scholarly journals Skeletal development in the African elephant and ossification timing in placental mammals

2012 ◽  
Vol 279 (1736) ◽  
pp. 2188-2195 ◽  
Author(s):  
Lionel Hautier ◽  
Fiona J. Stansfield ◽  
W. R. Twink Allen ◽  
Robert J. Asher
Keyword(s):  
Skeletal Development ◽  
Loxodonta Africana ◽  
African Elephant ◽  
Gestation Period ◽  
Ossification Centre ◽  
Unique Data ◽  
Gestation Time ◽  
Sequence Method ◽  
Ossification Sequences ◽  
Sequence Heterochrony

We provide here unique data on elephant skeletal ontogeny. We focus on the sequence of cranial and post-cranial ossification events during growth in the African elephant ( Loxodonta africana ). Previous analyses on ossification sequences in mammals have focused on monotremes, marsupials, boreoeutherian and xenarthran placentals. Here, we add data on ossification sequences in an afrotherian. We use two different methods to quantify sequence heterochrony: the sequence method and event-paring/Parsimov. Compared with other placentals, elephants show late ossifications of the basicranium, manual and pedal phalanges, and early ossifications of the ischium and metacarpals. Moreover, ossification in elephants starts very early and progresses rapidly. Specifically, the elephant exhibits the same percentage of bones showing an ossification centre at the end of the first third of its gestation period as the mouse and hamster have close to birth. Elephants show a number of features of their ossification patterns that differ from those of other placental mammals. The pattern of the initiation of the ossification evident in the African elephant underscores a possible correlation between the timing of ossification onset and gestation time throughout mammals.

scholarly journals Luteal maintenance of pregnancy in the African elephant (Loxodonta africana)

Reproduction ◽  
2012 ◽  
Vol 143 (6) ◽  
pp. 845-854 ◽  
Author(s):  
F J Stansfield ◽  
W R Allen
Keyword(s):  
Loxodonta Africana ◽  
Hydroxysteroid Dehydrogenase ◽  
Interstitial Cells ◽  
African Elephant ◽  
Oestrous Cycle ◽  
Degenerative Changes ◽  
Gestation Period ◽  
Placental Lactogen ◽  
Corpora Lutea ◽  
Luteal Cells

The ovaries of eight African elephant foetuses and their mothers between 2 and 22 months of gestation, and those of two cycling and two lactating elephants, were examined grossly, histologically and immunocytochemically, with emphasis on the development and regression of accessory corpora lutea (CL) of pregnancy and the steroidogenic capacities of the accessory CL and the foetal ovaries. The results supported recent findings that the accessory CL form as a result of luteinisation, with and without ovulation, of medium-sized follicles during the 3-week inter-luteal period of the oestrous cycle. They enlarge significantly and become steroidogenically active around 5 weeks of gestation, probably in response to the placental lactogen which is secreted by the implanting trophoblast of the conceptus. The large luteal cells stained strongly for 3β hydroxysteroid dehydrogenase (3βHSD) activity throughout the 22-month gestation period although they showed vacuolation and other degenerative changes in the final months of gestation coincident with hypertrophy and hyperplasia of 3βHSD-positive interstitial cells in the foetal gonads. It is proposed that the progestagens secreted by the enlarged gonads of the elephant foetus may function both to assist the maternal ovaries in supporting the pregnancy state and to induce torpor and intrauterine immobility of the rapidly growing foetus.

Articular cartilage in the knee joint of the African elephant,Loxodonta africana, Blumenbach 1797

2007 ◽  
Vol 269 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Gunter F. Egger ◽  
Kirsti Witter ◽  
Gerald Weissengruber ◽  
Gerhard Forstenpointner
Keyword(s):  
Articular Cartilage ◽  
Knee Joint ◽  
Loxodonta Africana ◽  
African Elephant

scholarly journals Changes in African Elephant (Loxodonta africana) faecal steroid concentrations post-defaecation

Bothalia ◽  
2018 ◽  
Vol 48 (1) ◽  
Author(s):  
Judith T. Webber ◽  
Michelle D. Henley ◽  
Yolanda Pretorius ◽  
Michael J. Somers ◽  
Andre Ganswindt
Keyword(s):  
Reproductive Function ◽  
Loxodonta Africana ◽  
African Elephant ◽  
Sample Collection ◽  
Male And Female ◽  
Freeze Dried ◽  
Metabolite Concentrations ◽  
Endocrine Status ◽  
In The Wild ◽  
Sun And Shade

Background: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection and processing may influence steroid concentrations, as faecal bacterial enzymes can alter steroid composition post-defaecation.Objectives: This study investigated changes in faecal glucocorticoid (fGCM), androgen (fAM) and progestagen (fPM) metabolite concentrations in faeces of a male and female African elephant (Loxodonta africana) post-defaecation and the influence of different faeces-drying regimes.Method: Subsamples of fresh faeces were frozen after being dried in direct sun or shade for 6, 20, 24, 48 and 72 h and 7 and 34 days. A subset of samples for each sex was immediately frozen as controls. Faecal hormone metabolite concentrations were determined using enzyme immunoassays established for fGCM, fAM and fPM monitoring in male and female African elephants.Results: Hormone metabolite concentrations of all three steroid classes were stable at first, but changed distinctively after 20 h post-defaecation, with fGCM concentrations decreasing over time and fPM and fAM concentrations steadily increasing. In freeze-dried faeces fGCM concentrations were significantly higher than respective concentrations in sun-dried material, which were in turn significantly higher than fGCM concentrations in shade-dried material. In contrast, fAM concentrations were significantly higher in sun- and shade-dried faeces compared to freeze-dried faeces. Higher fPM concentrations were also found in air-dried samples compared to lyophilised faeces, but the effect was only significant for sun-dried material.Conclusion: The revealed time restriction for collecting faecal material for hormone monitoring from elephants in the wild should be taken into account to assure reliable and comparable results. However, if logistics allow a timely collection, non-invasive hormone measurement remains a powerful and reliable approach to provide information about an elephant’s endocrine status.

scholarly journals Plasma testosterone levels in relation to musth in the male African Elephant

Koedoe ◽  
1984 ◽  
Vol 27 (1) ◽  
Author(s):  
A.J Hall-Martin ◽  
L.A Van der Walt
Keyword(s):  
National Park ◽  
Loxodonta Africana ◽  
African Elephant ◽  
Plasma Testosterone ◽  
Term Study ◽  
Testosterone Levels ◽  
Long Term Study

A long-term study of the behaviour and ecology of the African elephant Loxodonta africana was begun in the Addo Elephant National Park in 1976. During the period June 1976 to March 1979 regular observations were made on all animals. Every individual elephant could be recognised (the population was less than 100 animals) and every individual was seen several times a month. From the start of the study records were kept of whether the temporal gland was secreting or not for every animal at every observation.

scholarly journals Unilateral phacoemulsification in a captive African elephant (Loxodonta africana)

2020 ◽  
Vol 9 (4) ◽  
pp. 294
Author(s):  
Katherine E.L. Manchip ◽  
Ghislaine Sayers ◽  
John C.M. Lewis ◽  
James W. Carter
Keyword(s):  
Loxodonta Africana ◽  
African Elephant

scholarly journals THE TESTIS OF THE AFRICAN ELEPHANT (LOXODONTA AFRICANA)

Reproduction ◽  
1967 ◽  
Vol 13 (1) ◽  
pp. 11-21 ◽  
Author(s):  
O. W. JOHNSON ◽  
I. O. BUSS
Keyword(s):  
Loxodonta Africana ◽  
African Elephant
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