Sexual dimorphism and biology of the large deepwater mastigoteuthid squid Idioteuthis cordiformis (Cephalopoda, Mastigoteuthidae) off Tasmania, Australia

2021 ◽  
pp. 1-7
Author(s):  
George D. Jackson ◽  
Christine H. Jackson
Keyword(s):  
Sexual Dimorphism ◽  
The Body ◽  
Total Weight ◽  
Mantle Length ◽  
Biological Information ◽  
Bright Orange ◽  
Significant Difference ◽  
Males And Females ◽  
Content Information ◽  
Total Fluid

Abstract This study provided biological information on 146 specimens of the poorly known deepwater mastigoteuthid squid Idioteuthis cordiformis. Mantle length ranged from 200–500 mm for males and 270–702 mm for females. The largest female weighed just under 12 kg. The majority of males were mature and all females were immature. The fins were larger and thicker than the mantle. Mantle weight of males and females was 44.8% and 55.2% of fin weight, respectively, and were significantly different. There was a significant sex effect on mantle length, total weight, mantle weight and fin weight, with females having greater values in all categories. There was a small season effect for mantle weight and fin weight. There was little ingested prey material except fluid and oil in the caecum that was typically bright orange or red. Total fluid volume ranged from 23–230 ml and 20–550 ml for males and females, respectively. The per cent oil component of total fluids in the caecum ranged from 6.9–50% and 10.8–50% for males and females, respectively, with no significant difference in per cent oil between males and females. There was a significant positive relationship between total weight and oil volume for females, and for males and females combined. The function of the oil is uncertain. While this study provided information on sex differences in the body size, sexual dimorphism and caecum oil content, information is still incomplete regarding reproduction due to the lack of any mature females captured in this study.

scholarly journals Pheromone Producing Dorsal Abdominal Glands in Leptocoris augur

2018 ◽  
Vol 15 (1) ◽  
pp. 187-193
Author(s):  
Ishana Qadir ◽  
Ayesha Qamar
Keyword(s):  
Integrated System ◽  
The Body ◽  
Basic Step ◽  
Sexual Behaviours ◽  
Bright Orange ◽  
Significant Difference ◽  
Males And Females ◽  
Dorsal Abdominal Glands ◽  
Pheromone Glands ◽  
Highly Evolved

Morphology of the scent (pheromone) glands is the first and basic step in understanding the mechanism of working of this highly evolved and integrated system of communication in insects. Leptocoris augur contains a pair of large and distinct symmetric exocrine dorsal abdominal glands (DAGs) found in the dorsal abdominal segments. The glands are simple, voluminous, sac-like and bright orange that turn brown and downsized with age. They are invested with a large and dense network of trachea and open to the exterior via minute slit shaped openings in the form of ostioles that remain permanently open to the outside. The functional specificity of these glands can be associated with the activities ranging from aggregation to sexual behaviours like courtship and mating. The mating is not restricted to a specific season, being distributed all-round the year; however, the insect prefers low and humid temperature for mating and they can be seen congregating in huge numbers when the hot summers subside and the rainy season arrives. We didn’t observe any considerable variation in size of these glands with respect to the body size in between the instars and the adults. Further, there were no significant difference between males and females in terms of the size of these DAGs.

Comparative assessment of odontometric parameters for gender determination: A hospital based cross-sectional study

2021 ◽  
Vol 8 (3) ◽  
pp. 147-152
Author(s):  
Mosmi Lomi ◽  
Jonathan Daniel M
Keyword(s):  
Sexual Dimorphism ◽  
Cross Sectional Study ◽  
Mean Value ◽  
The Body ◽  
Central Incisor ◽  
Maxillary Canine ◽  
Cross Sectional ◽  
Mean Values ◽  
Gender Determination ◽  
Significant Difference

Determining gender is one of the most important procedure in forensics. Teeth are made of the most enduring mineralized tissues in the body, as such, they have an extraordinary resistance to putrefaction and the effects of external agents (physical, thermal, mechanical, chemical or biological) which makes them invaluable material for anthropological, genetic, odontologic and forensic examinations.i)To assess the degree of sexual dimorphism in maxillary canine using maxillary canine index, maxillary first molar and central incisor using mesiodistal (MD) and buccolingual/buccopalatal (BL) dimensions of the crown. ii) To determine the accuracy of maxillary canine index, first molar and central incisor dimensions (mesiodistal and buccolingual/buccopalatal) in determining sex.This study consisted of total 30 participants (males=15, females=15) of age group ranging from 20 to 35 yrs. Measurement of dimensions of selected teeth were performed on maxillary cast using digital Vernier caliper, resolution 0.01mm. Data thus obtained were analyzed statistically.The mean values of all the measurements in males were greater than females. There was statistical significant difference in mean value of bucco-lingual width of molar, mesiodistal width of canine (on left side, right side and average) and the inter-canine distance between males and females. The buccolingual width of molar showed the highest % of sexual dimorphism (5.33%) and the mesiodistal width of molar showed the least % of dimorphism (0.7%). Bucco-lingual width of molar posed the highest prediction accuracy for gender determination. We conclude that buccolingual width of maxillary first molar can be used to predict the gender when only teeth of maxillary arch are available for forensic examination.

scholarly journals The occurrence of Contracaecum sp. larvae (Nematoda : Anisakidae) in the catfishClarias gariepinus (Burchell) from Lake Chivero, Zimbabwe

2004 ◽  
Vol 71 (1) ◽  
Author(s):  
M. Barson
Keyword(s):  
Significant Relationship ◽  
Condition Factor ◽  
Clarias Gariepinus ◽  
Parasite Prevalence ◽  
Body Cavity ◽  
The Body ◽  
Nematode Parasites ◽  
Significant Difference ◽  
Third Stage ◽  
Males And Females

Clarias gariepinus were collected from Lake Chivero, Zimbabwe, and examined for nematode parasites from November 2000 to May 2002. Of the 202 specimens collected, 42.6 % were infected with third-stage larvae of Contracaecum sp. in the body cavity. The intensity of the infection was 1-7 worms per fish (mean intensity = 2.2). Seasonal variation in the prevalence of the parasite was not obvious and there was no significant difference in the prevalence of infection between males and females (c2 = 2.228; P > 0.05). No significant relationship between host size and prevalence was established. There was also no significant relationship between intensity and the body condition factor (r = 0.11; P > 0.05). The low parasite prevalence may have been caused by the disruption of the infection cycle since piscivorous birds, which are the final hosts of the parasite, do not feed on C. gariepinus in Lake Chivero.

scholarly journals Study of Second and Fourth Digit Lengths and Their Ratios With Physical Attributes in Nepali Population

2018 ◽  
Vol 16 (2) ◽  
pp. 78-81
Author(s):  
Biswas Satyal ◽  
Abhishek Satyal
Keyword(s):  
Ring Finger ◽  
The Body ◽  
Behavioral Traits ◽  
Digit Ratios ◽  
Hand Deformities ◽  
Significant Difference ◽  
Physical Attributes ◽  
Physical Traits ◽  
Left And Right ◽  
Males And Females

Introduction: The ratio of the lengths of the index and the ring finger (2D:4D ratio) is generally different between men and women. A number of studies have shown a correlation between the 2D:4D digit ratio and various physical and behavioral traits. The aim of the present study is to investigate the association of the index (2nd) and ring (4th) digit ratios with some physical traits in Nepal population. Material & Method: 200 students (100 males and 100 females) between ages of 18 years and above were randomly selected with exclusion of those with hand deformities. The digit lengths were measured from the basal crease to the tips usingvernier calipers. The 2D:4D ratios were determined for each subject while height and weight were used to calculate the body mass index and data analyzed. The study was conducted between January 2018 to November 2018. Result: The result of the anthropometric study of the differences in index (2D) and ring (4D) and their ratios shows that there was a significant difference between the length of index finger (2D), ring finger (4D) and the ratios of right hand's 2D:4D in both males and females. There was appositive correlation between the second digit length and Height and weight in males and females both on right and left sides. The 2D:4D ratio for both left and right hand did not show any positive correlation with height, weight or BMI of an individual.

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

2018 ◽  
Vol 19 ◽  
pp. 1-21
Author(s):  
Oleg V. Kukushkin ◽  
Igor V. Dovgal
Keyword(s):  
Sexual Dimorphism ◽  
Morphometric Parameters ◽  
The Body ◽  
Body Proportions ◽  
Reliable Determination ◽  
Kerch Peninsula ◽  
The Crimea ◽  
Males And Females ◽  
Almost All

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.

scholarly journals Are there sex differences in the body size of the Eurasian red squirrel in Slovakia?

2015 ◽  
Vol 1 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Alexander Čanády ◽  
Ladislav Mošanský ◽  
Peter Krišovský
Keyword(s):  
Function Analysis ◽  
Tail Length ◽  
The Body ◽  
Red Squirrel ◽  
Sexual Interaction ◽  
Mean Values ◽  
Foot Length ◽  
Significant Difference ◽  
Hind Foot ◽  
Males And Females

Abstract Sexual dimorphism of the Eurasian red squirrel on five somatic variables (head-and-body length, tail length, hind foot length, ear length and body weight) was evaluated on 55 squirrels. The overlap of values of the measured traits among sexes was high, but in all traits (with exception of the tail length) males seem to exhibit slightly higher mean values than females. However, these differences were non-significant, with the exception of a small significant difference in the tail length and tail-to-head-and-body ratio. Similarly, the results of discriminant function analysis show no differences between the sexes. Positive correlation analyses, together with PCA values, confirmed that tail length and hind foot length are traits that play a significant role in overall variability. We suggest that this relationship could explain their mutual importance in locomotion, where the feet are essential for movement in the trees. By contrast, the tail maintains balance on thin branches, or during jumps from one crown to another. Longer tails also demonstrate differential selection on males and females for a locomotor trait. Similarly, we discuss whether variations in tail length were connected to female reproductive success. Our results suggest that the non-significant results regarding SSD provide the benefit of the same size for both sexes in the protection of territory as well as inter- and intra-sexual interaction.

scholarly journals Torticollis as the Main Presentation in a Child with Russell-Silver Syndrome: A Case Report

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Mohsen Javadzadeh ◽  
Hedieh Saneifard ◽  
Amir Hossein Hosseini
Keyword(s):  
Genetic Disorder ◽  
Postnatal Growth ◽  
The Body ◽  
Poor Growth ◽  
Triangular Face ◽  
Postnatal Growth Retardation ◽  
Significant Difference ◽  
Males And Females ◽  
Silver Syndrome ◽  
Two Sides

Russell-Silver syndrome is a genetic disorder the inheritance pattern of which is mostly sporadic. Some of the features of the syndrome are present at birth, and others appear in later years. The main clinical features include low birth weight, poor growth postnatally, short height, and discrepancies in size between the two sides of the body Abu-Amera et al. (2008), Binder et al. (2011). There is no statistical significant difference in prevalence between males and females. We report a case of Russell-Silver syndrome with intrauterine and postnatal growth retardation, triangular face, and body asymmetry, in addition to torticollis as a novel manifestation. In neck sonography, we found asymmetry of sternocleidomastoid muscles. In conclusion, we describe torticollis as a presentation of Russell-Silver syndrome.

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.

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

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.

scholarly journals Growth rates of the chokka squid Loligo reynaudii d’Orbigny, 1845 (Cephalopoda: Myopsida: Loliginidae) off South Africa, investigated over two years

2021 ◽  
Vol 29 (3) ◽  
Author(s):  
Collette H. Mwanangombe ◽  
Deon Durholtz ◽  
Dawit Yemane ◽  
Jean Githaiga-Mwicigi ◽  
Warwick H. H. Sauer ◽  
...  
Keyword(s):  
South Africa ◽  
Sexual Dimorphism ◽  
Growth Model ◽  
Growth Rates ◽  
Linear Growth ◽  
Maximum Size ◽  
Mantle Length ◽  
Daily Growth ◽  
Males And Females ◽  
Linear Growth Model

Growth of adult chokka squid Loligo reynaudii d’Orbigny was modelled using mantle length and age data derived from samples collected over two years (2003 and 2004) from a single, large cohort of mature and spawning squid. A total of 588 statoliths were examined (310 males, 278 females) from individuals of 71–425 mm mantle length (ML). The maximum size of chokka squid was 425 mm ML for males and 263 mm ML for females. The Francis Growth Model and Linear Growth model were selected for further analysis from six models considered. Males and females attain similar ages, although mantle length-based daily growth rates ranged from 0.75 to 1.02 (0.88 quantile _50) mm/day for males and 0.32–0.45 (0.38 quantile _50) mm/day for females, explaining the sexual dimorphism apparent in the sizes of individuals of this species.

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