scholarly journals Sexual Dimorphism of Flathead Mullet (Mugil cephalus) from Northern Mindanao Rivers Using Geometric Morphometric Analysis

2015 ◽  
Vol 45 ◽  
pp. 34-48
Author(s):  
Rose Ann Silos ◽  
Brent Joy Hernando ◽  
Juzavil Juario ◽  
Sheryl Patiño ◽  
Princess Angelie Casas ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Significant Variation ◽  
Body Shape ◽  
Function Analysis ◽  
The Body ◽  
Shape Variation ◽  
Predator Species ◽  
Geometric Morphology

Sexual dimorphism is biologically important for determining the morphological traits of marine species. Flathead mullet (Mugilcephalus) was examined based on the patterns of sexual dimorphism from the two rivers in Northern Mindanao. The samples were collected from Cagayan de Oro River and Mandulog River to investigate phenotypic divergence and sexual dimorphism in two different populations of wild-caught M. cephalus using geometric morphology based on landmark basis. A total of 17 landmarks were identified to describe the left and right body shapes of the specimen using the TpsRelw (version 1) to obtain the warp scores of each population. Results of the Relative Warp Analysis show no significant variation in the body shape within the sexes in the respective sampling sites. Results of the discriminant function analysis (DFA) show that in Cagayan de Oro River there is no significant variation in the body shape of mullets between sexes suggesting no sexual dimorphism in the flathead mullets in Cagayan de Oro River. In contrast , Discriminant Function Analysis show that there is significant variation in body shape between sexes in Mandulog River in Iligan City suggesting presence of sexual dimorphism in the area which can be due to the presence of abundant and highly diverse predator species in Mandulog River. Sexual dimorphosm can be used by fishes as an adaptive mechanism to maximize predator-escape performance and survival capacity. Furthermore, there is a significant shape variation between populations of mullets in Cagayan de Oro and Mandulog River which can be interpreted as due to geographic isolation which serves as physical barrier on the gene pool. In conclusion, many factors could account for variation in body shape of Mugilcephalus including predation and biogeographical barriers.

Use of Body Shape Information in Clothing Size Selection

2000 ◽  
Vol 44 (38) ◽  
pp. 715-718 ◽  
Author(s):  
Pierre Meunier
Keyword(s):  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Body Shape ◽  
Function Analysis ◽  
Three Dimensional ◽  
Shape Information ◽  
Size Selection ◽  
Best Fitting ◽  
Input Variables

To investigate the role of body shape information on clothing size selection, a sample of 143 males were measured and sized using a computerized digital-image based measurement system. Clothing sizes were initially determined by the system using traditional criteria for the long sleeve shirt, jacket and trousers of a military dress uniform. The best-fitting size was determined by trial and error based on subjective feedback and expert judgement, provided by clothing and sizing technicians. Discriminant function analysis was used to determine sizing rules for each garment, based on different sets of anthropometric input variables. Comparisons were made between the prediction performances of discriminant functions derived from traditional variables and those of functions derived from 3D landmark coordinates. The results indicate that the use of three-dimensional landmark coordinates, as input to a discriminant function analysis, is superior to the use of circumference measurements in predicting clothing sizes. The use of these landmarks is thought to improve the classification of cases by allowing a better characterization of body shape.

scholarly journals Sexual dimorphism in mud crabs: a tale of three sympatric Scylla species

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10936
Author(s):  
Hanafiah Fazhan ◽  
Khor Waiho ◽  
Yushinta Fujaya ◽  
Nita Rukminasari ◽  
Hongyu Ma ◽  
...  
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Function Analysis ◽  
Carapace Width ◽  
Sympatric Species ◽  
Sexually Dimorphic ◽  
Morphometric Characteristics ◽  
Mud Crabs

Sexual dimorphism is a common phenomenon in the animal kingdom. To test the consistency of sexual dimorphism patterns among sympatric species of the same genus, ten morphometric characteristics of mud crabs Scylla olivacea, S. tranquebarica and S. paramamosain were measured and compared using Discriminant Function Analysis (DFA). The descriptive analysis revealed that in all three species, body size dimensions and cheliped dimensions were significantly larger in males whereas the abdomen width was female-biased. Also, we described a morphological variation (carapace width, CW ≤ CW at spine 8, 8CW) that is unique to S. olivacea. Discriminant function analysis revealed that all nine morphometric characteristics were sexually dimorphic in S. olivacea, S. tranquebarica (except right cheliped’s merus length, ML) and S. paramamosain (except 8CW). The obtained discriminant functions based on the morphometric ratios (with CW as divisor) correctly classified 100% of adults of known sex of all three species. Further, based on the selected body traits, DFA was able to almost completely distinguish males (94%), but not females (74%), among the three Scylla species. This study highlights that congeneric species of portunids (e.g., Scylla spp.) show similar sexually dimorphic characteristics (body size and secondary sexual characteristics).

scholarly journals Best parameters for sexual dimorphism in the facial thickness tissue with ultrasonic assessment

2008 ◽  
Vol 13 (2) ◽  
pp. 60 ◽  
Author(s):  
Iván Claudio Suazo Galdames ◽  
Guillermo Enrique Salgado Alarcón ◽  
Daniela Alejandra Zavando Matamala
Keyword(s):  
Sexual Dimorphism ◽  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Function Analysis ◽  
Tissue Thickness ◽  
Significance Level ◽  
Ultrasound Measurements ◽  
Males And Females ◽  
Ultrasonic Assessment ◽  
Best Parameters

<p>Knowledge of facial tissue thickness is crucial to facial reconstruction procedures in forensic sculpture. The literature still brings some controversy on the validity of data obtained for different population groups. The purpose of this study was to investigate sexual dimorphism in the thickness of the facial tissues. The study sample consisted of 43 volunteers, between 24 and 48 years of age, and of normal body mass. Ultrasound measurements of facial tissue thickness were obtained at 14 median and paramedian landmarks. A T test was used to compare measurements from males and females, with a significance level of at least 0.05. Discriminant function analysis was used to determine the points that showed most distinction between the sexes. Measurements at paramedian landmarks were greater in males, while those at median landmarks were greater in female subjects, except for Down’s A and B points. We conclude that sexual dimorphism in facial thickness justifies the pre-assignment of sex in reconstruction procedures in forensic sculpture</p>

scholarly journals Sexual dimorphism in black jaw tiliapia (Sarotherodon melanotheron) and banded jewelfish (Hemichromis fasciatus) from the Great Kwa River, Calabar, Nigeria

2017 ◽  
Vol 75 (4) ◽  
pp. 122-131
Author(s):  
Oju Richard Ibor ◽  
George Eni ◽  
Andem Bassey Andem ◽  
Akanimo Joseph ◽  
Azubuike Victor Chukwuka
Keyword(s):  
Sexual Dimorphism ◽  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Standard Length ◽  
Function Analysis ◽  
Gonad Weight ◽  
Pectoral Fin ◽  
Body Depth ◽  
Sarotherodon Melanotheron ◽  
Fin Length

AbstractIn this study, the pattern and magnitude of sexual dimorphic differences have been investigated in black jaw tilapia (Sarotherodon melanotheron) (n = 160; 74 males and 86 females) and banded jewelfish (Hemichromis fasciatus) (n = 120; 42 males and 78 females) from the Great Kwa River, Calabar, Nigeria. Fish samples were collected between July and December 2015. Fourteen morphometric variables, including body weight, total length, standard length, body depth, cheek depth, pre-orbital length, postorbital length, pectoral fin length (right and left), pelvic fin length (right and left), head length, gonad weight, eye diameter and four meristic variables, including number of pectoral fins (right and left) and number of pelvic fins (right and left), were taken using standard methods. Size-adjusted morphometric measurements subjected to step-wise discriminant function analysis were used to determine predictor variables to morphologically differentiate sexes for both species; magnitude of dimorphism between sexes was estimated using percentage classification accuracy of the discriminant function analysis. From the discriminant function analysis, the pectoral fin length and gonad weight positively contributed significantly to morphometric dimorphism (magnitude=69.2%) in male and femaleS. melanotheronsuggesting adaptation for reproductive function; while forH. fasciatusthe body depth and standard length were important contributors to sexual dimorphism (magnitude=84.2%) suggesting size dimorphism for aggressiveness, territorial behavior and improving swimming performance. Overall, our results indicate that the different magnitude of sexual dimorphism between the two species could be attributable to the type and functional role of sexual dimorphic traits.

scholarly journals DETERMINATION OF THE GENDER FROM THE LENGTH OF SKULL SUTURES

2020 ◽  
Vol 4 (7) ◽  
Author(s):  
Gaurav Tiwari ◽  
Avinash Thakur ◽  
Murali Lalwani
Keyword(s):  
Discriminant Function ◽  
Forensic Medicine ◽  
Discriminant Function Analysis ◽  
Function Analysis ◽  
Cross Sectional Study ◽  
The Body ◽  
Age Group ◽  
Cross Sectional ◽  
Minimum Age

Background: Determination of the identity of an unknown dead body is one of the most important medico-legal roles of forensic medicine. The present study aimed to determine the gender of the deceased body using the length of the skull sutures. Material and Methods: A cross-sectional study was conducted in the department of forensic medicine, Gandhi Medical College, Bhopal between the periods of January 2016-June 2017. A total of 500 dead bodies were examined for this study. We utilized the discriminant function analysis to predict a relationship between the gender and the independent variables viz. skull sutures. Results: Maximum numbers of the case belonged to 20‐29 years age group and the least were in >70 age group.  The minimum age of any case was 20 years and the maximum age was 89 years, mean of age was 38.07(standard deviation 13.61) and the median age was 35. There was a total of 307 males and 193 females. In the present study, the length of the Coronal suture is the most predictive parameter out of three in determining the gender of the deceased person with a value of 0.946. A total of 66.6% of original grouped cases [263 among 307 males (85.7%) and 70 females from 193 (36.3%)] were correctly classified using discriminant function analysis score.  Conclusion:  The correct gender from the skull of the body was identified in about two-third of the cases.

Sign in / Sign up

Export Citation Format

Share Document