Sexual Maturity in the Female Bandicoot Isoodon-Macrourus (Gould) in Captivity

1986 ◽  
Vol 34 (2) ◽  
pp. 199 ◽  
Author(s):  
RT Gemmell
Keyword(s):  
Adult Female ◽  
Growth And Development ◽  
Sexual Maturity ◽  
Environmental Cues ◽  
Development Rates ◽  
In Captivity ◽  
The Mean

In Queensland the bandicoot breeds throughout the year, but the breeding rate decreases from April to June. In this study, it was found that animals born from April to June gave birth to their first litter at an earlier age than those born in January-March, October-December or July-September: 204.0, 229.7, 244.0 and 286.8 days respectively. Similarly, the mean weights of the mothers of the four groups when giving birth to their first litter increased from 845.0 g to 873.0, 938.2 and 954.1 g respectively. The 11 bandicoots born in July-September formed two groups: five animals gave birth at 193.8 � 7.3 days (range 176-212 days) at a weight of 734.0 � 17.3 g (range 680-780 g) six animals gave birth at 364.3 � 7.7 days (range 352-399 days) at a weight of 1137.5 � 42.2 g (range 1020-1307 g). The latter group appeared to have delayed their sexual maturity during the decreased or non-breeding part of the year. Bandicoots which delay their sexual maturity are heavier when they produce their first litter than the faster developing animals. Therefore it is unlikely that decrease growth and development rates during April-June prevents the onset of sexual maturity. It is probable that the environmental cues which inhibit breeding in the adult female also affect the maturation of juvenile females.

Growth of the Eastern Quoll, Dasyurus viverrinus (Shaw), (Marsupialia) in Captivity

1984 ◽  
Vol 11 (1) ◽  
pp. 21 ◽  
Author(s):  
JC Merchant ◽  
K Newgrain ◽  
B Green
Keyword(s):  
Litter Size ◽  
Adult Female ◽  
Growth And Development ◽  
Mammary Glands ◽  
Adult Females ◽  
In Captivity ◽  
Molar Teeth ◽  
Males And Females ◽  
At Will

The growth and development, from 10 to 270 days old, of eastern quolls in a captive colony was recorded. Young were able to detach from the teat by 65 days of age and their eyes were open by 80 days. Statistically significant differences in some measurements from males and females were found as early as 85 days of age. The weaning period commenced at 102 days ofage, and coincided with eruption ofthe first molar teeth. Total independence, determined by the cessation of lactation in the mother, was as early as 142 days in litters of one or as late as 200 days in larger litters. There was a high correlation between litter size and age at independence. Lactation was maintained in all previously suckled mammary glands of adult females after the death of young aged 65 days or over if some siblings remained. This was due to the ability of young of this age to detach and reattach to the teats at will. The implication of this observation is that the commonly held view that the numbers of surviving young in marsupial litters corresponds to the number of lactating teats in the adult female may not always be correct.

Breeding Biology of the Agile Wallaby, Macropus agilis (Gould) (Marsupialia : Macropodidae), in Captivity

1976 ◽  
Vol 3 (2) ◽  
pp. 93 ◽  
Author(s):  
JC Merchant
Keyword(s):  
Sexual Maturity ◽  
Post Partum ◽  
Cell Types ◽  
Morphological Characters ◽  
Oestrous Cycle ◽  
Vaginal Smear ◽  
Vaginal Smears ◽  
Main Cell ◽  
In Captivity ◽  
The Mean

Female agile wallabies in captivity reached sexual maturity at about 12 months old and males produced mature spermatozoa by 14 months. Breeding was continuous throughout the year and birth and oestrus were recorded in every month. The mean length of the oestrous cycle was 32.4 days, and the mean gestation period 29.4 days. Females exhibited post-partum oestrus, usually mating within 1 day of birth. Sixty-four young born in captivity comprised 24 males, 30 females and 10 of unknown sex. If a pouch young were removed or lost, the quiescent blastocyst resumed its development, to birth about 26.5 days later. Failure or absence of the blastocyst was followed by an oestrus at about the time of the corresponding post-partum oestrus. Both the oestrous cycle and the interval between removal of a pouch young and oestrus were significantly longer than when a pregnancy intervened. The oestrous cycle was characterized by changes in the proportions of the main cell types in the vaginal smear, and by changes in the appearance of the urogenital opening and the pouch and teats. The approach of oestrus could not be predicted from vaginal smears but the post-oestrous condition was always recognizable even without mating. Young animals first left the pouch for short periods between the ages of 176 and 211 days, and left permanently between 207 and 237 days. Animals of known age were measured and the development of various morphological characters noted at weekly intervals from about birth until 12 months old.

Observations on the breeding and growth of the marsupial Perameles nasuta Geoffroy, with notes on other bandicoots.

1964 ◽  
Vol 12 (3) ◽  
pp. 322 ◽  
Author(s):  
AG Lyne
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
The Body ◽  
Cube Root ◽  
Single Individual ◽  
Age Changes ◽  
Breeding Activity ◽  
In Captivity ◽  
The Mean ◽  
The Right

A study has been made of 521 bandicoots (Perameles nasuta, 324; P. gunnii, 111 ; Isoodon obesulus, 86). Near Sydney, P. nasuta breeds all the year round with no indication of any peaks of breeding activity. Limited observations on P. gunnii and I. obesulus in Tasmania also suggest that births occur in every season of the year. Parturition of a single individual of P. nasuta was witnessed. Fifteen new-born specimens of this species were measured and body weight records were obtained for five of them. The average dimensions of these specimens, and consecutive measurements of three specimens born in captivity and of known age, were used to age pouch young of unknown age. Age changes in the appearance of P. nasuta are described and illustrated. Hair emerges on the trunk at about 40 days after birth and at 2 months the coat is similar to that of the adult. The rate of body growth is extremely rapid just prior to the opening of the eyes (usually at 45-48 days), and the young first appear outside the pouch several days later. The pouch contains eight teats, and the mean litter sizes were: P. nasuta, 2.44 (52 litters); P. gunnii, 2.23 (22 litters); I. obesulus, 2.33 (9 litters). In 47 litters of P. nasuta, 73 young were on teats of the left side compared with 46 on the right side of the pouch. The sexes were equally represented in the pouch young of the three species examined. In P. nasuta, sexual maturity is reached at about 450 g in females and about 650 g in males. The linear equivalence (cube root of the body weight) is used as an overall measure of size with which the parts of the body are compared.

Reproduction of the whiptail wallaby, Macropus parryi Bennett (Marsupialia : Macropodidae), in captivity with age estimation of the pouch-young

1998 ◽  
Vol 25 (6) ◽  
pp. 635 ◽  
Author(s):  
P. M. Johnson
Keyword(s):  
Age Estimation ◽  
Sexual Maturity ◽  
Post Partum ◽  
Age Determination ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
Body Measurements ◽  
In Captivity ◽  
The Mean

Reproduction of the whiptail wallaby, Macropus parryi, was studied in captivity. The mean length of the oestrous cycle was 41.8 days while the mean length of the gestation period was 38.0 days. M. parryi bred throughout the year and post-partum oestrus was not recorded although mating did occur during the pouch life when the pouch-young was 118–168 days of age. The length of the pouch-life was 256–267 days and weaning occurred 104–215 days after emergence from the pouch. Sexual maturity for females occurred at 509–647 days of age. An age-determination table was produced and found useful for predicting age of pouch-young using body measurements.

Reproduction, Growth and Age Determinatipon in the Yellow Footed Rock Wallaby Petrogale xanthopus Gray, in Captivity

1985 ◽  
Vol 12 (2) ◽  
pp. 127 ◽  
Author(s):  
WE Poole ◽  
JC Merchant ◽  
SM Carpenter ◽  
JH Calaby
Keyword(s):  
Sex Ratio ◽  
Growth Rates ◽  
Sexual Maturity ◽  
Growth Curves ◽  
Oestrous Cycle ◽  
Season Of Birth ◽  
In Captivity ◽  
The Mean ◽  
Similar Growth

Yellow-footed rock-wallabies were studied in captivity over 13 years. Individuals of both sexes attained sexual maturity from age 18 months and were capable of breeding throughout the year. The ranges recorded were: for length of oestrous cycle 32-37 days; gestation 31-33 days; pouch life 190-201 days. Parturition was usually followed by an oestrus and mating with a consequent lactation-controlled embryonic quiescence. The mean interval from removal of pouch young to birth was 31.5 days, and to oestrus without an intervening birth, 34 days. Weight of the neonate within the 1st day was <500 mg; the sex ratio of 62 young of known sex revealed a significant departure from parity with 41 boys and 21 girls (100:51). Growth curves were fitted for length of head, ear, arm, leg, foot, tail and weight. These measurements provided a useful means of determining age within the 1st year and to a lesser extent the 2nd year, length of head being the best criterion. Both sexes maintained similar growth rates when within the pouch, but males grew larger once they vacated it. Patterns of molar eruption and molar progression provided a useful means of determining age in older animals but, on the data available, accuracy was restricted to the year and possibly no more than the season of birth.

Variation within and between Rivers in Adult Size and Sea Age at Maturity of Anadromous Brown Trout, Salmo trutta

1991 ◽  
Vol 48 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
Jan Henning L'Abée-Lund
Keyword(s):  
Brown Trout ◽  
Sexual Maturity ◽  
Salmo Trutta ◽  
Adult Size ◽  
Age At Maturity ◽  
Migration Distance ◽  
Spawning Area ◽  
Brown Trout Salmo Trutta ◽  
Males And Females ◽  
The Mean

I compared adult size and sea age at sexual maturity among nine populations of anadromous brown trout, Salmo trutta, in two Norwegian rivers to determine the extent of inter- and intrariverine variations. Variation in the mean length of spawners and in the mean sea age at sexual maturity were mainly dependent on the variations found within rather than between rivers. Mean lengths and mean age at maturity of males increased significantly with increasing altitude of the spawning area and with migration distance in freshwater. In females, positive significant correlations were found with mean lengths and altitude of the spawning area and with mean sea age at maturity and both spawning site altitude and migration distance. Mean lengths and ages of males and females were not significantly correlated with the rate of water discharge in the streams during spawning. The size of gravel substrate for spawning was of minor importance in explaining interpopulation variation in mean female size. The increase noted in mean length and in mean sea age at maturity of both males and females is probably an adaptation to greater energy expenditure to reach the uppermost natal spawning areas.

Growth and development of collagen fibrils in immature tissues from rat and sheep

1981 ◽  
Vol 212 (1186) ◽  
pp. 85-92 ◽  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Collagen Fibril ◽  
Growth And Development ◽  
Collagen Fibrils ◽  
Diameter Distribution ◽  
Rat Tissues ◽  
Transmission Electron ◽  
The Mean ◽  
Fibril Diameter

The collagen fibril diameter distribution of four immature tissues from both rat and sheep have been determined from transverse sections observed in the transmission electron microscope. In many instances before birth, the form of the distribution for the tissues is both unimodal and sharp and the mean diameters of the distributions lie close to a multiple of 80 Å. For some tissues, the collagen fibril diameter distributions may be resolved into a number of components, each of which represents a population of fibrils with a diameter close to a multiple of 80 Å (8 nm). These data confirm and extend previous observations by the authors that small collagen fibrils all have diameters that are multiples of about 80 Å and that the fibril growth occurs by the accretion of 80 Å units. The form of the collagen fibril diameter distribution at birth is broad for the sheep tissues but narrow for the rat tissues, thus confirming that the range of fibril diameters at this stage of life reflects the differing degree of development of precocious and altricious animals.

Growth and development of the barren-ground caribou. II. Postnatal growth rates

1968 ◽  
Vol 46 (5) ◽  
pp. 1023-1029 ◽  
Author(s):  
E. H. McEwan
Keyword(s):  
Growth And Development ◽  
Growth Characteristic ◽  
Growth Curves ◽  
Postnatal Growth ◽  
Maintenance Costs ◽  
Cyclical Pattern ◽  
Body Weights ◽  
In Captivity ◽  
Growth Constants ◽  
Slow Growing

The growth curves of minimum body weights of fast-growing caribou reared in captivity and slow-growing wild caribou are compared. Captive animals exhibit a cyclical pattern of growth characteristic of other cervid species. The differences in the declining growth constants of wild caribou compared to captive caribou are attributed to environmental factors and activity, resulting in higher maintenance costs.

scholarly journals Reproductive Biology of Round Sardinella (Sardinella Aurita) (Valenciennes, 1847) in Senegalese Coastal Waters

2018 ◽  
Vol 9 (1) ◽  
pp. 31
Author(s):  
Ismaïla NDIAYE ◽  
Alassane SARR ◽  
Alioune FAYE ◽  
Modou THIAW ◽  
Malick DIOUF ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Sexual Maturity ◽  
Reproductive Parameters ◽  
Monthly Variation ◽  
Relative Fecundity ◽  
The Mean ◽  
Sardinella Aurita ◽  
Somatic Index

In this study, a total of 1068 specimens Sardinella aurita of which 553 females and 515 males were examined. The objectif of this study was to determine the reproductive parameters of Sardinella aurita. The sex ratio was significantly in favor of females (55%). The size at first sexual maturity was estimated at 18.9 cm for females and 18.0 cm for males. The monthly variation of sexual maturity stages and gonado-somatic index (GSI) allowed to locate the reproduction periods from February to June and from September to December. The mean absolute fecundity was estimated at 110.794 ± 7582 oocytes whereas relative fecundity was about 422 ± 26 oocytes per gram of female.

THE ROLE OF EDUCATED LEADERS IN ECONOMIC GROWTH AND DEVELOPMENT: EVIDENCE FROM CENTRAL AFRICAN REPUBLIC AND SINGAPORE

2018 ◽  
Vol 65 (01) ◽  
pp. 81-102
Author(s):  
OLUWOLE OWOYE ◽  
OLUGBENGA A. ONAFOWORA
Keyword(s):  
Economic Growth ◽  
Growth And Development ◽  
Central African Republic ◽  
Economic Growth And Development ◽  
Highly Educated ◽  
Educational Attainments ◽  
Fundamental Causes ◽  
The Mean ◽  
Neoclassical Growth

This paper postulates that highly educated leaders matter in economic growth and development and that this is one of the fundamental causes of the differences in income between countries. To verify this assertion, we examine Central African Republic and Singapore within the neoclassical growth model that incorporates educational attainments of leaders as the functionally relevant explanatory variable. We found the mean years of schooling of educated leaders to be statistically and significantly different in both countries, but more importantly, educational attainments of leaders have a positive and statistically significant effect on economic growth in Singapore, but negative in Central African Republic.

Sign in / Sign up

Export Citation Format

Share Document