Physical and hormonal examination of Missouri River shovelnose sturgeon reproductive stage: a reference guide

Abstract

conducted monthly sampling of Lower Missouri River shovelnose sturgeon (Scaphirhynchus platorynchus) to develop methods for determination of sex and the reproductive stage of sturgeons in the field. Shovelnose sturgeon were collected from the Missouri River and ultrasonic and endoscopic imagery and blood and gonadal tissue samples were taken. The full set of data was used to develop monthly reproductive stage profiles for S. platorynchus that could be compared to data collected on pallid sturgeon (Scaphirhynchus albus). This paper presents a comprehensive reference set of images, sex steroids, and vitellogenin (VTG, an egg protein precursor) data for assessing shovelnose sturgeon sex and reproductive stage. This reference set includes ultrasonic, endoscopic, histologic, and internal images of male and female gonads of shovelnose sturgeon at each reproductive stage along with complementary data on average 17-b estradiol, 11-ketotestosterone, VTG, gonadosomatic index, and polarization index.

Reproductive biology of middle Mississippi River shovelnose sturgeon: insights from seasonal and age variation in plasma sex steroid and calcium concentrations

“…Changes in E2 concentrations among reproductive stages similar to those we observed have been described for other species of sturgeon and other shovelnose sturgeon populations, including female shovelnose sturgeon from the lower Missouri River (Amiri et al, 1996b;Barannikova et al, 2000;Barannikova et al, 2002;Barannikova et al, 2004;Bayunova et al, 2003;Wildhaber et al, 2007;Van Eenennaam et al, 1996).…”

“…Plasma sex steroid, vitellogenin (VTG, an egg protein precursor), and calcium profiles have provided valuable insights into the reproductive cycles of sturgeon populations (e.g., Amiri et al, 1996a;Van Eenennaam et al, 1996;Barannikova et al, 2000Barannikova et al, , 2004Ceapa et al, 2002;Wildhaber et al, 2006Wildhaber et al, , 2007. Plasma VTG binds free calcium (Ca 2+ ) in fish, triggering mobilization of body Ca 2+ reserves or increased Ca 2+ uptake from the water for maintenance of osmotoic balance (Linares-Casenave, 1993).…”

Evaluation of Reproductive Status in Atlantic Tripletail by Traditional and Nonlethal Approaches

“…Female tripletail VTG levels were generally greater than concentrations reported in spawning female Shovelnose Sturgeon Scaphirhynchus platorynchus (~400 µg/ mL; Wildhaber et al 2007). Increased VTG levels are not always clear indicators of the temporal and spatial distribution of spawning fish, but they can be used as a line of evidence for elucidating reproductive activities (Ceapa et al 2002).…”

“…Gonad histology and GSI analyses require sacrifice of the fish, and nonlethal alternatives for determining reproductive status are desired for rare species or those for which definitive population dynamics data are lacking or scarce, such as Atlantic Tripletail. Nonlethal methods have been used to determine the reproductive status of other fish species and have included the evaluation of blood plasma for the egg yolk precursor, vitellogenin (VTG; Heppell and Sullivan 2000;Ceapa et al 2002;Wildhaber et al 2007;Heise et al 2009). Vitellogenin is found at highest concentrations during the final oocyte maturation phase in most fishes; therefore, VTG can be an effective tool for determining sex and, in some cases, reproductive phase, although increased VTG levels are not always indicative of spawning locations (Heppell and Sullivan 2000;Ceapa et al 2002;Wildhaber et al 2007;Heise et al 2009).…”

Hierarchical Bayesian Markov Switching Models with Application to Predicting Spawning Success of Shovelnose Sturgeon

“…Specifically, data were collected in the early spring of 2004, 2005 and 2006 on female gravid shovelnose sturgeon at reproductive stage V (females at this reproductive stage indicate readiness to spawn); the reproductive stage was determined by using non-invasive methods (e.g. Wildhaber et al (2007)). On capture several biological measures were collected: standard length sl (mm), fork length fl (mm), weight wt (kg), polarization index PI, oestradiol level cape2 (pg ml −1 ), 11-ketotestosterone level cape11kt (pg ml −1 ) and cortisol level capc (ng ml −1 ).…”