16,576 research outputs found

    Latest Cretaceous Vertebrates from the Hateg Basin, Romania

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    The Late Cretaceous was a crucial time for the evolution of life on land, and despite its importance, this period is incompletely understood in many places around the world. The uppermost Cretaceous continental deposits of the HaŇ£eg Basin in western Romania have yielded one of the richest and most diverse vertebrate assemblages of Europe, thus being of paramount importance for understanding European Late Cretaceous ecosystems. Although the HaŇ£eg Basin looks back on a research history of more than 120 years, many open questions about the latest Cretaceous vertebrate assemblages remain. This includes, in particular, their diversity, their phylogenetic and biogeographical relationships, as well as palaeoecological aspects. In order to assess these questions, four key specimens were examined for this thesis, a partial turtle skeleton, two ornithopod braincases and one partial skull of a rhabdodontid dinosaur. The first specimen can be confidently referred to the Dortokidae, a European endemic clade of basal Pleurodires. It is morphologically similar to the genus Dortoka but differs significantly from all previously described species of that genus and thus is assigned to a new species, Dortoka vremiri. Phylogenetic analyses recovered the new taxon in a sister-group relationship with a Paleocene dortokid from western Romania, indicating local survival of the lineage across the K/Pg extinction, as opposed to subsequent immigration, as well as the presence of two distinct dortokid lineages, an eastern and a western European one. Additionally, it was possible to demonstrate that the new species occupied a different ecological niche than the only other sympatric turtle taxon from the HaŇ£eg Basin described before, Kallokibotion bajazidi. The two ornithopod braincase specimens have previously been referred to the rhabdodontid Zalmoxes, although they differ markedly from other braincase specimens of that genus described before. A detailed comparison with basal and more derived ornithopods demonstrated that the peculiar morphology of these two specimens is exclusively found in hadro-sauroids. Therefore, the two specimens are re-assigned to the basal hadrosauroid Telmatosaurus. The final specimen examined is a partial skull that resembles rhabdo-dontid dinosaurs. Despite these similarities, the specimen differs considerably from all other rhabdodontid skulls reported thus far and shows a unique and highly auta-pomorphic anatomy, and therefore, it is assigned to a new genus and species, Transylvanosaurus platycephalus. Two sets of phylogenetic analyses placed the new taxon within Rhabdodontidae but were unable to resolve the in-group relationships. Based on the high degree of similarity between Transylvanosaurus and Rhabdodon from southern France, a particularly close relationship between those taxa is suggested, which indicates a more complex biogeographical history than previously recognised. In addition, Transylvanosaurus differs widely from the sympatric rhabdo-dontid Zalmoxes in its skull proportions, indicating a certain degree of niche partitioning between the two genera. The results of this dissertation show that the alpha-level taxonomic diversity of certain groups was higher than previously thought. Moreover, the phylogenetic relationships of the new taxa indicate more complex biogeographical histories than reconstructed before and differential distribution patterns for different vertebrate groups. Finally, it was possible to detect some degree of niche partitioning between the members of the vertebrate groups.Die Oberkreide (100.5‚Äď66 Ma) war eine entscheidende Periode in der Entwicklungs-geschichte des Lebens an Land und trotz dieser Bedeutung, ist dieser Zeitabschnitt in vielen Teilen der Erde nur unvollst√§ndig verstanden. Die kontinentale Oberkreide des HaŇ£eg Beckens hat eine der reichhaltigsten und diversesten Ansammlungen von Wirbeltieren aus dieser Zeit geliefert, und ist daher von zentraler Bedeutung f√ľr unser Verst√§ndnis f√ľr die oberkretazischen √Ėkosysteme Europas. Obwohl das HaŇ£eg Becken auf eine mehr als 120-j√§hrige Forschungsgeschichte zur√ľckblickt, bleiben viele Fragen √ľber die oberkretazischen Wirbeltiere noch immer offen. Dies beinhaltet im Besonderen ihre Diversit√§t, ihre phylogenetischen und biogeographischen Beziehungen, sowie pal√§o√∂kologische Aspekte. Um diese Fragen zu beantworten, wurden vier Wirbeltierfossilien f√ľr diese Doktorarbeit untersucht, ein Teilskelett einer Schildkr√∂te, zwei Hirnsch√§del ornithopoder Dinosaurier und ein Teilsch√§del eines rhabdodontiden Dinosauriers. Das erste Fossil kann eindeutig den Dortokiden zugeordnet werden, einer endemischen Gruppe basaler Pleurodiren. Es √§hnelt morphologisch der Gattung Dortoka, unterscheidet sich aber erheblich von allen anderen bisher bekannten Arten dieser Gattung und wird daher einer neuen Art zugeordnet, Dortoka vremiri. Phylogenetische Analysen ergaben eine Schwester-gruppen-Beziehung der neuen Art mit Dortokiden aus dem Pal√§oz√§n West-Rum√§niens, was auf das lokale √úberleben dieser Gruppe w√§hrend des K/T Aussterbeereignisses hindeutet und nicht auf sp√§tere Immigration, sowie auf die Existenz zweier getrennter Dortokiden-Gruppen in Ost- bzw. Westeuropa. Des Weiteren konnte nachgewiesen werden, dass die neue Art eine andere √∂kologische Nische besetzte als die einzig andere bekannte Schildkr√∂te aus dem HaŇ£eg Becken, Kallokibotion bajazidi. Die zwei Ornithopoden Hirnsch√§del wurden zuvor dem Rhabdo-dontiden Zalmoxes zugeordnet, obwohl sie sich stark von anderen fossilen Hirn-sch√§deln dieser Gattung unterscheiden. Ein detaillierter Vergleich mit basalen und abgeleiteten Ornithopoden zeigte, dass die eigenartige Morphologie dieser beiden St√ľck ansonsten ausschlie√ülich bei Hadrosauroiden vorkommt. Daher werden beide St√ľcke stattdessen dem basalen Hadrosauroiden Telmatosaurus zugeordnet. Das letzte untersuchte Fossil ist ein Teilsch√§del der √Ąhnlichkeiten zu rhabdodontiden Dinosauriern aufweist. Trotz dieser √Ąhnlichkeiten, unterscheidet sich der Sch√§del deutlich von dem aller anderen Rhabdodontiden und zeigt eine einzigartige und stark autapomorphe Anatomie, und wird folglich einer neuen Gattung und Art zugeordnet, Transylvanosaurus platycephalus. Zwei voneinander unabh√§ngige phylogenetische Analysen ergaben, dass das neue Taxon den Rhabdodontiden angeh√∂rt, waren indes aber nicht in der Lage die Verwandtschaftsverh√§ltnisse innerhalb der Gruppe aufzul√∂sen. Aufgrund der starken √Ąhnlichkeit zwischen Transylvanosaurus und Rhabdodon aus S√ľdfrankreich, wird eine besonders nahe Verwandschaft zwischen diesen Taxa angenommen, was wiederum auf eine kompliziertere biogeographische Vergangenheit hinweist als bisher vermutet. Zudem deutet die stark unterschiedliche Sch√§delanatomie zwischen Transylvanosaurus und dem sympatrischen Zalmoxes auf die Besetzung unterschiedlicher √∂kologischer Nischen hin. Die Ergebnisse diser Dissertation zeigen, dass die Diversit√§t bestimmter Gruppen h√∂her war als bisher gedacht. Des Weiteren deuten die phylogentischen Beziehungen der neuen Taxa darauf hin, dass die Biogeographie komplizierter war als zuvor rekonstruiert und dass die verschiedenen Wirbeltiergruppen unterschiedliche Verbreitungsmuster aufweisen. Schlie√ülich war es m√∂glich die Bestzung unterschiedlicher √∂kologischer Nischen bei angeh√∂rigen derselben Gruppe aufzuzeigen

    ÔĽŅA new species of the genus Achalinus (Squamata, Xenodermatidae) from southwest Hunan Province, China

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    A new species of xenodermid snake, Achalinus nanshanensis H. Li, L.-Q. Zhu, Z.-Q. Zhang & X.-Y. Mo, sp. nov., is described based on three specimens collected from Nanshan National Park and Tongdao County of southwest Hunan Province. This new species is genetically distinct amongst its congeners with the mitochondrial COI uncorrected p-distance ranging from 4.4% (in A. yangdatongi) to 17.7% (in A. meiguensis). In addition, this new species can be distinguished from its congeners by a combination of the following morphological characters: (1) dorsal scales with 23 or 25 rows throughout and strongly keeled; (2) tail relatively longer so that TaL/ToL = 0.215‚Äď0.248; (3) length of suture between internasals significantly longer than that between prefrontals, LSBI/LSBP = 1.66‚Äď1.84; (4) single loreal scale present; (5) SPL 6 in number, with the fourth and fifth contacting eye; (6) IFL 6 in number, with the first three touching the first pair of chin shields; (7) TMP is 2-2-4/2-2(3)-4, with the anterior pair elongated and in contact with the eye; (8) ventrals 2 + 147‚Äď158; (9) subcaudals 64‚Äď77, unpaired; (10) dorsal body brownish black, with a bright yellow neck collar extending to the head and abdomen in the occipital region. The recognition of the new species increases the number of described Achalinus species to 28, of which 21 are found in China

    Genetic basis and expression of ventral colour in polymorphic common lizards

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    Colour is an important visual cue that can correlate with sex, behaviour, life history or ecological strategies, and has evolved divergently and convergently across animal lineages. Its genetic basis in non-model organisms is rarely known, but such information is vital for determining the drivers and mechanisms of colour evolution. Leveraging genetic admixture in a rare contact zone between oviparous and viviparous common lizards (Zootoca vivipara), we show that females (N‚ÄČ=‚ÄČ558) of the two otherwise morphologically indistinguishable reproductive modes differ in their ventral colouration (from pale to vibrant yellow) and intensity of melanic patterning. We find no association between female colouration and reproductive investment, and no evidence for selection on colour. Using a combination of genetic mapping and transcriptomic evidence, we identified two candidate genes associated with ventral colour differentiation, DGAT2 and PMEL. These are genes known to be involved in carotenoid metabolism and melanin synthesis respectively. Ventral melanic spots were associated with two genomic regions, including a SNP close to protein tyrosine phosphatase (PTP) genes. Using genome re-sequencing data, our results show that fixed coding mutations in the candidate genes cannot account for differences in colouration. Taken together, our findings show that the evolution of ventral colouration and its associations across common lizard lineages is variable. A potential genetic mechanism explaining the flexibility of ventral colouration may be that colouration in common lizards, but also across squamates, is predominantly driven by regulatory genetic variation

    KEANEKARAGAMAN HERPETOFAUNA PADA BEBERAPA TIPE HABITAT DI TAMAN NASIONAL KUTAI, KALIMANTAN TIMUR

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    Taman Nasional Kutai, Provinsi Kalimantan Timur merupakan salah satu kawasan konservasi dengan habitat yang beragam serta potensi keanekaragaman jenis herpetofauna yang tinggi. Penelitian ini bertujuan untuk membandingkan komposisi jenis herpetofauna, membandingkan keanekaragaman herpetofauna, serta menduga faktor-faktor lingkungan yang menentukan kehadiran herpetofauna pada pada berbagai tipe habitat di Taman Nasional Kutai. Pengamatan dilakukan menggunakan metode Visual Encounter Survey (VES) berdasarkan waktu yang dikombinasikan dengan jalur transek di mangrove, hutan dataran rendah, hutan kerangas, dan hutan rawa. Hasil penelitian mendapatkan 28 jenis reptil dari 9 famili serta 22 jenis amfibi yang berasal dari 6 famili. Hutan dataran rendah memiliki keanekaragaman serta kekayaan tertinggi (H’reptil =2,43; H’amfibi = 2,63). Kesamaan jenis antara empat tipe habitat sangat rendah yang menunjukkan bahwa setiap tipe habitat hanya mendukung jenis tertentu. Faktor lingkungan yang dominan memengaruhi kehadiran jenis-jenis reptil di jalur akuatik adalah kecepatan arus air, pH air, dan intensitas cahaya, sedangkan faktor lingkungan yang memengaruhi di jalur terestrial adalah ketebalan serasah, tutupan tajuk pohon, dan jarak jalur ke sumber air. Untuk amfibi, faktor dominan yang paling berperan dalam kehadiran jenis, yaitu kelembaban relatif (jalur terestrial) dan keberadaan substrat batu (jalur akuatik)

    Diversidad y composición de anfibios en el valle del río Cimitarra, sur de la serranía de San Lucas, Colombia

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    The serran√≠a de San Lucas (Colombia) is considered of high value for biodiversity conservation, but little is known about its fauna. Between late 2016 (rains) and early 2017 (drought), two field trips were conducted to characterize the amphibian fauna and estimate its taxonomic diversity in the Cimitarra river, south of this mountain range. We recorded 183 individuals belonging to 23 species, 15 genera and 8 families. Although the richness did not differ between seasons, diversity was almost double in dry season when compared to the rainy season. The fragmented natural forest was the most diverse cover with 14.2 species (q1). Amphibian composition was different between seasons and covers, with high ő≤-diversity values, mainly due to nesting in the assemblage. The amphibians of the Cimitarra river show a pattern of similarity with other localities depending on their geographic distance. These results contribute information that can be compared with amphibian diversity in more intervened areas of the Magdalena Medio and the rainforest in general. However, for San Lucas, spatiotemporal dynamics of amphibians should be analyzed on a longer time scale, and inter-annual variations should be evaluated.La serran√≠a de San Lucas (Colombia) se considera de alto valor para la conservaci√≥n de la biodiversidad, pero poco se sabe sobre su fauna. Entre finales de 2016 (lluvias) e inicios de 2017 (seca) se realizaron dos salidas de campo para caracterizar la fauna de anfibios y estimar su diversidad taxon√≥mica en el r√≠o Cimitarra, al sur de esta serran√≠a. Como resultado, se registraron 183 individuos pertenecientes a 23 especies, 15 g√©neros y 8 familias. Aunque la riqueza no difiri√≥ entre temporadas, la diversidad fue casi el doble en temporada seca que en la de lluvia, siendo el bosque natural fragmentado la cobertura m√°s diversa con 14,2 especies (q1). La composici√≥n de anfibios fue diferente entre temporadas y coberturas, con altos valores de diversidad ő≤ debido principalmente al anidamiento en el ensamblaje. Los anfibios del r√≠o Cimitarra muestran un patr√≥n de similitud con otras localidades dependiendo de su distancia geogr√°fica. Estos resultados contribuyen con informaci√≥n para ser comparada con la diversidad de anfibios en √°reas m√°s intervenidas del Magdalena Medio y el bosque h√ļmedo en general. Sin embargo, se debe analizar la din√°mica espaciotemporal de los anfibios en una escala de tiempo mayor y evaluar las variaciones interanuales

    A collection and analysis of amphibians and reptiles from Nicaragua with new country and departmental records

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    Nicaragua is a biodiverse country, but documented herpetological specimens are underrepresented compared to neighboring countries. In 2018 we conducted a collaborative expedition between the University of Michigan Museum of Zoology and Nicaraguan biologists. We visited sites in the Pacific Low‑ lands, Caribbean Lowlands, and the Central Highlands, representing the three major biogeographic regions of Nicaragua. We collected specimens of 100 species from a total of 106 encountered. We provide acces‑ sion numbers and morphological, genetic, and ecological information for these specimens. We recorded 23 new departmental records and the first country record of Metlapilcoatlus indomitus (Smith & Ferrari‑Castro, 2008), filling gaps in the known distribution of the species within Nicaragua and across Central America. When available for each species, we provide range maps and comparative genetic trees including conspecific reference sequences from the region, making this work a significant addition to existing checklists of the herpetofauna in Nicaragua

    Development and Application of Techniques for the Control of Captive Breeding in Elasmobranchs

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    Tesis por compendio[ES] Los tiburones y rayas aparecieron hace 420 millones de a√Īos, conformando el antiguo y ecol√≥gicamente diverso, grupo de vertebrados acu√°ticos conocido como elasmobranquios. Este variado grupo posee unas estrategias vitales que los hace muy vulnerables a los cambios r√°pidos del entorno, como los derivados de la acci√≥n antr√≥pica. Pese a ser elementos clave en la regulaci√≥n de los ecosistemas en los que habitan, en la actualidad, se trata de uno de los grupos vertebrados m√°s amenazados del planeta. Paralelamente a la conservaci√≥n in situ, los programas de conservaci√≥n ex situ se pueden utilizar para mejorar la situaci√≥n de algunas especies sensibles. Entre estos programas, los planes de cr√≠a en cautividad aumentar√≠an la sostenibilidad de acuarios p√ļblicos y centros de investigaci√≥n, adem√°s de permitir el desarrollo de estrategias de conservaci√≥n en estado salvaje. Sin embargo, para que sean efectivos, estos planes deber√≠an incluir el uso de t√©cnicas de reproducci√≥n asistida. Desafortunadamente, estas t√©cnicas apenas se han desarrollado en el pasado, por lo que su utilidad no se ha demostrado adecuadamente. Esta tesis aborda el uso de t√©cnicas de reproducci√≥n en elasmobranquios, con √©nfasis en la obtenci√≥n y preservaci√≥n del esperma. Inicialmente, se centr√≥ en dos especies modelo, Scyliorhinus canicula y Raja radula, pero luego se incluyeron otras especies. Esto revel√≥ variabilidad en las estructuras reproductivas, lo que puede afectar la eficacia y calidad de las t√©cnicas. Los cap√≠tulos 1 y 2 se enfocaron en catalogar y describir estas estructuras en diversas especies, destacando las mejores pr√°cticas de obtenci√≥n de gametos e inseminaci√≥n. La conservaci√≥n a corto, medio y largo plazo del esperma es esencial para planes ex situ, reduciendo el transporte de machos, conflictos durante el cortejo y endogamia. El Cap√≠tulo 3 detalla f√≥rmulas para mantener el esperma fresco y un medio para su supervivencia por m√°s de 30 d√≠as. Luego, se describe la criopreservaci√≥n del esperma de varias especies de rayas y tiburones mediante crioprotectores. El Cap√≠tulo 4 aborda desaf√≠os en la manipulaci√≥n de espermatozoides elasmobranquios debido a su morfolog√≠a helicoidal y la formaci√≥n de agregaciones llamadas espermatozeugma. Se resalta la importancia de la viscosidad en las t√©cnicas de reproducci√≥n asistida. En la Discusi√≥n, se compara la eficacia de los m√©todos y se exploran nuevas oportunidades al tener acceso a diversas especies. Esto incluye descripciones detalladas con an√°lisis de imagen, evaluaci√≥n de viscosidad y agregados en la preservaci√≥n, y la consideraci√≥n de inseminaciones artificiales.[CA] Els taurons i les ratjades van apar√®ixer fa 420 milions d'anys, formant el grup conegut com a elasmobranquis. Aquest grup divers posseeix estrat√®gies vitals que els fan molt vulnerables als canvis r√†pids de l'entorn. Malgrat ser elements clau en la regulaci√≥ dels ecosistemes on habiten, actualment s√≥n un dels grups m√©s amen√ßats del planeta. Els programes de conservaci√≥ ex situ es poden utilitzar per millorar la situaci√≥ d'algunes esp√®cies. Entre aquests programes, els plans de cria en captivitat augmentarien la sostenibilitat dels aquaris p√ļblics i els centres de recerca, a m√©s de permetre el desenvolupament d'estrat√®gies de conservaci√≥ a l'estat salvatge. No obstant aix√≤, aquests plans haurien d'incloure l'√ļs de t√®cniques de reproducci√≥ assistida. Desafortunadament, aquestes t√®cniques gaireb√© no s'han desenvolupat en el passat. Davant d'aquesta situaci√≥, aquesta tesi pret√©n omplir certes mancances en el coneixement sobre l'√ļs d'aquestes t√®cniques en diverses esp√®cies d'elasmobranquis. La nostra investigaci√≥ va comen√ßar centrant-se especialment en dues esp√®cies model, el taur√≥ gat Scyliorhinus canicula i la ratjada peluda Raja radula, per√≤ al llarg de l'estudi es va aconseguir tenir acc√©s a altres esp√®cies. Aquest acc√©s ens va permetre ser conscients de la gran variabilitat en la disposici√≥ de les estructures del sistema reproductor. Malgrat que en la literatura hi ha descripcions generals i, en ocasions, detallades dels sistemes reproductors de certes esp√®cies, aquestes descripcions mai s'han centrat en l'aplicaci√≥ pr√†ctica de les t√®cniques de reproducci√≥ assistida. Per aquest motiu, els cap√≠tols 1 i 2 es van centrar en la catalogaci√≥ i descripci√≥ de les diferents estructures d'esp√®cies que abasten un ampli espectre taxon√≤mic. La conservaci√≥ de l'esperma juga un paper clau per poder desenvolupar plans de conservaci√≥ en condicions ex situ. Disposar d'esperma de qualitat permet limitar el transport de mascles entre institucions, minimitzar problemes derivats de la manca de sincronia entre adults reproductors, reduir conflictes durant √®poques d'aparellament i reduir l'endog√†mia. El tercer cap√≠tol es centra en com es van desenvolupar i provar diferents f√≥rmules per aconseguir el manteniment en fresc de l'esperma, fins a aconseguir un medi on diluir l'esperma capa√ß de mantenir-lo amb vida durant m√©s de 30 dies. Posteriorment, mitjan√ßant l'addici√≥ de diversos crioprotectors (ou, DMSO i metanol) en diverses concentracions, s'explica com es va aconseguir la criopreservaci√≥ de l'esperma de diverses esp√®cies de ralles i, per primer cop, la criopreservaci√≥ de l'esperma de diverses esp√®cies de taurons. Un dels primers obstacles que es van detectar en treballar amb els espermatozoides es va deure a la morfologia d'aquestes c√®l¬∑lules en comparaci√≥ amb les d'altres esp√®cies. El cap dels espermatozoides presenta una forma helicoidal, amb un nombre variable de voltes en funci√≥ de l'esp√®cie. A m√©s, en moltes ocasions les c√®l¬∑lules no apareixen lliures en el fluid seminal, sin√≥ que formen agregacions estructurades anomenades espermatotzeugma. Al llarg del cap√≠tol 4 s'explora com aquestes dues caracter√≠stiques sorgeixen com a resultat de la fecundaci√≥ interna i les caracter√≠stiques mec√†niques del medi en qu√® han de realitzar la seva funci√≥. Per primer cop, es pot observar com les c√®l¬∑lules reaccionen davant mitjans amb diferents propietats, posant de relleu la import√†ncia de la viscositat en l'aplicaci√≥ de t√®cniques de reproducci√≥ assistida. Finalment, a la discussi√≥, es compara l'efic√†cia dels m√®todes emprats i s'explora nous camins d'acci√≥ sorgits de tenir acc√©s a m√©s individus de diferents esp√®cies. Aix√≤ inclou la possibilitat de fer descripcions detallades mitjan√ßant t√®cniques d'an√†lisi d'imatge, avaluar la import√†ncia de la viscositat i els agregats en els processos de preservaci√≥ i la possibilitat de realitzar inseminacions artificials.[EN] Sharks and rays emerged 420 million years ago, forming the ancient and ecologically diverse group of aquatic vertebrates known as elasmobranchs. This diverse group possesses vital strategies that make them highly vulnerable to rapid environmental changes, such as those resulting from human activities. Despite being key elements in the regulation of the ecosystems they inhabit, they are currently one of the most threatened vertebrate groups on the planet. In parallel with in-situ conservation efforts, ex-situ conservation programs can be used to improve the status of some sensitive species. Among these programs, captive breeding plans would enhance the sustainability of public aquariums and research centers, as well as enable the development of conservation strategies in the wild. However, for these plans to be effective, they should include the use of assisted reproduction techniques. Unfortunately, these techniques have been scarcely developed in the past, and their utility has not been adequately demonstrated. This thesis addresses the use of reproduction techniques in elasmobranchs, with an emphasis on sperm retrieval and preservation. Initially, it focused on two model species, Scyliorhinus canicula and Raja radula, but later, other species were included. This revealed variability in reproductive structures, which can affect the effectiveness and quality of the techniques. Chapters 1 and 2 focused on cataloging and describing these structures in various species, highlighting best practices for gamete retrieval and insemination. The short, medium, and long-term conservation of sperm is essential for ex-situ plans, reducing the need for transporting males, conflicts during courtship, and inbreeding. Chapter 3 details formulas for maintaining sperm freshness and a medium for its survival for over 30 days. Subsequently, sperm cryopreservation in several species of rays and sharks is described using cryoprotectants. Chapter 4 addresses challenges in handling elasmobranch sperm due to its helical morphology and the formation of aggregates called spermatozeugma. The importance of viscosity in assisted reproduction techniques is emphasized. In the Discussion, the effectiveness of the methods is compared, and new opportunities are explored by having access to various species. This includes detailed descriptions with image analysis, viscosity assessment, and aggregate preservation, as well as the consideration of artificial inseminations.This research was partially funded by the Fundaci√≥n Biodiversidad ( ). PGS has a PhD contract from the European Union through the Operational Program of the European Social Fund (ESF) of the Comunitat Valenciana 2014‚Äď2020 ACIF 2018 (ACIF/2018/147). VG has a postdoc contract from the MICIU, Programa Juan de la Cierva-Incorporaci√≥n (IJCI- 2017-34200).Garc√≠a Salinas, P. (2023). Development and Application of Techniques for the Control of Captive Breeding in Elasmobranchs [Tesis doctoral]. Universitat Polit√®cnica de Val√®ncia. https://doi.org/10.4995/Thesis/10251/201494Compendi

    Land-cover changes affect the diversity of amphibians and reptiles in a rural landscape of the Colombian Caribbean region

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    ¬† Los cambios en la cobertura del suelo debido a la expansi√≥n agr√≠cola y ganadera son las principales causas que influyen en la diversidad de las comunidades de anfibios y reptiles. En este estudio, evaluamos la variaci√≥n de la diversidad de anfibios y reptiles en cuatro tipos de cobertura del suelo (jag√ľeyes, pastizales, cultivos transitorios y vegetaci√≥n secundaria) en un paisaje rural de la regi√≥n Caribe colombiana. Los anfibios y reptiles fueron muestreados a trav√©s del m√©todo de relevamiento por encuentros visuales entre abril y agosto de 2018. Se registr√≥ un total de 19 especies de anfibios (ranas y sapos) y 23 especies de reptiles (14 lagartos, 7 serpientes, 1 tortuga y 1 caim√°n). La diversidad de especies difiri√≥ entre las coberturas del suelo, tanto para anfibios como para reptiles. La diversidad de anfibios fue mayor en los jag√ľeyes y menor en los pastizales, mientras que la de reptiles fue mayor en la vegetaci√≥n secundaria y menor en los cultivos transitorios. Nuestros resultados sugieren que el mantenimiento de jag√ľeyes y vegetaci√≥n secundaria podr√≠a ser importante para la conservaci√≥n de la herpetofauna en paisajes rurales donde predominan actividades antropog√©nicas como la agricultura y la ganader√≠a.Land cover changes resulting from agricultural expansion and cattle ranching are the primary factors influencing the diversity of amphibian and reptile communities. In this study, we assessed the variation in the diversity of amphibians and reptiles across four land-cover types (ponds, grasslands, temporary crops, and secondary vegetation) in a rural landscape in the Colombian Caribbean region. Amphibians and reptiles were sampled through visual encounter surveys between April and August 2018. A total of 19 species of amphibians (frogs and toads) and 23 species of reptiles (14 lizards, 7 snakes, 1 turtle, and 1 alligator) were recorded. Species diversity differed among land covers, for both amphibians and reptiles. Amphibian diversity was higher in ponds and lower in grasslands, whereas reptile diversity was higher in secondary vegetation and lower in temporary crops. Our results suggest that the maintenance of ponds and secondary vegetation could be important for the conservation of herpetofauna in rural landscapes where anthropogenic activities such as agriculture and cattle ranching predominate

    Keanekaragaman Jenis Reptil pada Ekosistem Hutan Rawa Gambut di Desa Sedahan Jaya Taman Nasional Gunung Palung Kalimantan Barat

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    Taman Nasional Gunung Palung (TNGP) salah satu taman nasional di Provinsi Kalimantan Barat yang memiliki tipe ekosistem beragam dan ditopang berbagai kawasan penyangga. Desa Sedahan Jaya sebagai salah satu kawasan penyangga TNGP memiliki ekosistem yang didominasi hutan rawa gambut. Kemampuan menyerap air yang tinggi pada hutan rawa gambut menjadikan kondisi tersebut cenderung lembap yang mana merupakan karakter bagi habitat reptil. Reptil yang ditemukan terbagi menjadi 2 ordo, Squamata dan Testudinata yang terdiri atas 13 famili, 24 genus, dan 28 jenis. C. pubisulcus dan Eutropis multifasciata jadi jenis reptil yang paling banyak ditemukan di semua jalur pengamatan. Hasil beberapa analisis indeks menunjukkan bahwa keanekaragaman tergolong sedang (2,05 ‚ȧ H¬ī ‚ȧ 2,49), kemerataan tergolong tinggi (0,85 ‚ȧ E ‚ȧ 0,88), tidak ada dominansi suatu jenis tertentu (0,13 ‚ȧ C ‚ȧ 0,15), serta kekayaan jenis yang tergolong tinggi di lokasi 1 dibandingkan lokasi 2 (Dmglokasi1: 4,23; Dmglokasi2: 3,19). Faktor lingkungan tidak menunjukkan perbedaan signifikan antar lokasi, suhu air berkisar 24,55-26,08¬įC, suhu udara 24,75-24,81¬įC, suhu tanah 25,25-25,56¬įC, pH air tergolong asam dengan nilai 3,88-5,60, pH tanah cenderung netral dengan nilai 6,22-7, kelembapan udara 72-74,38%, dan kelembapan tanah dengan rentang yang luas dari kering hingga lembap

    Using small mammals to reconstruct the climatic context of the late pleistocene Lagar Velho Rockshelter (Leiria, Portugal).

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    To reconstruct the climatic conditions of the Lagar Velho rockshelter during the late Pleistocene, we applied the bioclimatic model to the rodent assemblages, mainly composed of the vole species Arvicola sapidus, Microtus arvalis, Microtus agrestis, Microtus (Terricola) lusitanicus and Microtus (Iberomys) cabrerae and the field mouse Apodemus sylvaticus. Based on the distribution of these species by layers and percentages, considering different climate-types, and applying a series of functions, it was possible to estimate the mean annual temperature (MAT), the mean temperature of the coldest month (MTC), the mean temperature of the warmest month (MTW) and the mean annual precipitation (MAP). For comparative purposes, the resulting parameters were compared with climate data obtained for the last 30 years from nearby meteorological stations in order to attain averages and observe climatic fluctuations. The climatic parameters were then compared with the Köppen-Geiger classification in order to contrast our data with the current climate-types. Finally, we combined the results with chronological and environmental information to produce a climate framework within Marine Isotope Stage 2 (MIS 2)
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