Extreme olfactory sensitivity of silver and bighead carp to overlapping suites of 21-carbon steroids suggests that these species, and likely all other Cyprinoidei, employ them as pheromones.

Although well established that several fishes including goldfish in the suborder Cypinoidei within the family Cypriniformes use the maturation-inducing steroid 17,20β-dihydroxy-pregn-4-ene-3-one (17,20βP) and its metabolites as a priming pheromone which they detect with sensitivity and specificity, it is unclear whether and how other Cypriniformes might have evolved to do so. This study examined this question in the family Xenocyprididae. Using electro-olfactogram recording we tested the olfactory sensitivity of silver (Hypophthalmichthys molitrix) and bighead carp (H.

Spinal Manipulative Therapy for Nonspecific Low Back Pain: Does Targeting a Specific Vertebral Level Make a Difference?: A Systematic Review With Meta-analysis.

We aimed to examine whether targeting spinal manipulative therapy (SMT), by applying the intervention to a specific vertebral level, produces superior clinical outcomes than a nontargeted approach in patients with nonspecific low back pain. Systematic review with meta-analysis. MEDLINE, Embase, CENTRAL, CINAHL, Scopus, PEDro, and Index to Chiropractic Literature were searched up to May 31, 2023.

Hormonal Prostaglandin F2α Mediates Behavioral Responsiveness to a Species-Specific Multi-component Male Hormonal Sex Pheromone in a Female Fish.

Although hormonally-derived female sex pheromones have been well described in approximately a dozen species of teleost fish, only a few male sex pheromones have been characterized and the neuroendocrine underpinnings of behavioral responsiveness to them is not understood. Herein, we describe a study that addresses this question using the goldfish, Carassius auratus, an important model species of how hormones drive behavior in egg-laying teleost fishes. Our study had four components.

Nonlinear relationship between Silver Carp density and their eDNA concentration in a large river.

Although environmental DNA (eDNA) is increasingly being used to survey for the presence of rare and/or invasive fishes in aquatic systems, the utility of this technique has been limited by a poor understanding of whether and how eDNA concentrations relate to fish density, especially in rivers. We conducted a field study to systematically test whether the eDNA released by a model invasive fish, Silver Carp (Hypophthalmichthys molitrix), was related to the density of this species in a large river. We quantified fish density throughout the 460 km long Illinois River using hydroacoustic surveys at 23 sites while concurrently collecting 192 surface water samples for eDNA analysis.

Attracting Common Carp to a bait site with food reveals strong positive relationships between fish density, feeding activity, environmental DNA, and sex pheromone release that could be used in invasive fish management.

Measurement of environmental DNA (eDNA) is becoming a common technique to survey for rare and invasive fish due to its sensitivity and specificity. However, its utility is limited by an incomplete understanding of factors governing its sources and fates. Failure to detect eDNA is especially difficult to interpret so surveillance techniques often collect large numbers of samples across broad regions.

High levels of circulating prostaglandin F associated with ovulation stimulate female sexual receptivity and spawning behavior in the goldfish (Carassius auratus).

This study tested the hypothesis that blood-borne prostaglandin F (PGF) produced at the time of ovulation by female goldfish, a typical scramble-spawning, egg-laying cyprinid fish, functions as a hormone which stimulates female sexual receptivity, behavior, and pheromone release, thereby synchronizing female mating behavior with egg availability. We conducted 5 experiments. First, we tested whether PGF is found in the blood of female fish and if it increases at the time of ovulation.

The Chemical Sensitivity and Electrical Activity of Individual Olfactory Sensory Neurons to a Range of Sex Pheromones and Food Odors in the Goldfish.

Although it is well established that the olfactory epithelium of teleost fish detects at least 6 classes of biologically relevant odorants using 5 types of olfactory sensory neurons (OSNs), little is understood about the specificity of individual OSNs and thus how they encode identity of natural odors. In this study, we used in vivo extracellular single-unit recording to examine the odor responsiveness and physiological characteristics of 109 individual OSNs in mature male goldfish to a broad range of biological odorants including feeding stimuli (amino acids, polyamines, nucleotides), sex pheromones (sex steroids, prostaglandins [PGs]), and a putative social cue (bile acids). Sixty-one OSNs were chemosensitive, with over half of these (36) responding to amino acids, 7 to polyamines, 7 to nucleotides, 5 to bile acids, 9 to PGs, and 7 to sex steroids.

Silver, bighead, and common carp orient to acoustic particle motion when avoiding a complex sound.

Behavioral responses of silver carp (Hypopthalmichthys molitrix), bighead carp (H. nobilis), and common carp (Cyprinus carpio) to a complex, broadband sound were tested in the absence of visual cues to determine whether these species are negatively phonotaxic and the roles that sound pressure and particle motion might play mediating this response. In a dark featureless square enclosure, groups of 3 fish were tracked and the distance of each fish from speakers and their swimming trajectories relative to sound pressure and particle acceleration were analyzed before, and then while an outboard motor sound was played.

Chemical Cues which Include Amino Acids Mediate Species-Specific Feeding Behavior in Invasive Filter-Feeding Bigheaded Carps.

This study tested whether and how dissolved chemicals might assist food recognition in two filter-feeding fishes, the silver (Hypophthalmichthys molitrix) and the bighead carp (H. nobilis). These species evolved in Asia, are now invasive in the Mississippi River, and feed voraciously on microparticles including plankton.

Environment shapes the fecal microbiome of invasive carp species.

Background: Although the common, silver, and bighead carps are native and sparsely distributed in Eurasia, these fish have become abundant and invasive in North America. An understanding of the biology of these species may provide insights into sustainable control methods. The animal-associated microbiome plays an important role in host health.

Theory and Application of Semiochemicals in Nuisance Fish Control.

Controlling unwanted, or nuisance, fishes is becoming an increasingly urgent issue with few obvious solutions. Because fish rely heavily on semiochemicals, or chemical compounds that convey information between and within species, to mediate aspects of their life histories, these compounds are increasingly being considered as an option to help control wild fish. Possible uses of semiochemicals include measuring their presence in water to estimate population size, adding them to traps to count or remove specific species of fish, adding them to waterways to manipulate large-scale movement patterns, and saturating the environment with synthesized semiochemicals to disrupt responses to the natural cue.

Invasive Bighead and Silver Carps Form Different Sized Shoals that Readily Intermix.

Two species of congeneric filter-feeding microphagous carps from Asia, the bighead and the silver carp, were recently introduced to North America and have become highly invasive. These species of carp have similar food habits but the silver carp has the unique habit of jumping when disturbed. Both species have complex but poorly understood social behaviors and while both are thought to aggregate (form groups) and shoal (form tight social groups), this possibility has not yet been examined in these species.

Biological invasion by a benthivorous fish reduced the cover and species richness of aquatic plants in most lakes of a large North American ecoregion.

Biological invasions are projected to be the main driver of biodiversity and ecosystem function loss in lakes in the 21st century. However, the extent of these future losses is difficult to quantify because most invasions are recent and confounded by other stressors. In this study, we quantified the outcome of a century-old invasion, the introduction of common carp to North America, to illustrate potential consequences of introducing non-native ecosystem engineers to lakes worldwide.

Male-typical courtship, spawning behavior, and olfactory sensitivity are induced to different extents by androgens in the goldfish suggesting they are controlled by different neuroendocrine mechanisms.

Male-typical reproductive behaviors vary greatly between different species of fishes with androgens playing a variety of roles that appear especially important in the gonochorist cypriniform fishes. The goldfish is an important model for the cypriniformes and while it is clear that male goldfish are fully feminized by prostaglandin F2α(PGF2α), it is not clear whether females will exhibit normal levels of male-typical reproductive behaviors as well as olfactory function when treated with androgens. To answer this question, we exposed sexually-regressed adult female goldfish to several types of androgen and monitored their tendencies to court (inspect females) and mate (spawn, or attempt to release gametes) while monitoring their olfactory sensitivity until changes in these attributes were maximized.

Effects of Temperature and Trophic State on Degradation of Environmental DNA in Lake Water.

Degradation of environmental DNA (eDNA) in aquatic habitats can affect the interpretation of eDNA data and the ability to detect aquatic organisms. The effect of temperature and trophic state on the decay of Common Carp (Cyprinus carpio) eDNA was evaluated using lake water microcosms and quantitative PCR for a Common Carp-specific genetic marker in two experiments. The first experiment tested the effect of temperature on Common Carp eDNA decay.

Optimizing techniques to capture and extract environmental DNA for detection and quantification of fish.

Few studies have examined capture and extraction methods for environmental DNA (eDNA) to identify techniques optimal for detection and quantification. In this study, precipitation, centrifugation and filtration eDNA capture methods and six commercially available DNA extraction kits were evaluated for their ability to detect and quantify common carp (Cyprinus carpio) mitochondrial DNA using quantitative PCR in a series of laboratory experiments. Filtration methods yielded the most carp eDNA, and a glass fibre (GF) filter performed better than a similar pore size polycarbonate (PC) filter.

The relationship between the distribution of common carp and their environmental DNA in a small lake.

Although environmental DNA (eDNA) has been used to infer the presence of rare aquatic species, many facets of this technique remain unresolved. In particular, the relationship between eDNA and fish distribution is not known. We examined the relationship between the distribution of fish and their eDNA (detection rate and concentration) in a lake.

Anatomical and physiological studies of bigheaded carps demonstrate that the epibranchial organ functions as a pharyngeal taste organ.

The epibranchial organ (EO) is an enigmatic tubular organ found in the pharyngeal cavity of many filter-feeding fishes. We investigated whether it might function as a taste organ that mediates aggregation and ingestion of planktonic food within the buccal cavity. The EO and associated structures of bighead and silver carps, two successful and invasive planktivorous fishes, were examined using histological and electrophysiological techniques.

Behavioral analysis of pheromones in fish.

Pheromones are chemicals that pass between members of the same species which have inherent meaning. Because most fish pheromones are mixtures, and their actions can be complex, behavioral assays are required to identify them. This chapter describes a few strategies and two specific methods (one for measuring attraction and another for sexual arousal) that can serve this purpose in fishes that live in nonflowing water such as the carps.

Chemical analysis of aquatic pheromones in fish.

Pheromones are chemicals that pass between members of the same species that have inherent meaning. In the case of fish, pheromones are water-soluble and found in low concentrations. As such, sensitive and selective methods are needed to separate and analyze these pheromones from an environmental matrix that may contain many other chemicals.

Common carp implanted with prostaglandin F2α release a sex pheromone complex that attracts conspecific males in both the laboratory and field.

When ovulated, female fish of many species are known to release a F-prostaglandin-derived sex pheromone that attracts conspecific males. Recently, this pheromone was identified in the common carp as a mixture of prostaglandin F(2α) (PGF(2α)) and unidentified body metabolites, which we termed a 'pheromone complex.' The present study sought to test the activity of this pheromone complex in the field by developing a system using carps implanted with PGF(2α) as pheromone donors.

Polar metabolites synergize the activity of prostaglandin F2α in a species-specific hormonal sex pheromone released by ovulated common carp.

Many species of teleost fish detect and release F prostaglandins (PGFs), but the specific identities of these compounds and how they function as species-specific pheromones have yet to be resolved. This study addressed these questions in the common carp. An initial set of experiments established that mature male common carp were attracted to chemicals released by ovulated conspecifics, whereas the odor of female goldfish, a close relative, was less attractive.

Behavioral responses of adult male and female fathead minnows to a model estrogenic effluent and its effects on exposure regime and reproductive success.

Laboratory studies of adult male fathead minnows have shown that when they are exposed to estrogens, they lose their ability to compete for access to females and sire young, suggesting that estrogenic effluents may reduce the genetic fitness of populations of wild fishes. However, it is unknown whether wild fish which are exposed to effluent actually compete with unexposed fishes, how long effects of estrogen exposure last, and whether females are affected by estrogens. This study addressed these issues using the fathead minnow (FHM) and effluent from the Metropolitan Wastewater Treatment Plant (MWTP) a well-studied source of environmental estrogens (EEs) in the Mississippi River.

A multi-component species identifying pheromone in the goldfish.

Although it has been established that sexually-immature goldfish and their relatives recognize members of their own species by using chemicals that they release, the identity of this cue(s) and whether it might be produced and used by other life stages is not yet known. To address this question, this study tested the behavioral responses of sexually immature and mature goldfish to each other's body washings, their sensitivity to this cue, the role of the olfactory sense in detecting it, and whether it is comprised of either polar and/or non-polar compounds. Tests that used two-choice mazes discovered that juvenile, immature, mature male, and mature female goldfish all release and respond to a common chemical cue(s).

Synthesis and olfactory activity of unnatural, sulfated 5β-bile acid derivatives in the sea lamprey (Petromyzon marinus).

A variety of unnatural bile acid derivatives (9a-9f) was synthesized and used to examine the specificity with which the sea lamprey (Petromyzon marinus) olfactory system detects these compounds. These compounds are analogs of petromyzonol sulfate (PS, 1), a component of the sea lamprey migratory pheromone. Both the stereochemical configuration at C5 (i.