204 research outputs found

    The Evolution of Bat Vestibular Systems in the Face of Potential Antagonistic Selection Pressures for Flight and Echolocation

    Get PDF
    PMCID: PMC3634842This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    The Relative Influence of Competition and Prey Defenses on the Phenotypic Structure of Insectivorous Bat Ensembles in Southern Africa

    Get PDF
    Deterministic filters such as competition and prey defences should have a strong influence on the community structure of animals such as insectivorous bats that have life histories characterized by low fecundity, low predation risk, long life expectancy, and stable populations. We investigated the relative influence of these two deterministic filters on the phenotypic structure of insectivorous bat ensembles in southern Africa. We used null models to simulate the random phenotypic patterns expected in the absence of competition or prey defences and analysed the deviations of the observed phenotypic pattern from these expected random patterns. The phenotypic structure at local scales exhibited non-random patterns consistent with both competition and prey defense hypotheses. There was evidence that competition influenced body size distribution across ensembles. Competition also influenced wing and echolocation patterns in ensembles and in functional foraging groups with high species richness or abundance. At the same time, prey defense filters influenced echolocation patterns in two species-poor ensembles. Non-random patterns remained evident even after we removed the influence of body size from wing morphology and echolocation parameters taking phylogeny into account. However, abiotic filters such as geographic distribution ranges of small and large-bodied species, extinction risk, and the physics of flight and sound probably also interacted with biotic filters at local and/or regional scales to influence the community structure of sympatric bats in southern Africa. Future studies should investigate alternative parameters that define bat community structure such as diet and abundance to better determine the influence of competition and prey defences on the structure of insectivorous bat ensembles in southern Africa

    Resolving the Trophic Relations of Cryptic Species: An Example Using Stable Isotope Analysis of Dolphin Teeth

    Get PDF
    Understanding the foraging ecology and diet of animals can play a crucial role in conservation of a species. This is particularly true where species are cryptic and coexist in environments where observing feeding behaviour directly is difficult. Here we present the first information on the foraging ecology of a recently identified species of dolphin (Southern Australian bottlenose dolphin (SABD)) and comparisons to the common bottlenose dolphin (CBD) in Victoria, Australia, using stable isotope analysis of teeth. Stable isotope signatures differed significantly between SABD and CBD for both δ13C (−14.4‰ vs. −15.5‰ respectively) and δ15N (15.9‰ vs. 15.0‰ respectively), suggesting that the two species forage in different areas and consume different prey. This finding supports genetic and morphological data indicating that SABD are distinct from CBD. In Victoria, the SABD is divided into two distinct populations, one in the large drowned river system of Port Phillip Bay and the other in a series of coastal lakes and lagoons called the Gippsland Lakes. Within the SABD species, population differences were apparent. The Port Phillip Bay population displayed a significantly higher δ15N than the Gippsland Lakes population (17.0‰ vs. 15.5‰), suggesting that the Port Phillip Bay population may feed at a higher trophic level - a result which is supported by analysis of local food chains. Important future work is required to further understand the foraging ecology and diet of this newly described, endemic, and potentially endangered species of dolphin

    A dated phylogeny and collection records reveal repeated biome shifts in the African genus Coccinia (Cucurbitaceae)

    Get PDF
    Background: Conservatism in climatic tolerance may limit geographic range expansion and should enhance the effects of habitat fragmentation on population subdivision. Here we study the effects of historical climate change, and the associated habitat fragmentation, on diversification in the mostly sub-Saharan cucurbit genus Coccinia, which has 27 species in a broad range of biota from semi-arid habitats to mist forests. Species limits were inferred from morphology, and nuclear and plastid DNA sequence data, using multiple individuals for the widespread species. Climatic tolerances were assessed from the occurrences of 1189 geo-referenced collections and WorldClim variables. Results: Nuclear and plastid gene trees included 35 or 65 accessions, representing up to 25 species. The data revealed four species groups, one in southern Africa, one in Central and West African rain forest, one widespread but absent from Central and West African rain forest, and one that occurs from East Africa to southern Africa. A few individuals are differently placed in the plastid and nuclear (LFY) trees or contain two ITS sequence types, indicating hybridization. A molecular clock suggests that the diversification of Coccinia began about 6.9 Ma ago, with most of the extant species diversity dating to the Pliocene. Ancestral biome reconstruction reveals six switches between semi-arid habitats, woodland, and forest, and members of several species pairs differ significantly in their tolerance of different precipitation regimes. Conclusions: The most surprising findings of this study are the frequent biome shifts (in a relatively small clade) over just 6 - 7 million years and the limited diversification during and since the Pleistocene. Pleistocene climate oscillations may have been too rapid or too shallow for full reproductive barriers to develop among fragmented populations of Coccinia, which would explain the apparently still ongoing hybridization between certain species. Steeper ecological gradients in East Africa and South Africa appear to have resulted in more advanced allopatric speciation there

    Correlated Genetic and Ecological Diversification in a Widespread Southern African Horseshoe Bat

    Get PDF
    The analysis of molecular data within a historical biogeographical framework, coupled with ecological characteristics can provide insight into the processes driving diversification. Here we assess the genetic and ecological diversity within a widespread horseshoe bat Rhinolophus clivosus sensu lato with specific emphasis on the southern African representatives which, although not currently recognized, were previously described as a separate species R. geoffroyi comprising four subspecies. Sequence divergence estimates of the mtDNA control region show that the southern African representatives of R. clivosus s.l. are as distinct from samples further north in Africa than they are from R. ferrumequinum, the sister-species to R. clivosus. Within South Africa, five genetically supported geographic groups exist and these groups are corroborated by echolocation and wing morphology data. The groups loosely correspond to the distributions of the previously defined subspecies and Maxent modelling shows a strong correlation between the detected groups and ecoregions. Based on molecular clock calibrations, it is evident that climatic cycling and related vegetation changes during the Quaternary may have facilitated diversification both genetically and ecologically

    Phytoplankton evolution during the creation of a biofloc system for shrimp culture

    Full text link
    [EN] Microalgae play a key role in the dynamics of biofloc technology aquaculture systems. Some phytoplankton groups, such as diatoms, are desired for their high nutritional value and contribution to water quality. Other groups, such as cyanobacteria, are undesired because of their low nutritional value and capacity of producing toxins. So, monitoring the phytoplankton community structure and succession is key for managing biofloc systems. However, research on phytoplankton in these systems is scarce and mostly done by microscopy. The primary objective of this research was to estimate phytoplankton community structure in shrimp biofloc system water samples, using high-performance liquid chromatography methods and CHEMTAX software. The major groups present in our system were diatoms, euglenophytes, cyanobacteria and chlorophytes, while dinoflagellates were only remarkable at the initial period. We observed a clear dominance of diatoms all along the 5 months that comprised a complete biofloc system culture. The characteristic succession of autotrophic processes by heterotrophs of the biofloc systems, was observed by the reduction of net primary production. Light intensity played a key role in determining the phytoplankton composition and abundance. Algal pigment analyses using high-performance liquid chromatography and subsequent CHEMTAX analysis in water samples was useful for estimating the phytoplankton community structure in the biofloc systems. However, we found some limitations when the biofloc system was in heterotrophic mode. Under these conditions, some dinoflagellates and cyanobacteria behaved as heterotrophs and lost or decreased their biomarkers pigments. So, further research is needed to increase knowledge on the accuracy of high-performance liquid chromatography /CHEMTAX under these conditions.Financial support for this research was provided by Conselleria d’Educació, Investigació, Cultura i Esport of the Generalitat Valenciana, through the program VALi+D, fle number ACIF/2014/244. We would like to express our deepest thanks to Professor Luis Henrique da Silva Poersch of FURG (Universidade Federal do Rio Grande) and Ivan Vidal (Langostinos el Real) for his support. Finally, the authors wish to thank Le Gouessant and Michaël Metz for providing the commercial feed.Llario-Sempere, F.; Rodilla, M.; Escrivá-Perales, J.; Falco, S.; Sebastiá-Frasquet, M. (2018). Phytoplankton evolution during the creation of a biofloc system for shrimp culture. International Journal of Environmental Science and Technology. 1-12. https://doi.org/10.1007/s13762-018-1655-5S112Ahmed A, Kurian S, Gauns M, Chndrasekhararao AV, Mulla A, Naik B, Naik H, Naqvi SWA (2016) Spatial variability in phytoplankton community structure along the eastern Arabian Sea during the onset of south-west monsoon. Cont Shelf Res 119:30–39. https://doi.org/10.1016/j.csr.2016.03.005Avnimelech Y (1999) Carbon/nitrogen ratio as a control element in aquaculture systems. Aquaculture 176:227–235. https://doi.org/10.1016/S0044-8486(99)00085-XAvnimelech Y (2007) Feeding with microbial flocs by tilapia in minimal discharge bio-flocs technology ponds. Aquaculture 264:140–147. https://doi.org/10.1016/j.aquaculture.2006.11.025Avnimelech Y (2009) Biofloc technology. A practical guide book. The World Aquaculture Society, Baton RougeAzim ME, Little DC (2008) The biofloc technology (BFT) in indoor tanks: water quality, biofloc composition, and growth and welfare of Nile tilapia (Oreochromis niloticus). Aquaculture 283:29–35. https://doi.org/10.1016/j.aquaculture.2008.06.036Ballester ELC, Abreu PC, Cavalli RO, Emerenciano M, de Abreu L, Wasielesky WJ (2010) Effect of practical diets with different protein levels on the performance of Farfantepenaeus paulensis juveniles nursed in a zero exchange suspended microbial flocs intensive system. Aquac Nutr 16:163–172. https://doi.org/10.1111/j.1365-2095.2009.00648.xBaloi M, Arantes R, Schveitzer R, Magnotti C, Vinatea L (2013) Performance of Pacific white shrimp Litopenaeus vannamei raised in biofloc systems with varying levels of light exposure. Aquac Eng 52:39–44. https://doi.org/10.1016/j.aquaeng.2012.07.003Baumgarten MGZ, Wallner-Kersanach M, Niencheski LFH (2010) Manual de análises em oceanografia química. Furg, Rio GrandeBecerra-Dórame MJ, Martínez-Córdova LR, Martínez-Porchas M, Lopez-Elías JA (2011) Evaluation of autotrophic and heterotrophic microcosm- based systems on the production response of Litopenaeus vannamei intensively nursed without Artemia and with zero water exchange. Isr J Aquac Bamidgeh 63:7Brito LO, dos Santos IGS, de Abreu JL, de Araújo MT, Severi W, Gàlvez AO (2016) Effect of the addition of diatoms (Navicula spp.) and rotifers (Brachionus plicatilis) on water quality and growth of the Litopenaeus vannamei postlarvae reared in a biofloc system. Aquac Res 47:3990–3997. https://doi.org/10.1111/are.12849Campa-Córdova AI, Núñez-Vázquez EJ, Luna-González A, Romero-Geraldo MJ, Ascencio F (2009) Superoxide dismutase activity in juvenile Litopenaeus vannamei and Nodipecten subnodosus exposed to the toxic dinoflagellate Prorocentrum lima. Comp Biochem Physiol C Toxicol Pharmacol 149:317–322. https://doi.org/10.1016/j.cbpc.2008.08.006Casé M, Leça EE, Leitão SN, SantAnna EE, Schwamborn R, de Moraes Junior AT (2008) Plankton community as an indicator of water quality in tropical shrimp culture ponds. Mar Pollut Bull 56:1343–1352. https://doi.org/10.1016/j.marpolbul.2008.02.008Chen YC (2001) Immobilized microalga Scenedesmus quadricauda (Chlorophyta, Chlorococcales) for long-term storage and for application for water quality control in fish culture. Aquaculture 195:71–80. https://doi.org/10.1016/S0044-8486(00)00540-8Correia ES, Wilkenfeld JS, Morris TC, Wei L, Prangnell DI, Samocha TM (2014) Intensive nursery production of the Pacific white shrimp Litopenaeus vannamei using two commercial feeds with high and low protein content in a biofloc-dominated system. Aquac Eng 59:48–54. https://doi.org/10.1016/j.aquaeng.2014.02.002Duarte CM, Marrasé C, Vaqué D, Estrada M (1990) Counting error and the quantitative analysis of phytoplankton communities. J Plankton Res 12:295–304. https://doi.org/10.1093/plankt/12.2.295Ebeling J, Timmons M, Bisogni J (2006) Engineering analysis of the stoichiometry of photoautotrophic, autotrophic, and heterotrophic removal of ammonia–nitrogen in aquaculture systems. Aquaculture 257:346–358. https://doi.org/10.1016/j.aquaculture.2006.03.019El-Dahhar AA, Salama M, Elebiary EH (2015) Effect of energy to protein ratio in biofloc technology on water quality, survival and growth of mullet (Mugil cephalus). J Arab Aquac Soc 10:15–32. https://doi.org/10.12816/0026633Emerenciano MGC, Martínez-Córdova LR, Martínez-Porchas M, Miranda-Baeza A (2017) Biofloc technology (BFT): a tool for water quality management. In: Tutu H (ed) water quality. InTech, Rijeka. https://doi.org/10.5772/66416Figueroa F, Niell F, Figueiras F, Villarino M (1998) Diel migration of phytoplankton and spectral light field in the Ria de Vigo (NW Spain). Mar Biol 130:491–499Gaona CAP, Poersch LH, Krummenauer D, Foes GK, Wasielesky WJ (2011) The effect of solids removal on water quality, growth and survival of Litopenaeus vannamei in a biofloc technology culture system. Int J Recirc Aquac. https://doi.org/10.21061/ijra.v12i1.1354Garrido JL, Airs RL, Rodríguez F, Van Heukelem L, Zapata M (2011) New HPLC separation techniques. In: Roy S, Llewellyn CA, Egeland ES, Johnsen G (eds) Phytoplankton pigments: characterization, chemotaxonomy, and applications in oceanography. University Press, Cambridge, pp 165–194Ge H, Li J, Chang Z, Chen P, Shen M, Zhao F (2016) Effect of microalgae with semicontinuous harvesting on water quality and zootechnical performance of white shrimp reared in the zero water exchange system. Aquac Eng 72–73:70–76. https://doi.org/10.1016/j.aquaeng.2016.04.006Godoy LC, Odebrecht C, Ballester E, Martins TG, Wasielesky WJ (2012) Effect of diatom supplementation during the nursery rearing of Litopenaeus vannamei (Boone, 1931) in a heterotrophic culture system. Aquac Int 20:559–569. https://doi.org/10.1007/s10499-011-9485-1Grasshoff K (1976) Methods of seawater analysis. Verlag Chemie: Weinstei, New YorkGreen BW, Schrader KK, Perschbacher PW (2014) Effect of stocking biomass on solids, phytoplankton communities, common off-flavors, and production parameters in a channel catfish biofloc technology production system. Aquac Res 45:1442–1458. https://doi.org/10.1111/are.12096Gris B, Sforza E, Morosinotto T, Bertucco A, La Rocca N (2017) Influence of light and temperature on growth and high-value molecules productivity from Cyanobacterium aponinum. J Appl Phycol 29:1781–1790. https://doi.org/10.1007/s10811-017-1133-3Higgins HW, Wright SW, Schlüter L (2011) Quantitative interpretation of chemotaxonomic pigment data. In: Roy S, Llewellyn CA, Egeland ES, Johnsen G (eds) Phytoplankton pigments: characterization, chemotaxonomy, and applications in oceanography. Cambridge University Press, Cambridge, pp 257–313Hooker S, Firestone E, Claustre H, Ras J (2001) The first SeaWiFS HPLC analysis round-robin experiment (SeaHARRE-1). https://ntrs.nasa.gov/search.jsp?R=20010072242 . Accessed 19 July 2017Horabun T (1997) Relationships between water quality and phytoplankton in the Bangpakong river. http://agris.fao.org/agris-search/search.do?recordID=TH2000001898 . Accessed 19 July 2017Ismael AA (2003) Succession of heterotrophic and mixotrophic dinoflagellates as well as autotrophic microplankton in the harbour of Alexandria, Egypt. J Plankton Res 25:193–202. https://doi.org/10.1093/plankt/25.2.193Jeffrey SW, Sielicki M, Haxo FT (1975) Chloroplast pigment patterns in dinoflagellates. J Phycol 11:374–384. https://doi.org/10.1111/j.1529-8817.1975.tb02799.xJeong HJ, Yoo YD, Kim JS, Seong KA, Kang NS, Kim TH (2010) Growth, feeding and ecological roles of the mixotrophic and heterotrophic dinoflagellates in marine planktonic food webs. Ocean Sci J 45:65–91. https://doi.org/10.1007/s12601-010-0007-2Jory DE, Cabrera TR, Dugger DM, Fegan D, Lee PG, Lawrence L, Jackson C, Mcintosh R, Castañeda J, International B, Park H, Hwy N, Pierce F (2001) A global review of shrimp feed management: status and perspectives. Aquaculture 318:104–152Ju ZY, Forster I, Conquest L, Dominy W, Kuo WC, Horgen FD (2008) Determination of microbial community structures of shrimp floc cultures by biomarkers and analysis of floc amino acid profiles. Aquac Res 39:118–133. https://doi.org/10.1111/j.1365-2109.2007.01856.xKingston MB (1999) Effect of light on vertical migration and photosynthesis of Euglena proxima (euglenophyta). J Phycol 35:245–253. https://doi.org/10.1046/j.1529-8817.1999.3520245.xLatasa M, Scharek R, Vidal M, Vila-Reixach G (2010) Preferences of phytoplankton groups for waters of different trophic status in the northwestern Mediterranean Sea. Mar Ecol Prog Ser 40:27–42. https://doi.org/10.3354/meps08559Li Y, Swift E, Buskey EJ (1996) Photoinhibition of mechanically stimulable bioluminescence in the heterotrophic dinoflagellate Protoperidinium depressum (pyrrophyta). J Phycol 32:974–982. https://doi.org/10.1111/j.0022-3646.1996.00974.xLi A, Stoecker D, Adolf J (1999) Feeding, pigmentation, photosynthesis and growth of the mixotrophic dinoflagellate Gyrodinium galatheanum. Aquat Microb Ecol 19:163–176. https://doi.org/10.3354/ame019163Lin YC, Chen JC (2001) Acute toxicity of ammonia on Litopenaeus vannamei (Boone) juveniles at different salinity levels. J Exp Mar Biol Ecol 259:109–119. https://doi.org/10.1016/S0022-0981(01)00227-1Lin YC, Chen JC (2003) Acute toxicity of nitrite on Litopenaeus vannamei (Boone) juveniles at different salinity levels. Aquaculture 224:93–201. https://doi.org/10.1016/S0044-8486(03)00220-5Lohscheider JN, Strittmatter M, Küpper H, Adamska I, Heaney S, Cunningham C (2011) Vertical distribution of epibenthic freshwater cyanobacterial Synechococcus spp. Strains depends on their ability for photoprotection. PLoS ONE. https://doi.org/10.1371/journal.pone.0020134Lukwambe B, Qiuqian L, Wu J, Zhang D, Wang K, Zheng Z (2015) The effects of commercial microbial agents (probiotics) on phytoplankton community structure in intensive white shrimp (Litopenaeus vannamei) aquaculture ponds. Aquac Int 23:1443–1455. https://doi.org/10.1007/s10499-015-9895-6Mackey MD, Mackey DJ, Higgins HW, Wright SW (1996) CHEMTAX—a program for estimating class abundances from chemical markers: application to HPLC measurements of phytoplankton. Mar Ecol Prog Ser 144:265–283Maicá PF, de Borba MR, Wasielesky WJ (2012) Effect of low salinity on microbial floc composition and performance of Litopenaeus vannamei (Boone) juveniles reared in a zero-water-exchange super-intensive system. Aquac Res 43:361–370. https://doi.org/10.1111/j.1365-2109.2011.02838.xManan H, Moh JHZ, Kasan NA, Suratman S, Ikhwanuddin M (2016) Identification of biofloc microscopic composition as the natural bioremediation in zero water exchange of Pacific white shrimp, Penaeus vannamei, culture in closed hatchery system. Appl Water Sci. https://doi.org/10.1007/s13201-016-0421-4Marinho YF, Brito LO, Campos S, Severi W, Andrade HA, Galvez AO (2016) Effect of the addition of Chaetoceros calcitrans, Navicula sp. and Phaeodactylum tricornutum (diatoms) on phytoplankton composition and growth of Litopenaeus vannamei (Boone) postlarvae reared in a biofloc system. Aquac Res 48:4155–4164. https://doi.org/10.1111/are.13235Martins TG, Odebrecht C, Jensen LV, D’Oca MG, Wasielesky WJ (2016) The contribution of diatoms to bioflocs lipid content and the performance of juvenile Litopenaeus vannamei (Boone, 1931) in a BFT culture system. Aquac Res 47:1315–1326. https://doi.org/10.1111/are.12592Murphy J, Riley JP (1962) A modified single solution method for the determination of phosphate in natural waters. Anal Chim Acta 27:31–36. https://doi.org/10.1016/S0003-2670(00)88444-5Natrah FMI, Bossier P, Sorgeloos P, Yusoff FM, Defoirdt T (2014) Significance of microalgal-bacterial interactions for aquaculture. Rev Aquac 6:48–61. https://doi.org/10.1111/raq.12024Niemi G, Wardrop D, Brooks R, Anderson S, Brady V, Paerl H, Rakocinski C, Brouwer M, Levinson B, McDonald M (2004) Rationale for a new generation of indicators for coastal waters. Environ Health Perspect 112:979–986. https://doi.org/10.1289/ehp.6903Paerl H, Tucker C (1995) Ecology of blue-green algae in aquaculture ponds. J World Aquac 26:109–131. https://doi.org/10.1111/j.1749-7345.1995.tb00235.xPérez-Linares J, Ochoa JL, GagoMartínez A (2008) Effect of PSP toxins in white leg shrimp Litopenaeus vannamei Boone, 1931. J Food Sci 73:T69–T73. https://doi.org/10.1111/j.1750-3841.2008.00710.xPérez-Morales A, Band-Schmidt CJ, Martínez-Díaz SF (2017) Mortality on zoea stage of the Pacific white shrimp Litopenaeus vannamei caused by Cochlodinium polykrikoides (Dinophyceae) and Chattonella spp. (Raphidophyceae). Mar Biol 164:57. https://doi.org/10.1007/s00227-017-3083-3Ray AJ, Dillon KS, Lotz JM (2011) Water quality dynamics and shrimp (Litopenaeus vannamei) production in intensive, mesohaline culture systems with two levels of biofloc management. Aquac Eng 45:127–136. https://doi.org/10.1016/j.aquaeng.2011.09.001Schlüter L, Lauridsen T, Krogh G (2006) Identification and quantification of phytoplankton groups in lakes using new pigment ratios–a comparison between pigment analysis by HPLC and microscopy. Freshwater 51:1474–1485. https://doi.org/10.1111/j.1365-2427.2006.01582.x/fullSchlüter L, Behl S, Striebel M, Stibor H (2016) Comparing microscopic counts and pigment analyses in 46 phytoplankton communities from lakes of different trophic state. Freshw Biol 61:1627–1639. https://doi.org/10.1111/fwb.12803Schrader KK, Green BW, Perschbacher PW (2011) Development of phytoplankton communities and common off-flavors in a biofloc technology system used for the culture of channel catfish (Ictalurus punctatus). Aquac Eng 45:118–126. https://doi.org/10.1016/j.aquaeng.2011.08.004Sebastiá M, Rodilla M (2013) Nutrient and phytoplankton analysis of a Mediterranean Coastal area. Environ Manage 51:225–240. https://doi.org/10.1007/s00267-012-9986-3Sebastiá M, Rodilla M, Sanchis J, Altur V (2012) Influence of nutrient inputs from a wetland dominated by agriculture on the phytoplankton community in a shallow harbour at the Spanish Mediterranean coast. Agric Ecosyst Environ 152:10–20. https://doi.org/10.1016/j.agee.2012.02.006Seoane S, Garmendia M, Revilla M, Borja Á, Franco J, Orive E, Valencia V (2011) Phytoplankton pigments and epifluorescence microscopy as tools for ecological status assessment in coastal and estuarine waters, within the Water Framework. Mar Pollut 62:1484–1497. https://doi.org/10.1016/j.marpolbul.2011.04.010Sinden A, Sinang SC (2016) Cyanobacteria in aquaculture systems: linking the occurrence, abundance and toxicity with rising temperatures. Int J Environ Sci Technol 13:2855–2862. https://doi.org/10.1007/s13762-016-1112-2Sospedra J, Niencheski LFH, Falco S, Andrade CF, Attisano KK, Rodilla M (2017) Identifying the main sources of silicate in coastal waters of the Southern Gulf of Valencia (Western Mediterranean Sea). Oceanologia. https://doi.org/10.1016/j.oceano.2017.07.004Strickland J (1960) Measuring the production of marine phytoplankton. Bull Fish Res Bd Canada 122:172Ter Braak CJF (1994) Canonical community ordination. Part I: basic theory and linear methods. Écoscience 1:127–140. https://doi.org/10.1080/11956860.1994.11682237Ter Braak C, Smilauer P (2002) CANOCO reference manual and CanoDraw for Windows user’s guide: software for canonical community ordination (version 4.5). http://library.wur.nl/WebQuery/wurpubs/wever/341885 . Accessed 19 July 2017Utermohl M (1985) Zur Vervollkommnung der quantitative Phytoplankton-Methodik. Limnologie 9:1–38Van Wyk P, Scarpa J (1999) Water quality requirements and management. In: Institution Harbor Branch Oceanographic (ed) Farming marine shrimp in recirculating freshwater systems. Florida Department of Agriculture and Consumer Services, Florida, pp 128–138Vinatea L, Gálvez AO, Browdy CL, Stokes A, Venero J, Haveman J, Lewis BL, Lawson A, Shuler A, Leffler JW (2010) Photosynthesis, water respiration and growth performance of Litopenaeus vannamei in a super-intensive raceway culture with zero water exchange: interaction of water quality variables. Aquac Eng 42:17–24. https://doi.org/10.1016/j.aquaeng.2009.09.001Wright S, Jeffrey S, Mantoura R (1991) Improved HPLC method for the analysis of chlorophylls and carotenoids from marine phytoplankton. Mar Ecol Prog Ser 77:186–196Yu H, Jia S, Dai Y (2009) Growth characteristics of the cyanobacterium Nostoc flagelliforme in photoautotrophic, mixotrophic and heterotrophic cultivation. J Appl Phycol 21:127–133. https://doi.org/10.1007/s10811-008-9341-5Yusoff FM, Zubaidah MS, Matias HB, Kwan TS (2002) Phytoplankton succession in intensive marine shrimp culture ponds treated with a commercial bacterial product. Aquac Res 33:269–278. https://doi.org/10.1046/j.1355-557x.2002.00671.

    Bats in the anthropogenic matrix: Challenges and opportunities for the conservation of chiroptera and their ecosystem services in agricultural landscapes

    Get PDF
    Intensification in land-use and farming practices has had largely negative effects on bats, leading to population declines and concomitant losses of ecosystem services. Current trends in land-use change suggest that agricultural areas will further expand, while production systems may either experience further intensification (particularly in developing nations) or become more environmentally friendly (especially in Europe). In this chapter, we review the existing literature on how agricultural management affects the bat assemblages and the behavior of individual bat species, as well as the literature on provision of ecosystem services by bats (pest insect suppression and pollination) in agricultural systems. Bats show highly variable responses to habitat conversion, with no significant change in species richness or measures of activity or abundance. In contrast, intensification within agricultural systems (i.e., increased agrochemical inputs, reduction of natural structuring elements such as hedges, woods, and marshes) had more consistently negative effects on abundance and species richness. Agroforestry systems appear to mitigate negative consequences of habitat conversion and intensification, often having higher abundances and activity levels than natural areas. Across biomes, bats play key roles in limiting populations of arthropods by consuming various agricultural pests. In tropical areas, bats are key pollinators of several commercial fruit species. However, these substantial benefits may go unrecognized by farmers, who sometimes associate bats with ecosystem disservices such as crop raiding. Given the importance of bats for global food production, future agricultural management should focus on “wildlife-friendly” farming practices that allow more bats to exploit and persist in the anthropogenic matrix so as to enhance provision of ecosystem services. Pressing research topics include (1) a better understanding of how local-level versus landscape-level management practices interact to structure bat assemblages, (2) the effects of new pesticide classes and GM crops on bat populations, and (3) how increased documentation and valuation of the ecosystem services provided by bats could improve attitudes of producers toward their conservation

    Management of severe paediatric malaria in resource-limited settings

    Get PDF
    corecore