Abstract
A new scorpion species, Tityus imei sp. nov., is described, representing the first record of the genus for the southern foothills of Sierra de Portuguesa in the western Venezuelan state of Portuguesa. The species is morphologically related to T. sanarensis, from the state of Lara, and T. boconoensis, from state of Trujillo. Tityus imei sp. nov. can be distinguished by the array of dorsal trichobothria in the pedipalp femur (d3, d4, d5) and by the following combination of female metasomal segment II characters: (i) ventral keels double and parallel up to two thirds of the segment, whereupon they converge into a single keel and separate again in the base; (ii) full, parallel ventral keels, including a well defined central keel in the second half of the segment. A molecular approach was undertaken to estimate the genetic relationship between the new species, T. sanarensis, T. boconoensis, and T. discrepans. Sequencing of a 562 bp-segment encoding sectors M6 to M11 of the cytochrome oxidase subunit I revealed that T. imei sp. nov. diverges from T. sanarensis and T. boconoensis, particularly in the polymorphic sector I4, sharing more overall sequence similarity with the northcentral Venezuelan species, T. discrepans. The new species is of potential medical importance given the presence of venom components whose mass resembles that of scorpion neurotoxins affecting voltage-sensitive sodium channels, as indicated by MALDI-TOF MS analyses.
References
Borges, A. (1996) Escorpionismo en Venezuela. Acta Biológica Venezuélica, 16, 65–75.
Borges, A., Arandia, J., Colmenares-Árias, Z., Vargas, A. M. & Alfonzo, M.J. (2002) Caracterización epidemiológica y toxicológica del envenenamiento por Tityus zulianus (Scorpiones, Buthidae) en el estado Mérida, Venezuela. Revista de la Facultad de Medicina (Caracas), 25, 76–79.
Borges, A., Alfonzo, M.J., García, C.C., Winand, N.J., Leipold, E. & Heinemann, S.H. (2004) Isolation, molecular cloning and functional characterization of a novel b-toxin from the Venezuelan scorpion, Tityus zulianus. Toxicon, 43, 671–684.
Borges, A., García, C.C., Lugo, E., Alfonzo, M.J., Jowers, M.J. & Op den Camp, H. (2006) Diversity of long-chain toxins in Tityus zulianus and Tityus discrepans venoms (Scorpiones, Buthidae): molecular, immunological, and mass spectral analyses. Comparative Biochemistry and Physiology (In Press).
Campos, V., Guedez, V. & Osuna, S. (1979) Geología de la Serranía de Portuguesa, Estados Portuguesa y Lara. Boletín de Geología y Minas (Caracas), XIII, 3–47.
Delabre, M.L., Pasero, P. & Mariley, M. (1995) Promotor structure and intron-exon organization of a scorpion a-toxin gene. Biochemistry, 34, 6729–6736.
Dyason, K., Brandt, W., Prendini, L., Verdonck, F., Tytgat, J., du Plessis, J., Muller, G. & van der Walt, J. (2002) Determination of species-specific components in the venom of Parabuthus scorpions from southern Africa using matrix-assisted laser desorption time-of-flight mass spectrometry. Rapid Communications in Mass Spectrometry, 16, 768–773.
De Sousa, L., Parrilla-Álvarez, P. & Quiroga, M. (2000) An epidemiological review of scorpion stings in Venezuela. The northeastern Region. Journal of Venomous Animals and Toxins, 6, 127–165.
De Sousa, L., Manzanilla, J. & Parrilla-Álvarez, P. (2004) Nueva especie de Tityus (Scorpiones: Buthidae) del Macizo del Turimiquire, Estados Monagas y Sucre, Venezuela. Revista de Biología Tropical, 52 (In Press).
Fet, V. & Lowe, G. (2000) Family Buthidae C. L. Koch, 1837. In: Fet, V., Sissom, W.D., Lowe, G. & Braunwalder, M.E. (Eds) Catalog of the Scorpions of the World (1758–1998). New York Entomological Society, New York, pp. 54–286.
Fet, V., Gantenbein, B., Soleglad, M.E., Vignoli, V., Salomone, E., Fet, E., & Schembri, P.J. (2003) New molecular and morphological data on the "Euscorpius carpathicus" species complex (Scorpiones: Euscorpiidae) from Italy, Malta, and Greece justify the elevation of E. c. sicanus (C. L. Koch, 1837) to the species level. Revue suisse de Zoologie, 110, 355–379.
Gantenbein, B., Fet, V., Barker, M. & Scholl, A. (2000a) Nuclear and mitochondrial markers reveal the existence of two parapatric scorpion species in the Alps: Euscorpius germanus (C. L. Koch, 1837) and E. alpha Caporiacco, 1950, stat. novo (Scorpiones, Euscorpiidae). Revue suisse de Zoologie, 107, 843–869.
Gantenbein, B., Kropf, C., Largiader, C.R. & Scholl, A. (2000b) Molecular and morphological evidence for the presence of a new buthid taxon (Scorpiones: Buthidae) on the island of Cyprus. Revue suisse de Zoologie, 107, 213–232.
Gantenbein, B., Soleglad, M.E. & Fet, V. (2001) Euscorpius balearicus Caporiacco, 1950, stat. novo (Scorpiones: Euscorpiidae): molecular (allozymes and mtDNA) and morphological evidence for an endemic Balearic Islands species. Organisms, Diversity & Evolution, 1, 301–320.
González-Sponga, M.A. (1981) Seis nuevas especies del género Tityus en Venezuela (Scorpionida: Buthidae). Monografías Científicas Augusto Pi Suñer (Instituto Universitario Pedagógico, Caracas), 12, 3–86.
González-Sponga, M.A. (1984) Escorpiones de Venezuela. Cuadernos Lagoven, Caracas, 129 pp.
González-Sponga, M.A. (1996) Guía para identificar escorpiones de Venezuela. Cuadernos Lagoven, Caracas, 204 pp.
González-Sponga, M.A. (1997) Venezuelan arachnids. Two new species of the Tityus genus (Scorpionida: Buthidae) in the State of Lara. Journal of Venomous Animals and Toxins, 3, 295–310.
González-Sponga, M.A. (2002) Arácnidos de Venezuela. Cuatro especies nuevas del género Tityus (Scorpionida: Buthidae). Boletín de la Academia de Ciencias Físicas, Matemáticas y Naturales de Venezuela, LXII, 49–66.
González-Sponga, M.A., D´Suze, G. & Sevcik, C. (2001) Venezuelan Arachnids. Two new species of the Tityus genus (Scorpionida: Buthidae) and the chromatographic profile of venom as a possible taxonomic tool. Journal of Venomous Animals and Toxins, 7, 219–239.
Lourenço, W.R. (1997) Additions à la faune de scorpions néotropicaux (Arachnida). Revue Suisse de Zoologie, 104, 587–604.
Lourenço, W.R. (1998) Les Scorpions (Chelicerata, Scorpiones) de l'Equateur avec quelques considerations sur la biogeographie et la diversite des especes. Revue Suisse de Zoologie, 102, 61–88.
Lourenço, W.R. (2000) Synopsis of the Colombian species of Tityus Köch (Chelicerata, Scorpiones, Buthidae), with descriptions of three new species. Journal of Natural History, 34, 449–461.
Lourenço, W.R. & Cuéllar, O. (1995) Scorpions, scorpionism, life history strategies and parthenogenesis. Journal of Venomous Animals and Toxins, 1, 51–62.
Lourenço, W.R. & Bruehmueller Ramos, E.C. (2004) New considerations on the status of Tityus magnimanus Pocock, 1897 (Scorpiones: Buthidae), and description of a new species of Tityus from the state of Roraima, Brazil. Revista Ibérica de Aracnología, 10, 285–291.
Lowry, O.N., Rosebrough, N.H., Farr, A.L. & Randall, R.J., (1951) Protein measurement with the Folin phenol reagent. Journal of Biological Chemistry, 193, 257–265.
Lunt, D.H., Zhang, D.-X., Szymura, J.M. & Hewitt, G.M. (1996) The insect cytochrome oxidase I gene: evolutionary patterns and conserved primers for phylogenetic studies. Insect Molecular Biology, 5, 153–165.
Manzanilla, J., De Sousa, L., Quiroga, M., López, H. & Parrilla-Álvarez, P. (2002) Morfología externa de Rhopalurus laticauda (Scorpiones: Buthidae). SABER (Universidad de Oriente, Venezuela), 14, 94–102.
Manzanilla, J., Jowers, M.J., La Marca, E. & García-París, M. (2005) Taxonomic reassessment of Mannophryne trinitatis (Anura: Dendrobatidae) with description of a new species from Venezuela. Herpetological Journal (In Press).
Martin-Eauclaire, M.-F. & Couraud, F. (1995) Scorpion neurotoxins: effects and mechanisms. In: Chang, L.W. & Dyer, E.S. (Eds.) Handbook of Neurotoxicology, Marcel Dekker, New York, pp. 683–716.
Pimenta, A.M., De Marco Almeida, F., de Lima, M.E., Martin-Eauclaire, M.F. & Bougis, P.E. (2003) Individual variability in Tityus serrulatus (Scorpiones, Buthidae) venom elicited by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Rapid Communications in Mass Spectrometry, 17, 413–418.
Quiroga, M., De Sousa, L., Parrilla-Álvarez, P. & Manzanilla, J. (2004) The first report of Tityus (Scorpiones: Buthidae) in Anzoátegui State, Venezuela. A new species. Journal of Venomous Animals and Toxins including Tropical Diseases, 10, 10–33.
Simon, C., Frati, F., Beckenbach, A., Crespi, B., Liu, H. & Flook, P. (1994) Evolution, Weighting, and Phylogenetic Utility of Mitochondrial Gene Sequences and a Compilation of Conserved Polymerase Chain Reaction Primers. Annals of the Entomological Society of America, 87, 651–701.
Shulov, A. & Zlotkin, E. (1969) A simple device for collecting scorpion venom. Toxicon, 2, 331–332.
Sissom, W. D. (1990) Systematics, biogeography, and palaeontology. In: Polis, G.A. (Ed) The Biology of Scorpions. Stanford University Press, Stanford, California, pp. 64–160
Stahnke, H.L. (1970) Scorpion nomenclature and mensuration. Entomological News, 81, 297–316.
Tanaka, H., Roubik, D.W., Kato, M., Liew, F. & Gunsalam, G. (2001) Phylogenetic position of Apis nuluensis on northern Borneo and phylogeography of A. cercana as inferred from mitochondrial DNA sequences. Insectes Sociaux, 48, 44–51.
Thompson, J.D., Higgins, D.G. & Gibson, T.J. (1994) CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, positions-specific gap penalties and weight matrix choice. Nucleic Acids Research, 22, 4673–4680.
Vachon, M. (1974) Êtude des caractères utilisés pour classer les families et les genres de Scorpions (Arachnides). 1. La trichobothriotaxie en arachnologie. Singles trichobothriaux et types de trichobothriotaxie chez les Scorpions. Bulletin du Muséum National d´Histoire Naturelle (Paris) (Série 3, nº 140), Zoologie, 104, 857–958.
Valdez-Cruz, N.A., Davila, S., Licea, A., Corona, M., Zamudio, F.Z., Garcia-Valdes, J., Boyer, L. & Possani, L.D. (2004) Biochemical, genetic and physiological characterization of venom components from two species of scorpions: Centruroides exilicauda Wood and Centruroides sculpturatus Ewing. Biochimie, 86, 387–96.
Yamashita, T. & Fet, V. (2001) Molecular approaches to Biogeography. In: Brownell, P. & Polis, G. (Eds), Scorpion Biology and Research. Oxford University Press, Oxford, United Kingdom, pp. 347–369.