scholarly journals Morphological variation of Philodryas patagoniensis (Girard, 1858) (Serpentes, Dipsadidae) from Brazil, based on the study of pholidosis, coloration and morphometric features

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Rafaella Vallim Gouveia ◽  
Iara Alves Novelli ◽  
Fabiano Matos Vieira ◽  
Bernadete Maria de Sousa
Keyword(s):  
Sexual Dimorphism ◽  
Analysis Of Variance ◽  
Morphological Variation ◽  
Tail Length ◽  
Head Length ◽  
Adult Males ◽  
Adult Females ◽  
Morphometric Features ◽  
The Relationship

Abstract The current study aimed to verify the relationship between the patterns of coloration, the morphometrical features and pholidosis of specimens of Philodryas patagoniensis from Brazil, with the sexual dimorphism of this species. We studied specimens of P. patagoniensis deposited in several herpetological collections from Brazil. A total of 355 specimens were analyzed, of these 145 were males (87 adults and 58 juveniles) and 210 were females (134 adults and 76 juveniles). Adult specimens exhibit sexual dimorphism in snout-vent length, tail length, head length, number of ventral shields, and number of subcaudal shields. The analysis of variance showed that the adult females are significantly longer than adult males, both at snout-vent length and tail length. Females have a greater number of ventral shields (138-210) than males (151-200). The specimens studied also exhibit two distinct patterns of coloration unrelated to geographical or sexual variations.

scholarly journals The Diet and Sexual Differences of the Caspian Bent-Toed Gecko,Tenuidactylus caspius(Squamata: Gekkonidae), in Northern Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Vida Hojati ◽  
Reza Babaei Savasari
Keyword(s):  
Sexual Dimorphism ◽  
Culex Pipiens ◽  
Tail Length ◽  
Adult Males ◽  
Northern Iran ◽  
Widespread Distribution ◽  
Adult Females ◽  
Significant Difference ◽  
Males And Females ◽  
Prey Items

The Caspian bent-toed gecko,Tenuidactylus caspius, is one of the most common nocturnal lizards of Iran with widespread distribution especially in the northern provinces. This research was done in order to study the diet and sexual dimorphism of this species in Sari County from 5 May to 20 October. During this research, 40 specimens of them including 20 males and 20 females were studied for diet and 140 specimens including 70 adult males and 70 adult females were studied for sexual dimorphism. Prey items identified were insects that belong to 15 species of 8 families and 6 orders. The most common prey items wereCulex pipiensandMusca domestica. There is no significant difference between diets of males and females. Results show that the adult males in addition of having the apparent femoral and preanal pores are heavier than females and have larger body, head, and tail length.

A new species of Leptolalax (Anura: Megophryidae) from Laos

Zootaxa ◽  
2010 ◽  
Vol 2681 (1) ◽  
pp. 35 ◽  
Author(s):  
JODI J. L. ROWLEY ◽  
BRYAN L. STUART ◽  
STEPHEN J. RICHARDS ◽  
SOMPOUTHONE PHIMMACHAK ◽  
NIANE SIVONGXAY
Keyword(s):  
New Species ◽  
Dominant Frequency ◽  
Head Length ◽  
Evergreen Forest ◽  
Head Width ◽  
Adult Males ◽  
Adult Females ◽  
A New Species

We describe a new species of megophryid frog in the genus Leptolalax from southern Laos. Leptolalax aereus sp. nov. is distinguished from its congeners by a combination of size (25.1–28.9 mm in 28 adult males, 27.1–38.6 mm in 12 adult females), absence of distinct black or dark brown dorsolateral markings on head, near immaculate white chest and belly, head length greater than head width, no webbing or lateral fringing on fingers, rudimentary webbing between toes I–IV and no webbing between toes IV–V, toes with weak lateral fringing, and a call consisting of an average of 3–4 notes containing 1–2 pulses, and with a dominant frequency of 6187.5–7875 Hz. The new species is associated with rocky streams in semi-evergreen and evergreen forest between 284–511 m elevation.

scholarly journals Sexual dimorphism in the electric knifefish, Gymnorhamphichthys rondoni (Rhamphichthyidae: Gymnotiformes)

2019 ◽  
Vol 49 (3) ◽  
pp. 213-220
Author(s):  
Elisa Queiroz GARCIA ◽  
Jansen ZUANON
Keyword(s):  
Sexual Dimorphism ◽  
Body Height ◽  
Principal Component ◽  
The Body ◽  
Vertical Line ◽  
Head Length ◽  
Genital Papilla ◽  
Adult Males ◽  
Dioecious Species ◽  
Males And Females

ABSTRACT Sexual dimorfism refers to morphological differences between males and females of a species. It may be a result of different selection pressures acting on either or both sexes and may occur in any sexually-reproducing dioecious species, including fishes. We analyzed 63 females and 63 adult males of Gymnorhamphichthys rondoni (Gymnotiformes) collected by us or deposited in museum collections. Sex was identified through abdominal dissection. We measured length from snout to posterior end of anal-fin, anal-fin length, distance from anus to anal-fin origin, distance from genital papilla to anal-fin origin, body width at beginning of anal-fin, and head length. Morphometric data submitted to a Principal Component Analysis (PCA) grouped males and females according to variables related to body size (along the first component) and to head length and body height along the second and third components. Females were larger than males, whereas males had proportionally larger heads and higher bodies than females. The urogenital papilla of males and females showed differences in shape, size and relative position on the body. The female papilla was elongated horizontally, larger than that of males, and was located on a vertical line below the eye, while the papilla of the males was vertically elongated and located on a vertical line below the operculum. To our knowledge, this is the first recorded case of sexual dimorphism in a species of Rhamphichthyidae, a condition that is now known in all the currently recognized families of Gymnotiformes.

scholarly journals Sexual dimorphism in thyroid function and type 1 iodothyronine deiodinase activity in pre-pubertal and adult rats

2007 ◽  
Vol 192 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Michelle P Marassi ◽  
Rodrigo S Fortunato ◽  
Alba C Matos da Silva ◽  
Valmara S Pereira ◽  
Denise P Carvalho ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Adult Male ◽  
Gonadal Hormones ◽  
Adult Males ◽  
Adult Rats ◽  
Iodothyronine Deiodinase ◽  
Adult Females ◽  
Serum T3 ◽  
Serum Tsh

Iodothyronine deiodinase activities are regulated by sex steroids; however, the mechanisms underlying the reported sexual dimorphism are poorly defined. In the present report, we aimed to investigate whether type 1 deiodinase (D1) sexual dimorphism exists early in sexual development by studying pre-pubertal male (Pm) and female (Pf) rats, as well as adult controls (C) and gonadectomized male and females rats. Adult male Wistar rats were studied 21 days after orchiectomy (Tex), and adult females were studied 21 days after ovariectomy (Ovx), and after estradiol benzoate (Eb) replacement. Serum total triiodothyronine (T3) was higher in pre-pubertal (P) rats than in the matching adults, with no difference between genders, although in adult males T3 was significantly lower than in females. There were no sex or age differences in serum total T4. Serum TSH in pre-pubertal (P) rats was within the adult female range, and both were significantly lower than in adult males. D1 activity in liver was greater in Pm than in Pf. In adult females, liver D1 activity was lower, while in adult males it was higher than in P rats. The same pattern of D1 activity was found in kidney. In thyroid and pituitary, D1 activity was similar in Pm, Pf, and adult females, which were all significantly lower than in the adult male. There were no differences in serum T3 and T4 between C and Tex males, but serum TSH was significantly decreased in Tex rats. Hepatic and renal D1 activities were lower in Tex than in C, but no changes were detected in thyroid and pituitary. In Ovx females, T3 was significantly lower than in the C group. Serum T4 was significantly decreased by estradiol replacement therapy in Ovx rats, in both doses used, whereas TSH was unchanged. Eb replacement increased liver and thyroid D1 activity, but in the kidney, only the highest estradiol dose promoted a significant D1 increase. In conclusion, in males, hepatic and renal D1 activity appears to be significantly influenced by gonadal hormones, in contrast to females, in which only exogenous Eb treatment stimulated D1 activity. The comparison between pre-pubertal and adult rats suggests that serum T3 is not the main regulator of D1 activity, and other factors, besides T3 and gonadal hormones, can modulate D1 activity during murine maturation.

Some morphometric features of congeneric pipefish species (Syngnathus abaster Risso 1826, Syngnathus acus Linnaeus, 1758) distributed in Lake Bafa (Turkey)

2018 ◽  
Vol 47 (3) ◽  
pp. 239-247 ◽  
Author(s):  
Sule Gurkan ◽  
Deniz Innal
Keyword(s):  
Head Length ◽  
Congeneric Species ◽  
Morphometric Characteristics ◽  
Body Depth ◽  
Total Length ◽  
Morphometric Features ◽  
Mouth Width ◽  
The Mean ◽  
Lake Bafa ◽  
The Relationship

Abstract The study was carried out between November 2014 and March 2016 to determine certain morphometric characteristics of two pipefish species occurring in Lake Bafa, Syngnathus abaster and Syngnathus acus. A total of 211 pipefish were captured during the sampling, including 77 individuals of S. abaster (♀: 25; ♂: 44; immature: 8) and 134 individuals of S. acus (♀: 31; ♂: 76; immature: 27). The male-female ratios were 1:1.76 and 1:2.45, respectively. A difference was found in sex ratios between the two species (p < 0.05). The mean length of the captured fish was 86.63 ± 16.77 mm for S. abaster and 82.63 ± 16.02 mm for S. acus and the relationship between the total length and weight, referred to as the length-weight relationship, was as follows: W = 0.00000001L3.71 (R2 = 0.89), and W = 0.000000007L3.86 (R2 = 0.83), respectively. Seven morphometric characteristics were analyzed. The analyses revealed that S. acus and S. abaster were significantly different from each other in terms of their body depth (p = 0.006; p < 0.05), mouth width (p = 0.004; p < 0.05) and height (p = 0.008; p < 0.05). High correlation values were obtained for TL/BD and TL/HD in S. abaster and S. acus, respectively (r > 1). In conclusion, among the congeneric species occurring in Lake Bafa, S. abaster and S. acus are characterized by a shorter head length and total length compared to their sea counterparts.

Morphological variation in deer mice in relation to sex and habitat

1987 ◽  
Vol 65 (3) ◽  
pp. 527-533 ◽  
Author(s):  
Xuhua Xia ◽  
John S. Millar
Keyword(s):  
Body Length ◽  
Tail Length ◽  
Deer Mice ◽  
Body Measurements ◽  
Adult Males ◽  
Adult Females ◽  
Foot Length ◽  
Hind Foot ◽  
Similar Body ◽  
Juvenile Males

Peromyscus maniculatus borealis were collected in two habitats with contrasting physiognomic features in the Kananaskis Valley, Alberta, in the summer of 1983. We tested for differences between sexes and habitats using 4 body measurements (body length, tail length, hind foot length, and ear length) and 10 cranial (including mandibular) measurements of 222 and 192 adult P. m. borealis, respectively. Body measurements of 132 juveniles and five cranial (including mandibular) measurements from 124 juvenile skulls were analysed similarly. When differences in body length were controlled, adult males had significantly longer hind feet than adult females. The mandible was also significantly longer in adult males than in adult females. We interpreted the longer hind foot length in adult males as an adaptation to provide greater mobility, and the differences in mandibular morphology as a consequence of differential habitat use between the two sexes. No significant differences were found between juvenile males and females. Sexual dimorphism appeared to be age dependent rather than size dependent when adults and juveniles of similar body size were analysed.

A new species of stone loach (Teleostei: Nemacheilidae: Schistura) from Arunachal Pradesh, India

Zootaxa ◽  
2019 ◽  
Vol 4551 (1) ◽  
pp. 40
Author(s):  
HRISHIKESH CHOUDHURY ◽  
ABHINIT DEY ◽  
RATUL CH. BHARALI ◽  
DANDADHAR SARMA ◽  
WAIKHOM VISHWANATH
Keyword(s):  
New Species ◽  
Sexual Dimorphism ◽  
Colour Pattern ◽  
Adult Males ◽  
Arunachal Pradesh ◽  
Stone Loach ◽  
Adult Females ◽  
North Bank ◽  
Brahmaputra Basin ◽  
A New Species

Schistura rebuw, new species, is described from the Kameng River, a north-bank tributary of the Brahmaputra, Arunachal Pradesh, India. The new species is easily distinguished from all known congeners in the Brahmaputra basin by its unique sexual dimorphism, specifically a suborbital slit in adult females, and a suborbital flap in adult males; and a colour pattern of 10–11 blackish bars on a greyish-beige body, the pre-dorsal bars mostly broken or incomplete, coalescing dorsally in a more or less alternate fashion. 

scholarly journals The Roles of DNA Methyltransferases 1 (DNMT1) in Regulating Sexual Dimorphism in the Cotton Mealybug, Phenacoccus solenopsis

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 121 ◽  
Author(s):  
Mohamed A.A. Omar ◽  
Meizhen Li ◽  
Feiling Liu ◽  
Kang He ◽  
Muhammad Qasim ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Dna Methyltransferase ◽  
Dna Methyltransferases ◽  
Invasive Pest ◽  
Adult Males ◽  
Small Interfering Rnas ◽  
Phenacoccus Solenopsis ◽  
Adult Females ◽  
Cotton Mealybug ◽  
Gravid Females

The cotton mealybug, Phenacoccus solenopsis, is an invasive pest that can cause massive damage to many host plants of agricultural importance. P. solenopsis is highly polyphagous, and shows extreme sexual dimorphism between males and females. The functions of DNA methyltransferase (DNMT) enzymes in the cotton mealybug have not been well studied. Here, we carried out an investigation of DNMTs in cotton mealybug to study their roles in sexual dimorphism. We found that the cotton mealybug has two copies of PsDnmt1, but Dnmt3 is absent. We then amplified the full-length cDNAs of PsDnmt1A (2225 bp) and PsDnmt1B (2862 bp) using rapid amplification cDNA ends (RACE). Quantitative reverse transcriptase PCR shows that both PsDnmt1A and PsDnmt1B are highly expressed in adult males, while the expression of PsDnmt1B is 30-fold higher in gravid females than in virgin females. We knocked down PsDnmt1A and PsDnmt1B with small interfering RNAs (siRNAs), and both genes were successfully down-regulated after 24 h or 72 h in adult females and pupa (t-test, p < 0.05). Down-regulating the expression of these two DNMT genes led to offspring lethality and abnormal body color in adult females. Furthermore, the silencing of PsDnmt1B induced abnormal wing development in emerged adult males. Our results provide evidence that PsDnmt1 plays a crucial role in regulating sexual dimorphism in the cotton mealybug.

scholarly journals NATURAL HISTORY OF DEKAY’S BROWNSNAKE, STORERIA DEKAYI (HOLBROOK, 1836), AT A SITE IN NORTHWESTERN PENNSYLVANIA

2014 ◽  
pp. 28-39
Author(s):  
Brian S. Gray
Keyword(s):  
Population Structure ◽  
Site Fidelity ◽  
Additional Data ◽  
Tail Length ◽  
Adult Males ◽  
Morphometric Data ◽  
Erie County ◽  
Adult Females ◽  
History Of ◽  
A Site

A population of Dekay’s Brownsnake, Storeria dekayi was studied using mark-recapture techniques in Erie County, Pennsylvania, USA during the spring, summer and autumn of 2012. Morphometric data were similar to that reported for the species, with adult females averaging larger and more massive than adult males. However, sexual dimorphism in snout-vent length (SVL) and total length (TL) was not significantly different (P>0.05) in juveniles, although relative tail length (tl/TL) was dimorphic. Relative tail length in both juveniles and adults was greater in males (tl/TL = 0.22-0.27) than females (tl/TL = 0.18-0.23). Storeria dekayi were active from 21 March through 22 October, and displayed a bimodal activity pattern, with peaks in April and August. Using the Schnabel and the Schumacher-Eschmeyer methods, population size was estimated to be 122 ± 19 and 130 ± 35 individuals, respectively. Density was estimated to be 244 and 260 snakes/ha, and biomass 1.60 and 1.71 kg/ha. Additional data regarding population structure, mortality, diet, reproduction, body temperature, movements and site fidelity are also presented.

scholarly journals Chronic Arsenic Toxicity: Statistical Study of the Relationships Between Urinary Arsenic, Selenium and Antimony

2012 ◽  
Vol 2 (3) ◽  
pp. 11-20
Author(s):  
Analía Boemo ◽  
Irene María Lomniczi ◽  
Elsa Mónica Farfán Torres
Keyword(s):  
Statistical Study ◽  
Reference Value ◽  
Exposed Group ◽  
Human Consumption ◽  
Arsenic Toxicity ◽  
Adult Males ◽  
Urinary Creatinine ◽  
Urinary Arsenic ◽  
Adult Females ◽  
The Relationship

Background. The groundwater of Argentina's Chaco plain presents arsenic levels above those suitable for human consumption. Studies suggest skin disorders among local populations caused by arsenic intake. The relationship between urinary arsenic and arsenic in drinking water is well known, but urinary arsenic alone is not enough for risk assessment due to modulating factors such as the intake of selenium and antimony. Objectives. Determining the relationship between urinary arsenic, selenium and antimony could contribute to the study of arsenic metabolization in humans. Methods. Arsenic, selenium and antimony, relative to urinary creatinine, was quantified in urine samples to assess exposure to arsenic and its toxicity modulators. Results. Arsenic levels were higher than reference value in 89% of exposed group. Selenium concentrations were higher in 84%. Levels of antimony were also surprisingly high, not compatible with dietary intake. Urinary arsenic and selenium data showed highly significant correlations with age. Adult females presented higher urinary arsenic values than adult males. Conclusions. Values related to urinary creatinine were much higher than values considered normal. Concentrations of arsenic and selenium diminished with age for children and increased for adults. Women showed higher concentrations than men. Positive correlation was found between arsenic and selenium. No correlation was seen between urinary antimony, arsenic nor selenium.

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