The plight of freshwater fishes in southern Africa...
Transcript of The plight of freshwater fishes in southern Africa...
The plight of freshwater fishes in southern Africa: addressing the
taxonomic impediment
Tweddle et al. (2009)
- about 215 described species - high regional endemism - many areas remain largely unexplored
Fig 1. Five major threat categories and their
established or potential interactive impact on
freshwater biodiversity. [Dudgeon et al. 2006]
Freshwater fishes have become increasingly imperiled by multiple impacts
Clark et al. (2009) • Barbus andrewi • Langvlei redfin? • Eerster redfin • Langvlei Galaxias?
Tweddle et al. (2009)
- most well studied region of southern Africa - diversity and distribution generally well known
Incomplete knowledge of diversity and distribution:
“taxonomic impediment”
Galaxias
Pseudobarbus Galaxias
Sandelia
Marcusenius
Many of the lineages are narrow range endemics
Chakona et al. (2013)
’Giant redfin’ – last refuges
Alien threatens CR fish in Protected Area? Values?
Swartz et al. (2007)
Pseudobarbus afer species complex
Chakona et al. (2013)
Sandelia capensis species complex
Galaxias zebratus species complex
Swartz et al. (in prep)
Hex River December 2007
Hex River March 2008
Nameless and vulnerable
Current taxonomy impedes conservation of freshwater fishes in southern
Africa
Humphry Greenwood 1992 “Since taxonomy and systematics are basic to all
ichthyological research, I would consider the latter situation (poverty of practicing taxonomists) to be one of the major
non-environmental threats to the world of fishes”
Greenwood, P.H. 1992. Are the major fish faunas well-known? Netherlands Journal of Zoology 42, 131-138.
Only five species of freshwater fishes
described from South Africa between 1997
and 2015
Waters & Cambray (1997)
What are the issues?
1. Reduced taxonomic capacity
2. State of type specimens and access
• Type specimens form the basis of any taxonomic investigation
– Most types are very old, many are no longer in good condition, others have
been lost
– Type material not readily accessible for researchers from developing
countries – most have been deposited in museums overseas
– DNA cannot be extracted from these specimens – sequences of types are
required to verify whether the taxon that one is looking at is indeed new
3. Challenges with accessing original descriptions
• Old literature difficult to find
– Any new description requires reference to original description
– Access to this literature is difficult for students and researchers from
developing countries
• Language barrier
– Many old descriptions are not in English
4. Vague original locality details
• Some type localities are vague
– Clear streams of the Cape
– Tugela River
• Lack of human capacity
5. Pitfalls of barcoding blindly
• Emphasis should be placed on generating reference topogenetypes
SAIAB’s Topotypes Project
• Identify all type localities of freshwater fishes and frogs described from SA
• Provide original descriptions (including any illustrations)
• Collect topotypic material (vouchers and tissues) – this includes synonyms
• Generate DNA barcodes of all topotypes
• Provide morphometric and meristic data of holotypes and topotypes
• Provide photos and X-rays of Holotypes/Syntypes/Neotypes
• Live colour pictures and x-rays of topotypes
• Photos, GPS coordinates and directions to type localities (Google maps)
• Capacity building
• All data will be made openly available
Acknowledgements • NRF-FBIP for funding
• SAIAB
• CapeNature, Ezemvelo KZN Wildlife, Mpumalanga Tourism and Parks Agency and the
Department of Economic Development and Environmental Affairs (Eastern Cape Province)
for sampling permits
• Riaan Van der Walt
• Richard Simbelani
• Land owners
Thank you
Giant redfin: Pic by Riaan Van der Walt