scholarly journals Ontogeny of body size and shape of Antarctic and subantarctic fur seals

2007 ◽  
Vol 85 (12) ◽  
pp. 1275-1285 ◽  
Author(s):  
Sebastián P. Luque ◽  
Edward H. Miller ◽  
John P.Y. Arnould ◽  
Magaly Chambellant ◽  
Christophe Guinet

Pre- and post-weaning functional demands on body size and shape of mammals are often in conflict, especially in species where weaning involves a change of habitat. Compared with long lactations, brief lactations are expected to be associated with fast rates of development and attainment of adult traits. We describe allometry and growth for several morphological traits in two closely related fur seal species with large differences in lactation duration at a sympatric site. Longitudinal data were collected from Antarctic ( Arctocephalus gazella (Peters, 1875); 120 d lactation) and subantarctic ( Arctocephalus tropicalis (Gray, 1872); 300 d lactation) fur seals. Body mass was similar in neonates of both species, but A. gazella neonates were longer, less voluminous, and had larger foreflippers. The species were similar in rate of preweaning growth in body mass, but growth rates of linear variables were faster for A. gazella pups. Consequently, neonatal differences in body shape increased over lactation, and A. gazella pups approached adult body shape faster than did A. tropicalis pups. Our results indicate that preweaning growth is associated with significant changes in body shape, involving the acquisition of a longer, more slender body with larger foreflippers in A. gazella. These differences suggest that A. gazella pups are physically more mature at approximately 100 d of age (close to weaning age) than A. tropicalis pups of the same age.

1998 ◽  
Vol 76 (5) ◽  
pp. 978-983 ◽  
Author(s):  
Hugo Ochoa-Acuña ◽  
John M Francis ◽  
Daryl J Boness

The objectives of this study were to establish body mass at birth, postnatal growth rate, and the factors that influence these parameters for the Juan Fernández fur seal, Arctocephalus philippii. Females of this species have an unusual attendance pattern in which foraging trips and shore visits last, on average, 12.3 and 5.3 days, respectively. Pup mass was obtained from cohorts born during the reproductive seasons in 1988 through 1992. Birth masses of male and female pups were significantly different, averaging 6.1 and 5.5 kg, respectively (F = 13.2, P < 0.0003, n = 238). Birth masses also differed among cohorts, being lowest in 1992 and highest in 1990. During the first 2 months of life, male and female pups grew at the same rate (79 ± 61.5 g · day-1 (mean ± SD); F[1] = 0.03, P = 0.8562). Interannual differences in growth rate during the first month were significant (F[4] = 8.14, P < 0.0001), as was the interaction between month and year effects (F[2] = 6.81, P = 0.0012). Growth rates for the 1990 cohort were lower than those in all other years except 1992. Birth masses and postnatal growth rates of Juan Fernández fur seal pups are comparable to those of other otariid species.


1998 ◽  
Vol 76 (8) ◽  
pp. 1418-1424 ◽  
Author(s):  
Christophe Guinet ◽  
Jean Paul Roux ◽  
Marielle Bonnet ◽  
Valérie Mison

2019 ◽  
Vol 31 (6) ◽  
pp. 755-776
Author(s):  
Heekyung Jang ◽  
Jianhui Chen

Purpose The purpose of this paper is to use body shape analysis and develop a 3D virtual body formation and deformation model that can accurately express size and shape. Design/methodology/approach In this paper, 1,882 sets of direct measurement data of Korean women in their 20s (19–29 years) were analyzed. These data sets were sourced from the sixth and seventh “Size Korea” anthropometric survey data. Through body shape analysis, the authors classified them into seven body types and selected their representative bodies. A 2D image based on the height, breadth, depth and length was first formed, and the representative virtual body was modeled using the polygon technique. The authors calculated the grading ratios for each body type according to the clothing sizing system, and modified the virtual body size type by morphing technique. Findings In order to accurately evaluate the fit in a virtual fitting system, it is necessary to study the body size and shape of the target age; this makes it possible to form virtual body reflecting the size and shape. Originality/value In this paper, the authors propose a new 3D virtual body formation method that is more accurate in shape and size compared to the present system. Through this, it will be possible to grasp the accurate simulation state in the virtual fitting system, and thereby evaluate the accurate fit.


2001 ◽  
Vol 204 (9) ◽  
pp. 1547-1557 ◽  
Author(s):  
J. Lovvorn ◽  
G.A. Liggins ◽  
M.H. Borstad ◽  
S.M. Calisal ◽  
J. Mikkelsen

For birds diving to depths where pressure has mostly reduced the buoyancy of air spaces, hydrodynamic drag is the main mechanical cost of steady swimming. Drag is strongly affected by body size and shape, so such differences among species should affect energy costs. Because flow around the body is complicated by the roughness and vibration of feathers, feathers must be considered in evaluating the effects of size and shape on drag. We investigated the effects of size, shape and feathers on the drag of avian divers ranging from wing-propelled auklets weighing 75 g to foot-propelled eiders weighing up to 2060 g. Laser scanning of body surfaces yielded digitized shapes that were averaged over several specimens per species and then used by a milling machine to cut foam models. These models were fitted with casts of the bill area, and their drag was compared with that of frozen specimens. Because of the roughness and vibration of the feathers, the drag of the frozen birds was 2–6 times that of the models. Plots of drag coefficient (C(D)) versus Reynolds number (Re) differed between the model and the frozen birds, with the pattern of difference varying with body shape. Thus, the drag of cast models or similar featherless shapes can differ both quantitatively and qualitatively from that of real birds. On the basis of a new towing method with no posts or stings that alter flow or angles of attack, the dimensionless C(D)/Re curves differed among a size gradient of five auklet species (75–100g) with similar shapes. Thus, extrapolation of C(D)/Re curves among related species must be performed with caution. At lower speeds, the C(D) at a given Re was generally higher for long-necked birds that swim with their neck extended (cormorants, grebes, some ducks) than for birds that swim with their head retracted (penguins, alcids), but this trend was reversed at high speeds. Because swimming birds actually travel at a range of instantaneous speeds during oscillatory strokes, species variations in drag at different speeds must be considered in the context of accelerational stroking.


2003 ◽  
Vol 94 (4) ◽  
pp. 501-516 ◽  
Author(s):  
Martin J. Tovée ◽  
Philip J. Benson ◽  
Joanne L. Emery ◽  
Suzanne M. Mason ◽  
Esther M. Cohen-Tovée

Author(s):  
Nadia Maalin ◽  
Sophie Mohamed ◽  
Robin S. S. Kramer ◽  
Piers L. Cornelissen ◽  
Daniel Martin ◽  
...  

Abstract Accurate self-assessment of body shape and size plays a key role in the prevention, diagnosis, and treatment of both obesity and eating disorders. These chronic conditions cause significant health problems, reduced quality of life, and represent a major problem for health services. Variation in body shape depends on two aspects of composition: adiposity and muscularity. However, most self-assessment tools are unidimensional. They depict variation in adiposity only, typically quantified by the body mass index. This can lead to substantial, and clinically meaningful, errors in estimates of body shape and size. To solve this problem, we detail a method of creating biometrically valid body stimuli. We obtained high-resolution 3D body shape scans and composition measures from 397 volunteers (aged 18–45 years) and produced a statistical mapping between the two. This allowed us to create 3D computer-generated models of bodies, correctly calibrated for body composition (i.e., muscularity and adiposity). We show how these stimuli, whose shape changes are based on change in composition in two dimensions, can be used to match the body size and shape participants believe themselves to have, to the stimulus they see. We also show how multivariate multiple regression can be used to model shape change predicted by these 2D outcomes, so that participants’ choices can be explained by their measured body composition together with other psychometric variables. Together, this approach should substantially improve the accuracy and precision with which self-assessments of body size and shape can be made in obese individuals and those suffering from eating disorders.


1990 ◽  
Vol 64 (2) ◽  
pp. 300-318 ◽  
Author(s):  
James C. Brower

The dorsal cups of 17 calceocrinid species illustrate the relations between ontogeny and phylogeny for this unique family. Paedomorphosis in conjunction with increasing adult body size comprises the dominant pattern. During evolution, the plate structure of the dorsal cup was rearranged so that the hinge of advanced crinoids resembles the juvenile configuration of more primitive species. Consideration of allometric equations dealing with the size and shape of the dorsal cup and hinge suggests that most changes were caused by displacements of the initial intercepts and offsets of timing in development. The growth of the hinge moment of typical taxa produces hinges that are functionally equivalent in adult crinoids of different body sizes.


Zootaxa ◽  
2011 ◽  
Vol 2775 (1) ◽  
pp. 1 ◽  
Author(s):  
STANISŁAW SENICZAK ◽  
ANNA SENICZAK

Morphology of juvenile stages and ontogeny of Damaeus onustus C. L. Koch, 1844, Damaeus clavipes (Hermann, 1804) and Kunstidamaeus tecticola (Michael, 1888) was investigated. The juveniles of these species differ mainly in body shape and size, and shape of some setae on the gastronotum and legs. The nymphs of all species lose centrodorsal setae of the d-series, and carry the exuviae of previous instars, but D. onustus carries also compact humus mass adhering to exuviae, D. clavipes a lot of loose debris, while K. tecticola usually only exuviae. The kind of camouflage is partly determined by the shape of gastronotal setae; in D. onustus these setae are curved ventrally, in D. clavipes are raised, while in K. tecticola are raised, and strongly curved medial. The nymphs of these species, as the nymphs of all other known Damaeidae, have gastronotal cornicle, which connects the exuviae of previous instars to the gastronotum. The cornicle of particular species differs in shape and location on the gastronotum; in some species is located anteromedial to setae la, in the other between setae lm, and in the other yet between setae lp or h 3 . The adults of these species differ mainly in body size, presence and shape of cuticular apophyses on the body, length of some setae on the prodorsum and notogaster, and the number of setae on legs, including dorsal seta d on genua I–III and tibiae I–IV.


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