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Biology Faculty Publications

Research Methods in Life Sciences

Articles 1 - 16 of 16

Full-Text Articles in Ecology and Evolutionary Biology

Cold Shock Induces A Terminal Investment Reproductive Response In C. Elegans, Leah Gulyas, Jennifer R. Powell Jan 2022

Cold Shock Induces A Terminal Investment Reproductive Response In C. Elegans, Leah Gulyas, Jennifer R. Powell

Biology Faculty Publications

Challenges from environmental stressors have a profound impact on many life-history traits of an organism, including reproductive strategy. Examples across multiple taxa have demonstrated that maternal reproductive investment resulting from stress can improve offspring survival; a form of matricidal provisioning when death appears imminent is known as terminal investment. Here we report a reproductive response in the nematode Caenorhabditis elegans upon exposure to acute cold shock at 2 °C, whereby vitellogenic lipid movement from the soma to the germline appears to be massively upregulated at the expense of parental survival. This response is dependent on functional TAX-2; TAX-4 cGMP-gated channels …

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American Bullfrog (Lithobates Catesbeianus) Diet In Uruguay Compared With Other Invasive Populations In Southern South America, Gabriel Laufer, Noelia Gobel, Mauro Berazategui, Matías Zarucki, Sofía Cortizas, Alvaro Soutullo, Claudio Martinez Debat, Rafael O. De Sá Dec 2021

American Bullfrog (Lithobates Catesbeianus) Diet In Uruguay Compared With Other Invasive Populations In Southern South America, Gabriel Laufer, Noelia Gobel, Mauro Berazategui, Matías Zarucki, Sofía Cortizas, Alvaro Soutullo, Claudio Martinez Debat, Rafael O. De Sá

Biology Faculty Publications

Between 2000-2020, more than ten new populations of the invasive American bullfrog (Lithobates catesbeianus) have been reported in the southern cone of South America. We studied the stomach contents of 126 bullfrogs from a population at an early invasion stage in Uruguay (Acegua, Cerro Largo Department). We observed a rich diet, with extensive prey volume range (1 mm3 to more than 7 000 mm(3)); the most frequent items were Hymenoptera (19.6%), Coleoptera (16.4%), Amphipoda (13.3%), Anura (8.9%) and Heteroptera (8.7%). Despite some overlap, differences were observed in volume (chi(2) = 54.6, p <0.001, d.f. = 2) and prey quantity (F = 8.1, p <0.001, d.f. = 79) between males, females, and juveniles. Juveniles showed significantly higher consumption of terrestrial prey by count (82% of their total ingestion) than adults (29% for males and 32% for females) (chi(2) = 28.5, p <0.001, d.f. = 2). Adults, especially females, showed a high frequency of cannibalism (33% of their total ingestion; chi(2) = 20.9, p <0.001, d.f. = 2). Comparing our data with other bullfrog regional studies, we found great plasticity in trophic habits and differences in the incidence of cannibalism (higher incidence in the populations of Acegua, Uruguay, and Buenos Aires, Argentina). These differences could be related to local biodiversity, but also could be affected by the invasion phase. Cannibalism frequency was higher in small bullfrog populations, where it could be favoring the establishment success. This shift in foraging strategies during the invasion process had been insufficiently evaluated in amphibians. Knowing the ecological determinants for the invasion by bullfrogs can be useful to the development of management strategies.

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Larval Chondrocranial And Internal Oral Morphology Of The Neotropical Treefrog Boana Crepitans (Wied-Neuwied, 1824; Amphibia, Anura, Hylidae), Marianna Isabella Rosa Rodrigues De Oliveira, Luiz Norberto Weber, Johnny Sousa Ferreira, Anna Evelin Coimbra Liborio, André Masahide Guimaraes Takazone, Rafael O. De Sá May 2021

Larval Chondrocranial And Internal Oral Morphology Of The Neotropical Treefrog Boana Crepitans (Wied-Neuwied, 1824; Amphibia, Anura, Hylidae), Marianna Isabella Rosa Rodrigues De Oliveira, Luiz Norberto Weber, Johnny Sousa Ferreira, Anna Evelin Coimbra Liborio, André Masahide Guimaraes Takazone, Rafael O. De Sá

Biology Faculty Publications

We describe the internal oral morphology and chondrocranial anatomy for Boana crepitans tadpoles, and compare them with available descriptions for other species in the subfamily Cophomantinae. Among species of the Boana faber group, the chondrocranial anatomy has been reported only for one species internal oral morphology and cranial anatomy are similar to other described species of Boana and Cophomantinae. B. crepitans lacks unique features in the oral cavity and chondrocranium that would distinguish it from other congeneric species. We identify six characters from the internal oral anatomy of tadpoles unique for Cophomantinae. In addition, Boana has infralabial papillae projections, buccal …

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Presence And Distribution Of Leptodactylus Guianensis Heyer And De Sa, 2011 In Colombia: Comparisons With Other Species In The L. Latrans Group., Mariela Osorno Muñoz, Doris L. Gutiérrez-Lamus, Rafael O. De Sá Apr 2019

Presence And Distribution Of Leptodactylus Guianensis Heyer And De Sa, 2011 In Colombia: Comparisons With Other Species In The L. Latrans Group., Mariela Osorno Muñoz, Doris L. Gutiérrez-Lamus, Rafael O. De Sá

Biology Faculty Publications

Leptodactylus guianensis is reported for the first time for Colombia along with a distributional map of the species. The species is the fifth species of the L. latransspecies group documented in the country. Males possess a single, conical and slightly chisel-shaped thumb spine; only three species in the group have a single thumb spine. In collections, specimens of L. guianensis are misidentified as L. macrosternum, L. latrans or L. bolivianus. We provide morphological, colouration and habitat descriptions for where the species occurs in Colombia.

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First Record Of The Genus Leptodactylus (Anura: Leptodactylidae) In Cuba: Leptodactylus Fragilis, A Biological Invasion?, Tomás M. Rodríguez-Cabrera, L. Yusnaviel García-Padrón, Andrés R. Acosta Galvis, Rafael O. De Sá, Roberto Alonso Bosch Aug 2018

First Record Of The Genus Leptodactylus (Anura: Leptodactylidae) In Cuba: Leptodactylus Fragilis, A Biological Invasion?, Tomás M. Rodríguez-Cabrera, L. Yusnaviel García-Padrón, Andrés R. Acosta Galvis, Rafael O. De Sá, Roberto Alonso Bosch

Biology Faculty Publications

The Neotropical genus Leptodactylus is currently represented by three species in the West Indies (Leptodactylus albilabris, Leptodactylus fallax and Leptodactylus validus). Based on morphological, acoustic and molecular evidence, we document the presence of a fourth species in the Caribbean region, Leptodactylus fragilis (Brocchi, 1877). The species was found at two localities in western Cuba, and molecular data suggest a northern South American origin, possibly Venezuela, for these populations. We discuss the potential invasive status of L. fragilis, based on its known distribution, relative abundance, behaviour and possible impacts on native species of Cuban amphibians.

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Chondrocranium And Internal Oral Morphology Of The Tadpole Of Corythomantis Greeningi (Anura: Hylidae), Marianna Isabella Rosa Rodrigues De Oliveira, Luiz Norberto Weber, Rafael O. De Sá, Johnny Sousa Ferreira, Anna Evelin Coimbra Libório, André Masahide Guimarães Takazone Jul 2017

Chondrocranium And Internal Oral Morphology Of The Tadpole Of Corythomantis Greeningi (Anura: Hylidae), Marianna Isabella Rosa Rodrigues De Oliveira, Luiz Norberto Weber, Rafael O. De Sá, Johnny Sousa Ferreira, Anna Evelin Coimbra Libório, André Masahide Guimarães Takazone

Biology Faculty Publications

Corythomantis greeningi is a casque-headed frog that occurs in xeric and sub-humid regions of northeastern Brazil. Individuals are often found on rocks on banks of temporary streams or in ponds upon “lajedos”. Suctorial tadpoles are often found clasping to the rocks in the streams so as not to be dragged by the current; therefore, they have modified external and internal morphology. Here, we describe the internal oral anatomy and the chondrocranium of the tadpole of C. greeningi and compare it to the available descriptions of Lophyohylinae and other suctorial tadpoles. The internal oral morphology in C. greeningi resembles pond-dwelling casque-headed …

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Photography-Based Taxonomy Is Inadequate, Unnecessary, And Potentially Harmful For Biological Sciences, Luis M. P. Ceríaco, Eliécer E. Gutiérrez, Alain Dubois, Rafael O. De Sá, Et Al. Nov 2016

Photography-Based Taxonomy Is Inadequate, Unnecessary, And Potentially Harmful For Biological Sciences, Luis M. P. Ceríaco, Eliécer E. Gutiérrez, Alain Dubois, Rafael O. De Sá, Et Al.

Biology Faculty Publications

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per …

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Chondrocranium And Visceral Skeleton Of Atelopus Tricolor And Atelophryniscus Chrysophorus, E O. Lavilla, Rafael O. De Sá Jan 2001

Chondrocranium And Visceral Skeleton Of Atelopus Tricolor And Atelophryniscus Chrysophorus, E O. Lavilla, Rafael O. De Sá

Biology Faculty Publications

Atelopus tricolor and Atelophryniscus chrysophorus have gastromyzophorous tadpoles. Aside from specific differences, the larval chondrocrania and visceral skeletons show several shared character states, including an almost quadrangular, open chondrocranium , cornua trabeculae with expanded tips, cartilago suprarostralis as a single element, a posteriorly projected arcus subocularis quadrati, a closed muscular tunnel, and a simplified branchial basket, with only three pairs of ceratobranchiales. They are compared with diverse character states of suctorial larvae considering them as causally related to the stream life adaptations.

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The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá Jun 1999

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.

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Development Of The Suprarostral Plate Of Pipoid Frogs, Rafael O. De Sá, Charles C. Swart Apr 1999

Development Of The Suprarostral Plate Of Pipoid Frogs, Rafael O. De Sá, Charles C. Swart

Biology Faculty Publications

The rostral region of nonpipoid tadpoles has two sets of cartilages, the cornua trabeculae and the suprarostral cartilages, whereas the rostral region in pipoid larvae is occupied by a single and continuous cartilage, the suprarostral plate. The homology of this region in pipoid and nonpipoids tadpoles has been controversial. We examined the early formation and development of the suprarostral plate using serially cross-sectioned specimens of Rhinophrynus, Xenopus, and Hymenochirus. We conclude that the cartilaginous structures present in the rostral area of pipoid and nonpipoid larvae are homologous. Furthermore, we found two different developmental patterns among pipoid larvae. The chondrocranium …

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Osteological Analysis Of The Killifish Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá Jan 1999

Osteological Analysis Of The Killifish Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá

Biology Faculty Publications

Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the variation and utility of osteological characters for phylogenetic analysis was done using cleared and double-stained specimens representing 21 species of Cynolebias. This analysis showed that some of the characters previously used to diagnose this genus and some of the species are polymorphic. Osteologically, Cynolebias can be diagnosed by the following synapomorphies: (1) triangular-shaped parietal, (2) vomer positioned ventral to the parasphenoid, (3) long ventral process of the dentary, (4) teeth on fourth ceratobranchial, and (5) teeth on first epibranchial. In addition, characters that help …

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The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá May 1998

The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá

Biology Faculty Publications

The Biology of Xenopus presents a summary of current knowledge about a single genus resulting from a symposium held at the Zoological Society of London in September 1992. This approach to summarizing available information has also been taken for other taxa, such as Atelopus (Lotters, 1996). However, the task of compiling data for Xenopus is enormous relative to any other amphibian group, because Xenopus laevis has become a model system for molecular and development research (Cannatella and de Sa, 1993). Unfortunately, most of our knowledge of Xenopus is biased toward this single species. There are about 20 recognized species of …

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The Tadpole Of Pseudis Minuta (Anura: Pseudidae), An Apparent Case Of Heterochrony, Rafael O. De Sá, Esteban O. Lavilla Jan 1997

The Tadpole Of Pseudis Minuta (Anura: Pseudidae), An Apparent Case Of Heterochrony, Rafael O. De Sá, Esteban O. Lavilla

Biology Faculty Publications

The external morphology, oral disc, and coloration pattern of the larva of Pseudis minuta are described. Tadpoles are mostly bottom dwellers that have a small, terminal oral disc with a labial tooth row formula 1(1-1)/(1-1)2. Internal oral anatomy is characterized using scanning electron microscopy, representing the only description available for the family Pseudidae. The coloration pattern of P. minuta tadpoles is compared with that of other pseudids. Pseudis minuta larvae do not exhibit the ontogenetic coloration change reported for P. paradoxa. Considering larval coloration, larval size, and reports of adult size, acceleration or hypermorphosis are suggested as possible heterochronic mechanisms …

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External Morphology Of The Chorion Of The Annual Fishes Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá Dec 1996

External Morphology Of The Chorion Of The Annual Fishes Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá

Biology Faculty Publications

Members of the family Rivulidae (killifishes) inhabit temporary bodies of freshwater in South and Central America (one species is also found in North America). The most remarkable characteristic of the family Rivulidae is that species have an annual life cycle with a drought-resistant egg during the dry season. Parenti's (1981) analysis of the order Cyprinodontiformes considered a single genus, Cynolebias, whereas Cos- ta's (1990) phylogenetic analysis of the family Rivulidae separates Cynolebias from Cynopoecilus. One of Costa's synapomorphies to separate Cynopoecilus is the unique structure of their egg's chorion, which is shared with Leptolebias and Campellolebias.

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Xenopus Laevis As A Model Organism, David C. Cannatella, Rafael O. De Sá Dec 1993

Xenopus Laevis As A Model Organism, David C. Cannatella, Rafael O. De Sá

Biology Faculty Publications

Model organisms are often assumed to be representative of some more inclusive taxon of which the species is a part. This assumption leads to mistaken generalizations about the evolutionary and comparative significance of the data gathered. This paper reviews com? parative and evolutionary studies of Xenopus laevis and its relatives. Phylogenetic analysis of data from DNA sequences and morphology indicate that Xenopus is monophyletic and that Silurana is its sister group. The most basal lineages of Pipidae diverged prior to the breakup of Gondwana. The bizarre morphology of Xenopus is in part due to changes in the mode of meta? …

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Ribosomal Dna And The Phylogeny Of Frogs, David M. Hills, Loren K. Ammerman, Michael T. Dixon, Rafael O. De Sá Mar 1993

Ribosomal Dna And The Phylogeny Of Frogs, David M. Hills, Loren K. Ammerman, Michael T. Dixon, Rafael O. De Sá

Biology Faculty Publications

Phylogenetic analysis of 1656 aligned sites in the 28S ribosomal RNA gene of frogs supports some of the recently recognized higher groups of anurans but provides counter-support for others. The 28S rDNA data support the monophyly of the recently recognized Pipanura (me- sobatrachians plus neobatrachians), which in turn indicates paraphyly of archaeobatrachians. Me- sobatrachians (pelobatoids plus pipoids), which are either considered paraphyletic or weakly sup- ported as monophyletic in morphological analyses, also receive support as a monophyletic group from the 28S rDNA data. Hyloidea (=Bufonoidea), which is widely recognized but lacks morphological support, receives some molecular support as being monophyletic. …

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