Sexual dimorphism in wolves (Canis lupus) of the Keewatin District, Northwest Territories, Canada

1996 ◽  
Vol 74 (4) ◽  
pp. 721-725 ◽  
Author(s):  
Tracy L. Hillis ◽  
Frank F. Mallory
Keyword(s):  
Sexual Dimorphism ◽  
Northwest Territories ◽  
Body Mass ◽  
Canis Lupus ◽  
Foraging Strategy ◽  
Division Of Labour ◽  
Body Region ◽  
Male Body ◽  
Anterior Body

Twenty-two skeletal, visceral, and adipose parameters were compared in 425 wolves collected from the central Arctic between 1987 and 1989. Fifteen parameters differed significantly by sex. Males were usually larger than females; however, the degree of sexual dimorphism varied with structure. Male skeletal parameters ranged between 3 and 6% greater than those of females, and significant differences were largely associated with the anterior body region and the limbs. Male body mass was 18% and male visceral parameters ranged between 12 and 24% heavier than those of females. Patterns of adipose deposition were also significantly different. Sternum and inguinal fat depths and total external and mesentery fat indices were significantly greater in males (5–44%), while rump fat depth was significantly greater in females (1%). These results support the conclusion that sexual dimorphism in wolves has evolved primarily as a foraging strategy, owing to division of labour between the sexes, and males are more highly specialized for capturing and killing large ungulate prey, while females are more specialized for a nurtural role.

Fetal development in wolves, Canis lupus, of the Keewatin District, Northwest Territories, Canada

1996 ◽  
Vol 74 (12) ◽  
pp. 2211-2218 ◽  
Author(s):  
Tracy L. Hillis ◽  
Frank F. Mallory
Keyword(s):  
Sexual Dimorphism ◽  
Northwest Territories ◽  
Body Mass ◽  
Canis Lupus ◽  
Fetal Development ◽  
Morphological Features ◽  
Contour Length ◽  
Morphological Parameters ◽  
Stage Of Development ◽  
Gravid Females

Of 205 female wolves (Canis lupus) shot by Inuit hunters between 1987 and 1989 in the Keewatin District, Northwest Territories, Canada, 97 were parous, and 16 gravid females carried 73 identifiable fetuses. Fetuses grew at a mean rate of 5.17 g/day between day 32 post coitus and parturition. During the same period, fetuses increased in length at a mean rate of 0.204 cm/day. No significant sexual dimorphism in body mass or other morphological features was found at this stage of development. Cranio-caudal length ranged from 3 mm shortly after implantation to approximately 185 mm at parturition. All correlations of morphological parameters with cranio-caudal length were significant, and with the exception of humerus length and contour length, all parameters increased faster than cranio-caudal length. The results are discussed in relation to reproductive and developmental strategies in canids.

scholarly journals Effects of additional anterior body mass on gait

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Simone V. Gill ◽  
Maureen Ogamba ◽  
Cara L. Lewis
Keyword(s):  
Body Mass ◽  
Anterior Body

scholarly journals A Novel Body Plan Alters Diversification of Body Shape and Genitalia in Live-Bearing Fish

2021 ◽  
Vol 9 ◽  
Author(s):  
R. Brian Langerhans ◽  
Eduardo Rosa-Molinar
Keyword(s):  
Complex Traits ◽  
Body Shape ◽  
Body Plan ◽  
The Body ◽  
Sperm Transfer ◽  
Body Region ◽  
Adaptive Divergence ◽  
Male Body ◽  
Correlated Evolution ◽  
Anterior Transposition

Major evolutionary innovations can greatly influence subsequent evolution. While many major transitions occurred in the deep past, male live-bearing fishes (family Poeciliidae) more recently evolved a novel body plan. This group possesses a three-region axial skeleton, with one region—the ano-urogenital region—representing a unique body region accommodating male genitalic structures (gonopodial complex). Here we evaluate several hypotheses for the evolution of diversity in this region and examine its role in the evolution of male body shape. Examining Gambusia fishes, we tested a priori predictions for (1) joint influence of gonopodial-complex traits on mating performance, (2) correlated evolution of gonopodial-complex traits at macro- and microevolutionary scales, and (3) predator-driven evolution of gonopodial-complex traits in a post-Pleistocene radiation of Bahamas mosquitofish. We found the length of the sperm-transfer organ (gonopodium) and its placement along the body (gonopodial anterior transposition) jointly influenced mating success, with correlational selection favoring particular trait combinations. Despite these two traits functionally interacting during mating, we found no evidence for their correlated evolution at macro- or microevolutionary scales. In contrast, we did uncover correlated evolution of modified vertebral hemal spines (part of the novel body region) and gonopodial anterior transposition at both evolutionary scales, matching predictions of developmental connections between these components. Developmental linkages in the ano-urogenital region apparently play key roles in evolutionary trajectories, but multiple selective agents likely act on gonopodium length and cause less predictable evolution. Within Bahamas mosquitofish, evolution of hemal-spine morphology, and gonopodial anterior transposition across predation regimes was quite predictable, with populations evolving under high predation risk showing more modified hemal spines with greater modifications and a more anteriorly positioned gonopodium. These changes in the ano-urogenital vertebral region have facilitated adaptive divergence in swimming abilities and body shape between predation regimes. Gonopodium surface area, but not length, evolved as predicted in Bahamas mosquitofish, consistent with a previously suggested tradeoff between natural and sexual selection on gonopodium size. These results provide insight into how restructured body plans offer novel evolutionary solutions. Here, a novel body region—originally evolved to aid sperm transfer—was apparently co-opted to alter whole-organism performance, facilitating phenotypic diversification.

scholarly journals Inconsistent association of male body mass with breeding success in captive white-tailed deer

2011 ◽  
Vol 92 (3) ◽  
pp. 527-533 ◽  
Author(s):  
Phillip D. Jones ◽  
Bronson K. Strickland ◽  
Stephen Demarais ◽  
Randy W. DeYoung
Keyword(s):  
Body Mass ◽  
Breeding Success ◽  
Male Body

scholarly journals Response: An exploration of the association between male body mass index and semen quality

2012 ◽  
Vol 24 (4) ◽  
pp. 483-484
Author(s):  
Ahmad Ghiyath Shayeb ◽  
Kirsten Harrild ◽  
Eileen Mathers ◽  
Siladitya Bhattacharya
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Semen Quality ◽  
Male Body

Helminths of wolves, Canis lupus L., in the Yukon and Northwest Territories

1973 ◽  
Vol 51 (10) ◽  
pp. 1087-1091 ◽  
Author(s):  
L. P. E. Choquette ◽  
G. G. Gibson ◽  
E. Kuyt ◽  
A. M. Pearson
Keyword(s):  
Northwest Territories ◽  
Echinococcus Granulosus ◽  
Canis Lupus ◽  
Trichinella Spiralis ◽  
Gastrointestinal Helminths ◽  
Taenia Hydatigena ◽  
First Time ◽  
Toxascaris Leonina

Wolves from the Yukon and Northwest Territories harbored the following gastrointestinal helminths: Alaria americana (10 of 171), A. arisaemoides (2/171), Diphyllobothrium sp, (1/171). Mesocestoidcs kirbyi (3/171), Taenia hydatigena (54/111), T. krabbei (63/111), T. pisiformis (2/111), T. serialis (41/111), Echinococcus granulosus (24/171), Toxascaris leonina (83/171). Uncinaria stenocephala (11/171), Spirocerca arctica (1/171), and S. lupi (1/171). Larval Trichinella spiralis occurred in 72 of 153 diaphragms. A. arisaemoides, M. kirbyi, and S. arctica were found for the first time in Canis lupus, while S. lupi, S. arctica, and the prevalence of T. spiralis in wolves are reported for the first time in Canada.

Body size, sexual dimorphism, and seasonal mass fluctuations in a larger sika deer subspecies, the Hokkaido sika deer (Cervus nippon yesoensis Heude, 1884)

2001 ◽  
Vol 79 (1) ◽  
pp. 154-159 ◽  
Author(s):  
Masatsugu Suzuki ◽  
Manabu Onuma ◽  
Mayumi Yokoyama ◽  
Koich Kaji ◽  
Masami Yamanaka ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Body Mass ◽  
Body Length ◽  
Sika Deer ◽  
Cervus Nippon ◽  
Total Body Mass ◽  
Foot Length ◽  
Hind Foot ◽  
Total Body ◽  
Cervus Nippon Yesoensis

Measurements of shoulder height, body length, hind-foot length, and total body mass were collected from 309 Hokkaido sika deer (Cervus nippon yesoensis Heude, 1884) (115 males and 194 females) and analyzed statistically for sexual dimorphism and seasonal body mass fluctuations. The von Bertalanffy equation was fitted to the growth curves that resulted. Asymptotic shoulder height, body length, and hind-foot length were 106.2, 112.6, and 52.9 cm in males and 94.8, 103.9, and 49.4 cm in females, respectively. Total body mass showed distinct seasonal fluctuations, ranging between 102.8 and 151.0 kg in adult males and 68.0 and 99.8 kg in adult females. Male/female ratios in shoulder height, body length, hind-foot length, and total mass were 1.12, 1.08, 1.07, and 1.51, respectively. These results indicate that the Hokkaido sika deer is one of the largest subspecies, at least in skeleton size. A larger body and longer hind foot would seem to be evolutionary adaptations to Hokkaido's cold, snowy environment.

Effects of a Single Gene on Worker and Male Body Mass in the Fire Ant Solenopsis invicta (Hymenoptera: Formicidae)

1999 ◽  
Vol 92 (4) ◽  
pp. 563-570 ◽  
Author(s):  
Michael A. D. Goodisman ◽  
Paul D. Mack ◽  
Devon E. Pearse ◽  
Kenneth G. Ross
Keyword(s):  
Body Mass ◽  
Solenopsis Invicta ◽  
Single Gene ◽  
Fire Ant ◽  
Male Body

Assessing the intensity of sexual selection on male body mass and antler length in roe deer Capreolus capreolus: is bigger better in a weakly dimorphic species?

Oikos ◽  
2010 ◽  
Vol 119 (9) ◽  
pp. 1484-1492 ◽  
Author(s):  
Cécile Vanpé ◽  
Jean-Michel Gaillard ◽  
Petter Kjellander ◽  
Olof Liberg ◽  
Daniel Delorme ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Body Mass ◽  
Roe Deer ◽  
Capreolus Capreolus ◽  
Male Body ◽  
Dimorphic Species

Estrogen receptor regulation of pulmonary alveolar dimensions: alveolar sexual dimorphism in mice

2006 ◽  
Vol 290 (5) ◽  
pp. L866-L870 ◽  
Author(s):  
Donald Massaro ◽  
Gloria DeCarlo Massaro
Keyword(s):  
Estrogen Receptor ◽  
Sexual Dimorphism ◽  
Surface Area ◽  
Body Mass ◽  
Female Rats ◽  
Female Mice ◽  
Alveolar Surface Area ◽  
Rats And Mice ◽  
Alveolar Surface ◽  
Respective Species

Female rats and mice have smaller and, per body mass (BM), more alveoli and alveolar surface area (Sa) than males of their respective species. This sexual dimorphism becomes apparent about the time of sexual maturity. It is prevented in rats (not tested in mice) by ovariectomy at age 3 wk. In female mice, estrogen receptor (ER)-α and ER-β are required for formation of alveoli of appropriate size and number. We now report the average volume of an alveolus (v̄a) and the number of alveoli per body mass (Na/BM) were not statistically different between ER-α−/− and wild type (wt) males. However, the combination of a larger value for v̄a and a smaller value for Na/BM, though neither parameter achieved a statistically significant intergroup difference, resulted in a statistically significant lower Sa/BM in ER-α−/− males compared with wt males. In ER-β−/− males, v̄a was bigger and Na/BM and Sa/BM were lower compared with wt males. Wt males had larger alveoli and lower Na/BM and Sa/BM than wt females. The wt sexual dimorphism of v̄a, Na/BM, and Sa/BM was absent in ER-α−/− mice. Alveolar size did not differ between ER-β−/− females and males but Na/BM and Sa/BM were greater in ER-β−/− females than in ER-β−/− males. The results in male mice, with prior findings in female mice, 1) demonstrate estrogen receptors have a smaller effect on alveolar dimensions in male than female mice, 2) show ER-α and ER-β are required for the sexual dimorphism of alveolar size, and 3) show ER-α is needed for the sexual dimorphism of body mass-specific alveolar number and surface area.

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