Observations on the Tasmanian Devil, Sarcophilus harrisii (Marsupialia : Dasyuridae) II. Reproduction, breeding and growth of pouch young

1970 ◽  
Vol 18 (1) ◽  
pp. 63 ◽  
Author(s):  
ER Guiler
Keyword(s):  
Sex Ratio ◽  
Reproductive Potential ◽  
Tasmanian Devil ◽  
Embryonic Diapause ◽  
Time Of Breeding ◽  
Young Stage ◽  
Poor Recruitment ◽  
The Mean ◽  
The Devil ◽  
Sarcophilus Harrisii

The Tasmanian devil, S. harrisii, is polyovular and monoestrus and embryonic diapause was not found. The mean number of pouch young for 69 litters was found to be 2.95. The number of young in a litter varies with the age of the mother. More young are born than can be accommodated in the pouch. The time of breeding varies from year to year, mating taking place in March. The percentage of breeding females varies annually as well as from place to place, being found to be as low as 31 % in one area. The devil has a high reproductive potential because there are no losses at the pouch-young stage. This is offset by poor recruitment of juveniles into the population. Pseudopregnancy was found to occur. The sex ratio of both pouch young and adults favoured the female. The development and growth of the young is described.

scholarly journals Curse of the devil: molecular insights into the emergence of transmissible cancers in the Tasmanian devil (Sarcophilus harrisii)

2020 ◽  
Vol 77 (13) ◽  
pp. 2507-2525 ◽  
Author(s):  
Amanda L. Patchett ◽  
Andrew S. Flies ◽  
A. Bruce Lyons ◽  
Gregory M. Woods
Keyword(s):  
Tasmanian Devil ◽  
The Devil ◽  
Sarcophilus Harrisii

scholarly journals Relict or reintroduction? Genetic population assignment of three Tasmanian devils ( Sarcophilus harrisii ) recovered on mainland Australia

2017 ◽  
Vol 4 (4) ◽  
pp. 170053 ◽  
Author(s):  
Lauren C. White ◽  
Jeremy J. Austin
Keyword(s):  
Tasmanian Devil ◽  
Nucleotide Polymorphisms ◽  
Genetic Population ◽  
Single Nucleotide ◽  
Mainland Population ◽  
Devil Facial Tumour Disease ◽  
Eastern Australia ◽  
The Devil ◽  
Disease Free ◽  
Sarcophilus Harrisii

Today, the Tasmanian devil ( Sarcophilus harrisii ) is found only on the island of Tasmania, despite once being widespread across mainland Australia. While the devil is thought to have become extinct on the mainland approximately 3000 years ago, three specimens were collected in Victoria (south-eastern Australia) between 1912 and 1991, raising the possibility that a relict mainland population survived in the area. Alternatively, these devils may have escaped captivity or were deliberately released after being transported from Tasmania, a practice that has been strictly controlled since the onset of devil facial tumour disease in the early 1990s. Such quarantine regimes are important to protect disease-free, ‘insurance populations’ in zoos on the mainland. To test whether the three Victorian devils were members of a relict mainland population or had been recently transported from Tasmania we identified seven single nucleotide polymorphisms (SNPs) in the mitochondrial genome that can distinguish between Tasmanian and ancient mainland populations. The three Victorian devil specimens have the same seven SNPs diagnostic of modern Tasmanian devils, confirming that they were most likely transported from Tasmania and do not represent a remnant population of mainland devils.

Development and evaluation of electroejaculation techniques in the Tasmanian devil (Sarcophilus harrisii)

2012 ◽  
Vol 24 (7) ◽  
pp. 1008 ◽  
Author(s):  
T. Keeley ◽  
M. Harris ◽  
P. D. McGreevy ◽  
D. Hudson ◽  
J. K. O'Brien
Keyword(s):  
Diurnal Variation ◽  
Reproductive Potential ◽  
Serum Testosterone ◽  
Serum Cortisol ◽  
Tasmanian Devil ◽  
Sperm Cryopreservation ◽  
Wildlife Species ◽  
Cryopreservation Techniques ◽  
Episodic Fluctuations ◽  
Sarcophilus Harrisii

Electroejaculation (EEJ) has been used successfully to collect samples suitable for genome resource banking from a variety of endangered wildlife species. Ejaculates can also be used to evaluate the reproductive potential of individuals and provide information on seminal characteristics to aid in the development of sperm cryopreservation techniques. Electroejaculation techniques used for marsupial and eutherian species were tested on Tasmanian devils (n = 35). Spermic ejaculates were collected in 54% (19/35) of EEJ attempts. Spermic ejaculates were low in volume (3.9 ± 6.5 × 102 µL, range 10–3000 µL) and contained low numbers of spermatozoa (3.3 ± 7.8 × 103 spermatozoa per ejaculate, range 6–33 000). The osmolality and pH of presumptive urine-free ejaculates were 389 ± 130 mOsm kg–1 (range 102–566) and 7.0 ± 0.9 (range 6.0–8.0), respectively. Prostatic bodies were observed in 79% (26/33) of ejaculates. Episodic fluctuations in serum testosterone concentrations were not detected during the EEJ procedure (P > 0.05). Increases observed in serum cortisol concentrations during EEJ were less (P < 0.05) than those observed after an adrenalcorticotropic hormone challenge and diurnal variation suggested that cortisol concentrations are greater during the day than at night (P < 0.05). This information can be used to provide range values for the future examination of basic endocrine responses and the adrenal–pituitary axis of this species. This study also demonstrated that spermatozoa-rich devil electroejaculates are more difficult to obtain and poorer in quality than those of other marsupials.

Parasitization of Helicoverpa zea (Lepidoptera: Noctuidae) by Palexorista laxa (Diptera: Tachinidae): Influence of Host Developmental Stage on Host Suitability and Progeny Production

1992 ◽  
Vol 27 (2) ◽  
pp. 164-171
Author(s):  
W. R. Martin ◽  
Donald A. Nordlund ◽  
William C. Nettles
Keyword(s):  
Sex Ratio ◽  
Developmental Stage ◽  
Helicoverpa Zea ◽  
Developmental Stages ◽  
Reproductive Potential ◽  
Host Suitability ◽  
Progeny Production ◽  
Adult Parasitoid ◽  
The Mean ◽  
Lepidoptera Noctuidae

Palexorista laxa (Curran) (Diptera: Tachinidae) successfully parasitized 2nd through 5th instars and prepupal Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in the laboratory. Percent successful parasitization (that which resulted in the production of adult parasitoid progeny) increased with host developmental stage, reaching 97% in 5th instars, but fell to 75% in prepupae. The mean number of fly puparia and adults produced per successfully parasitized larva was greatest in 5th instar hosts, reaching 7.8 ± 0.6 (SEM) and 5.5 ± 0.4, respectively. The sex ratio of adult parasitoid progeny per host larval stadium was variable. Host favorability indices were calculated for each host stadium, and was highest in 5th instars. This index allows a direct comparison of the overall impact and reproductive potential of P. laxa attacking hosts of varying developmental stages.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

The Status of the School Shark Fishery in South-Eastern Australian Waters

1959 ◽  
Vol 10 (2) ◽  
pp. 150 ◽  
Author(s):  
AM Olsen
Keyword(s):  
Maximum Yield ◽  
Reproductive Potential ◽  
South Australia ◽  
Slow Growth Rate ◽  
South Eastern ◽  
Pregnant Females ◽  
The Status ◽  
History Of ◽  
Annual Total ◽  
The Mean

The maximum yield of the school shark fishery in south-eastern Australian waters was 4.09 million lb in 1949. The catch has fluctuated since then about a declining trend to 3.18 million lb in 1956. In 1944, 7.3 hooks were required to catch a shark of mean weight 14.7 lb. In 1956 the number of hooks required was almost doubled: 13.6 hooks were needed to catch sharks of mean weight 13.7 lb; the catch per hook dropped from 2.01 to 0.99 lb. Whereas the catch per boat-month remained relatively stable at 4765 lb for 1944 and 4643 for 1956, the number of hooks used per boat-month increased from 2366 to 4668 hooks in 12 years. Throughout this period the mean weight of sharks in eastern Bass Strait remained fairly steady (11-13 lb) whereas there was a drop of 3 lb from a mean weight of 17-20 lb in the predominantly mature portion of the stock in western Bass Strait. Fishermen in South Australia have reported a comparable drop in the mean weight of sharks in their catches. During the period 1941-46 there was unrestricted inshore fishing of juveniles and pregnant females with a consequent severe drop in the inshore population. The subsequent decline in the annual total catch is believed to be due not only to a too intensive offshore fishery but also to the resultant reduced recruitment and depressed reproductive potential caused by the earlier destruction of juveniles and pregnant females. In the data presented in this paper there is evidence that the school shark fishery, which is operating on a single stock of sharks with a slow growth rate, a late sexual maturity, and a low fecundity, shows trends which are suggestive of depletion. Because similar trends in the soupfin shark fishery of California and in the dogfish fishery of British Columbia were followed by depletion, it has been inferred that regulations to protect the vulnerable phases of the life history of the school shark of Australia may be required. Measures for conservation are discussed.

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.

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.

scholarly journals Biology and parasitic potential of Doryctobracon areolatuson Anastrepha fraterculus larvae

2011 ◽  
Vol 46 (6) ◽  
pp. 669-671 ◽  
Author(s):  
Adrise Medeiros Nunes ◽  
Dori Edson Nava ◽  
Fernanda Appel Müller ◽  
Rafael da Silva Gonçalves ◽  
Mauro Silveira Garcia
Keyword(s):  
Biological Control ◽  
Sex Ratio ◽  
Adult Emergence ◽  
Parasitism Rate ◽  
Anastrepha Fraterculus ◽  
The Mean ◽  
Parasitoid Development

The objective of this work was to study the biology and parasitic potential of Doryctobracon areolatus on larvae of Anastrepha fraterculus. The egg-adult period, the sex ratio, the longevity, the pupal viability, and the parasitism rate of D. areolatus were determined in laboratory, using A. fraterculus as host. The parasitoid development from oviposition to adult emergence required 25.00±1.70 days, the sex ratio was 0.62±0.09, and the mean longevity was 16.36±3.62 days for males and 10.24±1.71 days for females. The mean parasitism rate was 53.50±8.93%, varying from 41.60 to 68.60%, which shows the potential of this parasitoid for biological control of A. fraterculus.

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