The plight of freshwater fishes in southern Africa...

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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

Transcript of The plight of freshwater fishes in southern Africa...

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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

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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

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Clark et al. (2009) • Barbus andrewi • Langvlei redfin? • Eerster redfin • Langvlei Galaxias?

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Tweddle et al. (2009)

- most well studied region of southern Africa - diversity and distribution generally well known

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Incomplete knowledge of diversity and distribution:

“taxonomic impediment”

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Galaxias

Pseudobarbus Galaxias

Sandelia

Marcusenius

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Many of the lineages are narrow range endemics

Chakona et al. (2013)

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’Giant redfin’ – last refuges

Alien threatens CR fish in Protected Area? Values?

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Swartz et al. (2007)

Pseudobarbus afer species complex

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Chakona et al. (2013)

Sandelia capensis species complex

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Galaxias zebratus species complex

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Swartz et al. (in prep)

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Hex River December 2007

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Hex River March 2008

Nameless and vulnerable

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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.

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Only five species of freshwater fishes

described from South Africa between 1997

and 2015

Waters & Cambray (1997)

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What are the issues?

1. Reduced taxonomic capacity

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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

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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

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4. Vague original locality details

• Some type localities are vague

– Clear streams of the Cape

– Tugela River

• Lack of human capacity

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5. Pitfalls of barcoding blindly

• Emphasis should be placed on generating reference topogenetypes

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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

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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

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Thank you

Giant redfin: Pic by Riaan Van der Walt