SEXUAL DIMORPHISM IN PSEUDOPUS APODUS (REPTILIA: SAURIA: ANGUIDAE) FROM THE STEPPE CRIMEA

The current paper is focused on sexual dimorphism of a giant glass lizard, or sheltopusik, Pseudopus apodus apodus (Pallas, 1775) from its northernmost populations inhabiting the Crimea. In total, 72 P. apodus individuals (45 males and 27 females) were collected at the Kerch Peninsula during 2013–2017. To estimate the variability, 13 morphometric parameters and 18 indices characterizing the head and body proportions were used. It was found that males and females differed significantly by means of almost all parameters, except the body and tail sizes. Besides that, the differences by 10 ratios characterizing head proportions were revealed as well. However, a reliable determination of the lizard sex using linear sizes and/or ratios values seems to be impossible because of the strong overlap of the variability ranges in both sexes. At the same time, the use of the canonical discriminant analysis by the complex of morphometric parameters and by ratios has shown that the males and females in both datasets are classified correctly basing on the sex with an accuracy approximating 100%. The differences in the allometric growth of males and females partially define the sexual dimorphism of P. apodus on head size and shape. A sex-related differences in the development of at least one pair of parameters (head and snout lengths) were clearly evident, since isometry was established for males, while allometry ‒ for females. Moreover, the systems of correlation between the body and head parts differ in both sexes. Thus, male characterisitics correlate significanly, while the female ones were less toughly connected, and some pairs of parameters did not correlate at all.

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Investigations of Variability of Morphometric Characteristics in Stone Crayfish in Order to Preserve Autochthonous Genome

Quality of Life (Banja Luka) - APEIRON ◽

10.7251/qol2001011r ◽

2020 ◽

Vol 18 (1-2) ◽

Author(s):

Rajko Roljić ◽

Vera Nikolić ◽

Nebojša Savić

Keyword(s):

Sexual Dimorphism ◽

Carapace Length ◽

Carapace Width ◽

Morphological Variability ◽

The Body ◽

Morphometric Characteristics ◽

Baited Traps ◽

Males And Females ◽

Austropotamobius Torrentium ◽

Stone Crayfish

This paper presents the information about morphological variability and sexual dimorphism of the stone crayfish (Austropotamobius torrentium) in the area of Korana River in Mrkonjic Grad. The crayfish were caught by hand made baited traps from October 2018 to May 2019. A total of 46 crayfish were caught, of which 33 males and 13 females. The dimensions of eight morphometric characteristics: body weight (W), body length (TBL), rostrum length (ROL), rostrum width (ROW), claw length (CLL), carapace length (CPL), carapace width (CPW) and abdomen length (ABL), were analyzed, both in males and females. Also, the body condition was determined for all individuales. The measurements results of morphometric characteristics partially matched into the alredy known range of variations. These data presens first ones for the observed area. By using Mann-Whitey U-test, it was noted that there are significant differences between the sexes for W, TBL, CLL, CPL, CPW and ABL. These resuls could be explained by sexual dimorphism of the stone crayfish.

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Relative growth of freshwater prawn Macrobrachium brasiliense (Decapoda, Palaemonidae) and its implications for reproduction

Iheringia Série Zoologia ◽

10.1590/1678-4766e2019005 ◽

2019 ◽

Vol 109 ◽

Cited By ~ 1

Author(s):

Caio dos Santos Nogueira ◽

Marcela Silvano de Oliveira ◽

Giuliano Buzá Jacobucci ◽

Ariádine Cristine de Almeida

Keyword(s):

Sexual Dimorphism ◽

Sexual Maturity ◽

Carapace Length ◽

Freshwater Prawn ◽

Relative Growth ◽

Guarding Behavior ◽

Males And Females ◽

One Year ◽

Almost All

ABSTRACT The main objective of this study was to estimate the morphological sexual maturity of Macrobrachium brasiliense (Heller, 1862) and to analyze the relative growth of the species. During one year of sampling, from July 2012 to June 2013, 199 specimens were collected in a stream located in a Cerrado biome, in the Triângulo Mineiro region, state of Minas Gerais. Once identified and sexed, the length of the carapace, the length of the segments of the chelipeds (ischium, merus, carpus, propodus and dactyl) and width of the pleura were measured (mm). The maximum and mean sizes of the carapace length measured 20.5 mm (Mean: 9.6 ± 4.2 mm) and 20.1 mm (Mean: 7.7 ± 3.4 mm) for males and females, respectively. The propodus length for males, and the pleura width for females, were used for the classification of the specimens into juvenile and adult, using K-means analysis and discriminant analysis. The relative growth of the species was also evaluated through covariance analysis for all structures (ANCOVA, α = 0.05). In females, the growth of most structures occurred equally between juveniles and adults, with the exception of the merus and pleura structures. On the other hand, the growth of almost all structures of males differed between juveniles and adults. Only the carpus and the pleura growth were similar. We also estimated the size at onset of morphological sexual maturity at 8.64 mm CL for males (CL50% r = 1.71) and 8.03 mm CL for females (CL50% r = 0.07). Our results contribute to the understanding of some important questions related to the reproductive biology of M. brasiliense. We noted that males grow differently from females and become the largest individuals in the population, resulting in a sexual dimorphism. Such sexual dimorphism might promote the development of the temporary mating guarding behavior, a reproductive strategy very important for caridean shrimps.

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Sex Determination Using Inion-Opistocranium-Asterion (IOA) Triangle in Nigerians’ Skulls

Anatomy Research International ◽

10.1155/2014/747239 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

C. N. Orish ◽

B. C. Didia ◽

H. B. Fawehinmi

Keyword(s):

Sexual Dimorphism ◽

Linear Regression ◽

Coefficient Of Variation ◽

Individual Identification ◽

Male And Female ◽

Gender Determination ◽

Important Concern ◽

Males And Females ◽

The Right

Background. Determination of sex is an important concern to the forensic anthropologists as it is critical for individual identification. This study has investigated the existence of sexual dimorphism in the dimensions and the area of the IOA triangle. Methods. A total of 100 adult dry skulls, (78 males; 22 females) from departments of anatomy in Nigerian universities were used for this study. Automatic digital calliper was used for the measurement. Coefficient of variation, correlation, linear regression, percentiles, and sexual dimorphism ratio were computed from the IOA triangle measurements. The IOA triangle area was compared between sexes. Results. The male parameters were significantly (P<0.05) higher than female parameters. The left opistocranium-asterion length was 71.09±0.56 and 61.68±3.35 mm and the right opistocranium-asterion length was 69.73±0.49 and 60.92±2.10 mm for male and female, respectively. A total area of IOA triangle of 1938.88 mm2 and 1305.68 mm2 for male and female, respectively, was calculated. The left IOA indices were 46.42% and 37.40% in males and females, respectively, while the right IOA indices for males and females were 47.19% and 38.87%, respectively. Conclusion. The anthropometry of inion-opistocranium-asterion IOA triangle can be a guide in gender determination of unknown individuals.

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Revision of the Australian Eviphididae (Acari: Mesostigmata)

Zootaxa ◽

10.11646/zootaxa.2596.1.1 ◽

2010 ◽

Vol 2596 (1) ◽

pp. 1

Author(s):

R. B. HALLIDAY

Keyword(s):

New Species ◽

Sexual Dimorphism ◽

The Body ◽

Dorsal Shield ◽

Typical Member ◽

The Third ◽

Unidentified Species ◽

Males And Females ◽

Rich Fauna ◽

Mite Family

The Australian fauna of the mite family Eviphididae (Acari: Mesostigmata) is revised. A total of 14 species is recorded, 10 of which are described as new: Alliphis halleri (G. & R. Canestrini), A. transversus sp. nov., Evimirus pentagonius Karg, E. scutellatus sp. nov., E. uropodinus (Berlese), Scarabaspis masani sp. nov., S. orientalis (Berlese), S. sternalis sp. nov., S. victoriensis sp. nov., Thinoseius helenae sp. nov., T. jarretti sp. nov., T. papillatus sp. nov., T. peltatus sp. nov., and T. variabilis sp. nov.. These species occur in soil, leaf litter, dung, compost, and seaweed, where they appear to prey on nematodes. A key for identification of these genera and species is provided. Several of the new species have character states that are unusual for their genera. In Alliphis transversus, the first pair of sternal lyrifissures are large, and oriented transversely to the long axis of the body, instead of obliquely, as is normal for the genus. Scarabaspis sternalis is unusual in having the third pair of sternal pores on the sternal shield. It also shows extensive geographic variation in the amount of ornamentation of the dorsal shield. Scarabaspis victoriensis has only one of the setae on coxa I modified into a flat oval-shaped disc instead of both, as is usual for the genus. Scarabaspis masani has normal setiform setae on both coxae I and II, but otherwise appears to be a typical member of the genus. The five species of Thinoseius described here show strong sexual dimorphism, which makes it impossible to associate the males and females of some species. Deutonymphs of an unidentified species of Thinoseius sp. are recorded as phoretic on flies of the genus Thoracochaeta (Sphaeroceridae). The eviphidid fauna of Australia is much smaller than that of Europe. This appears to be the result of the absence of small or monotypic genera, and the fact that Australian native mammals do not produce large quantities of wet dung suitable for the development of a rich fauna of coprophilous mites and dung beetles.

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

Acta Amazonica ◽

10.1590/1809-4392201804392 ◽

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.

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Sex-specific body mass ageing trajectories in adult Asian elephants

10.1101/2020.12.17.423208 ◽

2020 ◽

Author(s):

Lucas D. Lalande ◽

Virpi Lummaa ◽

Htoo H. Aung ◽

Win Htut ◽

U. Kyaw Nyein ◽

...

Keyword(s):

Sexual Dimorphism ◽

Body Mass ◽

Life Histories ◽

The Body ◽

Captive Population ◽

Natural Death ◽

Asian Elephants ◽

Female Body Mass ◽

Males And Females ◽

Longitudinal Dataset

Sex-specific life-histories are thought to shape senescence patterns differently for males and females. In species with marked sexual dimorphism and where one sex is undergoing stronger intrasexual competition, it is expected that this sex ages earlier or quicker. Here, we utilise a unique, longitudinal dataset of a semi-captive population of Asian elephants (Elephas maximus) to describe the body mass ageing trajectories in this species with marked sexual dimorphism in size and lifespan, with males being larger and living shorter. Our results show sex-specific ageing trajectories: males gained weight throughout their life, at a diminishing rate until natural death. In contrast, adult female body mass did not change significantly with age until an abrupt decline during the last year of life. Our study shows that sex-specific life-histories shape ageing patterns contrary to those predicted by classical theory and expands the previously described diversity of ageing dynamics.

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The Effects of Locality and Host Plant on the Body Size of Aeolothrips intermedius (Thysanoptera: Aeolothripidae) in the Southwest of Poland

Insects ◽

10.3390/insects10090266 ◽

2019 ◽

Vol 10 (9) ◽

pp. 266 ◽

Cited By ~ 1

Author(s):

Gruss ◽

Twardowski ◽

Cierpisz

Keyword(s):

Host Plant ◽

Body Length ◽

Host Plants ◽

Wing Length ◽

Morphological Variability ◽

The Body ◽

Head Width ◽

Morphometric Features ◽

Males And Females ◽

Almost All

Aeolothrips intermedius is a thrips predator often found in phytocoenoses worldwide. Both the adults and larvae of this species prey on small invertebrates, including phytophagous species from Thysanoptera group. The aim of this study was to determine the morphological variability of the A. intermedius relative to the locality and, indirectly, to the species of host plant. Insects were collected from five localities in southwest Poland and five different host plants. For each of the sexes, six morphometric features were assessed: body length, length of antennae, wing length, head length, head width and length of pronotum. Additionally, the body mass for each individual was estimated. The findings revealed that in females, both the locality and host plant had a significant impact on almost all of these features. In males, the morphometric features under study correlated strongly with locality and only moderately with the host plant. Certain differences were observed between males and females, mainly in terms of antennae length. The results show that A. intermedius exhibits significant variability in this respect, which is indicative of the species’ phenotypic plasticity. The body length was the trait with the most distinct response to the locality and host plant.

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An overview of the sexual dimorphism in Echiniscus (Heterotardigrada, Echiniscoidea), with the description of Echiniscus masculinus sp. nov. (the virginicus complex) from Borneo

Zoosystematics and Evolution ◽

10.3897/zse.96.49989 ◽

2020 ◽

Vol 96 (1) ◽

pp. 103-113

Author(s):

Piotr Gąsiorek ◽

Katarzyna Vončina ◽

Łukasz Michalczyk

Keyword(s):

New Species ◽

Sexual Dimorphism ◽

Southeast Asia ◽

Current Knowledge ◽

The Body ◽

Genetic Evidence ◽

Body Proportions ◽

Dioecious Species

Members of the genus Echiniscus C.A.S. Schultze, 1840 are mostly unisexual, with thelytokously reproducing females. Therefore, every newly described dioecious species in the genus is particularly interesting. Here, we describe Echiniscus masculinussp. nov. from Gunung Kinabalu, the highest peak of Borneo and the entire Southeast Asia. The new species belongs in the predominantly parthenogenetic E. virginicus complex, and its females are confusingly similar to females of the pantropical E. lineatus Pilato et al., 2008, another member of this group. However, genetic evidence and noticeable sexual dimorphism clearly delineate the new species. Males of E. masculinussp. nov. are unlike females in the body proportions, cuticular sculpturing, and appendage configuration. The new discoveries provide a justification to review the current knowledge about evolution and forms of sexual dimorphism within Echiniscus.

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Sexual dimorphism in the baiji, Lipotes vexillifer

Canadian Journal of Zoology ◽

10.1139/z92-205 ◽

1992 ◽

Vol 70 (8) ◽

pp. 1484-1493 ◽

Cited By ~ 6

Author(s):

Gao Anli ◽

Zhou Kaiya

Keyword(s):

Sexual Dimorphism ◽

Body Length ◽

Young Female ◽

The Body ◽

Analysis Of Covariance ◽

Adult Males ◽

Genital Aperture ◽

Condylobasal Length ◽

Males And Females ◽

Width Measurements

Dimorphism was detected in body length and in skull dimensions of the baiji, Lipotes vexillifer. The age of a sample comprising 22 females and 14 males was estimated. A single-phase Laird growth model was fitted to the body length versus age data for females. Two curves were required for the males, one for those with 4 dentinal growth layer groups (GLGs) and another for those above that age, i.e., with more than 4 GLGs. Males and females have about the same growth rate until they have about 4 GLGs, after which males grow more slowly than females. Sexual dimorphism was also found in 9 external measurements, based on t-tests. Analysis of covariance showed that once the effect of body length was removed, only 1 of the 9 measurements, from the tip of the upper jaw to the genital aperture, differed significantly between males and females. Differences in skull measurements resulted mainly from an early slowdown in the rate of longitudinal growth of the male, before the increase in body length slowed. Females and males could be correctly sexed by discriminant analysis using the body length, condylobasal length, and zygomatic width, and also the condylobasal length, width of the rostrum at the base, and the zygomatic width, except for one young female. Eight skull length measurements were greater in adult females than in adult males after the effect of body length was removed, and five skull width measurements were greater in males when the effect of condylobasal length was removed. Asymmetry in the position of the blowhole and in skew of the skull is pronounced and is independent of body length and sex.

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STUDI KEKERABATAN IKAN FAMILIA CYPRINIDAE YANG TERTANGKAP DI SUNGAI SERAYU KABUPATEN BANYUMAS

Scripta Biologica ◽

10.20884/1.sb.2014.1.2.437 ◽

2014 ◽

Vol 1 (2) ◽

pp. 129

Author(s):

Dwi Sekar Putri J ◽

Muh. Nadjmi Abulias ◽

Dian Bhagawati

Keyword(s):

Morphological Characteristics ◽

Morphological Characters ◽

The Body ◽

Survey Method ◽

Fish Diversity ◽

Sample Collection ◽

The Family ◽

Upgma Cluster Analysis ◽

Almost All

Cyprinidae is a family of freshwater fish that has quite a lot of valuable members and spread almost all over the world. The purpose of this study was to determine the number of fish of the family Cyprinidae in Serayu River and their relationships. This study used survey method with purposive random sampling. Research materials were members of Cyprinidae taken from the River Serayu Banyumas, which was the collection of Mrs. Dian Bhagawati. The sequence of this study included sample collection, sample preservation, sample observation in the laboratory, i.e., identification, determination of morphological characters and species name of fish and their relationships. Observed variables were morphological characters that included body shape, colors, fins specification, the total and standard length of the body, the shape of the lateral line, the shape of the caudal fin, the position of the mouth, body length, the height and width of the caudal peduncle. The data were then computed to get the coefficient of association among species (S), clustered using UPGMA Cluster Analysis as implemented in Numerical Taxonomy System (NTSYS) version 2.02i. The observed data were also descriptively analyzed based on phenogram obtained. The fish diversity recorded were eight species i.e., Puntius orphoides, Barbodes gonionotus, Osteochilus sp., Osteochilus vittatus, Osteochilus hasselti., Labiobarbus leptocheilus, Cyprinus carpio, and Rasbora sp.. The results showed that the closest relationship based on morphological characteristics was between Puntius orphoides and Rasbora sp. which had the greatest association coefficient of 0.8292. The smallest value of the association was followed by P. orphoides and Osteochilus sp. with the value of 0.3000. This study was expected to provide information of Cyprinid fish in Serayu River and their phenetic relationship.

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