Serum concentrations of reproductively-related circulating steroid hormones in the free-ranging lemon shark,Negaprion brevirostris

1993 ◽  
Vol 38 (1-3) ◽  
pp. 167-174 ◽  
Author(s):  
Lois E. L. Rasmussen ◽  
Samuel H. Gruber
Keyword(s):  
Steroid Hormones ◽  
Serum Concentrations ◽  
Lemon Shark ◽  
Negaprion Brevirostris ◽  
Free Ranging

scholarly journals Assortative interactions and leadership in a free-ranging population of juvenile lemon shark Negaprion brevirostris

2011 ◽  
Vol 423 ◽  
pp. 235-245 ◽  
Author(s):  
TL Guttridge ◽  
SH Gruber ◽  
JD DiBattista ◽  
KA Feldheim ◽  
DP Croft ◽  
...  
Keyword(s):  
Lemon Shark ◽  
Negaprion Brevirostris ◽  
Free Ranging

Long-term studies of Serum Concentrations of reproductively related Steriod Hormones in individual captive Carcharhinids

1992 ◽  
Vol 43 (1) ◽  
pp. 273 ◽  
Author(s):  
LEL Rasmussen ◽  
FL Murru
Keyword(s):  
Steroid Hormones ◽  
Mature Female ◽  
Serum Concentrations ◽  
Carcharhinus Plumbeus ◽  
Short Term ◽  
Serum Samples ◽  
Negaprion Brevirostris ◽  
Serial Serum ◽  
Long Term Studies

Valuable information on maturity and reproductive status can be obtained by the measurement of the concentrations of steroid hormones in the serum of captive carcharhinid sharks. The sharks at Sea World of Florida, Orlando, Florida, include mature females of several species of placental sharks. Serial serum samples from four mature female Carcharhinus plumbeus, one maturing female C. leucas, and one mature and one nearly mature female Negaprion brevirostris were used to determine serum concentrations of 17�-oestradiol, progesterone, testosterone and dihydrotestosterone. The data from these mature placental sharks were then compared with concentrations measured in immature female and male conspecifics and in mature female Eugomphodus taurus (family Odontaspididae). Evidence of repetitive cyclical patterns was obtained from a mature female N. brevirostris. This shark was monitored from June 1988 to July 1990 by means of more than 50 samples that were often obtained at weekly intervals. Concentrations of 17�-oestradiol in the serum of this shark varied in a cyclical fashion, with the highest values obtained in Year 1 (1988-89) being during April (the normal mating season) and those in Year 2 (1989-90) being during June. Concomitant elevations of testosterone concentrations were observed either simultaneously or immediately before or after maximal oestradiol concentrations were noted. Progesterone concentrations were low except for definitive spikes that immediately preceded the maximal concentrations of testosterone and 17�-oestradiol. These periodicities suggest, for placental sharks, that consistently rising oestradiol concentrations may set in motion preovulatory events, that testosterone may be important for the initiation of subsequent ovulatory events, and that transitory elevations of progesterone concentrations may have specific short-term roles. These cyclical changes in the concentrations of steroid hormones observed in captive elasmobranchs support observations of hormone concentrations during reproduction in wild carcharhinids.

scholarly journals Small Blubber Samples (50 mg) Sufficient for Analyses of 10 Stress and Reproductive Steroid Hormones in Gray and Fin Whales via Liquid Chromatography Mass Spectrometry

2022 ◽  
Vol 8 ◽  
Author(s):  
Christiana Wittmaack ◽  
Jorge Urbán Ramírez ◽  
Daniela Bernot-Simon ◽  
Sergio Martínez-Aguilar ◽  
Seenivasan Subbiah ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Steroid Hormones ◽  
Endogenous Hormones ◽  
Tissue Mass ◽  
Fin Whale ◽  
Calibration Methods ◽  
Fin Whales ◽  
Fitness And Health ◽  
Free Ranging

Information on stress, reproductive fitness, and health is difficult to obtain in wild cetaceans but critical for conservation and management. The goal of this study was to develop a methodology requiring minimal blubber mass for analysis of reproductive and stress steroid hormones and, hence, suitable for cetacean biopsies. Blubber biopsies and samples were collected from free-ranging and stranded gray and fin whales. Steroid hormones were extracted from blubber samples as small as 50 mg using liquid-liquid extraction methodology developed to handle the high fat content of blubber. Samples were analyzed via liquid chromatography with tandem mass spectrometry for 10 hormones: aldosterone, androstenedione, cortisol, cortisone, corticosterone, 17β-estradiol, estrone, 17α-hydroxyprogesterone, progesterone, and testosterone. As part of the optimization, homogenization via bead beating and blade dispersion were compared, and the former found superior. To investigate optimal yet minimal tissue mass required, hormone panels were compared among paired 50, 150, and 400 mg samples, the latter two being commonly reported masses for hormone blubber analysis. Results indicated that 50 mg of blubber was suitable and sometimes superior. Additionally, significant differences in precision values were observed between species, possibly stemming from differences in blubber composition, and relevant to homogenization technique selection and calibration methods that use blubber matrix matches obtained from a species other than the study species. Based on recovery and precision values, our methodology was accurate and precise in the measurement of spiked known quantities for all 10 hormones, confirming the methodology capabilities in 50 mg blubber mass in both species. Altogether, and in our specific sample sets, all endogenous hormones, except corticosterone, were identified above the detection limit in 50 mg gray whale blubber samples while all endogenous hormones, except aldosterone, cortisone, estrone, and progesterone, were detected in 50 mg fin whale blubber samples. We present a robust methodology for the analysis of multiple reproductive and stress steroid hormones in minimal masses of cetacean blubber compatible with small biopsies. Finally, we identified statistically significant differences in corticosteroid concentrations between stranded and free ranging animals.

Anatomy of the feeding apparatus of the lemon shark,Negaprion brevirostris

1995 ◽  
Vol 226 (3) ◽  
pp. 309-329 ◽  
Author(s):  
Philip J. Motta ◽  
Cheryl A. D. Wilga
Keyword(s):  
Feeding Apparatus ◽  
Lemon Shark ◽  
Negaprion Brevirostris

Serum 25-hydroxyvitamin D Concentrations in Captive and Free-ranging, White-tailed Deer (Odocoileus virginianus)

2009 ◽  
Vol 79 (3) ◽  
pp. 180-187 ◽  
Author(s):  
W. Ray Waters ◽  
Brian J. Nonnecke ◽  
Samantha E. J. Gibbs ◽  
Michael J. Yabsley ◽  
Stephen M. Schmitt ◽  
...  
Keyword(s):  
Metabolic Disease ◽  
Odocoileus Virginianus ◽  
Seasonal Variations ◽  
Additional Research ◽  
Serum Concentrations ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Free Ranging ◽  
Low Serum

Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were determined for free-ranging and captive white-tailed deer (WTD). Effects of gender, season, and age on 25(OH)D concentrations were determined as well as comparisons to concentrations in serum from captive reindeer and elk. Seasonal variations in 25(OH)D concentrations were detected for both captive and free-ranging WTD with greatest concentrations detected in August/September (~ 25 ng/mL) and lowest concentrations in February (~ 5 – 10 ng/mL). Free-ranging WTD < 1 year of age had lower 25(OH)D concentrations (~ 6 ng/mL) than did free-ranging WTD > 1 year of age (~ 12 ng/mL). For captive WTD fawns, 25(OH)D concentrations increased from 1 to 9 days of age (exceeding 100 ng/mL) and then steadily declined to ~ 10 ng/mL by 3 months of age. In general, differences in 25(OH)D concentrations based on gender were not detected. 25(OH)D concentrations in captive WTD did not differ from that of captive reindeer; yet, 25(OH)D concentrations were lower in WTD than in captive elk. Additional research is necessary to determine if low serum 25(OH)D concentrations during the winter or pre-weaning period are associated with increased rates of infectious and metabolic disease.

RECONSTRUCTION OF PARENTAL MICROSATELLITE GENOTYPES REVEALS FEMALE POLYANDRY AND PHILOPATRY IN THE LEMON SHARK, NEGAPRION BREVIROSTRIS

Evolution ◽  
2004 ◽  
Vol 58 (10) ◽  
pp. 2332 ◽  
Author(s):  
Kevin A. Feldheim ◽  
Samuel H. Gruber ◽  
Mary V. Ashley
Keyword(s):  
Lemon Shark ◽  
Negaprion Brevirostris
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