Presence Of Bluegill Research Articles

Visibility from roads predict the distribution of invasive fishes in agricultural ponds.

Propagule pressure and habitat characteristics are important factors used to predict the distribution of invasive alien species. For species exhibiting strong propagule pressure because of human-mediated introduction of species, indicators of introduction potential must represent the behavioral characteristics of humans. This study examined 64 agricultural ponds to assess the visibility of ponds from surrounding roads and its value as a surrogate of propagule pressure to explain the presence and absence of two invasive fish species. A three-dimensional viewshed analysis using a geographic information system quantified the visual exposure of respective ponds to humans. Binary classification trees were developed as a function of their visibility from roads, as well as five environmental factors: river density, connectivity with upstream dam reservoirs, pond area, chlorophyll a concentration, and pond drainage. Traditional indicators of human-mediated introduction (road density and proportion of urban land-use area) were alternatively included for comparison instead of visual exposure. The presence of Bluegill (Lepomis macrochirus) was predicted by the ponds' higher visibility from roads and pond connection with upstream dam reservoirs. Results suggest that fish stocking into ponds and their dispersal from upstream sources facilitated species establishment. Largemouth bass (Micropterus salmoides) distribution was constrained by chlorophyll a concentration, suggesting their lower adaptability to various environments than that of Bluegill. Based on misclassifications from classification trees for Bluegill, pond visual exposure to roads showed greater predictive capability than traditional indicators of human-mediated introduction. Pond visibility is an effective predictor of invasive species distribution. Its wider use might improve management and mitigate further invasion. The visual exposure of recipient ecosystems to humans is important for many invasive species that spread with frequent instances of human-mediated introduction.

Mensurative approach to examine potential interactions between age-0 yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus)

Bluegill (Lepomis macrochirus) and yellow perch (Perca flavescens) populations are often sympatric in the Great Plains region of the U.S.A. and portions of Canada; however, very little attention has been given to potential interactions between these species for available resources, especially during the early life stages. Relationships between age-0 bluegill and yellow perch growth and relative abundance were explored across multiple lakes and years within the Nebraska Sandhill region, USA. In addition, four habitat patch types (open water, Phragmites spp., Typha spp., Scirpus spp.) were sampled for age-0 bluegill and yellow perch, and food habits were examined for each species during August, September, and October of 2009 in one of these lakes. Age-0 yellow perch growth was negatively related to age-0 bluegill relative abundance across a spatiotemporal scale. Age-0 bluegill and yellow perch exhibited similar habitat use (moderate–high overlap), but generally consumed different important and dominant prey taxa (bluegill consumed both macroinvertebrates—56 % and zooplankton—44 %, while yellow perch consumed more zooplankton—66 %), which resulted in low overall diet overlap between species. Previous research indicates that age-0 yellow perch diet ontogeny often results in feeding predominately on macroinvertebrates and positively selecting them (and avoiding zooplankton prey) at sizes observed in our study. Therefore, yellow perch growth rates may be compromised by the presence of bluegill because of the need to consume less energetically profitable prey items such as zooplankton.

Influence of behavior and mating success on brood-specific contribution to fish recruitment in ponds

One source of uncertainty in predicting the response of populations to exploitation is individual differences within a population in both vulnerability to capture and contribution to population renewal. For species with parental care, individuals engaged in nesting behavior are often targeted for exploitation, but predicting outcomes of this nonrandom vulnerability will depend in part on an understanding of how parental traits are related to potential for brood contribution to the population. Variation in brood-specific contribution to recruitment of largemouth bass (Micropterus salmoides), a fish species with extended parental care, was quantified to determine if differences in mating success, parental care behaviors, and timing of reproduction influenced offspring recruitment. Dependence of these relationships on brood predation was tested in communities that differed in the presence of bluegill, Lepomis macrochirus, an important nest predator. Daily snorkel surveys were conducted in experimental ponds during spring to monitor male spawning and parental care behaviors in populations of largemouth bass. Tissue samples collected from larvae in nests were used to develop brood-specific DNA fingerprints for determining nest origins of fall recruits. Largemouth bass spawning period in bluegill ponds was longer and more variable in duration, with lower, more variable mating success, than in ponds without bluegill. In all populations, only one or two broods provided the majority of recruits, and these were broods produced during the earliest days of spawning by the oldest, largest males. In bluegill ponds, brood contribution from earliest nests also increased with brood size. Earliest nesters were the oldest males, and recruits from these nests were often above average in body size. Offspring needed to be guarded to at least swim-up larval stage to contribute any recruits. Termination of parental protection before offspring were free swimming mainly occurred with broods guarded by smaller males in ponds with brood predators. These age- and size-specific differences in timing of spawning and duration of parental care are consistent with influences of residual reproductive value and energetic constraints on reproductive behavior. Furthermore, these patterns of individual contribution to recruitment imply that fisheries that selectively target either nesting individuals or larger, older males could potentially decrease recruitment at the population scale.

The roles of predator identity and group size in the antipredator responses of American toad (Bufo americanus) and bullfrog (Rana catesbeiana) tadpoles

Summary Prey must integrate several cues to assess predation risk and determine appropriate antipredator responses. Few studies on anuran tadpoles have simultaneously varied multiple cues related to predation risk. We examined how American toad (Bufo americanus) and bullfrog (Rana catesbeiana) tadpoles respond to predator identity (e.g., dytiscid beetle larvae or bluegill sunfish), group size, and, for American toads, tadpole size. American toads were less active in control and with bluegill, and higher with dytiscids. American toads did not alter habitat use with bluegill, but solitary tadpoles avoided vegetation when with dytiscids. American toads in pairs or groups of 8 used vegetation more than solitary tadpoles in the presence of dytiscids. Smaller American toad tadpoles were more active and used open water more than larger tadpoles. Bullfrogs were less active in the presence of either predator relative to the control. Bullfrogs did not adjust habitat use with dytiscids, but used vegetation less in the presence of bluegill. Bullfrogs in groups of 8 were more active than solitary tadpoles or tadpoles in pairs. Group size in bullfrogs affected the response to predator cues. In conclusion, the behavior of tadpoles responds to a variety of factors, including group size, predator cues, and tadpole size.

Growth of Non-Native Rio Grande Cichlids (Herichthys cyanoguftatus) at Different Salinities and in the Presence of Native Bluegill (Lepomis macrochirus)

ABSTRACT The Rio Grande cichlid (Herichthys cyanoguttatus) is a non-native fish that has become established in the greater New Orleans metropolitan area. We conducted laboratory experiments to determine if H. cyanoguttatus growth was impacted either by salinity or the presence of bluegill (Lepomis macrochirus), a native fish. There was no significant difference in growth of H. cyanoguttatus held at three different salinities (0, 8, and 16 psu) for 14 d. When H. cyanoguttatm and L. macrochirus were held at 0 psu for 28 d both with and without the other species present (n = 6 per trial), there was a significant difference in growth between species. Lepomis macrochirus held on their own grew faster than H. cyanoguttatus on their own and faster than H. cyanoguttatus held with L. macrochirus (p < 0.005). Also, L. macrochirus housed with H. cyanoguttatus grew faster than H. cyanoguttatus on their own and faster than H. cyanoguttatus with L. macrochirus (p < 0.001). A second 28 d trial compared growth of individual H. cyanogutatus and L. macrochirus held together with different relative sizes (half with a largerH. cyanoguttatus as invader [n=7]; half with a smaller H. cyanoguttatus as invader [n=7]). This experiment showed no significant difference in growth between the species (p = 0.064). These results indicate that salinity levels will not limit H. cyanoguttatus dispersal in southeastern Louisiana, while biotic resistance in the form of native L. macrochirus may or may not impact growth of this non-native species.

MULTIPLE STRESSORS IN AMPHIBIAN COMMUNITIES: EFFECTS OF CHEMICAL CONTAMINATION, BULLFROGS, AND FISH

A leading hypothesis of amphibian population declines is that combinations of multiple stressors contribute to declines. We examined the role that chemical contamination, competition, and predation play singly and in combination in aquatic amphibian communities. We exposed larvae of American toads (Bufo americanus), southern leopard frogs (Rana sphenocephala), and spotted salamanders (Ambystoma maculatum) to overwintered bullfrog tadpoles (R. catesbeiana), bluegill sunfish (Lepomis macrochirus), the insecticide carbaryl, and ammonium nitrate fertilizer in 1000-L mesocosms. Most significantly, our study demonstrated that the presence of multiple factors reduced survival of B. americanus and A. maculatum and lengthened larval periods of R. sphenocephala. The presence of bluegill had the largest impact on the community; it eliminated B. americanus and A. maculatum and reduced the abundance of R. sphenocephala. Chemical contaminants had the second strongest effect on the community with the insecticide, reducing A. maculatum abundance by 50% and increasing the mass of anurans (frogs and toads) at metamorphosis; the fertilizer positively influenced time and mass at metamorphosis for both anurans and A. maculatum. Presence of overwintered bullfrogs reduced mass and increased time to metamorphosis of anurans. While both bluegill and overwintered bullfrog tadpoles had negative effects on the amphibian community, they performed better in the presence of one another and in contaminated habitats. Our results indicate that predicting deleterious combinations from single-factor effects may not be straightforward. Our research supports the hypothesis that combinations of factors can negatively impact some amphibian species and could contribute to population declines.

Chemical cues from multiple predator-prey interactions induce changes in behavior and growth of anuran larvae.

Chemical signals are used as information by prey to assess predation risk in their environment. To evaluate the effects of multiple predators on prey growth, mediated by a change in prey activity, I exposed small and large bullfrog (Rana catesbeiana) larvae (tadpoles) to chemical cues from different combinations of bluegill sunfish (Lepomis macrochirus) and larval dragonfly (Anax junius) predators. Water was regularly transferred from predation trials (outdoor experiment) to aquaria (indoor experiment) in which activity and growth of tadpoles was measured. The highest predation mortality of small bullfrog larvae in the outdoor experiment was due to Anax, and it was slightly lower in the presence of both predators, probably resulting from interactions between predators. There was almost no mortality of prey with bluegill. The activity and growth of small bullfrog larvae was highest in the absence of predators and lowest in the presence of Anax. In the presence of bluegill only, or with both predators, the activity and growth of small bullfrog tadpoles was intermediate. Predators did not affect large tadpole activity and growth. Regressing mortality of small bullfrog tadpoles against activity and growth of bullfrog tadpoles revealed a significant effect for small bullfrog larvae but a non-significant effect for large bullfrog larvae. This shows that the response of bullfrog tadpoles to predators is related to their own body size. The experiment demonstrates that chemical cues are released both as predator odor and as alarm substances and both have the potential to strongly alter the activity and growth of prey. Different mechanisms by which chemical cues may be transmitted to species interactions in the food web are discussed.

Multiple predator effects on size‐dependent behavior and mortality of two species of anuran larvae

This study examined the effects of multiple predators on size‐specific behavior and mortality of two species of anuran larvae. Particularly, we focused on how trait changes in predators and prey may be transmitted to other species in the food web. In laboratory experiments, we examined the effects of bluegill sunfish, Lepomis macrochirus, and the odonate larva Anax junius on behavior and mortality of tadpoles of the bullfrog, Rana catesbeiana, and the green frog R. clamitans. Experiments were conducted with predators alone and together to assess effects on behavior and mortality of the tadpoles. The experiments were replicated on five size classes of the tadpoles to evaluate how responses varied with body size. Predation rates by Anax were higher on bullfrogs than on green frogs, and both bullfrogs and green frogs suffered greater mortality from Anax than from bluegill. Bluegill only consumed green frogs. Predation rates by both predators decreased with increasing tadpole size and decreased in the non‐lethal (caged) presence of the other predator. Both anuran larvae decreased activity when exposed to predators. Bullfrogs, however, decreased activity more in the presence of Anax than in the presence of bluegill, whereas green frogs decreased activity similarly in the presence of both predators. The largest size class of green frogs, but not of bullfrogs, exhibited spatial avoidance of bluegill. These responses were directly related to the risk posed by the different predators to each anuran species. Anax activity (speed and move frequency) also was higher when alone than in the non‐lethal presence of bluegill. We observed decreased predation rate of each predator in the non‐lethal presence of the other, apparently caused by two different mechanisms. Bluegill decreased Anax mortality on tadpoles by restricting the Anax activity. In contrast, Anax decreased bluegill mortality on tadpoles by reducing tadpole activity. We discuss how the activity and spatial responses of the tadpoles interact with palatability and body size to create different mortality patterns in the prey species and the implications of these results to direct and indirect interactions in this system.

An Experimental Study of Competition Between the Native Sacramento Perch (Archoplites interruptus) and Introduced Bluegill (Lepomis macrochirus)

The Sacramento perch (Archoplites interruptus), a sunfish (Centrarchidae) native only to the Central Valley of California, has been eliminated from most of its native range. To examine the role of interspecific competition in this decline, a series of experiments were conducted to assess the growth, aggressive behavior, and habitat use of Sacramento perch in the presence of bluegill (Lepomis macrochirus), an introduced centrarchid. The experiments indicate that (1) Sacramento perch gain less weight and show reduced growth when placed with bluegill, but that this interaction only occurs with food limitation, and is not affected by overall fish density; (2) Sacramento perch demonstrate less aggressive behavior than bluegill, but become more aggressive when they are conspicuously larger than bluegill; (3) Sacramento perch shift their habitat use in the presence of bluegill. Overall the results imply that Sacramento perch and bluegill exhibit interspecific competition where the mechanism of interaction is aggressive dominance by bluegill. It is suggested that long term persistence of Sacramento perch may require a habitat that is free of introduced centrarchid fishes, or one controlled by a naturally variable hydrological regime.

Growth, Density, and Interspecific Influences on Pumpkinseed Sunfish Life Histories

I collected data on 27 pumpkinseed (Lepomis gibbosus) populations in eastern and central Ontario and conducted a transplant experiment with one of these populations to test growth and competition—related predictions of several life history models. The predictions are that early maturity and high gonadal investment will occur: (1) in large and fast—growing juveniles; (2) in populations with low adult: juvenile growth ratios; (3) in populations with low density; and (4) in the absence of bluegill sunfish (Lepomis macrochirus), a competing congener. Predictions 1 and 4 were fully supported and Prediction 2 was partly supported, but Prediction 3 was not. The earliest maturing juveniles within populations were significantly larger than conspecifics of the same age that did not mature. Females from a lake population that were transplanted into a fishless pond exhibited both significantly faster growth and a significantly higher gonad to body mass ratio (gonado—stomatic index) that females living in the lake. At the population level, juvenile growth was significantly correlated with age at maturity (r = 0.52), but not with gonadostomatic index, whereas the Adult : Juvenile Growth Ratio showed a significant, negative correlation wih gonadosomatic index (r = 0.66), but not with mean age at maturity. Mean age at maturity showed a stronger correlation with the indicator of life—span and adult survival rate (r = 0.74), suggesting that mortality is more important than growth in the shaping of reproductive life histories of pumkinseed. High population density was associated with early maturity and high gonadal investment, the opposite of what was predicted. However, pumpkinseed populations that co—occurred with bluegills did mature significantly later and at a larger size and tended to have a lower gonadal investment than populations living in waterbodies without bluegills. This difference in reproductive patterns in the presence of bluegill is consistent with two—stage life history theory and may be the result of a direct effect of bluegills on pumpkinseed growth and survivorship, as well as differences in environmental conditions were the two species do or not co—occur.

Experimental Study of the Impacts of Bluegill (Lepomis macrochirus) and Largemouth Bass (Micropterus salmoides) on Pond Community Structure

We examined community impacts of bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides) in a summer experimental pond study of factorial design with four treatment combinations (fishless, bluegill, largemouth bass, and bluegill with largemouth bass). Ceriodaphnia reticulata, Daphnia pulicaria, Chaoborus sp., Volvox sp., anisopteran and zygopteran nymphs, and dissolved oxygen levels were suppressed in the presence of bluegill. Diaptomus sp., Conochiloides sp., Cyclotellas sp., Navicula sp., Oocystis sp., Anabaena sp., Ceratium sp., algal fluorescence, turbidity, 5- to 12.7-μm particles, and total phosphorus and total nitrogen were enhanced in the presence of bluegill. Daphnia pulicaria was enhanced and Cyclotella sp. and Oocystis sp. were suppressed in the presence of largemouth bass. Although the effects of the two fish were not independent, as indicated by significant bluegill × largemouth bass interactions for some plankton taxa, we found little evidence of bluegill impacts being reversed by largemouth bass. While total bluegill biomass was reduced and bluegill biomass distributions were shifted toward larger individuals, bluegill remained abundant in the presence of largemouth bass.