Marisa Esteban Ruiz Esteban: [Dirección] [E-mail] ESTEBAN, M.; GARCIA-PARIS, M.; BUCKLEY, D. & CASTANET, J. 1999. Bone growth and age in Rana saharica, a water frog living in a desert environment. Annales Zoologici Fennici. 36: 53­62. The structure and the histological expression of annual bone growth marks of Moroccan water frogs (Rana saharica) from an arid climate region (northern edge of the Sahara desert) differ from the pattern observed in water frogs from temperate climate regions. At early ages, when growing rates are high, the osteogenic activity of the froglets never stops completely, and during the resting period the histological marks formed in the bone are mostly annuli. However, growth marks formed in older individuals are mostly well defined thin LAGs, which correspond to a complete stop in of osteogenesis. Males and females mature when they are two years old. The oldest males and females were six years old. One-year-old froglets showed a wide range in body size (22.4 to 40.9 mm) associated with an extended period of metamorphosis. Considering LAG diameter as the diameter of the phalange at a given age, we obtained successive phalange diameters for each individual corresponding to each year of its life. The diameter of the LAG1 of adults of Rana saharica is significantly larger than the diameter of the LAG1 of one year old juveniles. We found similar results studying the tibiofibulae of the sister taxon of R. saharica, R. perezi. Larger froglets were thus more successful than smaller ones in generating the adult samples suggesting the existence of size mediated selection. Extended breeding periods, which allow various metamorphosis peaks along the year, would be apparently disadvantageous for the species, since only froglets of a few subcohorts would be able to survive. However, this strategy could be of importance in Mediterranean and desert areas where local conditions change dramatically from year to year. ESTEBAN, M.; CASTANET, J. & SANCHIZ, B. 1998. Inferring age and growth from remains of fossil and predated Recent anurans: a test case using skeletochronology. Canadian Journal of Zoology, 76: 1689-1695. Large amounts of vertebrate remains regurgitated by owls are potentially available for continuous monitoring of predated populations, without human interference or the need to sacrifice any specimens. Presumably, Pleistocene and Holocene fossil microvertebrate assemblages found in caves or shelters are also principally the result of predation by nocturnal bird . Our study tests, for the first time, the standard skeletochronological technique on such prey remains. We analyse two Spanish samples from the genus Discoglossus (Amphibia, Anura, Discoglossidae), a living population of D. galganoi (n= 65 individuals) predated by the European Barn Owl, Tyto alba, and a Pliocene-Pleistocene sample of an extinct species (n= 22) presumably predated by Tyto balearica, a closely related ancestor of T. alba. The histological peculiarities and alterations found in bones of both samples are described, but the results indicate that, in general, this type of material is suitable for skeletochronological applications. In the living population, both size and longevity were greater than previously recorded for the species. For both studied samples, size and age are positively, though weakly, weakly correlated. Comparisons by age-class show that the extinct species is larger than the living one, particularly for the 4- and 5- year-old individuals. Growth rates in juveniles (or larvae) of the extinct species should have been slightly higher than in the living species, with similar growth rates after the third year. Recorded longevity is higher in the extinct species. All these life-history traits support a distinct taxonomic status for the extinct Balearic Discoglossus species. ESTEBAN, M. & SANCHIZ, B. 1997. Descripción de nuevas especies animales de la Península Ibérica e Islas Baleares (1978-1994): Tendencias taxonómicas y listado sistemático. Graellsia 53: 111-175. During the period 1978-1994 about 2000 new animal species have been described in the Iberian Peninsula and the Balearic Islands. A complete list of these new species for 1978-1993, taxonomically arranged, and their bibliographic references is given in an appendix. Global trends in this process of biodiversity inventory demostrate a moderate but continuous increment in the number of taxa descriptions, as well as a higher contribution of Spanish authors. The number of articles published in journals listed by the Science Citation Index, and the use of the English language, are clearly growing. Most of the different phyla, classes or orders show an extreme variation in the number of described species per year, probably due to the small absolute number of publications. Insects clearly are the most studied group, but a certain decrease in its relative importance can be observed, related to the increase of studies on poorly known groups, such as nematodes. ESTEBAN, M., BELLO, E. & GARCIA-VALDECASAS, A. 1997. La Zoología en Internet. Graellsia 53: 3-27. The main goal of this paper is to facilitate the access of the zoologist to the information online in Internet (mainly through World Wide eb pages). After a presentation of the principal search engines, a number of server address are given for the different zoological specialities, from zoological software, databases, etc. We hope to promote the use of this wealth of information. MARQUEZ, R.; ESTEBAN, M. & CASTANET, J. 1997. Size dimorphism and age in midwife toads A. obstetricans and A. cisternasii. Journal of Herpetology, 31 (1): 52-59. We studied sexual size dimorphism is in two breeding populations of midwife toads (Alytes obstetricans and Alytes cisternasii ) from which skeletochronological data provide information on individual age. The populations values show that females are larger than males in both species (Alytes obstetricans , SVLmale = 41.74 mm, SVLfemale = 49.69 mm; A. cisternasii, SVLmale = 35.79 mm, SVLfemale = 38.58). The values obtained for population size dimorphism (Ln (xmale)-Ln(xfemale) -0.174 for Alytes obstetricans and -0.074 for A. cisternasii ) are higher than the age-specific values (range -0.126 to -0.055 for A. obstetricans; -0.101 to -0.043 for A. cisternasii ). Differences between age-specific and population dimorphism values are particulary marked in A. obstetricans, where the age distribution of the sample of males and females differ the most. This result suggests that caution should be used when considering population data on size dimorphism to test evolutionary hypotheses about the evolution of this phenomenon. The dimorphism values obtained for the two species are not markedly different from those obtained from other temperate anurans without male parental care. This result does not support the prediction of the investment hypothesis (Williams, 1966; Trivers, 1972) that male parental care may act as a limitation on sexual selection on male size. ESTEBAN, M.; GARCIA-PARIS, M. & CASTANET, J. 1996. Bone growth and life history traits of frogs (Rana perezi) from a warm temparate climate area. Canadian Journal of Zoology, 74: 1914-1921. The structure and the histological expression of annual growth marks of Iberian water frogs (Rana perezi) from a warm temperate climate region (southwestern Spain) differ markedly from the pattern observed in colder climate populations. Forty-eight percent of winter growth marks appeared to be annuli; 52% are lines of arrested growth but 20% of theseare weakly expressed. Annuli or lines of arrested growth were very diffuse or absent in 7% of the 103 individuals studied, suggesting that the variations in climate have a stronger influence on growth mark formation than previously considered. Males and females are sexually mature at their second year, although some males mature at 1 year of age and some females at 3 years. The oldest males were 4 years old, 1 year younger than males from northern populations. The oldest female is 6 years old. The wide range of body sizes among the 1-year-old froglets can be explained by the extended period of metamorphosis, from July to November. ESTEBAN, M.; CASTANET, J. & SANCHIZ, B.1995. Size inferences based on skeletal fragments of the common European frog (Rana temporaria L.). Herpetological Journal, 5: 229-235. Based on a museum collection of skeletons of adult Rana temporaria (Ranidae) from a single population in the French Doubs region, equations for regression that predict the size (total length) and mass (total weight) of the animals are presented. Twenty-six measurements based on skeletal elements were selected as independent variables for the regressions, representing the most common fragments recovered in ecological and paleontological studies. Equations are given for males on all variables, and for males and females jointly in the 11 variables that showed no significant sexual dimorphism in the three-year age class subsample. Proximo-distal lengths are better predictors in general than trasverse. BUCKLEY, D.; ARANO, B.; HERRERO, P.; LLORENTE, G.A. & ESTEBAN, M. 1995. Moroccan water frogs vs Rana perezi: Allozyme studies show up their differences. Zool. Pol. 39 (3-4): 365-375. Water frogs populations from Morocco and Algeria were compared electrophoretically with Rana perezi from the Iberian Peninsula in order to determine their status and to delimit the southern distribution of R. perezi. Two loci, LdhB and Sod proved to be good markers for didtinguishing Iberian from African water frogs. Moroccan populations were very homogeneous, i.e. genetic distances between them were very low (DN = 0.02). Distances between Iberian and African populations were high, indicating a strong differentiation between the water frogs of these geografic areas. The populations from Morocco were also genetically different from the Algerian ones (Dn = 0.22) pointing to the presence of two distinct forms of water frogs belonging to the R. saharica group. Our results also confirm the absence of R. perezi from the North of Africa and of hybridogenesis. SANCHIZ, B. & ESTEBAN, M. 1994. Herpetofauna del Pleistoceno Terminal de Laminak II. (Pleistocene herpetofauna of Laminak II). Kobie, Revista del Museo Arqueológico, Etnográfico e Histórico Vasco. 21: 235-242. The herpetofauna of the lastest Pleistocene site Laminak II (Berriatua, Basque country), dated ca. 11000BP, include some remains of the Caudata amphibians Salmandra salamandra, Triturus helveticus and an unidentified Salamandrid newt. It is recorded, among anurans, the presence of Alytes obstetricans (Discoglossidae), Bufo bufo (Bufonidae), as well as an abundant sample of Rana temporaria (Ranidae). Among reptiles there are remains of Anguis fragilis (Anguidae), as well as unidentified lacertids and colubrids. Bufo bufo and R. temporaria are frequent components of the European Pleistocene faunas, but the record of Triturus helveticus would be one of the first for the Iberian peninsula as fossil. A biometrical comparative analysis indicates that the frog from Laminak II does not show significant differences with respect to the Recent form of Rana temporaria from the Pyrenees, but it differs from the two Cantabrian subspecies and also from the other brown frogs living in the Iberian Peninsula. GARCIA-PARIS, M.; HERRERO, P.; MARTIN, C.; DORDA, J.; ESTEBAN, M. & ARANO, B. 1993. Morphological characterization, geographical distribution and cytogenetic analysis of the pygmy merbled newt Triturus marmoratus pygmaeus (Wolterstorff, 1905) (Caudata: Salamandridae). Bijdragen tot de Dierhunde, 63 (1): 3-14. Triturus marmoratus pygmaeus, a problematic subspecies of the Marbled Newt from the southern part of the Iberian Peninsula, is redescribed using specimens collected in the "typical" area. Diagnostic external morphological features are provided to permit the accurate determination of the specimens belonging either to T. m. marmoratus or to T. m. pygmaeus. These diagnostic features were applied to individuals both from the field and from museum collections. The results indicate a larger distributional area for T. m. pygmaeus than was previously recognized. The distribution of T. m. marmoratus ranges over the northern half of the Iberian Peninsula and most of France; T. m. pygmaeus occupies the southwestern part of the Iberian Peninsula. The contact area between the two subspecies seems to be located along the Central Range Mountains (Sistema Central) in Portugal and Spain. T. m. marmoratus extends southwards beyond this borderline in three areas: Serra da Estrela (Portugal), Sierra de Gata (Spain) and Sierra de Guadarrama (Spain). The only point at which T. m. pygmaeus reaches northwards beyond the Central System is near Puerto de Malagón (Madrid Province, Spain). No cases of strict sympatry, nor individuals with intermediate morphological features have been observed. The results of an extensive cytogenetical analysis do not show any differences between T. m. pygmaeus and T. m. marmoratus. Interestingly, however, the T. m. pygmaeus populations from Doñana (Huelva Province, Spain) showed an exclusive, though little differentiated, C-banding pattern. ARANO, B.; ESTEBAN, M. & HERRERO, P. 1993. Evolutionary divergence of the species of the Rana temporaria group. Ann. Sci. Nat. Zool., 14: 49-57. An allozyme study of different Iberian species and populations of brown frogs Rana iberica , R. temporaria et R. dalmatina has allowed the electrophoretic characterization of these groups. The analysis of their genetic variability has shown a clear differentiation among these three species, with the loci Mdh-1, Mdh-2 and Pep-B being diagnostic for each of the species examined. The electrophoretic data support a dating of cladogenetic events among living lineages clearly much older than the Plio-Pleistocene boundary, probably Miocene. Furthermore, the results of the analysis at the population level have made evident the clear genetic differentiation present within R. temporaria. Loci Icd-2 and Ldh-2 are diagnostic for the populations belonging to R. temporaria parvipalmata. This result, together with that of the cluster analysis, based on genetic distances supports R. temporaria parvipalmata as a well characterised subspecies which might be approaching the specific status. A Pliocene origin for this subspecies is also suggested. HERRERO, P.; ARANO, B. & ESTEBAN, M. 1990. Karyotypic characterization of brown frogs from the Iberian Peninsula (Ranidae: Rana) . En E. Olmo (ed), Citogenetics of Amphibians and Reptiles. Ed: Birkhäuser Verlag, Basel, pp.: 135-140. Three species of "brown frogs" (Rana temporaria, Rana iberica and Rana dalmatina) and one of "green frog" species (Rana perezi) from the Iberian Peninsula have been cytogenetically analyzed using different chromosome banding techniques. Paleontological evidence points to R. perezi as closest to the ancestral morphotype of Rana found in the Peninsula. Based on this and on the chromosomal data R. iberica woul clearly represent the most derived group among the brown frog species studied, with R. temporaria being its closest related species. The different distribution of constitutive heterochromatine between iberian and central european populations of R. temporaria indicates a reproductive isolation corresponding to subspecific level. ESTEBAN, M. & SANCHIZ, B. 1990. Sobre la presencia de Rana iberica en el Pleistoceno burgalés. Revista Española de Herpetología, 5 : 93-96. Based on a morphological analysis of the ilium, and with the proposal of new measurements for this element in frogs, the presence of Rana iberica is detected in the Pleistocene site Cueva Millán (Burgos province, Spain), dated about 37600 BP and located outside the present range of the species. GARCIA-PARIS, M. y ESTEBAN, M. 1989. Nouvelles données sur la réaction de défense reflexe ('Unken-reflex') chez Rana temporaria Linnaeus; 1758 (Anura; Ranidae). Bulletin de la Société Herpétologique de France, 51 : 33-36. Incomplete "unken reflex" reactions in Rana temporaria from Spain and Poland are described. The presence of this reflex in phylogenetically unrelated species suggests the existence of a generalized proto-reflex in Anura. A specialized phylogenetical derivation of this proto-reflex would corespond to the "unken reflex" typical in Bombina. Contacto - Departamento de Biodiversidad y Biología evolutiva - Museo Nacional de Ciencias Naturales (CSIC) - c/José Gutiérrez Abascal, 2. Madrid. 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