BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers,academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.

The Occurrence of Large Branchiopod Crustaceans in PerennialPans: A Research NoteAuthor(s): M. Ferreira, V. Wepener & J.H.J. van VurenSource: African Zoology, 46(1):176-178. 2011.Published By: Zoological Society of Southern AfricaDOI: http://dx.doi.org/10.3377/004.046.0108URL: http://www.bioone.org/doi/full/10.3377/004.046.0108

BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in thebiological, ecological, and environmental sciences. BioOne provides a sustainable onlineplatform for over 170 journals and books published by nonprofit societies, associations,museums, institutions, and presses.

Your use of this PDF, the BioOne Web site, and all posted and associated content indicatesyour acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use.

Usage of BioOne content is strictly limited to personal, educational, and non-commercial use.Commercial inquiries or rights and permissions requests should be directed to the individualpublisher as copyright holder.

The occurrence of large branchiopod crustaceansin perennial pans: a research noteM. Ferreira*, V. Wepener & J.H.J. van Vuren

Centre for Aquatic Research, Department of Zoology, University of Johannesburg, Auckland Park,

P.O. Box 524, Johannesburg, 2006 South Africa

Received 14 July 2010. Accepted 14 October 2010

Pans are isolated, shallow depressions that are endo-rheic in nature. Because of the natural hydrologicalfunctioning of pans, these systems are usually restrictedto arid regions and complete desiccation occurs season-ally. In the eastern provinces of South Africa manypans are perennial in nature often remaining inundatedfor several years. A study of the aquatic invertebratecommunity structure of selected perennial pansindicated that when these systems undergo completedesiccation, the communities are comparable to thecommunities of ephemeral ecosystems. During theseperiods the community displays normal successionpatterns with branchiopod crustacean dominatingthe community structure a few weeks after inundation.These perennial ecosystems are comparable to similarhabitats around the world but are under increasingthreat due to an increase in mining and agriculturalactivities within the study area.

Key words: hydroperiod, large branchiopods, pans.

Pans are classified as wetlands in South Africa,but have been neglected in terms of research

and monitoring when compared to other wetlandecosystems (Allen, 1987; Ewart-Smith et al. 2006).Pans are isolated, shallow depressions, generallylacking an inlet or outlet. Water in these systems isgained through rainfall and subsurface flows andlost to evaporation (Geldenhuys 1982). Because ofthese characteristics, pans are often restricted toarid regions with complete desiccation occurringseasonally. Most of the scientific knowledge onpans is based on research conducted on ephemeralecosystems in the arid northwestern regions ofSouth Africa (Weir 1969; Meintjies et al. 1994;Meintjies 1996; Belck & Brtek 1997; De Roeck et al.2007), the salt lakes of Africa (Williams 1985; Seamanet al. 1991), as well as playa lakes, prairie potholewetlands and similar habitats in other parts of theworld (Hancock & Timms 2002).

Although generally restricted to the drier westernparts of South Africa, pans are also present in theeastern Highveld region of South Africa where

rainfall often exceeds 750 mm per annum. This hasled to many of the pans in the MpumalangaProvince of South Africa being perennial innature, often remaining inundated for decades(Hutchinson et al. 1932). Apart from the lack ofseasonal desiccation, these perennial pans aresimilar to ephemeral pans in terms of habitat andhydrological functioning. Ephemeral pans generallyprovide a biological template for a unique group offauna in the form of different branchiopod crusta-ceans and insects that are able to adapt to thisharsh environment. The branchiopod crustaceansproduce eggs that are resistant to desiccation,only hatching when the correct environmentalconditions are present (Thiéry 1991; Brendock1996). This has led to many of these crustaceansbeing allopatric (i.e. not always co-occurring) andusually restricted to these temporary ecosystem(Rzóska 1961; Weir 1969; Williams 1985; Thiéry1991; Hamer & Martens 1998). Because of thislifecycle adaptation and a constantly changingenvironment, the aquatic invertebrate communi-ties of ephemeral pans often undergo succession(Meintjies 1996; Jocqué et al. 2007), triggered by thedesiccation and inundation cycles. These crusta-ceans have a short lifecycle, growing rapidly andreproducing early (Hamer & Appleton 1991).With the perennial pans of the eastern Highveldremaining inundated for very long periods, itcould be expected that the invertebrate communi-ties if these systems should be different from thecommunities in ephemeral pans.

A study was conducted seasonally between 2007and 2009 on nine perennial pans in the region.Seven of the pans were sampled on a seasonalbasis between July 2007 and July 2009 (eightsampling surveys) and an additional two pansin the autumn (May) of 2009. The invertebratecommunities of these pans were studied on aseasonal basis to assess the ecological functioningof these pans and to determine the impact ofchanges in the invertebrate communities brought*Author for correspondence. E-mail: martinf@uj.ac.za

African Zoology 46(1): 176–178 (April 2011)

about by coal mining and agricultural activities.Aquatic invertebrate communities were sampledfrom a variety of microhabitats in each pan. Sampleswere collected by using a variety of nets, includinga sweep net (500 μm) and a plankton net (63 μm),benthic grabs, and submerged light traps illumi-nated with a 6-inch cyalume dive stick. Samplesfrom each micro-habitat were placed in polyethyl-ene jars and fixed using 5% neutrally bufferedformalin and stained by using rose bengal. In thelaboratory invertebrates were removed and placedinto 70% ethanol. Invertebrates were then identi-fied to the lowest taxonomic level possible andenumerated. The invertebrate communities werestudied by following both a diversity and func-tional approach. These approaches are often seenas being complementary (Brucet et al. 2005; Ruhiet al. 2009). This paper represents preliminaryresults that were obtained for the diversity assess-ment of certain of these pans. During the two-yearsampling period, three of the pans underwentcomplete desiccation, remaining dry for at least sixweeks. One of the pans (according to local com-munities living around the pan) dried up for thefirst time in approximately 15 years. Coal miningactivities are currently taking place within the im-mediate catchment of this pan. The invertebratecommunity structure of these pans could not bestudied prior to desiccation as the pans were drywhen the study commenced. After the first inun-dation, the invertebrate communities of these threepans were studied and representatives of sixdifferent large branchiopod crustacean familieswere recorded, including Streptocephalidae,Thamnocephalidae, Triopsidae, Lynceidae,Cyzicidae, and Leptestheriidae (Table 1). Five ofthese families were found coexisting in a singlepan. After two months the invertebrate communi-ties of these systems were sampled again. Theinvertebrate communities of the three perennialpans that dried up showed typical successionpatterns, with the communities being dominatedby predatory insect taxa (Meintjies 1996). Afterinundation the invertebrate community structureof the three pans resembled the invertebrate com-munities of the other pans that formed part of thestudy which did not undergo desiccation.

It was thus evident that despite being inundatedfor extended periods (up to 15 years), the resistanteggs of certain large branchiopod crustaceansremained dormant in these perennial pans untilfavourable environmental conditions were pre-sented. Owing to the prolonged inundation of

these pans, branchiopods may thus not be sam-pled in their adult form. These large branchiopodswere only sampled after desiccation and were notsampled in any of the pans that were part of thestudy that remained inundated. Fish were alsopresent in the pan that dried for the first time in15 years after the pan was inundated for morethan a year. Studying the branchiopod egg banksthus becomes important especially as these stud-ies are considered vital for conservation of thesecrustaceans (Maffei et al. 2002, Brendonck & DeMeester 2003). Information on these egg banks arebecoming increasingly important as both agricul-tural activities and coal mining activities surround-ing some of the perennial pans are contributing tosedimentation in these systems (Danga et al. 2002;Naden et al. 2003). The successful hatching of theseegg banks depend on a number of environmentalfactors (Vanschoenwinkel et al. 2010) and distur-bances like sedimentation may lead to a loss inbranchiopod diversity in these ecosystems (Gleasonet al. 2003)

The invertebrate communities of these perennialpans are thus representative of ephemeral pansuntil prolonged inundation occurs. It is clear thatthese pans can function as ‘seasonally astatic’ orperennial ecosystems depending on the period ofinundation. The aquatic invertebrate communitystructure of the perennial pans is comparable tocommunities of similar habitats in other parts ofthe world (Seaman et al. 1991; Collinson et al. 1995;Hancock & Timms 2002; Wissinger 2009). Thesesystems could thus be considered to be uniqueand with limited scientific information availablefurther research is necessary to conserve theseecosystems. This is becoming increasingly importantas the ecological integrity of many pans (ephemeraland perennial) is threatened by numerous humanactivities.

This study was made possible through the provisionof funding by the Intenational Foundation for Science aswell as funding and facilities by the University of Johan-nesburg.

Short communications 177

Table 1. List of branchiopod Crustacea sampled in thethree pans that were completely desiccated.

Taxa Abundance

Branchinella sp. Sayce, 1903 11Streptocephalus cafer (Loven, 1847) 13Triops granarius (Lucas, 1921) 2Lynceus pachydactylus Barnard, 1929 2Cyzicus australis Loven, 1847 3Leptestheria rubidgei (Baird, 1862) 3

REFERENCES

ALLAN, D. 1987. Types of pans in South Africa. AfricanWildlife 41(5): 220–221.

BELK, D. & BRTEK, J. 1997. Supplement to ‘Checklist ofAnostraca’. Hydrobiologia 359: 243–245.

BRENDONCK, L. (1996). Diapause, quiescence, hatch-ing requirements: what we can learn from largefreshwater branchiopods (Crustacea: Branchiopoda:Anostraca, Notostraca, Conchostraca). Hydrobiologia320: 85–97.

BRENDONCK, L. & DE MEESTER, L. 2003. Egg banks infreshwater zooplankton: evolutionary and ecologicalarchives in sediment. In: E. Vandonk, M. Boersma &P. Spaak (Eds), Recent Developments in Fundamentaland Applied Plankton Research. Hydrobiologia 491:65–84.

BRUCET, S., BOIX, D., LÓPEZ-FLORES, R., BADOSA,A., MORENO-AMICH, R. & QUINTANA, X.D. 2005.Zooplankton structure and dynamics in permanentand temporary Mediterranean salt marshes: taxon-based and size-based approaches. Archiv für Hydro-biologie 162: 535–555

COLLINSON, N.H., BIGGS, J., CORFIELD, A.,HODSON, M.J., WALKER, D., WHITFIELD, M. &WILLIAMS, P.J. 1995. Temporary and permanentponds: an assessment of the effects of drying out onthe conservation value of aquatic macroinvertebratecommunities. Biological Conservation 74: 125–133.

DANGA, Z., LIUB, C. & HAIGH, M.J. 2002. Mobility ofheavy metals associated with the natural weatheringof coal mine spoils. Environmental Pollution 118:419–426.

DE ROECK, E.R., VANSCHOENWINKEL, B.J., DAY, J.A.,XU, Y., RAITT, L. & BRENDONCK, L. 2007. Conserva-tion status of large branchiopods in the WesternCape, South Africa. Wetlands 27(1): 162–173.

EWART-SMITH, J., OLLIS, D., DAY, J. & H. MALAN, H.2006. National wetland inventory: development of awetland classification system for South Africa. FinalReport, Project number: K8/652. Water ResearchCommission, Pretoria, South Africa.

GELDENHUYS, J.N. 1982. Classification of the pans ofthe western Orange Free State according to vegeta-tion structure, with reference to avifaunal communi-ties. South African Journal of Wildlife Research 12: 55–62.

GLEASON, R.A., EULISS, N.H., HUBBARD, D.E. &DUFFY, W.G. 2003. Effects of sediment load onemergence of aquatic invertebrates and plants fromwetland soil egg and seed banks. Wetlands 23(1): 26–34.

HAMER, M.L. & APPLETON C.C. 1991. Life historyadaptations of phyllopods in response to predators,vegetation, and habitat duration in north-easternNatal. Hydrobiologia 212: 105–116.

HAMER, M.L & MARTENS, K. 1998. The largeBranchiopoda (Crustacea) from temporary habitatsof the Drakensberg region, South Africa. Hydrobiologia384: 151–165.

HANCOCK, M.A. & TIMMS B.V. 2002. Ecology of fourturbid clay pans during a filling-drying cycle in theParoo, semi-arid Australia. Hydrobiologia 479: 95–107.

HUTCHINSON, G.E., PICKFORD, G.E. & SCHUUR-MAN, J.F.M. 1932. A contribution to the hydrobiologyof pans and inland waters of South Africa. Archives fürHydrobiologie 24: 1–154.

JOCQUÉ, M., GRAHAM, T. & BRENDONCK, L. 2007.Local structuring factors of invertebrate communi-ties in ephemeral freshwater rock pools and theinfluence of more permanent water bodies in theregion. Hydrobiologia 592: 271–280.

MAFFEI, C., MURA, G. & ZARATTINI P. 2002. Assessinganostracan (Crustacea: Branchiopoda) cyst bank size:an attempt at a standardized method. Hydrobiologia486: 255–261.

MEINTJIES, S. 1996. Seasonal changes in the inverte-brate community of small shallow ephemeral pans atBain’s Vlei, South Africa. Hydrobiologia 317: 51–64.

MEINTJIES, S., SEAMAN, M.T & KOK, D.J. 1994.Variations in the morphological characteristics ofTriops granarius (Lucas) (Notostraca: Crustacea) in apan system at Bain’s Vlei, South Africa. Hydrobiologia277(3): 179–186.

NADEN, P., SMITH, B., JARVIE, H., LLEWELLYN, N.,MATTHIESSEN, P., DAWSON, H., SCARLETT, S. &HORNBY, D. 2003. Siltation in rivers. A review ofmonitoring techniques. Conserving Natura 2000Rivers Conservation Techniques Series No. 6. EnglishNature, Peterborough.

RUHÍ, A., BOIX, D., SALA J., GASCÓN, S. & QUIN-TANA, X.D. 2009. Spatial and temporal patterns of pi-oneer macrofauna in recently created ponds:taxonomic and functional approaches. Hydrobiologia634: 137–151

RZÓSKA, J. 1961. Observations on tropical rainpools andgeneral remarks on temporary waters. Hydrobiologia17: 265–286.

SEAMAN, M.T., ASHTON P. & WILLIAM W.D. 1991.Inland salt waters of southern Africa. HydrobioIogia210: 75–91.

THIÉRY, A. 1991. Multispecies coexistence of branchio-pods (Anostraca, Notostraca and Spinicaudata) intemporary ponds of Chaouia plain (western Morocco):sympatry or syntopy between usually allopatricspecies. Hydrobiologia 212: 117–136.

VANSCHOENWINKEL, B., SEAMAN, M. & BREN-DONCK, L. 2010. Hatching phenology, life historyand egg bank size of fairy shrimp Branchipodopsis spp.(Branchiopoda, Crustacea) in relation to the ephe-merality of their rock pool habitat. Aquatic Ecology.DOI 10.1007/s10452-010-9315-y

WEIR, J.S. 1969. Studies on central African pans. III.Fauna and physico-chemical environment of someephemeral pools. Hydrobiologia 33: 93–116.

WILLIAMS, W.D. 1985. Biotic adaptations in temporarylentic waters, with special reference to those insemiarid and regions. Hydrobiologia 125: 85–110.

WISSINGER, S.A., GREIG H. & McINTOSH A. 2009.Absence of species replacements between perma-nent and temporary lentic communities in NewZealand. Journal of the North American BentholologicalSociety 28(1): 12–23.

Responsible Editor: J.H. van Wyk

178 African Zoology Vol. 46, No. 1, April 2011