Food Preferences, Food Intake, and Growth of the F\u3csub\u3e1\u3c/sub\u3e Hybrid of Grass Carp ♀ X Bighead Carp ♂

Hybrid carp from the cross grass carp Ctenopharyngodon idella ♀ X bighead carp Aristichthys nobilis ♂ preferred filamentous algae and Najas guadalupensis over Ceratophyllum demersum. Medium-sized (273 g) and large hybrids (360 g) consumed more plant material and grew faster than small hybrids (77 g) at 14 and 22 C in aquaria. Aquarium data suggest that it will require at least twice as many hybrids as grass carp of the same size to obtain the same level of vegetation control

Operational Comparison of Three Electrofishing Systems

Three different electrofishing systems were compared to determine their relative efficiency with respect to species and numbers of fish collected. These results indicated that modifications or changes in electrofishing gear during a monitoring program should not be made unless it can be demonstrated that collecting efficiency is not altered

Accuracy and Precision of Age Estimates for Pallid Sturgeon from Pectoral Fin Rays

Accurate age information is critical to the biological understanding and management of most fish species, but particularly for species of concern, such as the pallid sturgeon Scaphirhynchus albus. The accuracy and precision of pallid sturgeon age estimates from pectoral fin ray sections has never been established, yet all accumulated age information for the species was collected using this technique. To examine the accuracy and precision of age estimates, 16 pectoral fin ray samples from age-6 pallid sturgeon were obtained from Gavins Point National Fish Hatchery, South Dakota. The fin rays were sectioned, mounted, and independently examined twice by each of two readers. Only 28.1% of the age estimates accurately reflected the known age of the fish. Multiple readings of the same sample by the same reader (within-reader precision) only agreed 25% of the time, differences being as great as 5 years between the two estimates. Between-reader agreement was 46.9%, the two readers\u27 estimates of the same fish differing by as much as 2 years. Because of low accuracy and precision, estimated ages from pallid sturgeon pectoral fin rays should be viewed with caution

Plasma-binding globulins and acute stress response

Within studies of acute stress physiology an increase in glucocorticoid secretion is thought to be the primary mediator of tissue response to stress. Corticosteroid-binding globulin may regulate tissue availability of steroids, but has not been considered a dynamic component of the acute stress response. Here, we examined CBG level over the common 60-minute time frame in an acute capture and handling protocol to investigate whether CBG capacity is dynamic or static over short stressors. Using a comparative approach, we measured CBG response to capture and handling stress in nine species of birds, representing five orders and nine families. CBG capacity significantly declined within 30-60 minutes of capture in five of the nine species examined. This decline may serve to significantly increase the level of corticosterone reaching tissues during acute stress. © Georg Thieme Verlag KG Stuttgart

Plasma-binding globulins and acute stress response

Within studies of acute stress physiology an increase in glucocorticoid secretion is thought to be the primary mediator of tissue response to stress. Corticosteroid-binding globulin may regulate tissue availability of steroids, but has not been considered a dynamic component of the acute stress response. Here, we examined CBG level over the common 60-minute time frame in an acute capture and handling protocol to investigate whether CBG capacity is dynamic or static over short stressors. Using a comparative approach, we measured CBG response to capture and handling stress in nine species of birds, representing five orders and nine families. CBG capacity significantly declined within 30-60 minutes of capture in five of the nine species examined. This decline may serve to significantly increase the level of corticosterone reaching tissues during acute stress. © Georg Thieme Verlag KG Stuttgart

Continuous grid monitoring to optimize sedimentation management

Fluves and GTC monitor since November 2015 continuously a sediment trap with dimensions 200 x 20 meters managed by the Flemish Environmental Agency (VMM) in Belgium. The continuous follow-up of sedimentation of the trap provides insights on temporal and spatial evolution of trapping efficiency. VMM will use the insights to optimize operational dredging decisions and for optimizing the design of future traps. The installed measuring system is based on distributed temperature sensing with a fiber optic cable of more than 2 km. A digital terrain model (DTM) of the sediment trap is transmitted to the client on a hourly to daily basis. Results after winter floods from November 2015 till February 2016 show a significant spatial variation in sedimentation through the sedimentation trap. Also, zones with different temporal evolution of filling of the trap could be observed. The technique shows great potential for detailed spatial and temporal observation of sedimentation processes in large areas, as well as the ability to detect thin sedimentation layers