scholarly journals Geographic variation in the morphology of the sand-dwelling lizard Nothobachia ablephara (Squamata: Gymnophthalmidae)

2019 ◽  
Vol 18 (2) ◽  
pp. 195-207
Author(s):  
Carolina Nisa Ramiro ◽  
Renato Sousa Recoder ◽  
Miguel Trefaut Rodrigues
Keyword(s):  
Geographic Variation ◽  
Morphological Traits ◽  
Geographical Variation ◽  
Multivariate Analyses ◽  
Molecular Study ◽  
Northeastern Brazil ◽  
Sexually Dimorphic ◽  
Morphometric Variation ◽  
The One ◽  
Two Populations

Geographic variation in the morphology of the sand-dwelling lizard Nothobachia ablephara (Squamata: Gymnophthalmidae). Nothobachia ablephara is a small microteiid lizard with an elongated body and reduced limbs; it occurs in isolated dune felds in the state of Bahia (Xique-Xique and Alagoado) and small sandy patches in northeastern Brazil. A previous molecular study found a marked mtDNA divergence between populations of N. ablephara from Alagoado and Xique-Xique dunes, suggesting that the two populations diverged from one another between 3 and 4 million years ago. Given this isolation, it is interesting to explore whether morphological traits of the lizards refect the reported genetic divergence of the populations. Scale counts of the sexes and the populations differ signifcantly, but there is considerable overlap of values. Univariate and multivariate analyses revealed signifcant morphometric variation between sexes and populations; however, this is mostly explained by size differences. Females are larger than males in all characters that are sexually dimorphic, and individuals from Xique-Xique are larger than those from Alagoado in all characters that vary geographically. The sample from Alagoado has more sexually dimorphic characters than the one from Xique-Xique. Although N. ablephara displays some geographical variation, the two populations could not be unequivocally distinguished by scale counts and morphometric data.

Geographical variation and taxonomy of the snail-eating snake Dipsas albifrons (Sauvage, 1884), with comments on the systematic status of Dipsas albifrons cavalheiroi Hoge, 1950 (Serpentes: Colubridae: Dipsadinae)

Zootaxa ◽  
2005 ◽  
Vol 1013 (1) ◽  
pp. 19 ◽  
Author(s):  
PAULO PASSOS ◽  
RONALDO FERNANDES ◽  
MARCOVAN PORTO
Keyword(s):  
Geographic Variation ◽  
Geographical Variation ◽  
Multivariate Analyses ◽  
Taxonomic Status ◽  
External Morphology ◽  
Island Population ◽  
Systematic Status ◽  
Qualitative Analyses

The taxonomic status of Dipsas albifrons is revised and geographic variation of external morphology and hemipenis are described. Multivariate analyses suggest that the pattern of geographical variation is correlated with gap sampling, probably indicating a northernward cline in segmental counts (mainly ventral and subcaudal scales). Quantitative and qualitative analyses reveal that the island population (Dipsas albifrons cavalheiroi) is not divergent from mainland populations and, herein, is considered a junior synonymy of Dipsas albifrons. A lectotype of Dipsas albifrons is designated.

Density-dependent polyphenism and geographic variation in size among two populations of lubber grasshoppers (Romalea microptera)

2009 ◽  
Vol 34 (5) ◽  
pp. 644-651 ◽  
Author(s):  
JASON E. JANNOT ◽  
ALEXANDER E. KO ◽  
DUSTIN L. HERRMANN ◽  
LAURA SKINNER ◽  
EMILY BUTZEN ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Density Dependent ◽  
Two Populations

Relation of geographic variation in the skull of Microtus pennsylvanicus to climate

1983 ◽  
Vol 61 (6) ◽  
pp. 1232-1241 ◽  
Author(s):  
Richard R. Snell ◽  
Kimberly M. Cunnison
Keyword(s):  
Low Temperature ◽  
Geographic Variation ◽  
Multiple Regression ◽  
Minimum Spanning Tree ◽  
Climatic Factors ◽  
Principal Component ◽  
Microtus Pennsylvanicus ◽  
Annual Number ◽  
Simple Correlation ◽  
Morphometric Variation

Analyses of geographic variation in the skull of meadow voles (Microtus pennsylvanicus) indicate that phenetic distances among samples are not related to geographic distance: a minimum spanning tree based on average taxonomic distance superimposed on a map of 38 localities provides no particular phenetic clustering of those samples geographically proximate. A multiple regression of phenetic component one (skull size) onto orthogonally rotated climatic factors explains much less morphometric variation (25.6%) than a simple correlation with recorded extreme low temperature (38.9%). Multiple regression of phenetic principal component two (interorbital width) onto the same climatic factors explains minimally more morphological variation (42.1%) than a simple correlation with mean annual number of days with frost (41.7%). Microtus pennsylvanicus shows a pattern of size variation that is the reverse of Bergmann's rule: these voles are large where it is warm and small where it is cold. Since small size reduces total energy expenditure, we predict that during times of extreme low temperature (i) smaller voles will be less energetically stressed than larger voles and (ii) large size will be actively selected against.

Phytoseiidae mites associated with native and cultivated solanaceous in Central-West Brazil

2021 ◽  
Author(s):  
Mércia Elias Duarte ◽  
Peterson Rodrigo Demite ◽  
Renata Santos De Mendonça ◽  
Miguel Michereff-filho ◽  
Maria Luiza Santa Cruz De Mesquita Alves ◽  
...  
Keyword(s):  
Biological Control ◽  
Morphological Traits ◽  
Common Species ◽  
Predatory Mites ◽  
Natural Environments ◽  
Phytoseiid Mites ◽  
Control Programs ◽  
Phytophagous Mites ◽  
Wild Host ◽  
The One

Predatory mites represent important biological control agents and those belonging to the Phytoseiidae family are the most promising for the control of phytophagous mites and small insects. The control of key pests of tomato and other solanaceous crops, highlighting phytophagous mites, has been a challenge and the biological control constitutes a promising strategy. Prospecting predatory mites in wild host plants, natural environments as well as in agroecosystems is relevant because these non-crop and crop areas can serve as reservoirs for promising species for biological control programs. This study aimed to know the Phytoseiidae fauna associated with wild and cultivated solanaceous plants in a poorly prospected area in Brazil, the Central-West Region. A detailed taxonomic identification of phytoseiid mites was conducted, and the most important morphological traits are presented for each species. In addition, associated phytophagous mites mainly belonging to the Tetranychidae, Tenuipalpidae and Eriophyoidea were identified. Surveys were carried out in 23 species of solanaceous collected in the Distrito Federal (12 areas) and Goiás State (1 area), from February 2017 to January 2018. Nineteen species of predators belonging to ten genera were recorded: Amblyseius (2 species), Euseius (3), Galendromus (1), Iphiseiodes (1), Neoseiulus (3), Paraphytoseius (1), Phytoseius (3), Proprioseiopsis (2), Typhlodromalus (2, one probably new to science) and Typhlodromips (1). Solanum lycocarpum was the solanaceous that harbored the highest richness (11 species), as well as the one with the highest abundance of phytoseiids (250 specimens). Typhlodromalus aripo was the most common species, being the most abundant (423 specimens; 32%) and registered on the largest number of hosts (14). Many of phytoseiid species found present morphological traits that facilitate their occurrence in leaves with trichomes, as in the case of tomato and other cultivated solanaceous. These traits and the association between predators and phytophagous mites may indicate that these species are promising for biological control programms. Thus, extensive studies to assess the efficiency of the identified predatory mites to control key solanaceous pests are required.

scholarly journals Germination Patterns in Seeds Produced in Apical and Basal Fruits of Two Thlaspi arvense Populations

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 756
Author(s):  
Eva Edo-Tena ◽  
Russ W. Gesch ◽  
Aritz Royo-Esnal
Keyword(s):  
Germination Percentage ◽  
Temperate Climate ◽  
Oilseed Crop ◽  
Seed Selection ◽  
Thlaspi Arvense ◽  
Production Site ◽  
Field Pennycress ◽  
Selection For ◽  
The One ◽  
Two Populations

The aim of the present work is to study possible differences in the germination behavior of apical and basal seeds (produced in the upper and lower fruits of the infruitescence), of two populations of field pennycress (Thlaspi arvense), both produced in a Mediterranean and a continental temperate climate. The results showed that among the three studied factors (population, seed type, production site), only the production site was relevant for the total germination, germinating those produced in Morris in a greater amount than those produced in Lleida. Germination models could be applied only to seeds produced at Morris (>10% germination), and despite the lack of differences in the total germination percentage, germination rates (speed—b parameter—and time to 50% germination—G50) differed between population and seed types—apical seeds from the Spanish population germinated faster (lower b parameter) than the rest, while apical seeds of both populations germinated faster than the corresponding basal seeds (lower G50). The results show, on the one hand, the importance of the seed production site if this species was considered as a commercial oilseed crop and, on the other hand, differences that will help seed selection for seed germination and establishment improvement of pennycress.

scholarly journals Drivers of molecular and morphometric variation in Triatoma brasiliensis (Hemiptera: Triatominae): the resolution of geometric morphometrics for populational structuring on a microgeographical scale

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Edgard H. Kamimura ◽  
Maria Carolina Viana ◽  
Maurício Lilioso ◽  
Fernanda H. M. Fontes ◽  
Dayane Pires-Silva ◽  
...  
Keyword(s):  
Mitochondrial Gene ◽  
Northeastern Brazil ◽  
Canonical Variate ◽  
Geographic Scale ◽  
Morphometric Variation ◽  
Mantel Tests ◽  
Variate Analysis ◽  
Semiarid Areas ◽  
The Right ◽  
Source Of Information

Abstract Background The protozoan Trypanosoma cruzi circulates in semiarid areas of northeastern Brazil in distinct ecotopes (sylvatic, peridomestic and domestic) where Triatoma brasiliensis Neiva, 1911 is the most important Chagas disease vector. In this study, we analyzed microevolutionary and demographic aspects of T. brasiliensis populations at the ecotypic, micro and macro-geographic scales by combining morphometrics and molecular results. Additionally, we aimed to address the resolution of both markers for delimiting populations in distinct scales. Methods We sampled populations of T. brasiliensis from distinct ecotypic and geographic sites in the states Rio Grande do Norte (RN) and Paraíba (PB). The geometric morphometry was carried out with 13 landmarks on the right wings (n = 698) and the genetic structure was assessed by sequencing a region of cytochrome b mitochondrial gene (n = 221). Mahalanobis distance (MD) and coefficient of molecular differentiation (ΦST) were calculated among all pairs of populations. The results of comparisons generated MD and ΦST dendrograms, and graphics of canonical variate analysis (CVA). Results Little structure was observed for both markers for macro-geographic scales. Mantel tests comparing geographic, morphometric and genetic matrices showed low correlation (all R2 < 0.35). The factorial graphics built with the CVA evidenced population delimitation for the morphometric data at micro-geographic scales. Conclusions We believe that T. brasiliensis carries in its genotype a source of information to allow the phenotypical plasticity across its whole distribution for shaping populations, which may have caused a lack of population delimitation for CVAs in morphometric analysis for macro-geographic scale analysis. On the other hand, the pattern of morphometric results in micro-geographic scales showed well-defined groups, highlighting the potential of this tool to inferences on the source for infestation.

Demography and home range of the eastern barred bandicoot (Perameles gunnii) in south-eastern Tasmania

2000 ◽  
Vol 27 (1) ◽  
pp. 103 ◽  
Author(s):  
Stephen A. Mallick ◽  
Michael M. Driessen ◽  
Gregory J. Hocking
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Home Range ◽  
Home Ranges ◽  
Sexually Dimorphic ◽  
South Eastern ◽  
Small Width ◽  
Live Trapping ◽  
Dry Conditions ◽  
Two Populations

We used live-trapping to study the demography and movement of two populations of the eastern barred bandicoot, Perameles gunnii, in south-eastern Tasmania from 1992 to 1996. Densities were 0.35–2.35 animals ha–1. Sex ratios were male-dominated on Grid I and female-dominated on Grid II. The average body weight for sexual maturity was 700g for males and 680g for females, while the lowest recorded weight for a breeding female was 570g. Perameles gunnii was sexually dimorphic, with males having a greater body weight and pes length than females. Recruitment was 25.4–32.1%, residence 46.7–100.0%, and emigration 16.5–25.5% of the population. Three juveniles were recruited to the Grid I population, 55 to Grid II, with a steady decline in the number of juveniles recruited to Grid II over the four years of the study. Breeding occurred year-round. Mean litter size was 2.53, with 78.2% of all litters having either 2 or 3 young. Mean longevity for male and female P. gunnii was 7.91 and 10.54 months, respectively. Home ranges of males (4.29 ha) were significantly larger than those of females (2.34 ha), although this may represent a significant underestimate due to the small width of our grids (200m) relative to the home-range area. There was only moderate overlap (19.3%) between home ranges of males and females. The overlap between male/male home ranges (4.4%) was significantly less than the overlap between female/female home ranges (15.8%). Perameles gunnii carried both ticks and fleas, with flea infestation being significantly higher on Grid I than on Grid II. Both populations underwent a significant decline over the study period, apparently the result of the unusually dry conditions over the first 3 years of the study. A deterioration in conditions was associated with a steady loss of resident adults, declining recruitment of juveniles and an increase in the male/female sex ratio. The sex ratio of P. gunnii populations may provide a convenient index of habitat quality, with poor or deteriorating conditions apparently associated with a high or increasing numbers of males to females.

scholarly journals Kisspeptin Neurons from Mice to Men: Similarities and Differences

Endocrinology ◽  
2012 ◽  
Vol 153 (11) ◽  
pp. 5105-5118 ◽  
Author(s):  
Robert L. Goodman ◽  
Michael N. Lehman
Keyword(s):  
Strong Evidence ◽  
Species Differences ◽  
Mammalian Species ◽  
Limited Area ◽  
Sexually Dimorphic ◽  
Functional Consequences ◽  
Similarities And Differences ◽  
Reproductive Neuroendocrinology ◽  
Two Populations

Abstract The discovery that kisspeptin was critical for normal fertility in humans ushered in a new chapter in our understanding of the control of GnRH secretion. In this paper, we will review recent data on the similarities and differences across several mammalian species in the role of kisspeptin in reproductive neuroendocrinology. In all mammals examined to date, there is strong evidence that kisspeptin plays a key role in the onset of puberty and is necessary for both tonic and surge secretion of GnRH in adults, although kisspeptin-independent systems are also apparent in these studies. Similarly, two groups of kisspeptin neurons, one in the arcuate nucleus (ARC) and the other more rostrally, have been identified in all mammals, although the latter is concentrated in a limited area in rodents and more scattered in other species. Estrogen has divergent actions on kisspeptin expression in these two regions across these species, stimulating it the latter and inhibiting expression in the former. There is also strong evidence that the rostral population participates in the GnRH surge, whereas the ARC population contributes to steroid-negative feedback. There may be species differences in the role of these two populations in puberty, with the ARC cells important in rats, sheep, and monkeys, whereas both have been implicated in mice. ARC kisspeptin neurons also appear to participate in the GnRH surge in sheep and guinea pigs, whereas the data on this possibility in rodents are contradictory. Similarly, both populations are sexually dimorphic in sheep and humans, whereas most data in rodents indicate that this occurs only in the rostral population. The functional consequences of these species differences remain to be fully elucidated but are likely to have significance for understanding normal neuroendocrine control of reproduction as well as for use of kisspeptin agonists/antagonists as a therapeutic tool.

Geographic variation in the advertisement call of Crinia signifera (Anura:Myobatrachidae) on Kangaroo Island and across southern south-eastern Australia

2008 ◽  
Vol 56 (4) ◽  
pp. 223 ◽  
Author(s):  
Murray J. Littlejohn
Keyword(s):  
Geographic Variation ◽  
Pulse Number ◽  
Advertisement Call ◽  
Regional Study ◽  
South Eastern ◽  
Island Sample ◽  
Eastern Australia ◽  
Continental Islands ◽  
Two Populations ◽  
South Eastern Australia

The male advertisement call of anuran amphibians has a major role in mate choice, and regional variation in this attribute can act as an indicator of speciation and a marker for genetic differentiation. As part of a regional study of geographic variation in the male advertisement call of Crinia signifera across south-eastern Australia and adjacent larger continental islands, samples of advertisement calls from two populations on Kangaroo Island and two populations on the adjacent Fleurieu Peninsula were compared. Four call attributes were considered: pulse number, call duration, pulse rate and dominant frequency. Pulse number is considered the most reliable for comparative purposes because it is not influenced by effective temperature or audio recording and analysis. The two island populations (central and eastern, ~24 km apart) differ significantly in pulse number, with contact but no overlap of interquartile ranges. The eastern sample differs markedly from those on the nearby Fleurieu Peninsula – which are both similar to the more distant central island sample. Geographic variation in pulse number in these four samples and 11 others from two recent publications is then interpreted in the light of land bridges and lower temperatures of the late Pleistocene and early Holocene.

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