scholarly journals Aspects of reproduction and sexual dimorphism of Lygophis flavifrenatus (Dipsadidae: Xenodontinae)

2019 ◽  
Vol 109 ◽  
Author(s):  
Fernando Marques Quintela ◽  
Daniel Loebmann
Keyword(s):  
Sexual Dimorphism ◽  
Tail Length ◽  
Late Summer ◽  
Great Majority ◽  
Mature Female ◽  
Late Winter ◽  
Head Width ◽  
Mato Grosso ◽  
Body Dimensions ◽  
New Information

ABSTRACT Lygophis flavifrenatus Cope, 1862 is a terrestrial dispsadid distributed in subtropical Brazil, Paraguay, Uruguay, and Argentina. Herein, we present data on sexual dimorphism and reproductive biology of this very poorly studied species. A total of 108 specimens (55 females, 50 males, three hatchlings with unidentified sex) from Brazilian states of Rio Grande do Sul, Santa Catarina and Mato Grosso do Sul were analyzed. Sexual dimorphism by size, body dimensions (tail length, head length, head width) and a number of ventral and subcaudal scales is not well marked in the species. Mature females attain the greater size and have a higher number of ventral scales than mature males. Mature males, in turn, presented longer tail, longer and wider head and a higher number of subcaudal scales. Meanwhile, marked overlaps were observed in ranges of all body dimensions proportions and a number of ventral and subcaudal scales. Females attained sexual maturity at a greater size than males. The smallest mature female showed snout-vent length (SVL) = 402 mm while the smallest mature male presented SVL = 285 mm. Females presented a seasonal reproductive cycle, with advanced stages (advanced development of secondary follicles and development of eggs) occurring in late winter and spring. Hatchlings were found in late summer. It is supposed that only one clutch is laid per cycle, considering that the great majority of secondary follicles found in females carrying eggs were irregular or lamellar shaped (possibly atresic). Clutch sizes varied from 6 to 12 eggs (mean = 8.2) and presented a tendency for positive correlation with progenitors SVL. The present study adds new information to the knowledge about the natural history of snakes from subtropical Neotropics.

Sexual dimorphism, deformations, and epibionts of Phrynops tuberosus (Testudines, Chelidae)

2015 ◽  
Vol 65 (3-4) ◽  
pp. 311-320 ◽  
Author(s):  
João Fabrício Mota Rodrigues ◽  
José Roberto Feitosa Silva
Keyword(s):  
Sexual Dimorphism ◽  
Natural History ◽  
Tail Length ◽  
Condition Index ◽  
Head Width ◽  
Body Condition Index ◽  
Future Studies ◽  
History Of ◽  
One Year ◽  
Effective Conservation

Studies focusing on the natural history of species are essential for developing effective conservation measures and evaluating ecological hypotheses. To this end, we describe natural history data of the Cotinga River toadhead turtle, Phrynops tuberosus, in the Banabuiú River in Ceará, Brazil, and evaluated sexual dimorphism, epibionts, and mutilation effects. We hand-captured 134 individuals by snorkeling, over a period of one year, resulting in the capture of 94 males, 24 females, and 16 juveniles. Females had larger head width and body mass than males, while males had longer tail length. One quarter of the turtles captured had some sort of injury or deformation, most common injuries being missing claws, mutilations, and shell deformations. We found no difference in body condition index between mutilated and non-mutilated animals. Mollusks, insects, and leeches were found as epibionts on P. tuberosus and most of the captured turtles had extensive algal cover. Future studies should focus on understanding the effect of mutilations on animal fitness and reproductive success.

Natural history of the New Caledonian whiptailed skink Tropidoscincus variabilis (Bavay, 1869) (Squamata: Scincidae)

2009 ◽  
Vol 30 (2) ◽  
pp. 207-220
Author(s):  
Ross Sadlier ◽  
Aaron Bauer ◽  
Hervé Jourdan ◽  
Glenn Shea
Keyword(s):  
New Caledonia ◽  
Tail Length ◽  
Late Summer ◽  
Head Length ◽  
Head Width ◽  
Ontogenetic Change ◽  
Positive Allometry ◽  
Wide Range ◽  
Depth Increase ◽  
One Year

AbstractTropidoscincus variabilis is a medium-sized, long-limbed and long-tailed skink from New Caledonia with strong ontogenetic change in coloration, juveniles being very brightly coloured. It is primarily an inhabitant of forested habitats, but also occurs in maquis heathlands. Mature females are similar in size to mature males, but have proportionally longer bodies and shorter heads and limbs, and a less brightly orange venter. Body length (axilla-groin length) increases in positive allometry to snout-vent length (SVL), while limb lengths and head length increase in negative allometry to SVL (except in males, where limb length increases isometrically). Head width and depth increase in positive allometry to head length, while tail length increases in isometry with SVL. Reproduction is seasonal in both sexes, with gonadal cycles peaking in late spring. Females lay 2-4 eggs in summer, and young hatch in late summer. More than one year of growth is required to attain maturity. Diet consists of a wide range of invertebrates, particularly arthropods, and with large numbers of spiders and crickets. Juveniles eat more spiders, bugs and isopods than adults. The long limbs and ontogenetic change in coloration of this species are not explained by its known biology.

scholarly journals Sexual dimorphism in morphological characteristics of two Nigerian indigenous goat breeds

2020 ◽  
Vol 44 (5) ◽  
pp. 1-4
Author(s):  
C. Alphonsus ◽  
G. N. Akpa ◽  
P. P. Barje ◽  
B. I. Nwagu ◽  
M. Orunmuyi ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Characteristics ◽  
Tail Length ◽  
West African ◽  
Head Width ◽  
Body Depth ◽  
Coefficients Of Variation ◽  
Indigenous Goat ◽  
Indigenous Goats ◽  
Red Sokoto Goat

Themorphological traits of 594 indigenous goats comprised of 316 and 279 Red Sokoto goat (RSG) and West African dwarf (WAD) goats, respectively, were measured to determine the presence or otherwise of sexual dimorphism in the morphological characteristics of the two indigenous goats. The morphological traitsmeasured were body length (BL), withers height (WH), rumps height (RH), heart girth (HG), body depth (BD), tail length (TL), head length (HL), head width (HW), ear length (EL), and horn length (HL). Also recorded were body weight (BW) and sex of each animal.The data collected were analysed using descriptive statistics and analysis of variance of fixed effect of sex on themorphological characteristics. The result revealed the presence of marked sexual dimorphism in morphological characteristics of both the RSG and WAD goats. The adult females were significantly (P< 0.05-0.01) heavier and larger in size than the males. The respective coefficients of variation (CV) between breeds were high in most of the morphological traits suggesting high heterogeneity, an indication of the amount of opportunity available for improving the breeds through selection.

Sexual dimorphism and female reproduction in two sympatric toad-headed lizards, Phrynocephalus frontalis and P. versicolor (Agamidae)

2011 ◽  
Vol 61 (2) ◽  
pp. 139-151 ◽  
Author(s):  
Lu-Xi Mao ◽  
Jian-Fang Gao ◽  
Xiang Ji ◽  
Yan-Fu Qu
Keyword(s):  
Sexual Dimorphism ◽  
Egg Size ◽  
Species Difference ◽  
Tail Length ◽  
Reproductive Traits ◽  
Sympatric Species ◽  
Offspring Size ◽  
Head Width ◽  
Female Reproduction ◽  
Female Reproductive Traits

AbstractWe studied sexual dimorphism and female reproduction in two sympatric species of toad-headed lizards, Phrynocephalus frontalis and P. versicolor, from Inner Mongolia, North China. The smallest reproductive females of P. frontalis and P. versicolor we recorded were 43.5 mm and 44.2 mm SVL, respectively. Females were the larger sex in P. versicolor, whereas female and male adults of P. frontalis did not differ in mean SVL. Females of P. frontalis were on average smaller than females of P. versicolor, so were males of P. frontalis. In both species females were larger in abdomen length (AL) but smaller in head length (HL), head width (HW) and tail length (TL); adults of P. frontalis were larger in HL and TL but smaller in AL and HW than adults of P. versicolor of the same size. Females of both species laid a single clutch of 2-6 eggs per breeding season. The trade-off between size and number of eggs was evident in both species. Of the examined female reproductive traits, only clutch size and egg size differed between the two species, with females of P. frontalis laying fewer but larger eggs than did females of P. versicolor of the same SVL. However, as the observed between-species difference in egg size (and thus, offspring size) was small, any niche divergence resulting from this difference could be less important in reducing competitions between these two sympatric species of lizards.

scholarly journals An Improved Approach to Measuring Sexual Dimorphism in Snakes: Morphological Variation in the Bahamian Racer (Cubophis vudii vudii)

2020 ◽  
Vol 27 (2) ◽  
pp. 137-146
Author(s):  
Scott Johnson ◽  
William K. Hayes
Keyword(s):  
Body Size ◽  
Natural Selection ◽  
Sexual Dimorphism ◽  
Linear Models ◽  
Geometric Mean ◽  
Tail Length ◽  
Head Width ◽  
Island Populations ◽  
Total Length ◽  
New Providence

Sexual dimorphism in animals exists in many forms, including overall size difference between the sexes (sexual size dimorphism, SSD) and size and structural differences in body components (sexual body component dimor­phism, SBCD). Studies of sexual dimorphism seek to determine whether dimorphic traits result from sexual selection, natural selection, or non-adaptive processes. Characterizing sexual dimorphism depends on identifying an unbiased character for overall body size, which can then be used to assess both SSD and SBCD. Most studies of snakes use snout-vent length (SVL) for this purpose, but SVL may itself be dimorphic. In this study, we examined SSD and SBCD in three island populations of the Bahamian Racer (Cubophis vudii vudii). Discriminant function analysis (DFA) showed that head width (females wider) and tail length (males longer) best discriminated between the sexes, and total length provided the least discrimination. Linear models using total length as the least-biased measure for overall size revealed an absence of SSD, but SBCD existed for head size (width 8.9% greater in females, length similar), trunk length (4.3% longer in females), and tail length (9.8% longer in males). Linear models also revealed differences among island populations for total length (New Providence < Eleuthera = Allen Cay) and head length (Allen Cay < Eleuthera < New Providence), but not head width or tail length. Extent of SBCD varied depending on choice of character to control for overall body size, with total length yielding the most female-biased values, and geometric mean, principal component 1 (PC1) of a principal components analysis, and SVL providing increasingly more male-biased values, respectively. Body condition was statistically similar for the two sexes and three seasons (spring, summer-fall, winter), but the mod­erate and large effect sizes, respectively, suggest that females were heavier than males, and both sexes were heaviest in spring. Females, which represented 64.9 of all snakes, suffered injuries disproportionately to males (19.7% and 3.1%, respectively), but no differences in sex ratio or frequency of injury existed among the island populations. Collectively, these findings illustrate the utility of using DFA and other approaches (geometric mean, PC1) to identify a relatively unbiased reference character for overall body size and suggest that sexual and natural selection interact to shape the morphology of these snakes.

scholarly journals Infestation of weed species in monocrop coffee or intercropped with banana, under agroecological system

2014 ◽  
Vol 32 (4) ◽  
pp. 665-674 ◽  
Author(s):  
G. Concenço ◽  
I.S. Motta ◽  
I.V.T. Correia ◽  
S.A. Santos ◽  
A. Mariani ◽  
...  
Keyword(s):  
Cropping Systems ◽  
Late Summer ◽  
Late Winter ◽  
Weed Species ◽  
Importance Value ◽  
Mato Grosso ◽  
Weed Infestation ◽  
Ecological Planting ◽  
The City ◽  
Mato Grosso Do Sul

We aimed with this study to compare weed infestation in coffee under two different cropping managements: conventional coffee grown alone, or intercropped with banana plantation in a year-round basis (late spring, late summer, late fall and late winter). The experiment was installed in 2009 under field conditions at the Escola Municipal Rural Benedita Figueiró de Oliveira, in the city of Ivinhema in the state of Mato Grosso do Sul, Brazil. Assessments of weed occurrence were made three years after employment, on both cropping systems, and density, frequency, dominance and the importance value for each plant species in each system and season were quantified. Plant diversity within each system was estimated by Simpson and Shannon-Weiner indexes. Similarity between cropping systems were also assessed by the binary asymmetric similarity coefficient of Jaccard. Absolute infestation and spontaneous species differed between the two cropping systems in all seasons. Overall species diversity is higher in the monocrop compared with the intercrop, and it is associated in this study with the higher incidence of troublesome species. Areas were similar in terms of weed composition only in the Fall. Shading provided by the banana trees shows to be an efficient culture management aiming to suppress weeds in agro-ecological planting systems.

scholarly journals Seasonal population dynamics of Octopus vulgaris in the eastern Mediterranean

2006 ◽  
Vol 63 (1) ◽  
pp. 151-160 ◽  
Author(s):  
Stelios Katsanevakis ◽  
George Verriopoulos
Keyword(s):  
Eastern Mediterranean ◽  
Late Summer ◽  
Main Peak ◽  
Octopus Vulgaris ◽  
Late Winter ◽  
Visual Census ◽  
The Common ◽  
Specific Growth Rates ◽  
Seasonal Population ◽  
Seasonal Population Dynamics

Abstract The population density of Octopus vulgaris was measured by visual census with scuba diving in coastal areas in Greece (eastern Mediterranean). A time-variant, stage-classified, matrix population model was developed to interpret the seasonal variation of octopus stage densities and to estimate several life cycle parameters. An annual and a semi-annual periodic cycle were found in the stage densities. A main peak of benthic settlement was observed during summer and a secondary, irregular one during late autumn. Two spawning peaks were estimated, a main one during late winter–spring and a secondary one during late summer–early autumn. More than 50% of the just-settled individuals will eventually die after 3 months. Mortality rate declines, as individuals grow larger, reaches a minimum approximately 6 months after settlement, and then grows again probably because of terminal spawning. The life expectancy of recently settled individuals (<50 g) during their summer peak is approximately 5 months. The lifespan of the common octopus is estimated to be between 12 and 15 months. The octopuses' mean specific growth rates (±s.d.) in their natural environment were 1.61 ± 0.30 d−1 for 50–200 g individuals and 1.19 ± 0.31 d−1 for 200–500 g individuals.

Preliminary investigations into the life cycle of Ventruia inaequalis (Cooke) WINT. in South Australia.

1953 ◽  
Vol 4 (4) ◽  
pp. 415 ◽  
Author(s):  
MW Jeffery
Keyword(s):  
Life Cycle ◽  
Primary Infection ◽  
South Australia ◽  
Late Summer ◽  
Relative Importance ◽  
New Information ◽  
One Year

Investigation into the possible sources of primary infection by the fungus Ventruia inaequalis (Cooke) Wint. in spring has been carried out. The results present new information on the life cycle of the pathogen under South Australian conditions. Sources of primary infection, such 'as lesions on one-year-old wood or overwintering superficial conidia on the trees, do not appear important. Bud-scale infection of dormant buds has been shown, and its relative importance is discussed. Ascospores are the most important source of primary infection. Their period of discharge extends to a later date than previously reported for South Australia and is considered in relation to leader shoot and late summer spot infection.

scholarly journals Genotype, gestation length, season, parity and sex effects on growth traits of two rabbit breeds and their crosses

2014 ◽  
Vol 30 (4) ◽  
pp. 717-729 ◽  
Author(s):  
S.S.A. Egena ◽  
G.N. Akpa ◽  
I.C. Alemede ◽  
A. Aremu
Keyword(s):  
Growth Traits ◽  
Tail Length ◽  
The Body ◽  
Gestation Length ◽  
Body Measurements ◽  
Season Of Birth ◽  
Trunk Length ◽  
Body Dimensions ◽  
Sex Effects ◽  
Foundation Stock

One hundred and thirty rabbits were used to evaluate the effect of genotype, gestation length, season, parity and sex on growth traits of two breeds of rabbit and their crosses. The rabbit used for the experiment were breeds of the New Zealand White (NZW) and Chinchilla (CH) breed. Six breeding bucks (three/breed) and eighteen breeding does (nine/breed) served as the foundation stock. Traits measured include: body weight (BW), nose to shoulder length (NTS), shoulder to tail length (STL), heart girth (HG), trunk length (TL) and length of ear (LE). Results revealed that, BW of the rabbits were influenced (p<0.05) by genotype, gestation length and season. CH x (CH x NZW) progenies had better BW at 35-d and 49-d of age while NZW x CH progenies had better BW at 21-d of age. Kittens born late (32-34 days) had better BW at 21-d, 35-d and 49-d while kittens kindled during early dry season had better BW at 21-d, 35-d and 49-d. Genotype affected (p<0.05) all the body measurements at 21-d, 35-d and 49-d. Gestation length affected (p<0.05) all the body measurements except for NTS at 21-d and HG at 49-d respectively. Season of birth also influenced (p<0.05) all the body measurements except for LE 21-d. Parity and sex had no effect (p>0.05) on BW, NTS, STL, HG, TL and LE. It was concluded that genotype, gestation length and season influenced BW and body dimensions of the two breeds of rabbit and their crosses while parity and sex had no effect.

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