Microsatellite Analysis of Trophy Largemouth Bass from Arkansas Reservoirs

The Arkansas Game and Fish Commission (AGFC) has introduced Florida largemouth bass (FLMB; Micropterus salmoides floridanus) to water bodies historically containing the northern largemouth bass (NLMB; Micropterus salmoides salmoides) subspecies since the late 1970s in an attempt to produce a trophy LMB fishery. Since 2006, the AGFC has been biannually sampling reservoirs stocked with FLMB to determine levels of admixture. Here, total sampling efforts between 2006 and 2011 have been combined, and LMB heavier than 2,268 g (5 lb) were analyzed in an effort to investigate distribution of bass by their genetic composition designated as trophy LMB by the AGFC. Of the 148 trophy LMB sampled, 123 possessed FLMB alleles (83.1%). Thirty-two of the heaviest 50 (64.0%) LMB sampled, including a potential state record that was nullified, were genetically confirmed to be FLMB. Distributions of trophy bass within reservoirs were preferentially represented by Fx-FLMB and FLMB

Identification of Florida Largemouth Bass Alleles in Arkansas Public and Private Aquaculture Ponds

The Florida subspecies of the largemouth bass (LMB) has often been introduced into waters outside of its range, with escape of individuals into associated waterways common. Sustaining pure lines within controlled hatchery settings is also difficult. The present study investigated LMB populations by way of allozyme analysis of three diagnostic loci of 115 LMB in three public and seven private aquaculture ponds within Arkansas. The goal was to determine the success of hatcheries in maintaining pure subspecies. None of the pond populations studied were fixed for all alleles. Private ponds had northern LMB allele frequencies of up to 0.40 in putative Florida LMB ponds. State fish hatcheries had higher proportions of predicted alleles. Most bass surveyed were intergrades (63%)

Temporal Changes of Largemouth Bass Alleles in a Northern Arkansas Reservoir Stocked with Florida Bass

Southwest Electric Power Company (SWEPCO) Lake in northwest Arkansas is a thermal cooling pond for the Flint Creek Power Station. This reservoir has been regularly stocked with Florida bass (Micropterus floridanus) on top of a pre-existent largemouth bass (M. salmoides) population since its creation in 1976. Allozyme analysis of diagnostic loci in 1995-1996 revealed that 62% of the alleles were Florida bass alleles and that most fish were FX hybrids (77%). Microsatellite analysis of diagnostic loci in 2006 revealed that 78% of the alleles were Florida bass alleles and that most fish were FX-Florida hybrid bass (59%), with the remainder designated as Florida bass. The ongoing stocking of Florida bass and the possibility of a selective advantage for Florida bass alleles in a thermal pond may account for these temporal reductions in largemouth bass allele frequencies

Introduction of Florida Bass Alleles into Largemouth Bass Inhabiting NortheastArkansas Stream Systems

Florida bass (Micropterus floridanus) have been introduced throughout much of the southern U.S. over the past 50 years. This species readily hybridizes with the extant largemouth bass (M. salmoides). Within Arkansas, the Florida bass is currently stocked in the southern half of the state. Previous studies of a northern Arkansas hatchery and a reservoir revealed the existence of Florida bass alleles in each. Other studies in Oklahoma and Texas have revealed the presence of Florida bass alleles in stream systems proximal to lakes stocked. Our goal was to investigate, using microsatellite analysis of 7 diagnostic loci, the presence of Florida bass alleles in 8 northeastern Arkansas streams to determine if Florida bass or hybrids had escaped from private farm ponds as compared to stocked reservoirs. We found rare instances of Florida bass alleles in most drainages, consistent with previous studies demonstrating a lack of containment of Florida bass once stocked. In Cane Creek, which flows adjacent to privately stocked farm ponds, one-third of the individuals had Florida bass alleles

Age, Growth and Condition of Largemouth Bass, Micropterus salmoides, of Lake Ashbaugh, Arkansas

The population size structure, length at age and condition of 140 largemouth bass, Micropterus salmoides, were studied for Lake Ashbaugh, Arkansas. Scales and otoliths were used for age and length at age determination of individual bass. Length at age was determined by back-calculation and relative weight was used to measure condition. The Lake Ashbaugh population is dominated by young, slow growing bass in poor condition. Ninety-one percent of the largemouth bass in Lake Ashbaugh were less than four years of age, with age 3+ bass serving as the dominant year class. Proportional and relative stock density values were 25 and 3 %, respectively, significantly less than those of other surveyed Arkansas reservoirs. The mean relative weight for this population was 84, significantly less than that projected for healthy populations. Mean back-calculated lengths for largemouth bass ages I through age III were 141 mm, 190 mm, and 257 mm, respectively. Mean lengths at each age were significantly less than those obtained from a 1987 study of Lake Ashbaugh bass and for bass in other Arkansas reservoirs. Several factors may have contributed to the steady decline in the bass population of Lake Ashbaugh. Winterkills occurred in 1989-1991, which seemed to affect mostly mature largemouth bass. A380 mm length limit imposed in 1987 may have resulted in a stockpiling of bass less than 380 mm, increasing the competition for available prey for those size classes. These hypotheses are supported by consistent yearly declines over the past five years in the available prey/predator ratios and relative weights, particularly for the size classes between 226 mm-350 mm

Genetic Relationships of Some Common Arkansas Freshwater Sunfishes (Centrarchidae: Lepomis) Inferred From Restriction Endonuclease Analysis of Mitochondrial DNA

Geographic isolation and habitat specialization has aided in the evolution and maintenance of genetic integrity of the lepomid sunfishes (Lepomis: Centrarchidae) of North America. Our goal was to measure genetic distances between four of the eleven extant sunfish species by using mitochondrial DNA analysis. Mitochondrial DNA restriction fragment length polymorphisms (RFLPs) were examined in bluegill (L. macrochirus), redear sunfish (L. microlophus), longear sunfish (L. megalotis), and green sunfish (L. cyanellus) using 15 restriction endonucleases. The largemouth bass (Micropterus salmoides) was used as an outgroup. The phylogeny inferred from Dollo parsimony cladistic analysis largely concurred with published results from allozyme analyses and the fossil record, yet was inconsistent with published anatomical analyses. Genetic distances between species ranged from 0.1627 to 0.3328. The green sunfish was the basal member of the genus, whereas the bluegill was the most diverged from the largemouth bass. These four species diverged over a broad time frame, with estimated times of speciation occurring during Miocene (8.14 - 16.64 mya)

The symmetric inverse M-matrix completion problem

AbstractNecessary and sufficient conditions are given on the data for completability of a partial symmetric inverse M-matrix, the graph of whose specified entries is a cycle, and these conditions coincide with those we identify to be necessary in the general (nonsymmetric) case. Graphs for which all partial symmetric inverse M-matrices have symmetric inverse M-matrix completions are identified and these include those that arise in the general (positionally symmetric) case. However, the identification of all such graphs is more subtle than the general case. Finally, we show that our new cycle conditions are sufficient for completability of all partial symmetric inverse M-matrices, the graph of whose specified entries is a block graph

Size Selective Parasitism of Rainbow Trout (Oncorhynchus mykiss) by Chestnut Lampreys (Ichthyomyzon castaneus) in an Artificial Setting

Paradigms of optimal resource utilization by animals, both classical and more recent, were not originally developed in the context of parasitism. Though this oversight has slowly been reversed, little attention has been paid to optimal resource utilization by parasitic fishes, such as lampreys. Multiple explanations for host size selection by parasitic lampreys may be plausible, but results from previous studies have been inconsistent. We studied host size selection by Chestnut Lampreys (Ichthyomyzon castaneus) parasitizing Rainbow Trout (Oncorhynchus mykiss) in fish hatchery raceways in north central Arkansas during the late winter and early spring of 2013. Parasitized Rainbow Trout were significantly shorter than non-parasitized conspecifics. Using the relative weight metric of condition, evidence was found that parasitized Rainbow Trout were in better condition than non-parasitized Rainbow Trout. Our findings are not consistent with previous studies of parasitic lamprey host size selection, but do suggest that Chestnut Lampreys are capable of determining a fish’s suitability as a host based on their plumpness even in a setting with low host size heterogeneity and high host density