Geology topics

Karlie K Ditter

Publications and source records attributed to Karlie K Ditter.

5 recordsLinked to original sources

USGS2026

Chronic exposure to waterborne nickel significantly reduced growth of juvenile crayfish (Faxonius virilis)

Crayfish are critical functional components of aquatic ecosystems. Previous research has documented adverse effects of mineral extraction on crayfish. Here, we characterize potential risks of mining-derived waterborne nickel (Ni) to crayfish by documenting the effects of dissolved Ni on growth and food consumption of juvenile virile crayfish ( Faxonius virilis) in a 28-day chronic laboratory exposure. Nominal Ni concentrations ranged from 31.25 to 500 micrograms per liter (µg/L; pH = 7.96 ± 0.20, hardness = 150 ± 1 milligrams per liter as calcium carbonate). Crayfish survival, carapace length, and wet weight were measured. After 28 days of exposure, a 24-h feeding trial was performed to determine differences in food consumption. During the growth trial, 99% of crayfish survived. Change in wet weight and final wet weight were the most sensitive endpoints, with 20% effect concentrations of 24.8 and 22.6 µg/L Ni, respectively. Crayfish exposed to an average of 438 µg/L Ni consumed 41% less, and weighed 65.1% less, than control crayfish. These results suggest chronic, sublethal exposure to waterborne Ni may have negative effects on crayfish growth. Reduced growth and consumption rates in crayfish could have wide-ranging consequences throughout aquatic ecosystems since crayfish are consumers, prey, keystone trophic regulators, and ecosystem engineers. Finally, these results could inform bioenergetics and may be coupled with population models to predict potential changes in population sizes of native and invasive crayfishes.

Ecotoxicology↗

USGS2025

Comparative olfactory and behavioral response of grass carp ( Ctenopharyngodon idella ), bighead carp ( Hypophthalmichthys nobilis ), silver carp ( H. molitrix ) and black carp ( Mylopharyngodon piceus ) to chemical stimuli

Grass carp ( Ctenopharyngodon idella ), bighead carp ( Hypophthalmichthys nobilis ), silver carp (H. molitrix), and black carp ( Mylopharyngodon piceus ), collectively “invasive carp,” represent an ongoing management problem in the Mississippi and Missouri River basins of North America. Development of strategies to control their populations are also ongoing. As a follow-up to previous research, we tested two amino acids and an amino acid-based commercial feeding stimulant as olfactory stimulants that may attract or repel these species. We employed a two-pronged approach to test how invasive carp respond to the olfactory stimulants, using an electro-olfactogram (EOG) to measure olfactory response and a tank with a stimulant in one half to test behavioral response. Consistent with previous research, we found grass carp had a higher magnitude of EOG response to stimulants compared to bighead and, marginally, silver carp. Bighead, silver, and black carp did not differ from each other in EOG response. Grass carp produced significantly greater lysine and a marginally greater alanine EOG response than bighead and silver carp and significantly greater commercial feeding stimulant response than bighead carp. Black carp had marginally greater lysine response than bighead carp. In the behavioral tests, grass carp generally avoided the stimuli tested, while bighead carp were generally attracted to stimuli. Neither black nor silver carp showed a clear attraction or avoidance toward the stimuli tested. To further evaluate these solutions for management applications additional testing in ponds or open water may be necessary.

Management of Biological Invasions↗

USGS2024

Comparative behavioral responses of grass carp (Ctenopharyngodon idella), bighead carp (Hypophthalmichthys nobilis), and silver carp (H. molitrix) to free amino acids in water

Control and elimination of invasive fishes, like carps (Order Cypriniformes), may be possible by using chemical stimuli to congregate them for removal. To this end, we tested behavioral responses of grass ( Ctenopharyngodon idella ), bighead ( Hypophthalmichthys nobilis ), and silver carp ( H. molitrix ) to L-alanine, L-arginine, L-glutamic acid, and L-aspartic acid. In grass carp, the first three amino acids have been shown to be beneficial for growth, and all four produce a strong olfactory response in this species. This study used pairs of conspecific fish in a video-recorded, sound-insulated, clear acrylic, tube-shaped tank; during trials, an amino acid stimulus was delivered at one end of that tank. Changes in space use, velocity, and acceleration across all amino acids differed significantly among species. Changes in space use by grass carp indicated avoidance of only two amino acids, L-alanine and L-aspartic acid. There was no evidence for attraction to amino acids for grass or silver carp. For bighead carp, change in spatial use on exposure to amino acids indicated attraction across the four amino acids. This attraction was enhanced by lowered velocity. Our results suggested that olfactory sensitivity does not directly translate to behavioral responses. Other sensory cues, for example tactile, visual, and/or taste, may mediate the selective foraging of grass carp. Amino acids may serve as a better olfactory attractant for bighead carp compared to grass or silver carp.

Journal of Fish Biology↗

USGS2023

A review of grass carp and related species literature on diet, behavior, toxicology, and physiology focused on informing development of controls for invasive grass carp populations in North America

Grass carp ( Ctenopharyngodon idella ) are globally important in aquaculture and aquatic vegetation control. However, escaped grass carp have established invasive populations. A targeted keyword search was performed on a carp (order: Cypriniformes) literature database maintained by the U.S. Geological Survey to identify literature relevant to grass carp. Additional sources cited in reviewed documents and provided by numerous reviewers were also included. There were three focus areas designed to provide support for invasive grass carp management: (1) diet and behavior; (2) physiological constraints, toxicity, and biology; and (3) gut physiology. Each focus area provides information to guide development of potential pathways for invasive grass carp control. Information from other carp species was used to fill in gaps where grass carp information was lacking and provide additional, potential research directions. Diet-related information included food selection and aquacultural diet formulations. Behavioral information included stimuli and non-physical barriers to attract, repel, or stop movement. Physiological constraints, toxicology, reproductive control, and biological control provide a research review for control options. Gut physiology and related control pathways provide knowledge to improve toxin or pathogen delivery. This review provides a basis for developing approaches and research for controlling invasive grass carp populations, aquaculture, and native population management.

Fishes↗

USGS2023

Herbivorous grass carp (Ctenopharyngodon idella) exhibit greater olfactory response to amino acids than filter-feeding bighead (Hypophthalmichthysnobilis) and silver carp (Hypophthalmichthys molitrix)

Due to their invasiveness in North America, grass ( Ctenopharyngodon idella ), bighead ( Hypophthalmichthys nobilis ), and silver carp ( Hypophthalmichthys molitrix ) are management priorities. Comparing electrophysiological responses to olfactory cues, such as amino acids, could help identify stimuli to facilitate management efforts (i.e., repellants or baits). We assessed olfactory response magnitude to individual amino acids between fish species and amino acids using electro-olfactogram recording techniques (EOG). We measured EOG responses (peak EOG magnitude) of juvenile grass ( n = 21), bighead ( n = 21), and silver carp ( n = 22) to 10 −4 molar amino acid solutions containing one of L-alanine, L-arginine, L-aspartic acid, L-asparagine, L-glutamine, or L-glutamic acid. Amino acid EOG responses differed across species; grass carp had the greatest mean EOG response. Statistical analyses showed no inter- or intra-specific differences in EOG response among amino acids. The greater EOG response of grass carp matched their selective grazing habits compared to more passive, generalist-tending, filter-feeding bighead and silver carp. All amino acids elicited significant EOG responses in all species, meaning they are candidates for future behavioral research. Such research could explore the management potential of amino acids, testing if amino acids are attractants or deterrents that could facilitate the removal of these fish by congregating and/or directing movement.

Fishes↗