Richard A. Snow

Oklahoma Department of Wildlife Conservation, Oklahoma Fishery Research Laboratory, 500 E. Constellation Norman, OK 73072, USA

Black Bullhead Otolith Annual and Daily Increment Validation

SEAFWA Journal Volume 9, March 2022

Otolith age validation studies are essential to identify the accuracy of using otoliths to age fish; however, black bullhead (Ameiurus melas) otolith validation studies have not been conducted for either adult or age-0 individuals. Therefore, the objective of this study was to validate annu- lus and daily ring formation in lapilli otoliths of black bullheads. We assessed timing of annulus formation using marginal increment analysis on 409 black bullheads caught monthly from July 2015–June 2016 in Lake Carl Etling, Oklahoma. We evaluated daily growth increment deposition by batch-...

Using Pectoral Spines and Otoliths for Estimating Ages of Channel Catfish and Effects on Estimating Population Parameters

SEAFWA Journal Volume 9, March 2022

Accurate and precise age estimates are required to correctly estimate fish population metrics such as age, growth, mortality, and recruitment. Channel catfish (Ictalurus punctatus) are commonly aged using the lapilli otolith or the articular process of the pectoral spine. Many fisheries managers prefer to use pectoral spines because the process does not require the sacrifice of the fish, but this method may produce biased age estimates. To com- pare precision of the two methods, we used pectoral spines and lapilli otoliths to age 649 channel catfish collected from five Oklahoma...

Evaluation of Otoliths and Four Non-lethal Structures for Estimating Age and Population Characteristics of Three Black Bass Species

SEAFWA Journal Volume 9, March 2022

Black bass (Micropterus spp.) are the most popular freshwater sportfishes in North America and are intensively managed. Successful management of fish populations relies on dependable age data for estimation of age determined population rate functions (growth, mortality, and recruit- ment). Otoliths provide accurate age estimates compared to most other aging structures, but otolith removal requires fish to be sacrificed, leading some fisheries managers to rely on alternative, non-lethal methods for estimating ages of fish. However, non-lethal aging structures may produce biased age...

Diet and Population Characteristics of Stocked Age-0 Saugeye in an Oklahoma Reservoir

SEAFWA Journal Volume 7, March 2020

Fish growth early in life typically affects recruitment to adulthood. For this reason, fisheries managers stock fish of varying sizes (e.g., fingerling or advanced fingerling rather than fry, which are less expensive to produce) hoping that an initial size advantage results in improved survival. Saugeye (Sander vitreus x S. canadensis) are hatchery-produced hybrids that are stocked into many Midwestern and southern U.S. reservoirs to create sportfishing opportunities. A saugeye stocking program was initiated at Arcadia Reservoir, Oklahoma, in 2017 when 38,110 fingerlings were stocked. In...

Comparison of Browned and Standard Otolith Preparation Methods for Estimating Age of Catfish in Oklahoma

SEAFWA Journal Volume 7, March 2020

Catfish are highly regarded by recreational anglers as sportfish in some areas of North America and are intensively managed by fisheries biologists. Accurate population metrics (e.g., growth, mortality, recruitment, age, and size at maturity) are essential to manage these fisheries, which relies on accurate age estimates for fish in these populations. When otoliths are used for age estimation, they are typically sectioned or ground in a transverse plane, but otolith preparation prior to sectioning may differ. Browning otoliths prior to sectioning to help distinguish annuli has been used by...

Age Estimate Precision of Bluegill and Redear Sunfish Using Broken and Whole Otoliths

SEAFWA Journal Volume 7, March 2020

Age estimate precision is essential for fisheries managers when evaluating age structure, growth, and mortality rates for fish populations; therefore, establishing the method with the greatest precision for a particular species is critical. We compared ages estimated from broken and whole otoliths of 693 bluegill (Lepomis macrochirus) and 432 redear sunfish (L. microlophus) from five small impoundments (6.5?101 ha) in Oklahoma. Bluegill ages ranged from 0 to 10, and redear sunfish ranged from 0 to 9. We observed high agreement and precision between readers for ages estimated using broken...

Effects of Starvation on Thermal Tolerances of Juvenile Tiger Muskellunge

SEAFWA Journal Volume 5, March 2018

Geographical range of a species can be limited by environmental conditions such as temperature. This is important to understand when trying to establish a new fish population on the fringe of their range. The Oklahoma Department of Wildlife Conservation (ODWC) has been stocking tiger muskellunge (Esox masquinongy x E. lucius) in Lake Carl Etling in northwestern Oklahoma since 2014 with little success. This reservoir experiences a broad range of temperatures that could affect recruitment of tiger muskellunge, especially during times of the year when prey are not abundant. To explore the...

Comparison of Saugeye Age Estimates and Population Characteristics Using Otoliths and Dorsal Spines

SEAFWA Journal Volume 5, March 2018

Saugeye are hatchery produced hybrids (female walleye [Sander vitreus] and male sauger [S. canadensis]) that have been introduced to aquatic systems throughout the United States. The Oklahoma Department of Wildlife Conservation (ODWC) stocks reservoirs throughout Oklahoma with saugeye to control overcrowded, stunted white crappie (Pomoxis annularis) populations and to provide recreational fishing opportunities. Because sacrificing fish regularly to remove otoliths for age estimation is often unpopular with anglers, a non-lethal means of obtaining age estimates for saugeye to describe...

Validation of Daily Increments Periodicity in Otoliths of Spotted Gar

SEAFWA Journal Volume 4, March 2017

Accurate age and growth information is essential in successful management of fish populations and for understanding early life history. We validated daily increment deposition, including the timing of first ring formation, for spotted gar (Lepisosteus oculatus) through 127 days post hatch. Fry were produced from hatchery-spawned specimens, and up to 10 individuals per week were sacrificed and their otoliths (sagitta, lapillus, and asteriscus) removed for daily age estimation. Daily age estimates for all three otolith pairs were significantly related to known age. The strongest...

Effects of a Growth Check on Daily Age Estimates of Age-0 Alligator Gar

SEAFWA Journal Volume 3, March 2016

Accurate age and growth information is essential for a complete knowledge of life history, growth rates, age at sexual maturity, and average life span in fishes. Alligator gar are becoming increasingly managed throughout their range and because this species spawns in backwater flooded areas, their offspring are prone to stranding in areas with limited prey, potentially affecting their growth. Because fish growth is tightly linked with otolith growth and annulus formation, the ability to discern marks not indicative of annuli (age checks) in alligator gar would give managers some insight...