Analysis of Public Comments on Experimental Regulations for Protecting Black Bass during The Spawning Period in Eastern Ontario Reveals Both Stakeholder Acceptance and Skepticism.

Recreational angling of nesting largemouth bass (Micropterus nigricans) and smallmouth bass (M. dolomieu) can greatly increase nest abandonment, and in the northern clines of their range, decrease recruitment. This is the case in eastern Ontario, where high levels of non-compliance and difficult to enforce regulations have impacted black bass (Micropterus spp.) conservation and management. Effective January 1, 2024 until December 31st, 2025, novel and experimental fishing sanctuaries were imposed on portions of Charleston Lake and Opinicon Lake that prohibit recreational fishing of all types from April 15th to the Friday before the first Saturday in July (encompassing the full bass reproductive season). As part of the formal process to institute these experimental regulations, public comments were collected on the Environmental Registry of Ontario. We examined those comments and identified supportive and non-supportive themes related to these experimental regulations. While a majority of stakeholders were in support of the new regulations, we also noted sub-themes that may hinder regulation acceptance. Those sub-themes include: a perceived lack of enforcement negating the potential benefits of the sanctuaries, under-estimation of the extent of non-compliance with existing regulations such that new regulations are unnecessary, misunderstanding and misinformation, as well as distrust of government and the academic research community. Understanding and addressing these stakeholder perspectives will help researchers studying the new sanctuary areas and managers understand any lack of compliance while informing future decisions about bass management in eastern Ontario and beyond.

The influence of brood loss on nest abandonment decisions in largemouth bass Micropterus salmoides.

Largemouth bass Micropterus salmoides broods were experimentally reduced in size to test whether brood size (BS) and simulated brood depredation affect the decision by a male to continue providing care for its brood or to abandon that brood prematurely before its offspring reach independence. The highest ranked of the generalized linear models predicting brood abandonment was based on the number of offspring remaining in a nest following brood devaluation, indicating that parental male fish reassess the value of a brood following perturbation. Paternal M. salmoides were more likely to abandon their broods if initial BS was small before devaluation, and if there was a greater decrease in BS, indicating a threshold for both the amount of brood loss and remaining BS. Larger, older males were also less likely to abandon their brood than smaller, younger conspecifics. These results have broad implications for determining drivers of parental care trade-offs and how individuals assess the value of a brood.

The influence of selection for vulnerability to angling on foraging ecology in largemouth bass Micropterus salmoides.

Several traits related to foraging behaviour were assessed in young-of-the-year produced from largemouth bass Micropterus salmoides that had been exposed to four generations of artificial selection for vulnerability to angling. As recreational angling may target foraging ability, this study tested the hypothesis that selection for vulnerability to angling would affect behaviours associated with foraging ecology and prey capture success. Fish selected for low vulnerability to angling captured more prey and attempted more captures than high vulnerability fish. The higher capture attempts, however, ultimately resulted in a lower capture success for low vulnerability fish. Low vulnerability fish also had higher prey rejection rates, marginally shorter reactive distance and were more efficient at converting prey consumed into growth than their high vulnerability counterparts. Selection due to recreational fishing has the potential to affect many aspects of the foraging ecology of the targeted population and highlights the importance of understanding evolutionary effects and how these need to be considered when managing populations.

The effects of temperature change on the hatching success and larval survival of largemouth bass Micropterus salmoides and smallmouth bass Micropterus dolomieu.

In this study, the effects of abrupt temperature change on the hatching success and larval survival of eggs, yolk-sac larvae (YSL) and larvae above nest (LAN), for both largemouth bass Micropterus salmoides and smallmouth bass Micropterus dolomieu were quantified. Temperature had a significant effect on hatching success and time to 50% mortality, with large heat shocks causing accelerated mortality. The temperature changes shown to influence survival of all life stages, however, were beyond what is typically experienced in the wild. Micropterus salmoides had greater egg hatching success rates and increased survival rates at YSL and LAN stages, relative to M. dolomieu. Additionally, egg hatching success and survival of LAN varied across nests within the study. These findings suggest that temperature alone may not account for variations in year-class strength and may emphasize the need for protection of the nest-guarding male Micropterus spp. to ensure recruitment.

Hybridization among divergent stocks of largemouth bass (Micropterus salmoides) results in altered cardiovascular performance: the influence of genetic and geographic distance.

Animal populations exhibit wide ranges of divergence associated with both geographic and genetic distances. Here, we examined the role of crossing distance on the cardiovascular response to exhaustive exercise among differentiated stocks of largemouth bass Micropterus salmoides at 10 degrees C and 20 degrees C. Stocks of 2+ fish were produced using adults from three regions in the midwestern United States (southeastern Wisconsin, northwestern Wisconsin, and west central Minnesota) and were crossed with fish from central Illinois. Doppler flow probes were used to quantify cardiac output, heart rate, and stroke volume. Cardiac variables (both resting and maximal) were consistently lowest in pure Illinois fish relative to the F(1) interstock hybrids. Additionally, when exposed to exercise, cardiac variables for F(1) interstock hybrids required approximately 40% longer to return to resting levels compared with the pure Illinois stock. However, the time required to exhaust fish was similar across stocks. Interestingly, all of the stocks (including the interstock hybrids and pure Illinois) maintained cardiac scope. In general, the patterns observed in cardiovascular performance were consistent for both water temperatures. Multiple regression analysis was used to determine which of the divergence metrics contributed to variation in cardiovascular performance in interstock hybrids. Mitochondrial DNA data (genetic distance) were infrequently identified as a significant source of variation in cardiovascular performance. However, genetic distance data for the neutral allozyme markers revealed that these stocks have experienced significant divergence. Latitude (geographic distance) accounted for between 31% and 45% of variation observed in the recovery parameters. This study suggests that the magnitude of stock divergence is an important determinant in the degree to which cardiovascular performance of bass is altered from interstock hybridization and associated breakdown of coadapted gene complexes. Furthermore, these data suggest that translocating bass among even geographically discrete regions or among stocks with reasonable genetic similarity can result in substantial performance alterations at the F(1) generation.

Linkage relationships of nine enzyme Loci in sunfishes (lepomis; centrarchidae).

Linkage relationships of nine enzyme loci; aconitase (Acon ), esterase (Est), glucosephosphate isomerase A and B ( Gpi), glycerate-2-dehydrogenase (G2dh), malic enzyme (Me ), phosphoglycerate kinase (Pgk), phosphoglucomutase (Pgm ) and superoxide dismutase (Sod), were investigated in sunfishes (Lepomis, Centrarchidae). Reciprocal F(1) hybrids produced from crosses between green sunfish (Lepomis cyanellus) and redear sunfish ( L. microlophus) were backcrossed with each of the two parental species. A three-point linkage map comprising G2dh, Pgk and Sod is reported. The frequencies of recombination between G2dh and Pgk and between Pgk and Sod are estimated as 45.3 and 24.7%. The remaining six loci assort independently. Possible linkage conservation and homology of this linkage group with those of other vertebrate species are discussed.

Kinetic characterization of long chain fatty acyl coenzyme A ligase from rat liver mitochondria.

Long chain fatty acyl coenzyme A ligase (EC 6.2.1.3) purified from rat liver mitochondria has been characterized with respect to several kinetic parameters. Many of the kinetic properties of the mitochondrial enzyme are similar to those of the purified microsomal enzyme with respect to palmitoyl-CoA formation, but there are distinct differences. The fatty acid and nucleotide specificities of the mitochondrial enzyme are similar to those of the microsomal enzyme, as are the apparent Km values for ATP and coenzyme A. On the other hand, the mitochondrial enzyme differs from the microsomal enzyme in that it has a lower pH optimum, is different in molecular weight, and does not show simple saturation kinetics with palmitate as substrate. Of particular interest is the evidence presented which indicates that the mitochondrial long chain fatty acyl-CoA ligase, unlike short and medium chain ligases, does not utilize an acyladenylate as an intermediate in the formation of fatty acyl-CoA.

The effects of exogenous 11-ketotestosterone, testosterone, and cyproterone acetate on prespawning and parental care behaviors of male bluegill.

This study investigated the effect of exogenous 11-ketotestosterone (11KT) and testosterone (T), two important androgens involved in fish reproduction, as well as cyproterone acetate (CYA), an antiandrogen, on behaviors of male bluegill (Lepomis macrochirus) during prespawning and parental care periods. Parental male bluegill build nests in colonies, spawn with females, and then remain alone on these nests to provide care for their developing offspring. Implantation of pellets containing either 11KT or T did not induce parental males to build nests in early spring, before the onset of natural spawning, or during late spring and early summer, when the reproductive season was in progress. Treatment with pellets containing CYA inhibited reproduction in male bluegill and these fish did not spawn for the remainder of the reproductive season. The release of appropriate steroids from pellets to the serum was confirmed in all cases by a radioimmunoassay. Interestingly, nesting males that spawned successfully and were implanted with 11KT at the onset of the parental care phase displayed increased rim-circling, a behavior characteristic of the late prespawning period. Treatment with T or CYA, however, did not induce such behaviors in nesting bluegill. Finally, none of these treatments significantly affected antipredator aggressive behavior displayed by nesting males. Our results suggest that parental care behaviors in male bluegill are most likely expressed through nonandrogenic mechanisms.

Levels of duplicate gene expression in armoured catfishes.

Species of armoured catfishes differ significantly in their cellular DNA content and chromosome number. Starch gel electrophoresis of isozymes was used to determine whether each of 16 enzyme loci was expressed in a single or duplicate state. The percent of enzyme loci exhibiting duplicate locus expression in Corydoras aeneus, Corydoras julii, Corydoras melanistius, and Corydoras myersi was 37.5 percent, 18.75 percent, 12.5 percent, and 6.25 percent, respectively. The percentage of loci expressed in duplicate is higher in the species with higher haploid DNA contents, which are 4.4 pg, 3.0 pg, and 2.3 pg, respectively. These differences in DNA contents are also associated with differences in chromosome number. These data are consistent with the hypothesis that increases in DNA contents and enzyme loci occur both by tetraploidization and by regional gene duplication and that these increases are then followed by a partial loss of DNA and a reduction in the number of the duplicate isozyme loci expressed. Such analyses provide insight into the mechanisms of genome amplification and reduction as well as insights into the fats of duplicate genes.

Relative developmental success of interspecific Lepomis hybrids as an estimate of gene regulatory divergence between species.

The developmental success of interspecific Lepomis hybrids is used as an index of gene regulatory divergence between the green sunfish, L. cyanellus, and each of three other parental species, longear sunfish, L. megalotis, warmouth, L. gulosus, and bluegill, L. macrochirus. This gene regulatory divergence is compared to the degree of structural gene divergence among these four species (genetic distance [Nei, '78], D, ranged from 0.206 to 0.586). The developmental success of the hybrid embryos at the level of morphogenesis was higher than expected from the genetic distance between the parental species. The rates of morphogenesis of the hybrid embryos were the same as that for the green sunfish embryos. The percentage of embryos that hatched was relatively high in all crosses. However, two of the hybrid crosses resulted in enhanced percentages of hatched embryos. Slight increases in the extent of morphological abnormalities were observed in hybrids from crosses between more distantly related parental species. The schedules and levels of enzyme locus expression of the hybrids, assessed spectrophotometrically and electrophoretically for nine enzyme systems (encoded in a total of 14 loci), were different from each other and from those of the green sunfish embryos. Alterations in the time of first enzyme appearance and in the time of first increase in enzyme activity in the developing hybrid embryos were not correlated with genetic distance between parental species. However, the extents of alteration of enzyme activities over the entire period of hybrid embryogenesis were correlated with the genetic distance. We attribute the morphological and molecular anomalies observed in the hybrids to gene regulatory incompatibilities between species. Although the exact number of mutational differences and their relative developmental impacts are not known, some inferences can be drawn about the degree of divergence in gene regulation between species. It appears that an uncoupling of the rates of structural and regulatory gene evolution can occur between species of some taxa, an observation that has implications for the roles of gene regulatory differences in organismic evolution.

Gene regulatory divergence among species estimated by altered developmental patterns in interspecific hybrids.

Disturbances in the schedules of gene expression in developing interspecific fish hybrids have been used to draw inferences about the extent of gene regulatory divergence between species and about the degree to which this gene regulatory divergence is correlated with structural gene divergence, as estimated by genetic distance. Sperm from each of 10 different species representing six genera within the family Centrarchidae was used to fertilize eggs of the Florida largemouth bass (Micropterus salmoides floridanus). The genetic distances (D; Nei 1978) between the parental species used to form the hybrids ranged from 0.133 to 0.974. The developmental success and temporal patterns of gene expression of each of the hybrids were compared with those of the Florida largemouth bass. As the genetic distance between the paternal species and the Florida largemouth bass increased, there was a general decline in developmental success in the hybrid embryos as demonstrated by the observed reductions in the percentage of hatching and by progressively earlier and more extensive morphological abnormalities. Concomitantly, progressively more marked alterations in developmental schedules of expression of 15 enzyme loci occurred in the hybrids as the genetic distance between parental species increased. However, observed deviations from this trend for a few species may represent an uncoupling of the rates and modes of evolution of structural genes from those for genes regulating developmental processes.

Thermal kinetic differences between allelic isozymes of malate dehydrogenase (Mdh-B locus) of largemouth bass, Micropterus salmoides.

Two alleles are encoded at the malate dehydrogenase locus in largemouth bass, Micropterus salmoides. Populations in the extreme northern areas of the range of this fish are fixed or nearly fixed for the B1 allele, whereas populations in Florida are fixed for the alternative allele, B2. The MDH-B1B1 and MDH-B2B2 allelic isozymes were isolated by preparative starch gel electrophoresis and subjected to in vitro kinetic analyses. The apparent Km (oxaloacetate) for each of these allelic isozymes was determined at 25, 30, and 35 degrees C. The Km values for both isozymes increased with increasing temperature and were not significantly different from each other at 25 and 35 degrees C. However, at 30 degrees C the Km value for the MDH-B1B1 allelic isozyme was higher than that for the MDH-B2B2 isozyme (i.e., 5.4 X 10(-5) vs 3.3 X 10(-5)). These results are consistent with the hypothesis that the different environmental temperatures at different latitudes may be at least partially responsible for the north-south cline in Mdh-B allele frequencies.

Differences in tissue expressions of enzyme activities in interspecific sunfish (Centrarchidae) hybrids and their backcross progeny.

The extent of naturally occurring variations of enzyme locus expression was determined for three tissues (liver, muscle, and eye) in two species of sunfish (Centrarchidae), the green sunfish (Lepomis cyanellus) and the redear sunfish (L. microlophus). The genetic basis for species differences in tissue enzyme specific activities of malate dehydrogenase (EC 1.1.1.37), lactate dehydrogenase (EC 1.1.1.27), phosphoglucomutase (EC 2.7.5.1), and glucosephosphate isomerase (EC 5.3.1.9) was investigated by determining enzyme specific activities in the tissues of the reciprocal F1 hybrids and of their backcross progenies. The specific activities for most enzymes in hybrids were intermediate between those of the parental species. Significant differences in enzyme specific activity were detected among the F1 progeny as well as those of backcrosses. Variations in specific activity levels in one tissue were often independent of variations in specific activities in a different tissue. However, the changes in the specific activities of different enzymes within the same tissue were often positively correlated. The tissue glucosephosphate isomerase activity differences appear not to be due to different functional contributions of the glucosephosphate isomerase allelic isozymes. Cluster analysis of distributions of specific activities revealed no simple Mendelian pattern of inheritance for control of tissue enzyme activity. Our results suggest a polygenic control of tissue enzyme specific activity levels.

Serum 11-ketotestosterone and testosterone concentrations associated with reproduction in male bluegill (Lepomis macrochirus: Centrarchidae).

Male bluegill (Lepomis macrochirus) display a complex reproductive behavior involving two alternative life history pathways: delay of sexual maturation to become "parentals" or precocious maturation as "cuckolders." The purpose of our study was to investigate the association of two androgens, 11-ketotestosterone (11KT) and testosterone (T), with reproduction in these two types of males. Radioimmunoassay techniques were used to measure daily levels of the two androgens in the blood serum of parental male bluegill captured during the prespawning, spawning, and nesting periods throughout the reproductive season. Dramatic changes in the levels of 11KT and T were observed among parental males during these periods. Peaks occurred at the onset of spawning activity during each breeding bout. Compared to spawning parental males, spawning cuckolder males had significantly lower serum levels of 11KT. In contrast, the serum levels of T among parental and cuckolder males were not significantly different. These findings suggest that the elevated levels of 11KT are associated with the behaviors displayed by spawning parental males. The levels of T, however, seem to be associated with the occurrence of a phenomenon common to both parental and cuckolder males, such as development of gonads and/or spermiation.