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A BRIEF HISTORY OF THE HERPETOLOGY COLLECTION AT DITSONG: NATIONAL MUSEUM OF NATURAL HISTORY

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A BRIEF HISTORY OF THE HERPETOLOGY COLLECTION AT DITSONG: NATIONAL MUSEUM OF NATURAL HISTORY

By Lauretta Mahlangu, Junior Curator, Small Mammals: DITSONG: National Museum of Natural History

According to the catalogue records at the Transvaal Museum (now DITSONG: National Museum of Natural History), the first specimens were deposited in the herpetology collection in 1888. The oldest specimens were unfortunately later destroyed in a fire. The Transvaal Museum later established the Department of Lower Vertebrates and included herpetology in 1905. It was during this time that Dr Vivian FitzSimons wrote a book titled Lizards of South Africa (FitzSimons, 1943), which is still being used by scholars and researchers today. Dr Bob Brain and Mr Wulf Haacke were subsequent curators who also made significant contributions to the collection (Brain, 1962, 1969; Branch et al. 1988; Haacke, 2013), and made it known worldwide. Independent Departments of Herpetology and Invertebrates were established in 1991 and the fish collection was transferred to other institutions, including the South African Institute of Aquatic Biodiversity (formerly J.L.B. Smith Institute).

Expansion of the herpetology collection

The collection expands as a result of field trips, while donations by members of the public and material collected during faunal surveys undertaken by staff of nature conservation departments are other very important sources of new specimens. In this growing collection, there are 79 500 specimens of which 72 000 are from southern Africa, making it the largest collection in Africa representing southern African reptiles and amphibians. Lizards (part of a group of reptiles) make up an estimated 70% of the collection.

Preparation

Flat enamel trays are used to prepare the specimens. This enables the preparatory, who prepares specimens) to lay the specimens flat if they are ‘fresh’, and as far as possible to position the head and limbs in a natural position. Snakes are coiled into an oblong shape, whereas frogs, turtles and terrapins are positioned in their natural position.

Correct preparation of specimens is important to ensure the longevity of specimens. When preserved, they should be arranged in appropriate positions, to facilitate the collection of relevant information in years to come. This information includes diagnostic characteristics, such as scale counts, external measurements, the shape of fangs and extruded hemipenes in snakes and lizards. Specimens are fixed in 4% formalin buffered with hexamine.

Labels with the specimen’s data should always be attached to it; even during preparation, temporary labels are attached. After a few days, depending on the size of the specimen, it is taken out of the formalin, thoroughly rinsed in water to remove the remnants of formalin and then placed into 70% denatured ethanol. Failure to remove as much formalin as possible from the specimen will result in the remaining formalin degrading the bones of the specimen over time. Once fixed and transferred to their long-term preservation medium, specimens are ready for cataloguing.

Specimen labelling, cataloguing, storage and maintenance

Only specimens with locality information, date of collection and preferably the collector are catalogued. Each specimen is given a unique consecutive number with the prefix TM. A permanent label is attached to each specimen with the following information on it: area or farm name, province, location coordinates, the date on which the specimen was collected, and collector. Specimen labels are attached securely to the specimen. For consistency, labels are tied to the right hind limb and on snakes and legless lizards just behind the neck. Labels are tied loose enough not to distort the diagnostic structure of a specimen but tight enough for the label not to slip through. For small specimens, e.g. embryos, specimens are placed in plastic bags with labels and holes punched to allow alcohol to penetrate through.  Eggs, wet or dry are placed separately in jars with labels. This information is also entered into a database (Specify) for easy retrieval. 

Exposure to ultraviolet light and the preservatives themselves, are harmful causing the fading of colour and patterns over time. For long-term preservation, specimens are kept in steel cabinets to protect them from light; the other reason is that steel unlike wood does not release volatile organic compounds. They are kept in 70% alcohol, and should always be completely submerged in the alcohol. Lower alcohol concentrations cause specimens to rot over time, while higher concentrations will cause specimens to become hard and brittle over time. Consol glass jars ranging in size from 500 ml to 2 l, as well as 25 l to 50 l plastic drums, are used for storage.

Jars are arranged within the steel cabinets in the collection room according to the four former South African provinces of Natal, Orange Free State, the Cape and Transvaal. Holotypes, allotypes, syntypes and paratypes, together with the catalogue books, are kept separately in the strong room to keep them safe from fire and theft and to preserve the valuable information they possess for future use. Annual/seasonal checks are done to maintain the alcohol concentration and levels, as jars tend to contract in winter and condensation droplets may be observed on the inside of the glass jar above the alcohol level and also on the lids.  In summer the lids expand, and evaporation occurs as a result of the lids loosening. Loose lids are tightened and any damaged/torn / loose labels are repaired, tightened or replaced. Specimens are also verified as required by the DITSONG: Museums of South Africa’s (DMSA) Heritage Management Policy (2020). 

 

Breakdown of specimens in the herpetology collection by geographic region and type:

Area Number of specimens
Southern Africa ca. 71891 
Rest of Africa and Madagascar ca. 5261 
Rest of the world ca. 1050 
Types ca. 751 
   

Usage of collection

This collection is used for research and educational purposes. It is available to any bona fide researcher nationally and internationally. Students can also access the collection through their supervisors. The DITSONG: National Museum of Natural History is acknowledged in any research publications and theses resulting from the use of the collections or collection-related information.

Safety and threats

This collection like any other collection in the world faces the threat of being destroyed. Eminent threats are, but are not limited to, changing environmental climatic conditions that include fire (considering that in recent times our country has experienced devastating fires in buildings that one would expect to be fireproof, with tight security, and CCTV cameras that are well monitored 24\7), floods (ever-changing weather patterns exacerbated by global warming), and theft.  Rapid temperature fluctuations due to climate change also pose a risk as it is difficult for staff to go through the entire collection in a single year to do an alcohol check. As a result, some specimens may not be fully submerged in alcohol for an extended period of time before they can be noticed.

Conclusion

This valuable collection representing irreplaceable information on the past distribution of herpetofauna (reptiles and amphibians) particularly in the southern African region deserves to receive the necessary funding to properly curate and maintain it for the future use. Having been preserved in formalin, DNA cannot be easily extracted. However, it is still a valuable collection to many researchers throughout the world. 

References

  • Brain, C. K., Field observation on lizards (Scincidae: Mabuya) in the Kalahari Gemsbok National Park. Koedoe, 12, 1 (1969), pp.1-10. 
  • Branch, W.R., Baard, E.H.W., Haacke, W.D., Jacobsen, N., Poynton, J.C. and Broadley, D.G., 1988. A provisional and annotated checklist of the herpetofauna of southerAfrica. The Journal of the Herpetological Association of Africa34(1), pp.1-19.
  • C.K., 1962. A review of the gecko Station1962(2), pp.1-18.
  • Broadley D.G, 1974. A review of the cobra of the cobra of Naja nigricollis complex in Southwestern Africa (Serpents, Elapidae). DGD
  • R ShinePS Harlow, WR Branch, JK Webb – Copeia, 1996 Life on the lowest branch: sexual dimorphism, diet, and reproductive biology of an African twig snake, Thelotornis capensis (Serpentes, Colubridae)
  • Haacke, W.D. 1976. The burrowing geckos of southern Africa, 3 (Reptilia: Gekkonidae). Annotated taxonomic account (cont.) D. Genus Colopus Peters. Annals of the Transvaal Museum 30: 29–39.
  • Haacke, W.D., 1996. Description of a new species of Phyllodactylus Gray (Reptilia: Gekkonidae) from the Cape Fold Mountains, South Africa. Annals Transvaal Mus. 36 (18): 229–237.
  • Haacke W.D. 1997. Systematics and biogeography of the southern African scincine genus Typhlacontias (Reptilia: Scincidae). Bonner Zoologische Beiträge 47(1-2): 139–163.Snakes of Southern Africa.
  • Poynton, J.C. & Haacke, W.D. 1993. On a collection of amphibians from Angola, including a new species of Bufo LaurentiAnnals of the Transvaal Museum 36(2): 9–16.
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