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In oviparous vertebrates lacking parental care, resource allocation during reproduction is a major maternal effect that may enhance female fitness. In general, resource allocation strategies are expected to follow optimality models to solve the energy trade-offs between egg size and number. Such models predict that natural selection should optimize egg size while egg number is expected to vary with female size, thus maximizing offspring fitness and consequently, maternal fitness. Deviations from optimality predictions are commonly attributed to morphological constraints imposed by female size, such as reported for small-bodied turtle species. However, whether such anatomical constraints exist in smaller-bodied females within large-bodied clades remains unstudied. Here we tested whether resource allocation of the river turtle Podocnemis unifilis (a relatively smaller member of the large-bodied Podocnemididae) follows optimality theory, and found a pattern of egg elongation in smaller females that provides evidence of morphological constraints and of a reproductive trade-off with clutch size, whereas egg width supports the existence of an optimal egg size and no trade-off. Moreover, larger females laid larger clutches composed of rounder eggs, while smaller females laid fewer and relatively more elongated eggs. Elongated eggs from smaller females have larger volume relative to female size and to round eggs of equal width. We propose that elongated eggs represent a solution to a potential morphological constraint suffered by small females. Our results suggest that larger females may optimize fitness by increasing the number of eggs, while smaller females do so by producing larger eggs. Our data supports the notion that morphological constraints are likely more widespread than previously anticipated, such that they may not be exclusive of small-bodied lineages but may also exist in large-bodied lineages.. © 2017, Springer International Publishing AG. This study was partially funded by grants from the Wildlife Conservation Society, Sustainable Aquatic Resources Center, Saint Louis Zoo, Jersey Zoo, Organization of Tropical Studies, International Center for Tropical Ecology, Scott Neotropical Fund and the Graduate School-Dissertation Fellowship of the University of Missouri St Louis (all to TE). Field work was enabled by invaluable help from Cesar Escalona, Maria Edilia Varela, Miguel Estaba (and his family), Felix Daza (and his family), Conrad Vispo and Claudia Knab-Vispo, Andres Rosenschein and Ivonne Monge. We thank two anonymous reviewers for their thoughtful and valuable comments on our manuscript.

Podocnemis expansa Schw. ("tartaruga-da-Amazônia "), P. unifilis Troshell ("tracajá") e P. sextuberculata Cornalis ("pitiu") empregam 32 espécies vegetais em sua alimentação. A primeira espécie é a que possui hábito alimentar mais diversificado. Foram levantados os nomes populares, parte utilizada, época de ocorrência e hábito vegetativo das 32 espécies vegetais, distribuídas por 20 famílias, sendo Leguminosae e Gramineae as mais representadas. São consumi­dos na forma de planta inteira 53,1% das plantas; o restante, como frutos e sementes. Dentre os vegetais analisados, 86,2% oferecem alimento o ano todo, havendo assim boa disponibilidade de alimento para esses quelônios naquela área.

The diploid chromosome number of two species of sidenecked turtles (Podocnemis unifilis and P. expansa) was found to be 28. Under normal culture conditions, half of the chromosomes of P. unifilis consistently show one or two clear secondary constrictions. In P. expansa, the incidence of cells with chromosomes bearing secondary constrictions and the number of such chromosomes per cell are less. Cells of two P. unifilis cell lines maintained a normal diploid karyotype for two years following their initiation. Then one cell line shifted to a hypodiploid mode of 27 and half of the population of the second line became pseudodiploid, the other half remaining diploid. A single six-month-old cell line from P. expansa has maintained a normal diploid mode through 10 passages.

Made available in DSpace on 2018-11-26T15:31:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-09-27 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Instituto Chico Mendes de Conservacao da Biodiversidade - ICMBio and Sistema de Autorizacao e Informacao em Biodiversidade - SISBIO Banco Nacional de Desenvolvimento Economico e Social-BNDS Background: Cytogenetic studies were conducted in the Brazilian Amazon turtles, Podocnemis expansa Schweigger, 1912 (PEX) and Podocnemis unifilis Troschel, 1848 ( PUN) to understand their karyoevolution. Their chromosomal complements were compared using banding techniques (C, G-, Ag-NOR and Chromomycin A3) and fluorescence in situ hybridization ( FISH), and efforts were made to establish evolutionary chromosomal relationships within the Podocnemidae family. Results: Our results revealed that both species have a chromosome complement of 2n = 28. For PEX and PUN, the fundamental numbers (FNs) were 54 and 52, respectively and the karyotypic formulas (KFs) were 24 m/sm + 2st + 2a and 22 m/sm + 2st + 4a, respectively. G- banding evidenced homologies between the two species and allowed identify a heteromorphic pair (chromosome pair 10) in PUN. In PEX, constitutive heterochromatin (CH) was found in the centromeric regions of pairs 1, 2, 4, 6 and 11 and on 9p. In PUN, CH was observed in the centromeric regions of all chromosomes, and in small proximal bands on 1p, 2p, 3q, 4q, 5q, 9q, 10q and 11q. Moreover, CH amplification was seen in one of the homologs of pair 10 (the heteromorphic pair). The CMA3 staining results were consistent with the CH findings. Ag-NOR staining showed that nucleolar organizing regions (NORs) were localized in the pericentromeric region of pair 1 in both species, and this result was confirmed by the 18S rDNA FISH probe. FISH with telomeric probes identified telomeric sequences in the distal regions of all chromosomes. In addition, interstitial telomeric sequences (ITSs) were present in seven chromosome pairs of PUN, perhaps reflecting the amplification of telomere-like sequences. FISH with a probe against the transposable element (TE), Rex 6, revealed that it is dispersed in euchromatic regions of the first chromosome pairs of both species. This is the first report describing the FISH-based analysis of PEX and PUN for the 18S rDNA, Rex 6 and human telomeric sequences. Conclusions: Our results contribute to clarifying the chromosomal homologies and rearrangement mechanisms that occurred during the evolution of these species, and may help researchers uncover new markers that will improve our understanding of the taxonomy and systematic classification of Podocnemidae. Univ Fed Para, Lab Citogenet, Inst Ciencias Biol, Rua Augusto Correa,01 Guama, BR-66075110 Belem, Para, Brazil Univ Estadual Paulista, Lab Genom Integrat, Botucatu, SP, Brazil Univ Estadual Paulista, Lab Genom Integrat, Botucatu, SP, Brazil FAPESP: Proc2010/110447 Instituto Chico Mendes de Conservacao da Biodiversidade - ICMBio and Sistema de Autorizacao e Informacao em Biodiversidade - SISBIO: 42642-3 Banco Nacional de Desenvolvimento Economico e Social-BNDS: 2.318.697.0001

La enfermedad ulcerativa cutánea septicémica (SCUD) es un problema común en quelonios inmunocomprometidos, usualmente asociada a pobre calidad del ambiente y heridas en la piel. Se presenta el caso de un grupo mixto de tortugas semiacuáticas conformado por dos tortugas taricaya (Podocnemis unifilis) y cinco tortugas de orejas rojas (Trachemys scripta) que cohabitaban un ambiente en condiciones insalubres. Las dos tortugas P. unifilis presentaron signos clínicos severos compatible con SCUD (eritema, erosiones, letargia y anorexia) mientras que solo dos T. scripta presentaron signos leves de enfermedad (eritema). Las dos taricayas recibieron tratamiento a base de enrofloxacina (10 mg/kg, vía subcutánea, cada 24 h) y se mejoró el alojamiento de las otras tortugas. Una taricaya falleció al segundo día de tratamiento pero la otra se recuperó en 14 días. Septicemic cutaneous ulcerative disease (SCUD) is a common problem in immunocompromised chelonians, which is usually associated to poor environmental quality and skin lesions. It is reported the case of a mixed group of semi-aquatic turtles conformed by two yellow-spotted river turtle (Podocnemis unifilis) and five red-eared slider turtles (Trachemys scripta ) reared in a poor quality enclosure. The two P. unifilis showed severe clinical signs compatible with SCUD (erythema, skin erosions, lethargy and anorexia) whereas only two T. scripta showed mild signs of disease (erythema). The two P. unifilis were treated with enrofloxacin (10 mg/kg, subcutaneous, every 24 h) and the enclosure for the other animals was improved. One P. unifilis died at the second day of the treatment but the second turtle fully recovered in 14 days.

The feeding mechanisms of the pelomedusid turtle Podocnemis unifilis include a surface—skimming behavior, termed neustophagia, which permits utilization of fine particulate food associated with the water surface (neuston). This behavior and its mechanics are described. See full-text article at JSTOR