Smallmouth Buffalo (Ictiobus bubalus) is found predominately in eastern Oklahoma and recognized as a non-game species by the Oklahoma Department of Wildlife Conservation. The designation of non-game allows the species to be recreationally caught or harvested using any legal method and without limits. We examined the current state record (restricted division: allowing recreational harvest with no restriction) Smallmouth Buffalo caught using rod and reel on May 3, 2019 from Broken Bow Reservoir. The lapilli otoliths were removed from this specimen to estimate age, back calculate length-at-age (growth rates), and back calculate spawning year. The final estimated age of this fish was 62 years old. The growth curve using back-calculated length-at-age suggested this Smallmouth Buffalo initially grew rapidly (80% of total length within first 17 years), but the growth increments constricted with increasing age. Based on the estimated age of this fish, the state record Smallmouth Buffalo was spawned in 1957, indicating this fish was spawned prior to impoundment of Broken Bow Reservoir. Further, the hatch year of this fish corresponds with flooding, after a prolonged drought, demonstrating the importance of river flow to successful spawning of this species. Although this study is limited to a single specimen, it improves our knowledge of a long-lived, understudied species in Oklahoma.
Blue Catfish populations create popular recreational fisheries throughout the United States. Many of these populations were introduced due to their popularity as a sportfish. However, Blue Catfish introductions are not always successful, particularly in small reservoirs. In 2017, a Blue Catfish population was discovered in Meeker Reservoir, a small impoundment in central Oklahoma. Because Blue Catfish populations generally do not do well in small impoundments, an evaluation was implemented to describe population characteristics, recruitment dynamics, and estimate abundance of preferred-length (> 760 mm) Blue Catfish in Meeker Reservoir. Blue Catfish in this population have high longevity, slow growth, low annual mortality, and reach sexual maturity at small sizes. Recruitment of Blue Catfish was variable, although fish from 21 year classes were observed, of which three year classes were dominant (combine to make 58% of fish in the sample). Strong year classes were produced in years with higher mean annual temperatures (> 16.5°C). Overall, this population is overcrowded and stunted, but a small proportion of fish still reach preferred size. Slow growth of Blue Catfish in this population may be explained by some combination of competition, genetics, low reservoir productivity, and reproductive strategy. The small size structure of this population creates a challenging management scenario, because most fish are below the size that anglers are willing to harvest. Although this population may be anomalous, our results provide important information regarding Blue Catfish population characteristics and recruitment in a small impoundment.
Alligator Gar (Atractosteus spatula) is the largest fish species found in Oklahoma, which makes obtaining field measurements (particularly weight) by fisheries managers or recreational anglers challenging. A method to overcome the logistical hurdles associated with handling and measuring large fish in the field would be beneficial to managers and anglers. Therefore, the objective of this study is to develop length-weight and length-length relationships for Alligator Gar collected from Texoma Reservoir, Oklahoma using total length (TL), standard length (SL), and girth (G) measurements to predict weights and length measurements of Alligator Gar. A total of 339 Alligator Gars averaging 1,666 mm TL (range = 590 to 2,357 mm TL) and weighing 38.2 kg (range = 0.77 to 105.3 kg) were used in this evaluation. No significant differences in weight of Alligator Gar were detected between sex or season (winter-spring and summer-fall), so all fish were pooled for the remaining analyses. All simple linear regression and multiple regression models produced significant relationships (P ≤ 0.05), were highly correlated (r 2 = 0.88 to 0.99), and mean predicted error values were 60 kg. However, the simple linear regression model using TL and the multiple regression model using TL and G produced less biased weight estimates for fish up to 80 kg, but appeared to underestimate weights of Alligator Gar ≥ 100 kg. All of the models evaluated in this study provide managers and anglers with a relatively accurate estimate of Alligator Gar weights from Texoma Reservoir and provides fisheries managers with weight-length information to which other Alligator Gar populations can be compared.
Over the last few years, we have learned more about hematozoan (blood) parasites and helminth parasites of Oklahoma herpetofauna than we have gained in many years past. To that end, we continue to provide information on various intraerythrocytic hematozoans and helminths of amphibians and reptiles of the state. We document several new host and distributional records for these parasites.
Common Carp (Cyprinus carpio) is a highly invasive species and tolerates a diversity of habitats with a broad range of water-quality characteristics. Following extended drought conditions from 2005 - 2012, a noticeable increase in Common Carp densities was observed at Lake Carl Etling. Higher Common Carp numbers suggested other management techniques would be needed to control the population, which required knowledge of Common Carp population abundance. Therefore, our objective was to estimate the population size using a Schnabel estimator, body condition, and size structure of the carp population. We sampled the entire perimeter of the shoreline once monthly using boat electrofishing from May through November 2017. During the first sampling event in May, all Common Carp captured were measured (total length [TL], mm), weighed (g), given a hole punch mark through the left operculum, and released. In subsequent samples (June-November), each captured fish was examined for a hole punch mark on the left operculum, and if present was recorded as a recapture and released. However, if no mark was observed, the fish was measured, weighed, marked, and released. The mark recapture population estimate was constrained to Common Carp >200 mm because small fish (< 200 mm) were not fully recruited to the electrofishing gear. During the six month mark-recapture period, 2,848 Common Carp ranging 111 to 620 mm TL were collected. We marked and released 2,752 (≥ 200 mm TL) of the 2,848 fish captured. We recaptured 207 marked fish, resulting in a population estimate of 13,783 Common Carp (95% CI = 11,262-16,648). Common Carp density was estimated at 214 fish/ha -1 (95% CI = 181-267 fish/ha -1 ) and biomass was 148 kg/ha -1 (95% CI = 125-184 kg/ha -1 ). Most (93%) Common Carp in Lake Carl Etling were < quality size, but a small proportion exceeded preferred size. Condition of Common Carp in this population was below average (mean Wr = 90). Our results suggest the density of Common Carp in Lake Carl Etling is high and may be regulating size structure and condition of these fish. Further, based on our results fisheries managers can remove enough Common Carp from this system to improve water quality conditions and sport fish populations.
Globally, contamination of water bodies by microbial pathogens is a significant public health concern. Fecal indicator bacteria such as Escherichia coli (E. coli) typically identify the deterioration of water bodies. In order to determine water quality, monitoring E. coli concentrations is important. During collection, storage, and transportation of water samples, holding time can have a significant impact on the density of indicator pathogens. Although many studies have reported on the effects of holding time exceedances on water quality, there is a lack of comprehensive review of these studies. The objective of this work is to provide a complete review on the effects of holding time exceedances on water quality. The results of this study suggest that most E. coli samples can be analyzed beyond 8 hr and up to 48 hr after sample collection while still generating comparable data if the samples are stored below 10°C.
There are several reports of coccidian parasites (Apicomplexa) from plain-belliedwatersnakes, Nerodia erythrogaster collected from various locales in Arkansas and Texas. However, there are no reports of coccidians from this host or any other watersnake in Oklahoma. Here, we document, for the first time, Eimeria hydrophis from a N. erythrogaster collected in Oklahoma, as well as provide the first photomicrographs of the coccidian.
Hemipterans belong to the largest order of hemimetabolous insects. The number of species in the order is about 75,000, with a great diversity of forms, including the largest family, Miridae (plant bugs). It contains major insect pests and predatory groups that can be used as biological control agents. Here, we document three species of Miridae in Oklahoma, for the first time.
Current guidelines for Macrobrachium rosenbergii advise introduction into outdoor ponds when water is > 160 C. However, little is known about possible interactions between diet quality and temperature tolerance. We examined use of seven rations for prawns raised at suboptimal temperatures. Juvenile prawns readily consumed all seven rations presented. Growth and survivorship were best on shrimp- and silkworm-based rations; whereas, the poorest growth was on fishmeal- and Black Soldier Fly larvae meal (BSFLM)-based rations. Soybean-, cricket-, mealworm-, and fishmeal-based diets had similar survivorship. Mortality occurred within 24 hr after each feeding of the BSFLM-based diet, possibly related to antimicrobial compounds produced by BSFL. Prawns raised at lower temperatures may require better quality feed compared to guidelines based on previous studies at ideal temperatures. Producers must determine whether it is better to stock prawns at higher rates or feed more expensive rations to manage survivorship of juvenile at lower temperatures.
Metal-based compounds have been used to treat disease since as early as the 5th and4th century B.C. Cisplatin, a platinum-based chemotherapy drug, was one of the first metal-basedcompounds found to treat cancer. Other platinum drugs such as oxaliplatin and carboplatin havebeen the backbone of metal-based cancer treatment drugs as well. The potential therapeutic benefitsof metal complexes, in particular, transition metals, has gained attention due to exhibiting uniquecharacteristics including their capability to go through a redox reaction. Due to limitations like drugresistance and worsening side effects, ruthenium compounds have been developed that caused lesssevere and fewer side effects. Copper complexes have been found to exhibit cytotoxic propertieswith distinct mechanisms of actions and even have the ability to competitively bind to sites occupiedby different metals. It has been suggested that gold complexes have the potential to possess antitumorproperties if cisplatin cannot be used as a form of treatment. Silver complexes are another potentialtype of chemotherapeutic drug, found to exhibit greater selectivity against cancer cells and displaybetter cytotoxic action than cisplatin with comparably low toxicity. The potential for metal-basedchemotherapy drugs is continually expanding, and more research should be carried out in order tolearn all of the benefits these unique drugs have to offer the world.
The Redlich-Kwong-Soave equation of state for real gases and liquids has been modified in order to improve the match of calculated liquid molar volumes with measured data by allowing the b-parameter to be a function of the temperature and molar volume of real gases and liquids. Molecular dynamics simulations of the noble gas krypton, using the hard-sphere potential for a large number of krypton atoms, were performed to evaluate how the b-parameter varies with gas molar volume. The results of these simulations were applied when modifying the original Redlich-Kwong-Soave equation of state. In the modified Redlich-Kwong-Soave equation of state, the a-parameter is kept constant. Also, in this modified version, the measured critical molar volume is employed as well as the measured critical temperature and critical pressure values in parameter determination at the critical point. From this determination of parameters for a number of real gases, the same parameters can be approximately calculated using the measured critical compressibility factor avoiding numerical procedures. This results in an equation of state that matches closely with the measured critical point for many gases as well as improving the match between the model and measured liquid molar volumes.
Blue Catfish (Ictalurus furcatus) are the largest catfish found in Oklahoma and are native to the Red River and Lower Arkansas River (Miller and Robison 2004). Blue Catfish are now found in many areas of the state because the Oklahoma Department of Wildlife Conservation (ODWC) stocked Blue Catfish into many impoundments due to their popularity as a sport fish (Miller and Robison 2004, Snow et al. 2017). Blue Catfish are considered omnivorous due to their very diverse diet, often consuming vegetation, mollusks, insects, and crustaceans, with larger individuals shifting to piscivory (Schmitt et al 2017, Jennings et al. 2018). Their diverse forging ecology is likely caused by seasonal habitats shifts and opportunistic feeding strategy on abundant prey species (Magoulick and Lewis 2002, Jolley and Irwin 2003, Jennings et al. 2018)
Elmer Thomas Reservoir is a small impoundment in southwest Oklahoma that contains a high abundance of the invasive plant Eurasian Milfoil. Because dense vegetation can negatively affect Largemouth Bass, population characteristics (condition, growth, and mortality) of Elmer Thomas Reservoir Largemouth Bass were described. Dense vegetation can impact Largemouth Bass foraging and may reduce angler success, so diet and presence of angler hooking wounds (index of angler catchability) were evaluated on a subset of Largemouth Bass. Condition (mean relative weight) of Largemouth Bass was below average (Wr = 88), which may explain the size distribution skewed towards smaller fish (most Largemouth Bass between 275-400 mm TL). Catch-curve analysis indicates that survival of Largemouth Bass is high (77%). Although high survival estimates suggest that angler exploitation (fishing mortality) is low, it appears that angler catchability is still high (35% of Largemouth Bass had hooking injuries; 45% when corrected for imperfect hooking wound detection). Largemouth Bass diets consisted mainly of fish (76% by number), more specifically age- 0 Largemouth Bass comprised 28% by number and occurred in 20% of the diets. High incidence of age-0 Largemouth Bass in diets suggests a change in behavior as a result of dense vegetation and may help to explain the poor condition and growth of Largemouth Bass. This study suggests that Largemouth Bass are negatively affected by vegetation abundance at Elmer Thomas Reservoir. A vegetation management plan to reduce the vegetation to intermediate bundance levels (~30%) would likely benefit the Elmer Thomas Reservoir fish community and increase shoreline fishing opportunities for anglers.
Due to concerns of overexploitation and population decline caused by anthropogenic influences, fisheries managers have turned to hatchery produced Alligator Gar (Atractosteus spatula) stocking to supplement inconsistent wild year classes. Aquaculture can be a useful option to reestablish or supplement natural populations, as many states currently have stocking programs to reintroduce this species. Recent interest in Alligator Gar ecology and conservation has led the Oklahoma Department of Wildlife Conservation to attempt to better understand early life history characteristics of age-0 Alligator Gar in Lake Texoma by tracking growth, diet, habitat use, mortality and stocking contribution. A total of 33,900 Alligator Gar fingerlings were stocked into Lake Texoma in 2017. During June-September 2017, a total of 46 age-0 Alligator Gar were captured in 279 net nights of effort using mini-fyke nets. Mean CPUE (catch-per-unit-effort; number per net night) was highly variable with CPUE varying based on vegetation stem density in the location of the net set. Of the 46 Alligator Gar captured in 2017, 84.5% (39 of 46) were stocked (OTC mark present). During the 4-month sampling period, the daily mortality estimate for stocked age-0 Alligator Gar was 0.049%/day. After the first four months (4.7% mortality rate), 32,306 of the initial 33,900 Alligator Gar remained in the system. The annual estimated mortality rate is 16.7%. The mortality estimate of fish stocked into Lake Texoma is substantially lower than the 94.8% mortality rate observed in the hatchery over three months (1,043 of 20,001 age-0 Alligator Gar remained). Stocking Alligator Gar as fingerlings when water level and habitat availability is sufficient may be more beneficial than holding them in a hatchery setting. Conversely, stocking Alligator Gar early may not be beneficial in a marginal year when nursery habitat is limited and inflow is not consistent enough to maintain a constant pool elevation. During these years it may be better to grow-out fingerlings to larger sizes, such that when stocked they are not easily preyed upon.
Spotted Gar are found throughout Oklahoma and managed as a non-game species. Thisdesignation allows the species to be recreationally harvested using any legal methods.We examinedthree-state record (unrestricted division; harvested by bowfishing) Spotted Gars to estimate age,back calculate length-at-age (growth rates), and identify sex and stomach contents. Spotted Garsage estimates ranged from 32-43 years old. Back-calculated length-at-age displayed similar growthamong the three specimens. All Spotted Gar examined were females, and contained no stomachcontents. Although this study is limited in scope to the largest of Oklahoma specimens, it improvesour knowledge of an understudied species in Oklahoma.
Diet evaluations are conducted to understand predator-prey dynamics of fish communities.However, unless prey items are extracted from fish immediately after consumption, items can beobserved at various stages of decomposition due to digestion. Thus, the ability to accurately measureor identify prey fish is difficult. Fortunately, some skeletal structures, such as the cleithrum bone,are not easily digested and remain in fish stomachs. Cleithra have been used to estimate the totallength of a fish by determining the linear relationship between the total length, horizontal length,or vertical height of a cleithrum against known-sized fish from which the structure was taken.We used linear regression to develop equations to estimate body size for twelve common foragespecies found in Oklahoma reservoirs using cleithrum bones. The relationships between total fishlength:cleithrum length (r2= 0.94-0.99), total fish length:horizontal cleithrum length (r2= 0.90-0.98),and total fish length:vertical cleithrum length (r2= 0.88-0.98) were significant. Additionally, we alsodescribed cleithrum characteristics for each of the twelve fish species, such that fish can be identifiedeven when prey items are heavily digested. When used collectively, the regression equations anddiagnostic features of cleithra will provide a more accurate description of fish diets and a betterunderstanding of predator-prey relationships.
In our third contribution on the subject, we include noteworthy observations on the natural history and ecology of three species of crayfishes, eight native fishes, and two mammals in Oklahoma. Here, additional records of three uncommon species of crayfishes, early spawning dates for five fishes, an unusual occurrence of the egg filaments of Labidesthes sicculus entangled among the gill filaments and rakers of Menidia audens, and notable information on ecto- and endoparasites from two species each of fishes and mammals are documented. Our purpose is to help complement and fill gaps in our limited biological knowledge of this biota that should help in future studies conducted in the state.
