Temporal variation of taxonomic diversity and functional traits of aquatic macroinvertebrates in temporary rivers on Old Providence Island, Colombia
DOI:
https://doi.org/10.17533/udea.acbi.v39n107a10Keywords:
benthic fauna, temporary waters, functional ecology, stomach contents, insular rivers and streamsAbstract
Intermittent streams in Colombia are located principally in dry forest zones and are important in maintaining the hydrological cycle and sustaining biodiversity and the water supply for local human populations. Some aspects of the functioning of these systems are not known in detail, especially in insular areas. This study describes the changes in the species composition, diversity, and some functional traits of macroinvertebrates related to discharge fluctuations in three intermittent streams on Old Providence Island. Sampling was performed during dry and rainy seasons. Ten (10) and 50 functional traits categories were selected, including trophic, physiological, morphological, behavioral and life cycle characteristics. A principal component analysis confirmed a strong seasonality associated with changes in electric conductivity, alkalinity, and dissolved oxygen. Sixty genus-level morphotypes were identified, with highest diversity in the Chironomidae (Diptera). According to a Canonical Correspondence Analysis, Chironomus, Pyrgophorus, Haitia and Dero were associated with high values in electrical conductivity, dissolved oxygen, and total hardness. With respect to functional traits, during dry season mechanisms for resisting specialized to resist the desiccation (cocoon or diapause), asexual reproduction, seasonal short life cycles, preferences for litter microhabitat, and trophic habit scrapers redominated, such as Ancylidae, Dero, Anopheles, Microvelia and Neritina. During rainy season bodies protected with shells or cases, seasonal long life cycles, and trophic collectors were found, such as Macrobrachium, Polypedilum, Helicopsyche, Beardius andChironomus. In conclusion, hydrological conditions affect the taxonomic and functional structure of the macroinvertebrates, and some physiological traits and life histories are essential for persistence in temporal environments.Downloads
References
Aguilera M. 2010. Geografía económica del archipiélago de San Andrés, Providencia y Santa Catalina. Cartagena (Colombia): Banco de la república: centro de estudios económicos regionales (CEER). p.73.
Allan JD, Castillo MM. 2007. Stream Ecology: Structure and function of running waters. Inglaterra: Chapman y Hall. p. 436.
Amundrud SL, Srivastava DS. 2016. Trophic interactions determine the effects of drought on an aquatic ecosystem. Ecology, 97 (6): 1475-1483. DOI: 10.1890/15-1638.1
Armendáriz LC. 2008. Ciclo de vida de Dero (Aulophorus) costatus Marcus, 1944 (Tubificidae, Oligochaeta) en un cuerpo de agua con vegetación flotante en las talas, Argentina. Gayana (Concepción), 72 (1): 23-30.
Barroso CX, Matthews-Cascon H. 2009. Spawning and intra-capsular development of Neritina zebra (Bruguière, 1792) (Mollusca: Gastropoda: Neritidae) under laboratory conditions. Invertebrate Reproduction and Development, 53 (3): 137-143.
Bass D. 2003. A Comparison of Freshwater Macroinvertebrate Communities on Small Caribbean Islands. BioScience, 53 (11): 1094-1100. DOI: 10.1641/0006-3568(2003)053[1094:ACOFMC]2.0.CO;2
Beche LA, Mcelravy EP, Resh VH. 2006. Long‐term seasonal variation in the biological traits of benthic‐macroinvertebrates in two Mediterranean‐climate streams in California, USA. Freshwater Biology, 51 (1): 56-75. DOI: 10.1111/j.1365-2427.2005.01473.x
Belvédère TT. 2014. Reproductive Biology, Ecology and Brief Description of the Alien Isopoda Sphaeroma (Walkeri, Stebbing 1905) in Tunis Southern Lagoon (Tunisia: Central Mediterranean). Paripex: Indian Journal of Research, 3 (8): 175-179.
Bichuette ME, Trajano E. 2003. A population study of epigean and subterranean Potamolithus snails from southeast Brazil (Mollusca: Gastropoda: Hydrobiidae). Hydrobiologia, 505 (1-3): 107-117. DOI: 10.1023/B:HYDR.0000007299.26220.b8
Blanco JF, Scatena FN. 2007. The spatial arrangement of Neritina virginea (Gastropoda: Neritidae) during upstream migration in a split‐channel reach. River Research and Applications, 23 (3): 235-245. DOI: 10.1002/rra.974
Blanco JF, Tamayo S, Scatena FN. 2014. Phenotypic variability of the shell in Neritinidae (Gastropoda: Neritimorpha) in Puerto Rican rivers. Revista de Biología Tropical, 62 (Suppl 2): 53-68.
Blanco JF, Contreras E, Giraldo LP. 2015. El flujo y la transformación de la materia orgánica: proceso ecosistémico maestro en las cuencas pericontinentales. En: Lasso CA, Blanco-Libreros JF y Sánchez-Duarte P. XII. Cuencas pericontinentales de Colombia, Ecuador, Perú y Venezuela. Colombia: Instituto de Investigación de Recursos Biológicos Alexander von Humboldt. p. 171-188.
Boag DA, Pearlstone PS. 1979. On the life cycle of Lymnaea stagnalis (Pulmonata: Gastropoda) in southwestern Alberta. Canadian Journal of Zoology, 57 (2): 353-362.
Bogan MT, Lytle DA. 2011. Severe drought drives novel community trajectories in desert stream pools. Freshwater Biology, 56 (10): 2070-2081. DOI: 10.1111/j.1365-2427.2011.02638.x
Bogan MT, Boersma KS, Lytle DA. 2015. Resistance and resilience of invertebrate communities to seasonal and supraseasonal drought in arid‐land headwater streams. Freshwater Biology, 60 (12): 2547-2558. DOI: 10.1111/fwb.12522
Bonada N, Prat N, Resh V, Statzner B. 2006. Developments in aquatic insect biomonitoring: a comparative analysis of recent approaches. Annual Review of Entomology, 51: 495-523. DOI:10.1146/annurev.ento.51.110104.151124
Bonada N, Rieradevall M, Prat N. 2007. Macroinvertebrate community structure and biological traits related to flow permanence in a Mediterranean river network. Hidrobiologia, 589: 91-106. DOI: 10.1007/s10750-007- 0723-5
Boulton A. 1989. Over-summering refuges of aquatic macroinvertebrates in two intermittent streams in Central Victoria. Transactions of The Royal Society of South Australia, 113: 23-34.
Brinkhurst RO. 1971. A guide for the identification of British aquatic Oligochaeta. Toronto: Freshwater Biological Association. p. 55.
Brinkhurst RO, Wetzel MJ. 1984. Aquatic Oligochaeta of the world: supplement a catalogue of new freshwater species descriptions, and revisions. Sidney: Canadian Technical Report of Hydrography and Ocean Sciences No. 44. p. 109.
Byers GW, Gelhaus JK. 2008. Tipulidae. En: Merrit RW, Cummins KW, Berg MB. An introduction to the aquatic insects of North America. USA: Kendall Hunt Publishing Company. p. 773-800.
Chará-Serna AM, Chara JD, Zúñiga MDC, Pearson RG, Boyero L. 2012. Diets of leaf litter-associated invertebrates in three tropical streams. Annales de Limnologie-International Journal of Limnology, 48 (2): 139-144. DOI: 10.1051/limn/2012013
Chen WY. 2004. Insecta: Diptera, Tipulidae. En: Yule CM, Yong HS. Freshwater invertebrates of the Malaysian region. Kuala Lumpur: Academy of Sciences Malaysia. p. 775-785.
Chevenet F, Dolédec S, Chessel D. 1994. A fuzzy coding approach for the analysis of longterm ecological data. Freshwater Biology, 31: 295-309. DOI: 10.1111/j.13652427.1994.tb01742.x
Christensen B. 1984. Asexual propagation and reproductive strategies in aquatic Oligochaeta. Hydrobiologia, 115 (1): 91-95. DOI: 10.1007/BF00027898
Clarke KR. 1993. Non-parametric multivariate analysis of changes in community structure. Australian Journal of Ecology, 18:117-143. DOI: 10.1111/j.14429993.1993.tb00438.x
Clifford H. 1966. The Ecology of Invertebrates in an Intermittent Stream. Investigations of Indiana lakes y streams, 7 (2): 57-98.
Cranstons_Chiropage [Internet]. 2010. UC Davis Department of Entomology and Nematology. Fecha de acceso: 21 de octubre de 2014. Disponible en: <http://chirokey.skullisland.info/references/>
Cortés-Guzmán D, Ospina-Torres R. 2014. Comunidades de macroinvertebrados acuáticos en quebradas de la Isla de Providencia, mar Caribe colombiano. Intropica, 9: 9-22. DOI: 10.21676/23897864.1421
Cortés-Guzmán D, Linares EL. 2016. Gasterópodos dulceacuícolas de Providencia, archipiélago de San Andrés, Providencia y Santa Catalina, Colombia. Acta Zoológica Mexicana (n. s.), 32 (1): 101-110.
Courtney GW, Webb DW, Merrit RW. 2008. Aquatic Diptera. En: Merritt RW, Cummins KW, Berg MB. An Introduction to the Aquatic Insects of North America USA: Kendall - Hunt Publishing Company. p. 687-772.
Covich AP. 1988. Geographical and historical comparisons of neotropical streams: biotic diversity and detrital processing in highly variable habitats. Journal of the North American Benthological Society, 7 (4): 361-386. DOI: 10.2307/1467297
Cummins KW. 1973. Trophic relations of aquatic insects. Annual Review of Entomology, 18 (1): 183-206.
Datry T, Fritz K, Leigh C. 2016. Challenges, developments and perspectives in intermittent river ecology. Freshwater Biology, 61 (8): 1171-1180. DOI: 10.1111/fwb.12789/full
Deonier DL, Regensburg JT. 1978. Biology and immature stages of Parydra quadrituberculata (Diptera: Ephydridae). Annals of the Entomological Society of America, 71 (3): 341-353.
Dézerald O, Céréghino R, Corbara B, Dejean A, Leroy C. 2015. Functional trait responses of aquatic macroinvertebrates to simulated drought in a Neotropical bromeliad ecosystem. Freshwater Biology, 60 (9): 1917-1929. DOI: 10.1111/fwb.12621
Dieterich M, Anderson N. 2000. The invertebrate fauna of summer-dry streams in western Oregon. Archiv für Hydrobiologie, 147 (3): 273-295. DOI: 10.1127/archivhydrobiol/147/2000/273
Dillon RT. 2000. The ecology of freshwater molluscs. Cambridge: Cambridge University Press. p. 509.
Ding N, Yang W, Zhou Y, González-Bergonzoni I, Zhang J, Chen K, Vidal N, Jeppesen E, Liu Z, Wang, B. 2017. Different responses of functional traits and diversity of stream macroinvertebrates to environmental and spatial factors in the Xishuangbanna watershed of the upper Mekong River Basin, China. Science of The Total Environment, 574: 288-299. DOI: 10.1016/j.scitotenv.2016.09.053
Ditrich T, Papácek M. 2009. A question of voltinism of Microvelia reticulata (Veliidae) and Mesovelia furcata (Mesoveliidae) (Heteroptera: Gerromorpha) in Central Europe. České Budějovice, 20-23.
Dole-Olivier M, Marmonier P, Beffy J. 1997. Response of invertebrates to lotic disturbance: is the hyporheic zone a patchy refugium? Freshwater Biology, 37 (2): 257-276. DOI: 10.1046/j.13652427.1997.00140.x
EPA. 2014. [Internet]. United States Environmental Protection Agency. Fecha de acceso: 1 de octubre de 2014. Disponible en: <http://www.epa.gov/ncea/global/traits/>
Epler JH. 1992. Identification manual for the larval Chironomidae (Diptera) of Florida. Orlando: Departament of environmental regulation state of Florida. p. 526.
Fernández H, Domínguez E. 2001. Guia para la identificación de los artrópodos bentónicos suramericanos. Tucumán: Universidad Nacional de Tucumán- Facultad de Ciencias Naturales e Instituto M. Lillo. p. 654
Foote BA. 1990. Biology and immature stages of Coenia curvicauda (Diptera: Ephydridae). Journal of the New York Entomological Society, 98 (1): 93-102.
Gaviria EA. 1993. Claves para las especies colombianas de las familias Naididae y Tubificidae (Oligochaeta, Annelida). Caldasia, 17 (2): 237-248. DOI: 10.15446/caldasia
Gelthaus JK. 2002. Manual for identification for aquatic Crane Fly larvae for southeastern United States. Durham: Carolina Area Benthological Workshop. p. 206.
Gómez-Aguirre AM, Longo-Sánchez MC, Blanco JF. 2009. Macroinvertebrate assemblages in Gorgona Island streams: spatial patterns during two contrasting hydrologic periods. Actualidades Biológicas, 31 (91): 161-178.
Gómez-López D, Segura-Quintero C, Sierra-Correa P, Garay-Tinoco J. 2012. Descripción física del archipiélago de San Andrés, Providencia y Santa Catalina. En: I. y. Coralina, Atlas reserva de la biosfera seaflower: Archipielago de San Andrés, Providencia y Santa Catalina. Santa Marta: Instituto de Investigaciones Marinas y costeras "Jose Benito Vives de Andréiss" INVEMAR y corporación para el Desarrollo Sostenible del Archipiélago de San Andrés Providencia y Santa Catalina -CORALINA- . Serie de Publicaciones Especiales de INVEMAR. p. 35-53.
Gore JA. 2007. Discharge measurements and streamflow analysis. En: Hauer FR and Lamberti GA. Methods in stream ecology. San Diego (USA): Academic Press. p. 51-79.
Graziani CA, Chung KS, De Donato M. 1993. Comportamiento reproductivo y fertilidad de Macrobrachium carcinus (Decapoda: Palaemonidae) en Venezuela. Revista Biología Tropical, 41 (3): 657-665.
Guisande C, Vaamonde A, Barreiro A. 2011. Tratamiento de datos con S, STATISTICA y SPSS. España: Ediciones Díaz de Santos. p. 933.
Hooper DU, Solan M, Symstad A, Diaz S, Gessner MO, Buchmann N. 2002. Species diversity, functional diversity and ecosystem functioning. En: M. Loreau, S. Naeem, y P. Inchaust, Biodiversity and ecosystem functioning: synthesis and perspectives. United States: Oxford University Press. p. 195-208.
Huryn AD, Wallace JB, Anderson NH. 2008. Habitat, life history, secondary production and behavioral adaptation of aquatic insect. En: Merrit RW, Cummins KW y Berg MB. An introduction to the aquatic insects of North America. USA: Kendall Hunt Publishing Company. p. 55-104.
Hynes HB. 1970. The ecology of stream insects. Annual Review of Entomology, 15 (1): 25-42.
Jackson JK, Sweeney BW. 1995. Egg and larval development times for 35 species of tropical stream insects from Costa Rica. Journal of the North American Benthological Society, 14 (1): 115-130. DOI: 10.2307/1467728
Junk WJ, Bayley PB, Sparks RE. 1989. The flood pulse concept in river-floodplain systems. Canadian special publication of fisheries and aquatic sciences, 106 (1): 110-127.
Labbe T, Fausch KD. 2000. Dynamics of intermittent stream habitat regulate persistence of a threatened fish at multiple scales. Ecological Applications, 10 (6): 1774–1791.
Lake P. 2003. Ecological effects of perturbation by drought in flowing waters. Freshwater Biology, 48: 1161-1172. DOI: 10.1046/j.1365-2427.2003.01086.x
Lampert W, Sommer U. 2007. Limnoecology: The ecology of lakes and stream. New York: Oxford University Press. p. 323.
Larned ST, Datry T, Arscott DB, Tockner K. 2010. Emerging concepts in temporary‐river ecology. Freshwater Biology, 55 (4): 717-738. DOI: 10.1111/j.13652427.2009.02322.x
Lepŝ J, Ŝmilauer P. 2003. Multivariate analysis of ecological data using CANOCO. Cambridge: Cambridge University Press. p. 269.
Longo M, Blanco J. 2009. Sobre los filtros que determinan la distribución y la abundancia de los macroinvertebrados diádromos y no-díadromos en cada nivel jerarárquico del paisaje fluvial en islas. Actualidades Biológicas, 31 (91): 179-195.
Longo M, Blanco J. 2014a. Shredders are abundant and species-rich in tropical continental-island low-order streams: Gorgona Island, Tropical Eastern Pacific, Colombia. International Journal of Tropical Biology and Conservation, 62: 85-105. DOI:10.15517/rbt.v62i0.15980
Longo M, Blanco J. 2014b. Patterns at Multi-Spatial Scales on Tropical Island Stream Insect Assemblages (Gorgona Island Natural National Park, Colombia, Tropical Eastern Pacific). Revista de Biología Tropical, 62 (Suppl. 1): 65-83. DOI: 10.15517/rbt.v62i0.15979
Longo M, Cortés-Guzmán D, Contreras E, Motta A, Blanco-Libreros JF, Lasso CA, Ospina R. 2015. La entomofauna y otros macroinvertebrados acuáticos de sistemas insulares y pericontinentales de las cuencas del Pacífico y Caribe, Colombia. En: Lasso CA, Blanco-Libreros JF y Sánchez-Duarte P. XII. Cuencas pericontinentales de Colombia, Ecuador, Perú y Venezuela. Colombia: Instituto de Investigación de Recursos Biológicos Alexander von Humboldt. p. 141-169.
Longo M, Gómez-Aguirre A, Blanco J, Zamora-González H. 2009. Cambios multianuales y espaciales de la composición y estructura del ensamblaje de insectos acuáticos en las quebradas perennes de la Isla Gorgona, Colombia. Actualidades Biológicas, 31 (91): 141-160.
Longo M, Zarnora H, Guisande C, Ramírez JJ. 2010. Dinámica de la comunidad de macroinvertebrados en la quebrada Potrerillos (Colombia): Respuesta a los cambios estacionales de caudal. Limnetica, 29 (2): 195-210.
Luiza-Andrade A, de Assis Montag LF, Juen L. 2017. Functional diversity in studies of aquatic macroinvertebrates community. Scientometrics, 111 (3): 1643-1656 DOI 10.1007/s11192-017- 2315-0
Maasri A, Dumont B, Claret C, Archambaud-Suard G, Gandouin E, Franquet É. 2008. Tributaries under Mediterranean climate: their role in macrobenthos diversity maintenance. Comptes Rendus Biologies, 331 (7): 547-558. DOI: 10.1016/j.crvi.2008.04.009
McCafferty P, Provonsha A. 1981. Aquatic Entomology. Boston: Science Books International. p. 449.
McDonough O, Hosen J, Palmer M. 2011. Temporary streams: The hydrology, geography and ecology of non-perennially flowing waters. En: Elliot H, y Martin L. River ecosystems: Dynamics, management and conservation. Hauppauge, NY: Nova Science Publishers, Inc. p. 259-290.
Merrit RW, Cummins KW, Berg MB. 2008. An introduction to the aquatic insects of North America. USA: Kendall Hunt Publishing Company. p. 1158.
Muñoz I. 2003. Macroinvertebrate community structure in an intermittent and a permanent Mediterranean streams (NE Spain). Limnetica, 22 (3-4): 107-116.
Muraji M, Nakasuji F. (1990). Effect of photoperiodic shifts on egg production in a semi-aquatic bug, Microvelia douglasi (Heteroptera: Veliidae). Applied Entomology and Zoology, 25 (3): 405-407.
Nava M, Severeyn H, Machado N. 2011. Nava, M., Distribución y taxonomía de Pyrgophorus platyrachis (Caenogastropoda: Hydrobiidae), en el Sistema de Maracaibo, Venezuela. Revista de Biología Tropical, 59 (3): 1165-1172.
Pennak R. 1989. Fresh Water Invertebrates of the United States - Protozoa to Mollusca. New York: John Wiley y Sons, INC. p. 628. Pla L, Casanoves F, Di Rienzo J. 2012. Quantifying Functional Biodiversity. Venezuela: Springer. p. 96.
Rodrigues-Capítulo A, Muñoz I, Bonada N, Gaudes A, Tomanova S. 2009. La biota de los ríos: los invertebrados. En: Elosegi A, Sabater S. Conceptos y técnicas en ecología fluvial. España: Fundación BBVA. p. 253-270.
Schmera D, Heino J, Podani J, Erős T, Dolédec S. 2017. Functional diversity: a review of methodology and current knowledge in freshwater macroinvertebrate research. Hydrobiologia, 787 (1): 27-44. DOI: 10.1007/s10750-016- 2974-5
Skoulikidis NT, Sabater S, Datry T, Morais MM, Buffagni A, Dörflinger G, Zogaris S, Sánchez-Montoya MM, Bonada N, Kalogianni E, Rosado J, Vardakas L, De Girolamo AM, Tockner K. 2017. Non-perennial Mediterranean rivers in Europe: status, pressures, and challenges for research and management. Science of The Total Environment, 577: 1-18. DOI: 10.1016/j.scitotenv.2016.10.147
Southwood TE. 1977. Habitat, the templet for ecological. Journal of Animal Ecology, 46: 337-365.
Statzner B, Bady P, Dolédec S, Schöll F. 2005. Invertebrate traits for the biomonitoring of large European rivers: an initial assessment of trait patterns in least impacted river reaches. Freshwater Biology, 50 (12): 2136-2161. DOI: 10.1111/j.13652427.2005.01447.x
Stubbington R, Gunn J, Little S, Worrall TP, Wood PJ. 2016. Macroinvertebrate seedbank composition in relation to antecedent duration of drying and multiple wet‐dry cycles in a temporary stream. Freshwater Biology, 61 (8): 1293-1307. DOI: 10.1111/fwb.12770
Tachet H, Richoux P, Bournaud M, Usseglio-Polatera P. 2000. Invertébrés d’eau douce: systématique, biologie, écologie. París: CNRS Editions.
Tokeshi M. 1995. Life cycles and population dynamics. En: Armitage PD, Cranston P, Pinder LC. The Chironomidae: biology and ecology of non-biting midges. Londres: Chapman y Hall. p. 225-251.
Tomanova S. 2007. Functional aspect of macroinvertebrate communities in tropical and temperate running waters. [PhD thesis]. [Brno (Czech Republic)]: Masaryk University.
Tomanova S, Usseglio-Polatera P. 2007. Patterns of benthic community traits in neotropical streams: relationship to mesoscale spatial variability. Fundamental and Applied Limnology. Archiv für Hydrobiologie, 170 (3): 243–255. DOI: 10.1127/1863-9135/2007/0170- 0243
Tomanova S, Moya N, Oberdorff T. 2008. Using macroinvertebrate biological traits for assessing biotic integrity of neotropical streams. River Research and Applications, 24 (9): 1230-1239. DOI: 10.1002/rra.1148
Torres-Zambrano NN, Torres-Zambrano DR. 2016. Macroinvertebrados acuáticos de la quebrada Los Alisos, Firavitoba-Boyacá. Intropica, 11: 47-56. DOI: 10.21676/23897864.1860
Townsend CR, Hildrew AG. 1994. Species traits in relation to a habitat templet for river. Freshwater Biology, 31: 265-275. DOI: 10.1111/j.1365-2427.1994.tb01740.x
Valencia D, Campos M. 2007. Freshwater prawns of the genus Macrobrachium Bate, 1868 (Crustacea: Decapoda: Palaemonidae) of Colombia. Zootaxa, 1456: 1-44.
Valencia SM, Pérez GA, Lizarazo PX, Blanco JF. 2009. Patrones espacio-temporales de la estructura y composición de la hojarasca en las quebradas del Parque Nacional Natural Gorgona. Actualidades Biológicas, 31(91): 197-211.
Violle C, Navas ML, Vile D, Kazakou E, Fortune C, Hummel I, Garnier E. 2007. Let the concept of trait be functional! Oikos, 116 (5): 882-892. DOI: 10.1111/j.00301299.2007.15559.x
Williams D. 1996. Environmental constraints in temporary fresh waters and their consequences for the insect fauna. Journal of the North American Benthological Society, 15 (4): 634-650.
Williams D, Hynes HB. 1977. The ecology of temporary streams II. General remarks on temporary streams. Internationale Revue der gesamten Hydrobiologie und Hydrographie, 62 (1): 53-6.
Published
How to Cite
Issue
Section
License
Copyright (c) 2017 Actualidades Biológicas
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
The authors exclusively authorize the Actualidades Biológicas journal to edit and publish the submitted manuscript if its publication is recommended and accepted, without this representing any cost to the Journal or the University of Antioquia.
All the ideas and opinions contained in the articles are sole responsibility of the authors. The total content of the issues or supplements of the journal is protected under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, so they cannot be used for commercial purposes, but for educational purposes. However, please mention the Actualidades Biológicas journal as a source and send a copy of the publication in which the content was reproduced.