A surpreendente descoberta de uma assembléia de anuros terrícolas extremamente abundante, sintópica à fauna peculiar de lagartos, serpentes e anfisbenas, numa localidade dos mares de areia do médio Rio São Francisco (estado da Bahia, Brasil) motivou: (1) o estudo do uso de alimento e eletividades na dieta dos anuros locais, (2) a investigação de evidências de adaptação na sua dieta ao ambiente desafiador das dunas e (3) a avaliação do possível impacto que os anuros causam na assembléia sintópica de Squamata anteriormente estudada. O uso de alimento e as eletividades na dieta das três espécies de anuros mais abundantes, assim como suas variações ontogenéticas, foram descritas e premissas sobre adequação das estimativas de uso e disponibilidade de recursos alimentares foram testadas. Evidências de adaptação nas dietas dos anuros às dunas foram feitas comparando-se sua dieta com as de espécies filogeneticamente próximas. As estimativas de uso e de disponibilidade utilizadas foram consideradas adequadas. Bufo granulosus apresentou eletividade positiva por formigas. Pleurodema diplolistris e Physalaemus albifrons apresentaram ambos eletividade positiva por besouros e eletividade negativa por cupins e por formigas, respectivamente. Não houve variação ontogenética nos tipos de presa consumidas por nenhuma das espécies estudadas e isso não pôde ser atribuído à avaliação de uma pequena extensão de tamanhos dos anuros. Variações ontogenéticas no tamanho das presas foram observadas apenas para B. granulosus e P. diplolistris. Não houve evidência de apomorfia na dieta de B. granulosus e não houve dados disponíveis suficientes para realizar essa análise para P. diplolistris. As apomorfias registradas na dieta de P. albifrons podem ser explicadas por interações competitivas com outros componentes da herpetofauna local. Os anuros não parecem causar impacto forte sobre a assembléia de Squamata sintópica, devido a divergências nas eletividades por alimento e nos horários de atividade entre a maioria deles e grande parte desse padrão divergente parece ter se estabelecido antes da formação dessa assembléia. A eletividade positiva por formigas de B. granulosus e do tropidurídeo Tropidurus psammonastes pode apontar interação competitiva contemporânea entre eles, devido a suas grandes abundâncias locais. No entanto, é necessário haver indícios de limitação de recursos para levantar tal hipótese, porque a divergência nos horários de atividade deles impede competição por interferência. Mas formigas são abundantes na área. / The discovery of an extremely abundant anuran terrestrial assemblage, that is syntopic to a peculiar fauna of lizards, snakes, and worm snakes, in a locality at the sand dune fields of the Middle São Francisco River (Bahia state, Brazil) motivated: (1) the study of food use and electivities of local anurans, (2) investigations about evidences of adaptation in anurans’ diet to the challenges of a semi-arid environment, and (3) the assessment of the impact caused by anurans on the Squamata syntopic assemblage already studied. Food use, food electivities, and ontogenetic variation in diet of the three most abundant anuran species were described, and premises about the adequacy of the used estimates of food use and food availability were tested. Evidences of adaptation in diet were assessed by comparison of the diet of anurans from the dunes and that of phylogenetically related species. Estimates of food use and availability were considered suitable. Bufo granulosus showed positive electivity for ants. Pleurodema diplolistris and Physalaemus albifrons had both positive electivities for beetles and negative electivities for termites and ants, respectively. No species changed the types of prey it consumed during ontogeny and this was not a spurious result of a narrow range of anurans size analyzed. B. granulosus and P. diplolistris ate bigger preys as they grew. There was no evidence of adaptation in B. granulosus diet and insufficient data precluded this analysis with P. diplolistris diet. Apomorphies registered in P. albifrons diet can be explained by ecological contemporary interactions with local herpetofauna components. Anurans do not seem to cause a big impact on Squamata syntopic species, because in general anurans and squamates show divergent food electivities and/or activity times. Moreover, most of this divergent pattern has probably evolved before the establishment of the current assemblage. Coincident positive electivities for ants of B. granulosus and the tropidurid Tropidurus psammonastes can be an indicative of contemporary competitive interactions between them, principally because they are very abundant at the dunes. But evidence of limiting resources are necessary to rise this hypothesis because divergent activity times preclude interference competition, but ants are very abundant at the dunes.

Historical structuralism is presented as a research program in evolutionary biology. It uses patterns of common ancestry as initial hypotheses in explaining evolutionary history. Such patterns, represented by phylogenetic trees, or cladograms, are postulates of persistent ancestral traits. These traits are evidence of historical constraints on evolutionary change. Patterns and processes consistent with a cladogram are considered to be consistent with an initial hypothesis of historical constraint. As an application of historical structuralism, a phylogenetic analysis is presented for members of the digenean plagiorchioid genera Glypthelmins Stafford, 1905 and Haplometrana Lucker, 1931. The eight species studied are intestinal parasites of frogs and toads in North, Central, and South America. In a Wagner parsimony analysis of 21 morphological characters with both the PAUP and PHYSYS computer programs, a single phylogenetic tree with a consistency index of 84.8% can be inferred. This suggests strong historical constraint in the evolution of the characters examined. It is postulated that the eight species form a monophyletic group (clade), consisting of two less inclusive clades. Glypthelmins hyloreus and G. pennsylvaniensis comprise one of these clades; G. robustus, G. shastai, H. intestinalis, G. californiensis, G. quieta, and G. facioi comprise the other. G. robustus, found in Bufo marinus in Colombia, is both the southernmost and the most plesiomorphic member of its clade. Glypthelmins californiensis, G. quieta, and G. facioi form a clade, and parasitize frogs in the Rana pipiens complex in Mexico, eastern North America, and Central America, respectively. Glypthelmins shastai and H. intestinalis, the latter of which is the only member of its genus, form a western North American clade, and parasitize Bufo boreas and Rana pretiosa, respectively. The phylogenetic analysis includes a redescription of G. shastai, the synonymy of the genus Haplometrana with Glypthelmins, the redescription of H. intestinali s as G. intestinalis, an emended diagnosis of the genus Glypthelmins, and the first account of the life cycle of G. californiensis. Three aspects of phylogenetic analysis are examined in detail. These are the coding of multistate character trees, the use of parasite data to infer host relationships, and the properties of the Consistency Index and the F-Ratio. It is proposed that the Consistency Index be calculated without non-homoplasious autapomorphic characters. For the present study, this modification gives a value of 76.9%. Using the phylogenetic tree as a general reference system of patterns of common ancestry, it is inferred from developmental studies that (1) there is no conflict between the phylogenetic relationships indicated by only larval or only adult characters, and that (2) the evolution of some of the characters involved certain types of heterochrony. Paedomorphic heterochrony is inferred to have occurred in the evolution of the uterus in G. shastai, H. intestinalis, G. californiensis, G. quieta, and G. facioi. Peramorphic heterochrony is inferred to have occurred in the evolution of the penetration glands in G. facioi, and of the hindbody in H. intestinalis. The relatively longer hindbody of H. intestinalis was experimentally induced to show paedomorphic development by raising specimens of H. intestinalis in Bufo boreas, which is the host of G. shastai, its sister-species. By one year after infection, the relative length of the hindbody is shorter, and is equal to that of the primitive state found in G. shastai. The phylogenetic relationships among the anuran hosts are re-analyzed. There is 80% congruence between them and the postulated phylogenetic tree for their parasites, suggesting strong historical association between the parasite and host groups. This inference of coevolution is further supported by the concordance of the present geographical distributions of the parasites and their hosts with the historical geology of the areas in which they occur. This implies an historical association between the areas and the organisms. / Science, Faculty of / Zoology, Department of / Graduate

Thesis submitted to the Faculty ofScience, University of the Witwatersrand, Johannesburg in fulfilment of the requirements for the degree Gf'Doctol' ofPhilosophy, (! JOHANNESBURG January 1991 / This work examines aspects of sexual reproduction in the previously littlestudied Leaf-foldillg Frog, A£rixalus dellcatus, The taxonomic status of this species was determined using the Mate Recognition System to deUmJt the species boundary. Male social behaviour was investigated with particular reference to. the structure and functional partitioning of the twopart advertisement call; the maintenance of intermale spacing and the effects of chorus size on the sp'atial separation of males; chorus organisation; call site selecticn and fidelity to. call sites. The climatic factors influencing male behaviour were also examined. The mating success of calling and satellite males was determined and the possible causes of the variation in mating success were examined. Female behavioul' was also extensively studied, Females were found to produce a .$xnall numbel' of large eggs tI1at are protected in leaf nests. Oviposition site rf¥tq~em;(;;lntswere detertnined, and the concentration of nests examined. "~~l~a1ti;ll>ll ·Sl'P!OO'$$$ Wlll;S fou'DiGi'tobe lligh. Some females were found to be llol~atl:d~(;)llS, ma:~r:tfgwit~ up to three nl,ales. The behaviour of females in the 'cl.mQ~t:tsW~ observed andfemales were round to generally mate with one of the nearw ma1$s irrespective of morphology or behaviour. The potential and actual a,,(lcutacyormata loc.alisation was determined. This study of a species' mating system and its flexibility in relation to eeclogleal, ph1~o.1~~td and social pressures' allowed for a more thorough understanding oi anlllrtUl.rep:tod~etive behavlour and its evtiiution.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 25, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Raymond D. Semlitsch. Vita. Includes bibliographical references.

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There is no abstract available for this thesis.

Normal development of the urostyle is described during late stages of metamorphosis in five species of anurans: Xenopus laevis (Daudin), Bufo americanus Holbrook, Pseudacris triseriata (Wied), Hyla chrysoscelis Cope, and Rana pipiens Schreber.Tadpoles of these five species were reared in the laboratory, preserved in Bouin's fixative at various stages of metamorphosis (Gosner stages 34 to 44), and decalcified in 1% HC1 for 48 hours.A block of tissue containing the urotstyle was removed from the tadpole, embedded in paraffin, serially cross-sectioned, stained according to Mallory's trichromatic staining technique, and permanently mounted in Pro-Texx.The developing urostyle of all five species is composed of essentially the same cartilaginous elements: one pair of basidorsals above the notochord and' he hypochord below. Among the five species there is variation in such details as the number of spinal nerve foramina and the degree of fusion of the basidorsals; however, both the hypochord and basidorsals are quite similar in all five genera examined.The development of the urostyle as observed in this study provides insufficient basis for any conclusions about the phylogenetic trends in the five genera.The contradictory descriptions of the developing urostyle found in the literature appear to result from (1) varied methods of study (alizarin-staining of whole specimens or serial cross-sections), (2) the variety of species examined, and (3) the particular stage of development of the tadpole described by an investigator.

Thesis (M. Sc.)--University of Adelaide, Dept. of Zoology, 1987. / Includes bibliographical references (leaves 198-206).

Thesis (M.Sc.) - Dept. of Zoology, University of Adelaide, 1983. / Typescript (photocopy).

Thesis (doctoral)--Bern, 1903. / Includes bibliographical references.