Pectoral Spine Research Articles

Evaluation of age estimates and resulting population metrics using four aging methods from a Midwestern Blue Catfish population

Abstract Lapillus otoliths and several preparations of pectoral fin spines have been used to age Blue Catfish Ictalurus furcatus; however, there are limited studies examining relative precision of age estimates. Further, comparisons of population characteristics (e.g., growth, mortality) resulting from age structure evaluations are needed to help fisheries managers balance resources needed to conduct investigations with quality of subsequent data. We examined sectioned Blue Catfish lapillus otoliths and sectioned pectoral spine articulating processes, basal recesses, and articulating surfaces to compare relative precision of age estimates. Additionally, dynamic rate functions and resulting population models were examined to determine if variation in age estimates resulted in divergent interpretation of population characteristics. Generally, aging precision was greatest for articulating surface and lapillus otolith sections. Although growth models generated from each aging structured differed, mortality estimates and conclusions drawn from harvest-regulated population modeling were similar across structures. These results demonstrate that although there is variability in precision and growth modeling among different Blue Catfish aging structures, estimates for key population parameters remain consistent.

First record of Siluriformes from the northernmost portion of the Bauru Group (Upper Cretaceous) in the Center-West region of Brazil

This work presents the first record of bony fish from the Maastrichtian of the Marília Formation (Bauru Group) in Goiás State, Brazil. A fragment of a pectoral spine, recovered by screen-washing, clearly represents an important catfish (Siluriformes) record from the Late Cretaceous of South America. The material possesses similarities with forms from the Campanian - early-Maastrichtian of the Adamantina Formation and the Maastrichtian of the Marília (São Paulo State) and El Molino (Bolivia) formations. Inclusion of the new material from Goiás in the dataset for the aforementioned areas within a paleoenvironmental setting provides evidence that Late Cretaceous catfish had a wider distribution than previously known.

A personal account of work on anatomy, physiology, and behavior of fish sound production

My research has been devoted to neuromuscular control of sound production in toadfish, catfish, and other species along with an occasional foray into hearing. Toadfish utilize a heart shaped swim bladder and superfast muscles with small fibers and an unusual ultrastructure. Both sonic motor neurons and muscle fibers increase in size and number for multiple years, and large muscle fibers fragment and likely divide, maintaining energetic efficiency. Toadfish sonic muscles drive the swim bladder directly (a forced response), and the sound waveform parallels bladder movement. The forced response differs from traditional interpretations of swim bladders as underwater resonant bubbles. High water content in the swim bladder wall inhibits resonance by viscous damping at shallow but likely less effectively at deeper depths, suggesting both notions might apply. Catfish produce sounds with their pectoral spines by rubbing a ridged surface on the dorsal process against a rough surface on the cleithrum: a series of quick jerks produce sounds via a slip-stick mechanism. Recent discoveries on other species reveal novel adaptations for sound production and suggestions are made for future work.

A new gyracanthid from the Mississippian of Delta, Iowa, U.S.A.

ABSTRACT A new gyracanthid, Gyracanthus? jasperi, is described based on partially articulated and isolated elements from the Lower Carboniferous (Mississippian) lower Waugh Member of the Ste Genevieve Formation, at the early tetrapod site near Delta, Iowa, U.S.A. Pectoral fin spines of the new gyracanthid are characterized by the insertion on the fin spine being a half to one-third the length of the spine and maximum length:depth ratio 10:1. Ornament ridges on the pectoral fin spine converge at ≥90° along a low leading edge ridge, and ridge tubercles are oriented oblique to the ridge; the distal end of one pectoral is described using micro-computed tomography. The scapulocoracoids have an anteriorly curving bulbous apex, and a base length that is 35–40% of pectoral spine length. The procoracoid is associated with an unornamented ventral plate. A possible isolated dorsal fin spine is more symmetrical and less worn than the pectoral fin spines. Pelvic spines are dorsoventrally flattened, with oblique ridges meeting at approximately 100° proximally and 80° distally, along a smooth leading edge ridge. Scales, found on the partial articulated specimen and as isolated remains, are polyodontode with a flat base. Adults of the new taxon are estimated to have been about one meter long. Deposition was in debris flows, within a sinkhole lake most likely removed from the edge of the ocean. Other Carboniferous gyracanthids from North America are reviewed. http://zoobank.org/urn:lsid:zoobank.org:pub:5C26F98A-E630-4FD6-99A5-F08B5CBB1549

A new gyracanthid (stem Chondrichthyes) from the Late Devonian (Famennian) of the Eastern Cape, South Africa

ABSTRACT A new gyracanthid Gyracanthides riniensis is described from the Famennian (latest Devonian) Waterloo Farm Lagerstätte in the Witpoort Formation, near Makhanda/Grahamstown, South Africa. The new species is based on disarticulated remains including pectoral, pelvic, and median fin spines, endoskeletal shoulder girdle elements, and squamation patches preserved on or close to the same bedding plane. The new taxon is distinguished by having a relatively large, ornate median spine, and arrowhead-shaped tubercular ornament on the spine ridges. The species shows closest resemblance in pectoral spine proportions to Gyracanthides murrayi from the earliest Carboniferous of Australia, and in spine tubercular ornament to its Laurussian contemporary “Gyracanthus” sherwoodi. It differs in spine proportions and ornament from the older (Givetian) and younger (early Carboniferous) gyracanthids found in nearby localities. http://zoobank.org/urn:lsid:zoobank.org:pub:ADF4869C-45DC-4854-9F27-37D490F6D388

Age and growth assessment of the near-threatened fish Rita rita (Siluriformes: Bagridae) in the Ganges basin

Introduction: Rita rita is a freshwater catfish under threat of extinction, mainly from loss of breeding and nursing grounds. A reliable method for age and growth estimation is needed by fishery managers. Objective: To identify the best body structure for age and growth estimation. Methods: We assessed estimates precision based on Average Percent Error (APE), Coefficient Variation (CV), and Percent Agreement (PA) between readers separately analyzed each calcified structure. We used 390 fish samples from three rivers, Ganga, Yamuna and Ramganga, from September 2018 to August 2019. Results: The three indicators favored the use of vertebrae for age estimation; the growth band seems to be annual and formed from May to September. The growth equations were Lt = 90.19(1-e-0.145(t+0.51)) for Ganga; Lt = 91.19 (1-e-0.14(t+0.59)) for Yamuna and Lt = 89.63 (1-e-0.15(t+0.68)) for Ramganga. Conclusion: This species reaches moderate growth in these rivers, where vertebrae are the recommended age estimation structure, followed, in case of need, by sectioned otoliths, whole otoliths and opercular bones. Pectoral spines should be avoided, especially in older fish.

Sounds and associated morphology of Hypostomus species from South‐East Brazil

AbstractHypostomus is the most diverse genus within Loricariidae. These catfish species exhibit a very conservative morphology with relatively few external characteristics that differ between different species. In consequence, there is a challenge to understand the distinction of species of this genus. This study aims to describe the sounds produced by ten species of Hypostomus from Araguari River and Paraopeba River (Minas Gerais, Brazil), to examine whether acoustic features could be used to distinguish between the species, and to understand the corresponding sound production mechanisms. The fish were recorded making sounds by holding them in hand underwater, in a glass tank on the river shore next to where they had been caught. All ten species produced sounds, and no effect of body size on acoustic features was observed. Furthermore, the species could not be distinguished using acoustic features. Likewise, all the studied species exhibited similar bony ridges on the dorsal processes of the pectoral spine. Since the sounds produced by the fish do not seem to exhibit interspecific specificity, they do not appear to have a role in behaviours requiring conspecific recognition, such as reproduction. Sound production may have an alarm, distress, or acoustic aposematism function warning predators of the presence of pectoral spines, which have an anti‐predatory function in this clade.

Consumption of Non-Native Bigheaded Carps by Native Blue Catfish in an Impounded Bay of the Upper Mississippi River

Adult bigheaded carps Hypophthalmichthys spp. have never been observed in the diets of native fishes in the Mississippi River Basin. In addition, blue catfish Ictalurus furcatus diet preference and foraging behavior have never been studied in the presence of non-native bigheaded carps in the Mississippi River system. We examined the gut contents of adult blue catfish (567–1020 mm, n = 65), captured from a Mississippi River backwater using trammel nets. All items in diets were separated and enumerated, and all fish-like diet items were genetically identified to confirm species-level ID. Bigheaded carp ages were determined by sectioning hard structures (pectoral spines, post-cleithra, and vertebrae). Adult silver carp Hypophthalmichthys molitrix (age 3–5, mean = 3.9 years, SE = 0.2; n = 21) had the highest frequency of occurrence (70%) and constituted the greatest percentage by number (58%) and weight (60%) in/of blue catfish diets. Gizzard shad Dorosoma cepedianum ranked second by all three measures (34%, 25%, and 26%). Finally, 50% to 100% of probable age-based sizes of silver carp exceeded gape measurements of blue catfish, suggesting scavenging was the dominant means of predation. More intensive sampling efforts are required to determine the system-wide importance of bigheaded carp in blue catfish diets.

Growth Rates of Non-Native Bighead and Silver Carp in the Upper Mississippi River

Fish age and growth analyses can be used to infer spawning success, recruitment, and population age structure. Understanding these dynamics is important when assessing the impacts of invasive species, such as bighead carp, Hypophthalmichthys nobilis, and silver carp, H. molitrix, (bigheaded carp). These species have established throughout much of the Mississippi River Basin; however, Lock and Dam 19 (LD19) has slowed their establishment in the Upper Mississippi River, resulting in low-density populations with limited reproduction upstream. The age and growth of Bigheaded Carp in recently established populations, especially in this region, are poorly characterized. Therefore, we compared the age and growth of bigheaded carp for four low-density navigation pools of the Mississippi River near the invasion front with one long-established high-density population, separated by LD19. To assess growth rates and age at maturity, we estimated consensus age from pectoral spines, postcleithra, and vertebrae from 1229 bigheaded carp, 30 fish per 50 mm size class. Length at age of capture and back-calculated length-at-age were used to create growth curves using VBGC analysis. The analysis indicated higher growth rates of bighead carp and silver carp upstream of Lock and Dam 19 than downstream. Comparison of growth models with a likelihood ratio test indicated differences in length at time zero between the pools for bighead carp but not for silver carp. However, maximum length and growth rates were significantly different for silver carp upstream and downstream of the dam but not for bighead carp. These results will be used to better understand the population dynamics of this emerging population to inform control and containment actions.

Life-history Parameters of Shield-Head Catfish Synodontis Schall (Bloch and Schneider, 1801) in the Nile River, Egypt

Age and growth, mortality, and exploitation level of the shield-head catfish Synodontis schall inhabiting River Nile, Egypt are studied to evaluate its fishery status and proposed some reference points for its sustainability. A total number of 805 specimens comprising of 306 males and 499 females with the size range of 16.7 - 37.8 cm TL (mean = 26.71 ± 3.58) were investigated. The weight of specimens ranged from 60.0 to 650 g (mean = 194.88 ± 26.58). Statistically, there is no difference between males and females in the longevity and population parameters so all parameters were estimated for sexes combined. The maximum life span of this species was 4 years based on the pectoral fin spine sections. Asymptotic total length (L∞) was 42.25 cm, growth coefficient (K) was 0.42 yr-1, and theoretical age at zero-length (t0) was -0.36 yr, while the growth performance index (Ø’) was 2.87. The instantaneous total, natural, and fishing mortality coefficients were 1.23, 0.54, and 0.69 yr-1, respectively. The Exploitation rate (E) was 0.56. The body length at first sexual maturity (Lm) and mean selection length (Lc) were estimated at 24.1 and 23.6 cm, respectively. There is selective fishing mortality towards smaller fish sizes reflecting the adverse impact of fishing effort. Therefore, for management purposes, it is recommended to increase the length at first capture to maintain sufficient spawning biomass for recruitment and monitoring the exploitation level to control the fishing effort.

A new species of Glyptothorax (Teleostei: Sisoridae) from the Brahmaputra River basin, Arunachal Pradesh, India.

Glyptothorax rupiri, a new sisorid catfish, is described from the Brahmaputra River basin in Arunachal Pradesh, northeast India. It differs from its congeners in the Indian subcontinent by the following combination of characters: the presence of plicae on the ventral surface of the pectoral spine and first pelvic-fin ray; a posteriorly serrated dorsal-fin spine, its length 11.312.2% SL; body depth at anus 11.213.4% SL; a thoracic adhesive apparatus longer than broad, with a V-shaped median depression which opens posteriorly; an arrow-shaped anterior nuchal plate element; adipose-fin base length 10.912.6% SL; nasal barbel not reaching anterior orbital margin; 1418 serrae on posterior margin of the pectoral-fin spine; body with two longitudinal pale-cream stripes; densely tuberculated skin; and the presence of numerous tubercles on the dorsal surface of pectoral and pelvic-fin rays.

Marking fin spine of juvenile sturgeon (acipenseriformes: acipenseridae) using oxytetracycline and the comparing of growth performance

ABSTRACT This study aimed to describe and validate the formation of the rings in the spine of the pectoral fin and to determine the coherence of the OTC mark with the rings of three species of Caspian Sea sturgeon, the Persian sturgeon (Acipenser persicus), the Starry sturgeon (Acipenser stellatus) and Ship sturgeon (Acipenser nudiventris). Validation was achieved by comparing the total radius of the fin spine of fish of known age after one and two years of growth with the measured radius of the first and second rings in the zone. There was no overlap between the measured radius for the first year and the increase for the second. The Ship sturgeon showed the largest width of the second ring followed by the Persian sturgeon and Stellate sturgeon. The results indicate that the highest growth parameter belongs to the juvenile Ship sturgeon. This research showed that chemically marking the fin spines of juvenile Acipenseridae leads to unbiased estimates and contributes to the knowledge of the population dynamics of these species. The study found that the combination of the dial ring of the pectoral fin spine with growth validated the age estimation in juvenile sturgeon Ship, Persian, and Starry sturgeon.

Pseudobagarius eustictus, a new species of catfish from northern Laos (Siluriformes: Akysidae).

Pseudobagarius eustictus, new species, is described from the Nam Heung drainage (a tributary of the Mekong River) in northern Laos. It is distinguished from congeners in having a unique combination of the following characters: a weakly-produced snout in which the upper jaw extends only slightly beyond the margin of the lower jaw when viewed ventrally, 3 tubercles on the posterior margin of the pectoral spine, eye diameter 8% HL, head width 24.1% SL, dark yellow dorsal and lateral surfaces of the head, pectoral spine lacking elongate extensions, pectoral fin reaching the pelvic-fin base when adpressed against the body, dorsolateral surfaces of body without longitudinal series of prominent tubercles, body depth at anus 13.7% SL, length of adipose-fin base 17.7% SL, caudal-peduncle depth 7.0% SL, and 33 vertebrae.

Strategies to control invasion of Sailfin Armoured Catfish, Pterygoplichthys spp. in wastewater-fed aquaculture bheries of East Kolkata Wetland, India with suggestion of a modified barrier based on the biological and behavioural characteristics

Sailfin armoured catfish ( Pterygoplichthys spp.), an alien invasive species of family Loricariidae has invaded extensively in wastewater-fed large aquaculture ponds (locally called ‘bheries’) of East Kolkata Wetlands (EKW), West Bengal, India. As there is no viable controlling method at present, commonly these fishes are removed by different physical methods and discarded. In the present study, we investigated the effectiveness and suitability of different in-practice Pterygoplichthys spp. control methods, based on on-field sampling, biological and behavioural study of the fish and also response analysis of the stakeholder’s of EKW. The results indicate that in-practice eradication efforts, like ‘repeated seine netting’ with or without removal of Eichhornia sheath of the pond periphery and ‘dewatering of pond’ aiming to reduce or eradicate Pterygoplichthys spp., are not fully effective, because of the capture avoidance ability and burrowing habit of these fishes. We found deep and branching burrows of Pterygoplichthys spp. in aquaculture ponds of EKW, with maximum burrow depth of 58 cm, and water in that burrows even after 12 days of dewatering. Hence, it is suggested stakeholders to keep dewatered pond exposed to sunlight for at least four weeks or above to ensure complete water-out from the burrows in which Pterygoplichthys spp. take shelter or lay their eggs. ‘Multilayer bamboo fencing’ or ‘combination of bamboo fencing and net barrier’ use by the stakeholders of EKW to prevent intrusion or re-intrusion of Pterygoplichthys spp. were found only partially effective, because of the capability of these fishes to damage net-blocking through their hard dorsal and pectoral spines or entry through the holes dug across the barrier in beneath or banks of the sewage intake channel. Based on learning on the biological and behavioural characteristics of Pterygoplichthys spp., we then suggested a modified version of barrier to the stakeholder’s of EKW, incorporating a sewage feeder pipeline, a concrete collection chamber with size separation arrangement made of hard materials like wire mesh and a dam of specific dimensions across the channel, for effective prevention of intrusion of these fishes in their aquaculture bheries.

Evaluation of Potential Regulations for Improving Flathead Catfish Size Structure in Iowa’s Large Reservoirs

AbstractRelatively little research exists for lentic populations of Flathead Catfish Pylodictis olivaris, particularly in northern states, such as Iowa, where there are currently no harvest restrictions but where the interest in trophy opportunities is growing. We assessed size structure, age structure, growth, condition, and survival for Flathead Catfish populations in Lake Red Rock and Rathbun Lake to increase our understanding of populations in Iowa and determine parameter values to be used in simulating potential regulations. Using low‐frequency electrofishing, we captured Flathead Catfish during July and August 2019; all fish were measured and weighed, and a pectoral spine was collected for age estimation. Archived data collected in 2010–2013 were also included in analyses. Reducing harvest by using two potential protected slot limits (PSLs; 305–381 and 381–432 mm) or a maximum length limit (no restrictions on fish <381 mm and a reduced bag limit for fish >381 mm) was simulated to determine effects on the percentage of quality‐ and preferred‐size fish. Simulations indicated that both PSLs and the maximum length limit produced a greater percentage of quality‐ and preferred‐size fish than a “no regulation” scenario, with PSLs being more effective at low exploitation (0.05) and the maximum length limit being more effective at higher exploitation rates (>0.10). An understanding of the current status of Flathead Catfish populations will allow managers to better manage these populations via informed decision making and help to protect them as their popularity with anglers increases.

Evaluating Growth Rates of Two Newly Introduced Populations of Blue Catfish in Kansas

Blue Catfish Ictalurus furcatus have been introduced into many of Kansas reservoirs since 1972. They ranked sixth in terms of favorite fish to catch and target among licensed Kansas anglers in 2013 despite limited management. Blue Catfish were sampled and aged from two reservoirs located on the northern and western periphery of their current distribution.Fish were sampled using experimental gill nets, low frequency electrofishing, and float lines. Ages were assigned to a subset of captured fish by a panel of three independent readers examining a thin section cut from the articulating surface of a pectoral spine. Rapid growth was observed in Lovewell Reservoir with Blue Catfish reaching 659-mm by age 6. Growth of Blue Catfish was slower in Wilson Reservoir (552-mm by age 6) but comparable to other populations in the United States. Recruitment of stocked fish was variable but more consistent in Lovewell Reservoir. Year classes established by stockings that contained larger individuals at greater densities were more prevalent in both populations. These results demonstrate inconsistent recruitment patterns of Blue Catfish population development when stocked in large reservoirs.

Two new catfish species of typically Amazonian lineages in the Upper Rio Paraguay (Aspredinidae: Hoplomyzontinae and Trichomycteridae: Vandelliinae), with a biogeographic discussion

Two new species of particular biogeographic significance are described from the upper rio Paraguay basin, one of the genus Paracanthopoma (Trichomycteridae, Vandelliinae) and the other of the genus Ernstichthys (Aspredinidae, Hoplomyzontinae). The two species occur sympatrically in the Rio Taquarizinho, tributary of the Rio Taquari, in the upper Paraguay system. Paracanthopoma saci is distinguished from its only congener, P. parva, by a spatulate caudal peduncle; a minuscule premaxillary dentition (reduced to three delicate teeth); the supraorbital latero-sensory canals opening as two separate s6 pores; the caudal fin slightly convex or truncate with round edges; the skull roof entirely open, unossified; the origins of dorsal and anal fins approximately at same vertical; and the pelvic fin with three rays. Ernstichthys taquari is diagnosed among congeners by the narrow bony shields on dorsal and ventral series, not overlapping or contacting each other; by the presence of seven or eight serrations on the posterior margin of the pectoral spine; and by the pectoral-fin spine only slightly larger than subsequent soft rays. Both Paracanthopoma and Ernstichthys were previously unknown outside of the Greater Amazonian river systems (Amazon, Orinoco, Essequibo and smaller surrounding drainages). Their presence restricted to the Rio Taquari is unexpected and suggests a peculiar biogeographical history. Ancestral geographic distributions were reconstructed using S-DIVA and BBM methods in RASP. A majority of resulting hypotheses support that the two species reached the Paraguay from the Amazon. The alternative explanation accounts for their presence in the Paraguay by vicariant events. In no case, their presence in the Paraguay is an ancestral distribution with subsequent Amazonian dispersal. Though unusual, this pattern is also seen in a few other fish taxa, showing that the Rio Taquari is biogeographically hybrid, combining elements from both the Paraguay and Amazon drainages.

Population Dynamics and Simulated Effects of Length‐Based Trophy Regulations for Flathead and Channel Catfish in the Lower James River, South Dakota

AbstractCatfish are popular with anglers fishing southeastern South Dakota rivers, and a group of anglers has expressed concern about the perceived overharvest of trophy‐size catfish. However, existing data are insufficient for determining whether Flathead CatfishPylodictis olivarisand Channel CatfishIctalurus punctatusare being overharvested. Our objective was to determine the population dynamics of Flathead and Channel catfish and model potential outcomes of length‐based trophy regulations (one fish and no fish harvested over 610 mm) in the lower James River, South Dakota. Multiple gears were used to collect Flathead Catfish (low‐frequency electrofishing and trotlines) and Channel Catfish (baited hoop nets and low‐frequency electrofishing) during 2018, and samples were augmented with angler‐caught catfish collected from three angling tournaments. Pectoral spines were removed from a subsample of fish for age estimation; 305‐mm and larger fish received a Carlin dangler tag with a reward value of US$0, $10, or $100. Growth rates were slow to moderate for Flathead Catfish and moderate for Channel Catfish. Trophy‐size Flathead Catfish (TL ≥ 1,020 mm) were sampled, but few of the collected Channel Catfish exceeded preferred length (TL ≥ 610 mm). Total annual mortality was estimated at 25.7% for Flathead Catfish and 25.2% for Channel Catfish. Exploitation estimated from angler reward tag returns was less than 1% for each species. Yield‐per‐recruit models indicated that a regulation specifying one fish over 610 mm would slightly reduce yield for both species but would only increase the number of memorable‐length Flathead Catfish (860 mm) and Channel Catfish (710 mm) by less than 1%. A no‐harvest regulation would substantially reduce yield of Flathead Catfish and would increase the number of memorable‐length Flathead Catfish by approximately 2% and Channel Catfish by less than 1%. Information obtained during this study suggests that current Flathead and Channel Catfish populations have limited trophy potential and that length‐based trophy regulations would have limited impact on the abundance of large catfish in the lower James River.

Age and growth of Pseudoplatystoma corruscans (Siluriformes: Pimelodidae) at the confluence of the Paraná and Paraguay rivers

Abstract The age and growth of Pseudoplatystoma corruscans, is analyzed on specimens landed in Puerto Antequera, Province of Chaco, Argentina. The study is based on length frequency distribution of 1192 individuals and growth marks of 293 pectoral spines. Previously to age assignation based on spines readings, we performed analyses that ruled out age-associated resorption of rings and corroborated the annual periodicity of mark formation. The average sizes of the radius of each ring were obtained, and the total length of fish were back-calculated to the time of the ring formation, by the regression model fitted between the total radius of the spines to the respective sizes of each fish. Such data showed a good fitting to growth models of von Bertalanffy, Gompertz and logistic for both sexes separately. Results indicate that the study of the species growth must be carried out for each sex separately and that the fishing regulations must consider this characteristic of the species since the current management guidelines could be promoting differential capture by sexes.

Seasonal Sampling Influence on Population Dynamics and Yield of Channel Catfish and Walleye in a Large Great Plains Reservoir

AbstractFish samples collected during different times of the year can be subject to various biases, but the influence of sampling during different seasons on population dynamics and yield metrics in large reservoirs is not well reported. This study compared the age structure, growth, mortality, and yield estimates of Channel Catfish Ictalurus punctatus and Walleye Sander vitreus collected during spring and fall with standardized gill netting in a large Nebraska, USA, reservoir. We sampled fish by using the Nebraska Game and Parks Commission standardized gill net survey methodology. We estimated ages from pectoral spines of Channel Catfish and from sagittal otoliths of Walleye, derived age-length keys, and compared mean spring and fall ages with t-tests. We compared spring and fall von Bertalanffy growth curves with likelihood-ratio tests and mortality estimates from weighted catch curves with an analysis of variance. We visually compared spring and fall yield estimates derived from yield-per-recruit models to assess the impact of variable population dynamics estimates. Estimates of mean age, growth coefficient, mean asymptotic length, total annual mortality, and yield of Channel Catfish did not differ between spring and fall. Conversely, older age structure of Walleye in spring resulted in lower estimates of total annual mortality and higher yield than in fall. Estimates of mean asymptotic length and growth coefficient differed between spring and fall for female Walleye, and mean asymptotic length, growth coefficient, and theoretical time at age 0 estimates varied between spring and fall for male Walleye. Fall yield estimates were substantially lower than spring estimates for both male and female Walleye. These results demonstrate that the sample collection season can impact population dynamics estimates for certain species, whereas others remain relatively unaffected.