurus poorei, a new species and genus record to the country, is reported and described from deep sea habitats along the Agulhas Shelf, extending the distribution by >10,000 km across the Indian Ocean. Furthermore, three species are described as new to science, one each from the three most common families. The first of these, a deep-water species from a genus of the family Parapaguridae that was previously unknown to South Africa, Paragiopagurus atkinsonae n. sp., is fully described and illustrated, and compared with two other parapagurids that each play a dominant role in the regional benthic offshore invertebrate community. The other two species new to science, Diogenes n. sp. from the family Diogenidae, and Pagurus n. sp. from the family Paguridae, inhabit coastal reefs in subtidal waters off southern KwaZulu-Natal. For the first time in crustacean taxonomy, species descriptions, particularly the one of Pagurus n. sp., are informed by, or based on, µCT imagery of calcified body parts. Following on this technique, Chapter 6 is a short presentation of the 3D raw dataset of seven µCT scans of types and rare museum specimens used in this thesis, which is made publicly available for download. The taxonomic use of the scanning method, with disseminating volumetric data of hermit crabs, is discussed briefly. The final section investigates the fauna as a whole. In Chapter 7, 194 cytochrome c oxidase subunit I gene segments (COI ‘barcodes’) of 43 nominal species plus 12 additional putative species (n = 55 species-like units) were used to validate morphological identifications. Testing this dataset revealed high barcoding efficacy, with nearly 99% identification success rates, and with the best Kimura 2-parameter distance to safely delimit species of hermit crabs of about 3.5%. Chapter 8 updates the regional fauna and provides taxonomic accounts for 62 nominal species which have either been added subsequent to the previous monographic review, or which have undergone taxonomic revision since that time. Of these, 12 are added for the first time here, increasing the number of known South African hermit crab species to 72, an expansion of 56% since Barnard, and about 20% since a recent species list published by W. Emmerson in 2016. Because colour images are provided for 51 out of 72 species, Chapter 8 can also be used as a preliminary guide. However, this study has shown that the hermit crabs of South Africa are by far more diverse than originally thought, and the summary, which includes only the 72 nominal taxa and none of the additional 10 putative species included in the barcoding dataset, is speculated to be only 60–70% complete. Future taxonomic work, especially in the genera Diogenes and Paguristes, will most likely result in many more species descriptions. Therefore, this current study is to be seen as important step towards a fully illustrated taxonomic catalogue on the South African hermit crabs to be produced in the near future.
  • Thumbnail Image
    Item
    Open Access
    Review of the South African and Mozambican stomatopod fauna
    (2022) Brokensha, Rouane; Griffiths, Charles L; Landschoff, Jannes
    Mantis shrimps or stomatopods (Crustacea: Stomatopoda) form an important component of the marine benthos and are notorious predators. Globally some 480 species have been described. However, the current taxonomic knowledge on the mantis shrimp fauna of southern Africa remains limited and outdated, with the last taxonomic revision of the group being that of K.H. Barnard in 1950, who recorded 17 species from South Africa and southern Mozambique. The present study aims to collate literature records, examine existing museum specimens, update species accounts and distribution records, and report on new species records from both South Africa and Mozambique. This study is primary based on the stomatopod collection housed at the Iziko South African Museum, Cape Town, South Africa. A guide to the South African stomatopod fauna is presented in Chapter 1. Keys for South African superfamilies, families, genera and species are compiled to produce the first comprehensive and fully illustrated identification guide to the mantis shrimps of South Africa. Detailed taxonomic accounts of all known species are given, and drawn illustrations presented for those species for which material was available, which includes new feature variations for species and genera worldwide, as well as in South Africa. Five species are added as new records for the region, increasing the number of South African stomatopods from 26 to 31 species belonging to 20 genera from nine families. Lysiosquilla colemani is recorded for the second time globally as a new record for the Western Indian Ocean and South Africa. Another little-known species, Gonodactyllelus crosnieri, is also recorded for the second time and represents a new species record for South Africa. Furthermore, genus Odontodactylus comprised of two species, O. hansenii and O. scyllarus, is taxonomically presented from South African material for the first time. The second species of Clorida from South Africa, C. albolitura is also recognised as a new record for southern Africa. Chapter 2 reports on notable stomatopods from Mozambique present in the material housed in the Iziko South African Museum. Seven species are recorded for the first time from Mozambican waters, bringing the known Mozambican stomatopod fauna to 22 species in 17 genera and eight families. Taxonomic accounts of eight species are given, seven of these representing new species records, while the eighth description is of the previously poorly documented species, Erugosquilla woodmasoni, which is reported on from new material. The new record of Manningia australiensis represents the first record of the family Eurysquillidae from southern Africa. While this study examines existing collections of southern African stomatopods, it was not possible to sample additional fresh material and the stomatopod fauna of southern Africa, and especially Mozambique, remains highly under-sampled. The present guide and species additions provide a detailed account of the fauna, thereby improving our current understanding of this distinctive group in this unique geographic area. Using this guide and the collated information therein, future taxonomic work will be well-equipped to take advantage of modern techniques when collecting new material from previously under-sampled habitats.