scholarly journals Postnatal growth and development of Natalus mexicanus (Chiroptera: Natalidae)

Therya ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 105-113
Author(s):  
Matías Martínez-Coronel ◽  
Anubis Molina-Gutiérrez ◽  
Yolanda Hortelano-Moncada

Natalus mexicanus is a bat species distributed from northern México to Central America.  It inhabits various types of tropical vegetation, roosting mainly in caves with high relative humidity and temperature, and feeding mostly on arachnids.  This study investigated postnatal growth and flight development of populations under natural conditions inhabiting “Los Laguitos” cave, Chiapas, southern México.  Forty-four females and 50 males were monitored from birth to 55 days of age; at five-day intervals, we measured body mass, forearm length, cartilaginous epiphyseal gap of the fourth metacarpal-phalangeal joint, and development of four characters.  We used statistical analyses and growth models to quantify the changes in morphometric parameters.  Neonates are altricial; the ears began to unfold since day one, while the eyes opened at day 25.  Greyish hair appeared between 25 to 35 days.  Forearm length and body mass increased linearly over 35 days, then the growth rate decreased.  The cartilaginous epiphyseal gap increased in size until day 25 and then started to close.  The logistic equation yielded the best fit for forearm length (K = 0.07) and body mass (K = 0.10).  Sustained flight was first achieved at 35 days of age.  N. mexicanus neonates are altricial and relatively small compared with other bats.  Eye-opening and fur development took place at a slower rate than in most species of insectivorous bats.  In the Chiapas population, eye-opening, fur development, and volancy occurred more slowly relative to the population inhabiting Álamos, Sonora.  These differences are probably consequences of local variations.  The morphometric postnatal growth pattern of N. mexicanus was like that of other insectivorous bats, i. e., linear growth rate before the onset of flight and slowing down thereafter.  As in other studies, the logistic model best fitted the growth pattern of body mass and forearm length, but growth coefficients were lower versus other tropical bats.  The cartilaginous epiphyseal gap of the fourth digit closes at an intermediate age relative to other insectivorous bats.  Sustained flight was attained when the relative body mass and forearm length of individuals approached adult body dimensions, as in other bat species.

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.


Genome ◽  
2001 ◽  
Vol 44 (3) ◽  
pp. 350-360 ◽  
Author(s):  
A E Vinogradov ◽  
O V Anatskaya ◽  
B N Kudryavtsev

To elucidate possible causes of the elevation of genome number in somatic cells, hepatocyte ploidy levels were measured cytofluorimetrically and related to the organismal parameters (body size, postnatal growth rate, and postnatal development type) in 53 mammalian species. Metabolic scope (ratio of maximal metabolic rate to basal metabolic rate) was also included in 23 species. Body masses ranged 105 times, and growth rate more than 30 times. Postnatal growth rate was found to have the strongest effect on the hepatocyte ploidy. At a fixed body mass the growth rate closely correlates (partial correlation analysis) with the cell ploidy level (r = 0.85, P < 10–6), whereas at a fixed growth rate body mass correlates poorly with ploidy level (r = –0.38, P < 0.01). The mature young (precocial mammals) of the species have, on average, a higher cell ploidy level than the immature-born (altricial) animals. However, the relationship between precocity of young and cell ploidy levels disappears when the influences of growth rate and body mass are removed. Interspecies variability of the hepatocyte ploidy levels may be explained by different levels of competition between the processes of proliferation and differentiation in cells. In turn, the animal differences in the levels of this competition are due to differences in growth rate. A high negative correlation between the hepatocyte ploidy level and the metabolic scope indicates a low safety margin of organs with a high number of polyploid cells. This fact allows us to challenge a common opinion that increasing ploidy enhances the functional capability of cells or is necessary for cell differentiation. Somatic polyploidy can be considered a "cheap" solution of growth problems that appear when an organ is working at the limit of its capabilities.Key words: genome number, somatic polyploidy, nuclear ploidy, multinuclearity, metabolic scope.


2018 ◽  
Vol 66 (3) ◽  
pp. 201
Author(s):  
Jennefer Mclean ◽  
Ashleigh Johnson ◽  
Delaine Woods ◽  
Reinhold Muller ◽  
David Blair ◽  
...  

In Australia, the spectacled flying-fox (Pteropus conspicillatus) (SFF), is listed as ‘Vulnerable’. Many juvenile SFFs come into care at the Tolga Bat Hospital, a privately funded community organisation. The aims of this study were (1) to estimate postnatal growth rates for length of forearm and body mass; (2) to describe the association between body mass and length of forearm; and (3) to develop a milk feeding chart for infant SFFs. Cross-sectional data were collected for 2680 SFFs from the 2006–07 to the 2016–17 seasons. Forearm length increased by 0.55mm and body mass increased by 1.5g per day. Longitudinal data were collected during the 2016–17 season for 128 SFFs. According to these data, forearm length increased by 0.71mm and body mass increased by 3.4g per day. Both analyses indicated exponential associations between forearm length and body mass (P&lt;0.001). Reasons for the differences between the cross-sectional and longitudinal results might include the negative impact of tick paralysis in the cross-sectional study and the positive effect of human care in the longitudinal study. The proposed feeding chart is based on length of forearm. This study was established in a wildlife-care facility providing a model for similar work with other wildlife species.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando V. Ramirez Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  

AbstractThe Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka’s dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka’s deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV = 0.82). The Baka’s and South Americans’ dm2s were confirmed among the largest in our sample. Despite the Baka’s unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s’ morphology only.


1993 ◽  
Vol 67 (6) ◽  
pp. 922-934 ◽  
Author(s):  
Robert J. Elias ◽  
Dong-Jin Lee

Microborings in the Late Ordovician tabulate corals Catenipora rubra (a halysitid) and Manipora amicarum (a cateniform nonhalysitid) and in an epizoic solitary rugose coral differ from nearly all of those previously reported in Paleozoic corals. These microborings were formed within the coralla by endolithic algae and fungi located beneath living polyps. Comparable structures in the Late Ordovician tabulate Quepora ?agglomeratiformis (a halysitid) represent algal microborings, not spicules, and halysitids are corals, not sponges as suggested by Kaźmierczak (1989).Endolithic algae in cateniform tabulates relied primarily on light entering through the outer walls of the ranks rather than through the polyps; lacunae within coralla permitted appropriate levels of light to reach many corallites. The direction of boring was determined by corallum microstructure and possibly also by the distribution of organic matter within the skeleton. There is an apparent inverse correlation between boring activity and coral growth rate.The location and relative abundance of pyritized microborings within calcareous coralla can be established quantitatively and objectively from electron microprobe determinations of weight percent sulfur along appropriate traverses of the coral skeleton. The distribution of such microborings in Catenipora rubra and Manipora amicarum is comparable to algal banding in modern corals; this is the first report of such banding in the interiors of Paleozoic corals. Change in the intensity of boring within each corallum was evidently a response to variation in the linear growth rate of the coral, or to fluctuation in an environmental factor (perhaps light intensity) that could control both algal activity and growth rate in these corals. Change in the algal boring intensity and linear growth rate of the coral was generally but not always seasonal and usually but not invariably associated with change in the density of coral skeletal deposition.Cyclic bands of boring abundance maxima within fossil colonial corals provide a measure of annual linear growth comparable to the widely accepted method based on skeletal density bands. Algal bands are more sporadically developed than density bands within and among coralla, thus increasing the difficulty of interpretation. Fluctuations in the abundance of algal microborings apparently provide a detailed record of changes in the linear growth rate of colonies and of individuals within colonies. Combined analyses of microboring abundance and skeletal density will contribute significantly to our understanding of the biological and environmental factors involved in endolithic activity and coral growth.


2020 ◽  
Vol 152 ◽  
pp. 112-123
Author(s):  
Oleg S. Sukharev ◽  

The purpose of the study is to determine the existing growth models of the countries of the Eurasian Union by GDP expenditures and sectors (manufacturing, transactional raw materials). The research methodology is a macroeconomic analysis of the dynamics of the main indicator of economic development — gross domestic product. The research method is a structural analysis that allows you to get a structural formula for calculating the contribution of each component of GDP to the growth rate, as well as a comparative analysis of the dynamics models of the countries in question — Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia. The result of the study is the obtained structural relationships that make it possible to measure the influence of the investment structure on the growth rate, the criteria describing economic growth with a corresponding change in the country's national wealth, as well as the identification of models of economic dynamics by the countries of the Eurasian Union. It is indicative that the transaction sector dominates in Kazakhstan and Russia, while in other countries a mixed model is found, or industrial growth as in Belarus. According to the components of GDP and expenditures of the country, either a mixed or a consumer model is found (Kyrgyzstan, Russia), however, the contribution of government spending to the growth rate is provided only in Kazakhstan. It was also revealed that the reaction to the crisis of 2009 and 2015 was fundamentally different for the countries of the Eurasian Union. The search for the factor conditions of such a prevailing dynamics, as well as the influence of union economic relations on the formation of a growth model in each country, requires an expansion of research and an analytical perspective


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