Use of behavioral and physiological indicators to evaluate Scaphirhynchus sturgeon spawning success

Abstract

Thirty gravid, female shovelnose sturgeon (Scaphirhynchus platorynchus) were captured in the Lower Missouri River in March 2004 to evaluate the effectiveness of physiology, telemetry and remote sensor technology coupled with change point analysis in identifying when and where Scaphirhynchus sturgeon spawn. Captured sturgeons were instrumented with ultrasonic transmitters and with archival data storage tags (DST) that recorded temperature and pressure. Female sturgeon were tracked through the suspected spawning period. Thereafter, attempts were made to recapture fish to evaluate spawning success. At the time of transmitter implantation, blood and an ovarian biopsy were taken. Reproductive hormones and cortisol were measured in blood. Polarization indices and germinal vesicle breakdown were assessed on the biopsied oocytes to determine readiness to spawn. Behavioral data collected using telemetry and DST sensors were used to determine the direction and magnitude of possible spawningrelated movements and to identify the timing of potential spawning events. Upon recapture observations of the ovaries and blood chemistry provided measures of spawning success and comparative indicators to explain differences in observed behavior. Behavioral and physiological indicators of spawning interpreted along with environmental measures may assist in the determination of variables that may cue sturgeon reproduction and the conditions under which sturgeon successfully spawn.

A comparison of gastrically and surgically implanted telemetry transmitters in shovelnose sturgeon

“…Surgical transmitter implantation is the most common method used for transmitter implantation for pallid and shovelnose sturgeon (Quist et al 1999;Bramblett & White 2001;Hurley et al 2004;Jordan et al 2006;Delonay et al 2007). Surgical transmitter retention rate in this study was 100%.…”

Range-wide age and growth characteristics of shovelnose sturgeon from mark–recapture data: implications for conservation and management

“…The spatial extent that shovelnose sturgeon complete all or portions of their life history is not well understood. However, long-distance migrations of shovelnose sturgeon are common (DeLonay et al 2007), and previous research suggests that fish movement plays an important role in transporting different life stages across various landscape scales to occupy suitable habitats that are required to fulfill their life cycle (Schlosser and Angermeier 1995). Schrey et al (2009) collected genetic samples of shovelnose sturgeon from seven different geographic locations to determine the geographic stock structure.…”

Spatiotemporal variation in flow-dependent recruitment of long-lived riverine fish: Model development and evaluation

“…River hydrology has been hypothesized to play a critical role in fish spawning behavior and larval survival (e.g., DeLonay et al, 2007;Peterson and Kwak, 1999;Phelps et al, 2010). Field studies suggest that hydrological conditions such as flow and connectivity appear to drive spawning behavior (e.g., migration and congregation) of shovelnose sturgeon ), but other environmental cues such as water temperature and photoperiod or internal biological rhythms may be equally important for spawning events .…”