Aspects of reproduction in the genus Notomys (Muridae)

1974 ◽  
Vol 22 (4) ◽  
pp. 439 ◽  
Author(s):  
EG Crichton
Keyword(s):  
Reproductive Biology ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Interspecific Variations

Reproductive biology was studied in captive N. alexis, N. fuscus, N. mitchellii and N, cervinus. All were polyoestrous, the oestrous cycle averaging 7.0-8.0 days in N. alexis and N. mitchellii and 9.0 days in N. fuscus. In N. cervinus there was a considerable variation in length; this species may be easily stressed and less adaptable to captivity. Gestation in the non-lactating animal lasted 32, 34-37 and 38-43 days in N. alexis, N. mitchellii and N, cervinus respectively; all three had post-partum oestrus and mating. Lactation appeared to delay implantation in N, cervinus and probably in N. mitchellii, but not in N. alexis; it lasted 3-4 weeks, during which time the young clung tenaciously to the teats. Oestrus was not always suspended during lactation in N. alexis, and conception may take place during suckling in this species. Interspecific variations in this pattern of reproduction are discussed, and the information compared with data from other Australian Muridae.

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

Reproduction ◽  
2000 ◽  
pp. 49-57 ◽  
Author(s):  
SD Johnston ◽  
MR McGowan ◽  
P O'Callaghan ◽  
R Cox ◽  
V Nicolson
Keyword(s):  
Luteal Phase ◽  
Post Partum ◽  
Plasma Concentrations ◽  
External Genitalia ◽  
Oestrous Cycle ◽  
Phascolarctos Cinereus ◽  
Pregnant Females ◽  
Peripheral Plasma ◽  
The Mean ◽  
High Concentrations

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.

Reproductive Ecology of The Allied Rock-wallaby, Petrogale assimilis.

1996 ◽  
Vol 19 (2) ◽  
pp. 209
Author(s):  
R. Delaney
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Ecology ◽  
Oestrous Cycle ◽  
Embryonic Diapause ◽  
Minimum Age

Petrogale assimilis has a typical life history and reproductive ecology for a macropodid of its size. Both sexes are capable of reproducing continuously; gestation is about the same length as the oestrous cycle (approximately one month); a single young is born and, a post-partum oestrus and embryonic diapause probably occurs. The sex ratio of young is unbiased. Pouch young remain permanently attached to the teat until 110 - 143 days (n=11). Permanent exit from the pouch occurs at 180 - 231 days (mean=201 days, n=25), and weaning occurs between 267 - 387 days (n=5). Sexual maturity occurs at a minimum age of 17.5 months in females and 23 months in males.

Oestrous cycle and gestation length in the musky rat-kangaroo, Hypsiprymnodon moschatus (Potoroidae : Marsupialia)

2001 ◽  
Vol 49 (1) ◽  
pp. 37 ◽  
Author(s):  
Shan Lloyd
Keyword(s):  
Epithelial Cells ◽  
Captive Breeding ◽  
Common Ancestor ◽  
Post Partum ◽  
Reproductive Physiology ◽  
Oestrous Cycle ◽  
Gestation Length ◽  
Vaginal Smears ◽  
Breeding Colony ◽  
Male And Female

Wild-caught male and female H. moschatus were maintained in a captive breeding colony. Vaginal smears were taken three times a week until oestrous cycles were detected and gestation lengths approximated. Thereafter, smears were usually taken daily when oestrus was expected. The gestation period (considered to be the number of days from the detection of sperm in the smear until the day young were found in the pouch) was found to last 19 days. Sperm were usually detected in the smear two days before the influx of semi-cornified and cornified epithelial cells, which occurred 17 days before parturition. A pre- or post-partum oestrus was not detected and females did not return to oestrus until at least 6 days after the removal of the last pouch young. H. moschatus has the shortest recorded gestation for any macropod, and gestation occupies approximately 75% of the oestrous cycle. The reproductive physiology of H. moschatus is similar to that of most phalangerids, which may be indicative of a common ancestor.

Reproduction of the Red-Bellied Pademelon Thylogale billardierii (Marsupialia)

1982 ◽  
Vol 9 (1) ◽  
pp. 27 ◽  
Author(s):  
RW Rose ◽  
DJ McCatney
Keyword(s):  
Corpus Luteum ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Seasonal Breeder ◽  
The Mean ◽  
Duration Of Gestation

'Thylogale billardierii, which is abundant in Tasmania, is a seasonal breeder with most births in the months April, May and June. Parturition is followed by mating, and the zygote so produced remains dormant until either sucking becomes intermittent near the end of pouch life or the young is lost. The mean length of the oestrous cycle was determined at 30.3 days, not significantly longer than the duration of gestation (30.2 days). Removal of pouch young results in the birth of a new young 28.7 days later. Removal of the corpus luteum results in oestrus 11 days later. Pouch life is 202 days, and vacation of the pouch by the young coincides precisely with parturition and post-partum mating. The young mature at about 14-15 months.

The reproductive biology of deep-sea forcipulate seastars (Asteroidea: Echinodermata) from the N.E. Atlantic Ocean

1984 ◽  
Vol 64 (3) ◽  
pp. 587-601 ◽  
Author(s):  
P. A. Tyler ◽  
S. L. Pain ◽  
J. D. Gage ◽  
D. S. M. Billett
Keyword(s):  
Atlantic Ocean ◽  
Reproductive Biology ◽  
Deep Sea ◽  
Egg Size ◽  
Dorsal Surface ◽  
Oocyte Diameter ◽  
Interspecific Variations ◽  
Egg Diameter

Samples of the deep-sea forcipulate seastars Brisinga endecacnemos, Brisingella coronata, Freyella spinosa and Zoroaster fulgens have been collected at a number of stations in the N.E. Atlantic. Examination of their reproductive biology suggests subtle interspecific variations in their gametogenic cycles. The gonads of Brisinga endecacnemos are serially arranged under the dorsal arm surface, each cluster of gonad tubules having its own gonopore. In the closely related Brisingella coronata each gonad consists of up to 12 elongate tubules opening at a single gonopore at the dorsal surface. In both species the maximum egg diameter is about 1250 μm and fecundity may be up to 60000 eggs per individual. It appears that the eggs in Brisinga endecacnemos are produced in clusters whilst those of Brisingella coronata are produced continuously. InFreyella spinosa the gonad consists of a small tubular sac analogous to a single tubule of Brisinga endecacnemos. Maximum fecundity is only 2500 eggs per individual, and the maximum egg size is 1250 μm. In all three species eggs that are not spawned undergo internal oocyte degeneration. The gonads of Zoroaster fulgens show the typical asteroid configuration of two at the base of each arm, one either side of the ambulacrum. The maximum oocyte diameter is 950 μm. There is some evidence that there may be a seasonality of reproduction in this species. In all four species examined the large egg size and relatively low fecundity suggest direct demersal development with the subtle variations in their reproductive biology reflecting slightly different breeding habits.

Distribution, size and sex composition, reproductive biology and diet of sharks from Northern Australia

1991 ◽  
Vol 42 (2) ◽  
pp. 151 ◽  
Author(s):  
JD Stevens ◽  
KJ McLoughlin
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Annual Cycle ◽  
Post Partum ◽  
Austral Summer ◽  
Size Composition ◽  
Maximum Size ◽  
Northern Australia ◽  
Average Size ◽  
Size At Birth

The distribution, size composition, sex ratio, reproductive biology and diet of 17 species of shark from the families Triakidae, Hemigaleidae and Carcharhinidae from northern Australia were examined. In most of these species the sex ratio of the embryos is 1 : 1, whereas in the post-partum populations there were significantly more males than females. The results indicate four broad reproductive strategies among these sharks. In most species reproduction was distinctly seasonal with individual females giving birth each Austral summer (annual cycle) after a gestation period of 9-12 months. A second group had a very similar cycle except that individual females gave birth every second year (biennial cycle). A third group had an annual cycle but breeding was continuous throughout the year, these were mostly small bottom-associated sharks. One species had a seasonal cycle but gave birth twice each year (biannual cycle) after a 6-month gestation. The average size at birth varied from 27 to 75 cm and the average litter size varied from 2 to 34. The size at birth was about 40% of the size at maturity, which in turn was about 70% of the maximum size. Diets ranged from omnivorous to highly selective. Fish was an important component of the diet in all but one species. There was evidence of partitioning of food resources among sympatric, morphologically similar, sharks.

Hormonal changes at oestrus, parturition and post-partum oestrus in the tammar wallaby (Macropus eugenii)

1983 ◽  
Vol 96 (1) ◽  
pp. 155-161 ◽  
Author(s):  
C. H. Tyndale-Biscoe ◽  
L. A. Hinds ◽  
C. A. Horn ◽  
G. Jenkin
Keyword(s):  
Post Partum ◽  
Tammar Wallaby ◽  
Oestrous Cycle ◽  
High Peak ◽  
Rapid Decline ◽  
Hormonal Changes ◽  
Progesterone Concentration ◽  
Macropus Eugenii ◽  
Slow Decline ◽  
Prostaglandin F

Concentrations of progesterone, prolactin, LH and 13,14 dihydro-15-keto-prostaglandin F2α (PGFM) were measured in plasma of eight tammar wallabies at 8-hourly intervals during the end of pregnancy and post-partum oestrus initiated by removing the pouch young, and during the end of the oestrous cycle, similarly initiated. In the non-pregnant cycle oestrus occurred 29·7 ± 0·7 (mean ±s.e.m.) days after initiation of the cycle, was preceded by a slow decline in progesterone concentration from 1·6 nmol/l to less than 0·64nmol/l and was followed by a preovulatory peak of LH 5·3± 3·9 h later. In the pregnant cycle birth occurred 26·1±0·2 days after removing the pouch young and was followed 8·0 ± 2·1 h later by oestrus and 16·0± 2·5 h by an LH peak. The latter events thus occurred 3·2 days earlier in the pregnant than in the non-pregnant cycle. Parturition coincided with a very rapid decline in progesterone and a transient high peak of prolactin. In two females sampled less than 25 min after parturition there was a transient peak of PGFM but in all others the concentrations of PGFM remained basal throughout. It is suggested that the fetus and/or placenta is involved in both the premature decline in progesterone and the initiation of parturition and that onset of oestrus and ovulation, being a consequence of a decline in progesterone, are therefore also determined by the fetus.

Oestrous and ovarian activities of Finn-cross ewes during the post-partum and the seasonal anoestrous periods

1984 ◽  
Vol 103 (1) ◽  
pp. 155-160 ◽  
Author(s):  
D. Amir ◽  
Miriam Rosenberg ◽  
H. Schindler
Keyword(s):  
Sexual Activity ◽  
Reproductive Performance ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Ovarian Activity ◽  
Plasma Progesterone ◽  
Oestrus Induction ◽  
Autumn And Winter

SummaryThe seasonal and post-partum oestrus occurrence and ovarian activity, assessed by the plasma progesterone concentrations, were studied in Finn-cross ewes following autumn and winter lambings.The last seasonal oestrous cycle was followed by a silent ovulation in C0% of the Finn × Awassi ewes. Silent ovulations during midanoestrus occurred in 50% of the ewes, and in 90% of the animals a silent ovulation preceded the normal resumption of the seasonal sexual activity.The first post-partum oestrus occurred within C0 days after October lambings in about 90% of the ewes. Silent ovulations before the first post-partum oestrus were evident in 70% of the recycling ewes.It is suggested that breeding ewes with ovarian activity after oestrus induction during anoestrous periods might increase the reproductive performance of the flock in a frequent lambing system.

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.

Reproduction in the pseudomyine rodent Mesembriomys gouldii (Gray) (Muridae)

1969 ◽  
Vol 17 (5) ◽  
pp. 785 ◽  
Author(s):  
EG Crichton
Keyword(s):  
Epithelial Cells ◽  
Litter Size ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Pregnant Female ◽  
Corpora Lutea ◽  
Limited Data ◽  
Unmated Female

M. gouldii is polyoestrous and polyovular. In the non-pregnant female the oestrous cycle is 26 � 3.5 days (range 21-35 days). Mucus appears irregularly during the dioestrous interval and seems to be derived from epithelial cells of the vagina. Ovulation is spontaneous and usually alternate, one to four corpora lutea being formed. The corpora lutea of the unmated female are functional until the 15th-17th day of the cycle. Gestation lasted from 43 to 44 days, a "placental sign" occurring between the 22nd and 33rd day. A post-partum oestrus and mating occur but no delay in implantation was recorded. Litter size ranges from one to three. The young are well developed at birth, and cling tenaciously to the teats for the first few weeks. Growth is rapid and the young can be weaned after 42 days. This pattern of reproduction is compared with the limited data from other Australian Muridae.

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