Article

Development and Application of a Size Structure Index for Blue Sucker

Authors:
  • South Dakota Game, Fish and Parks
  • South Dakota Game, Fish and Parks
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Abstract

Blue Sucker Cycleptus elongatus is a species of concern across much of its native range due to population fragmentation and habitat loss. A key component of managing this species is monitoring various population characteristics including size structure. A common way to quickly index population size structure is to calculate the proportional size distribution (PSD). However, no standard length categories have been established for Blue Suckers, precluding the use of this index. We used databases, literature searches, field guides, and sampling records to find the largest recorded Blue Sucker. The maximum size Blue Sucker on record was 93 cm, so we propose the following standardized length categories: stock = 23 cm, quality = 38 cm, preferred = 51 cm, memorable = 58 cm, and trophy = 74 cm. We estimated mean PSD values using a generalized linear mixed model with a multinomial likelihood for populations of Blue Suckers from six rivers: the James, Big Sioux, Colorado, Red, Wabash, and Missouri. Most of these populations exhibited large size structure except the James River. These PSD length categories should provide an additional tool for evaluating spatial and temporal changes in size structure of Blue Sucker populations when monitoring the status of this species of concern.

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Basal recess and articulating process sections of pectoral spines are often used to estimate the age of channel catfish Ictalurus punctatus. However, identification of annuli in pectoral spine sections can be difficult. We developed and validated a method for estimating the age of channel catfish by using sagittal otoliths. We also validated a new method using pectoral spines in which a single cut is made through the dorsal and anterior processes (hereafter termed cut spines) and annuli are enhanced with side illumination. Age estimates from otoliths and cut spines were compared with age estimates from traditional articulating process sections of pectoral spines for channel catfish of known ages (1–4). Age estimates by the three methods were correct for more than 90% of fish after two experienced readers independently estimated ages and resolved disagreements by mutual examination. Otoliths were more accurate and less variable in estimating age. Otolith age estimates were always within 1 year and, after mutual examination of the structures in question, 97% of the assigned ages agreed with known age. The accuracy of cut spines and articulating process sections after mutual examination was similar; however, the cut-spine method was simpler than preparing articulating process sections. Otolith annuli were more distinguishable than pectoral spine annuli and were validated for age-1–4 channel catfish. Therefore, we recommend using otoliths to estimate the age of channel catfish.
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The goal of this study was to compare the possible locations, timing, and characteristics of potentially spawning shovelnose sturgeon (Scaphirhynchus platorynchus), blue sucker (Cycleptus elongatus), and associated species during the spring of 2007–2015 in the 149-km-long lower Wisconsin River, Wisconsin, USA, a large, shallow, sand-dominated Mississippi River tributary. A 5-km index station of two pairs of rocky shoals surrounded by sandy areas was electrofished for shovelnose sturgeon and blue sucker in a standardized fashion a total of 40 times from late March through mid-June, the presumed spawning period. On one date in 2008 and two dates in 2012, all rocky shoals and adjacent sandy areas in the lowermost 149 km of the river were also elec-trofished for both species. Shovelnose sturgeon and blue sucker appeared to spawn in the limited rocky areas of the river along with at least four other species: mooneye (Hiodon tergisus), quillback (Carpiodes cyprinus), smallmouth buffalo (Ictiobus bubalus), and shorthead redhorse (Moxostoma macrolepidotum), usually at depths of 0.8–2.0 m and surface velocities of 0.4–1.0 m/s. However, apparently spawning shovelnose sturgeon were found only on mid-channel cobble and coarse gravel shoals within a single 7-km segment that included the 5-km index station, whereas apparently spawning blue suckers were encountered on these same shoals but also more widely throughout the river on eroding bluff shorelines of bedrock and boulder and on artificial boulder wing dams and shoreline rip-rap. Both species showed evidence of hom-ing to the same mid-channel shoal complexes across years. Blue sucker tended to concentrate on the shoals earlier in the spring than shovelnose sturgeon, usually from late April through mid-May at water temperatures of 8.0–15.5°C along with quillback and shorthead redhorse. In comparison, shovelnose sturgeon usually concentrated on the shoals from mid-May through early June at 13.5–21.8°C along with mooneye and smallmouth buffalo. Based on recaptures of tagged fish, at least some shovelnose sturgeon and blue sucker returned to the shoals at one-year intervals, although there was evidence that female blue sucker may have been more likely to return at two-year intervals. Most shovelnose sturgeon could not be reliably sexed based on external characteristics. Spawning shovelnose sturgeon ranged from 487 to 788 mm fork length,
Article
Pallid sturgeon Scaphirhynchus albus relative condition has been observed to be declining along the Nebraska reach (rkm 1212.6–801.3) of the Missouri River over the past several years; therefore, pallid sturgeon capture data was synthesized from the entire Missouri and Middle Mississippi rivers to document and compare how pallid sturgeon condition varies spatially and temporally throughout much of their current range. The study area was subdivided into four river reaches based on a priori statistical differences for pallid sturgeon catches from 2003 to 2015. Pallid sturgeon in the Middle Mississippi River (Alton Dam [rkm 321.9]) to the confluence of the Ohio River (rkm 0.0) were in the best condition while pallid sturgeon in the Middle Missouri River (Fort Randall Dam [rkm 1416.2]) to the Grand River confluence (rkm 402.3) were in the poorest condition. Furthermore, pallid sturgeon condition in the Upper Missouri River (Fort Peck Dam [rkm 2850.9] to the headwaters of Lake Sakakawea [rkm 2523.5] and lower Yellowstone River) and the Lower Missouri River (Grand River confluence to the Mississippi River confluence [rkm 0.0]) were significantly less than in the Middle Mississippi River but significantly higher than the Middle Missouri River. Temporally, pallid sturgeon condition was highly variable. Relative condition in the Middle Mississippi River was consistently above average (Kn = 1.1). Comparatively, Kn throughout the Missouri River rarely exceeded “normal” (Kn = 1.0), with Kn in the middle and lower reaches of the Missouri River having declined to the lowest observed. As pallid sturgeon recovery efforts continue, understanding the range-wide differences and effects on condition could be critical, as poor condition may cause maturation delays, reproductive senescence or even mortality, which affects the likelihood of natural reproduction and recruitment.
Article
The goals of this study were to describe the biology, spawning season, and movements of Cycleptus meridionalis (Southeastern Blue Sucker) in the lower Alabama River, and evaluate possible spawning-site fidelity to Millers Ferry Lock and Dam. We also present fisheries, river discharge, and lock-use data in support of our recommendation to implement fish-passage operations at Claiborne and Millers Ferry locks and dams. We collected a total of 1094 Southeastern Blue Suckers—704 males, 355 females, and 35 sex-undetermined individuals—below Millers Ferry and Claiborne locks and dams from 1995 to 2005. Females were significantly longer and heavier per given total length than males. Spawning season lasted from March through April. Peak spawning occurred in mid-March when the water temperature was 15-20 °C. Age estimates ranged from 4 to 34 years for males and females. We recaptured 20% (206) of 1049 anchor-tagged fish multiple times (range = 1-10) at intervals between captures of 1-3618 d, and recaptures occurred 1-99 km downstream after release. We detected 75% (111) of 149 sonic-tagged fish 1-19 times at intervals between detections of 1-1288 d at distances of 4-250 km downstream after release. Spawning-site fidelity was confirmed by the recapture of 57 anchor-tagged fish and the detection of 15 sonic-tagged fish in or near Millers Ferry tailwater. Daily fish-passage operations completed at Claiborne and Millers Ferry locks and dams from January through April should increase upstream fish-migration success into the upper Alabama and Cahaba rivers without adversely affecting navigation, hydroelectric generation schedules, and industrial water needs along the river.
Article
Record weights of largemouth bass (Micropterus salmoides) exhibited a significant (P 0.05) inverse relationship to latitude throughout the Great Plains states. However, bluegill (Lepomis macrochirus) record weights from the same states exhibited no significant difference (P [>] 0.05). When northern (Montana) and southern (Oklahoma) populations of adult largemouth bass and bluegills were modeled in relation to geographical growth rates, longevity, and constant annual mortality, similar latitudinal relationships existed. Northern largemouth bass grew slower and failed to reach the maximum sizes attained by southern largemouth bass. The Proportional Stock Density value was 12 for the modeled northern largemouth bass population, while the southern largemouth bass population had a value of 50. Northern bluegills also exhibited lower growth rates than southern bluegills; however, the difference in maximum size was slight. The Proportional Stock Density value was 10 for the modeled northern bluegill population, while the southern bluegill population exhibited a value of 23. Analyses of modeled population structures indicated a greater reduction in the absolute sizes of predators on a latitudinal gradient than occurred among prey. This variation in the relationship between the sizes of predator and prey would have a distinct effect on prey vulnerability. Simulated adult bluegill populations in southern latitudes were nearly twice as vulnerable to largemouth bass predation as bluegills in northern ponds. Therefore, bluegill recruitment would seem to be more subject to natural control at southern latitudes.
Article
abstract: This is the third compilation of imperiled (i.e., endangered, threatened, vulnerable) plus extinct freshwater and diadromous fishes of North America prepared by the American Fisheries Society's Endangered Species Committee. Since the last revision in 1989, imperilment of inland fishes has increased substantially. This list includes 700 extant taxa representing 133 genera and 36 families, a 92% increase over the 364 listed in 1989. The increase reflects the addition of distinct populations, previously non-imperiled fishes, and recently described or discovered taxa. Approximately 39% of described fish species of the continent are imperiled. There are 230 vulnerable, 190 threatened, and 280 endangered extant taxa, and 61 taxa presumed extinct or extirpated from nature. Of those that were imperiled in 1989, most (89%) are the same or worse in conservation status; only 6% have improved in status, and 5% were delisted for various reasons. Habitat degradation and nonindigenous species are the main threats to at-risk fishes, many of which are restricted to small ranges. Documenting the diversity and status of rare fishes is a critical step in identifying and implementing appropriate actions necessary for their protection and management.
Article
The use of transverse sections of sagittal otoliths has been validated for estimating the ages of largemouth bass Micropterus salmoides to age 5. However, previous research has indicated that the accuracy of this method is low for fish older than age 5. We used known-age fish of ages 0-16 to confirm that the use of otoliths is valid for estimating the ages of older largemouth bass. The estimated ages were correct for 97% of the fish. We concluded that past difficulties with using otoliths were more likely the result of preparation and reader error than of the structures depicting incorrect ages. The preparation method used in this study was simpler and faster than conventional methods of preparing thin sections and therefore should yield results that are more consistent.
Article
Little is known about the relative abundance and biology of the blue sucker (Cycleptus elongatus), a species that may be declining in some parts of its range. We described the age, growth, condition, length distribution, and habitat preference of the blue sucker in two South Dakota rivers. Specimens were collected from the James River (n=74) and Big Sioux River (n=28) during the summer of 2000. Although five macrohabitats were sampled with electrofishing and hoopnets, most individuals were collected from riffle habitats and downstream of rock dams. Total length-weight relationships were log10 W= −6.14+3.37 (log10L) (r = 0.92) for blue suckers from the James River and log10 W= −6.52+3.50(log10L) (r = 0.97) for fish from the Big Sioux River. Mean condition factors (K = W(10)/L) of blue suckers were 0.79 (SE = 0.07) for the James River and 0.73 (SE = 0.07) for the Big Sioux River. Blue suckers between 500 and 700 mm dominated length distributions (range = 374–717 mm) of both samples. Ages ranged from two to nine years, but six-year-old fish were captured most frequently. Blue suckers grew rapidly during juvenile stages (< age 5); however, growth slowed afterward.
Article
Length-frequency data can be quantified using proportional stock density and relative stock density indices. However, standardized length categories must be available for each fish species. Thus, we developed standard length categories for calculation of stock density indices for pallid sturgeon (Scaphirhynchus albus.) Based on the longest fish (1,638 mm fork length) that we could find in sampling records or from angler catches, we propose the following length categories: stock = 33 cm (13 in); quality = 63 cm (25 in); preferred = 84 cm (33 in); memorable = 104 cm (41 in); and trophy = 127 cm (50 in). Using these length categories, we then calculated the size structure indices for pallid sturgeon populations in which recruitment had been supplemented with hatchery-produced fish.
Article
Basal recess and articulating process sections of pectoral spines are often used to estimate the age of channel catfish Ictalurus punctatus. However, identification of annuli in pectoral spine sections can be difficult. We developed and validated a method for estimating the age of channel catfish by using sagittal otoliths. We also validated a new method using pectoral spines in which a single cut is made through the dorsal and anterior processes (hereafter termed cut spines) and annuli are enhanced with side illumination. Age estimates from otoliths and cut spines were compared with age estimates from traditional articulating process sections of pectoral spines for channel catfish of known ages (1–4). Age estimates by the three methods were correct for more than 90% of fish after two experienced readers independently estimated ages and resolved disagreements by mutual examination. Otoliths were more accurate and less variable in estimating age. Otolith age estimates were always within 1 year and, after mutual examination of the structures in question, 97% of the assigned ages agreed with known age. The accuracy of cut spines and articulating process sections after mutual examination was similar; however, the cut-spine method was simpler than preparing articulating process sections. Otolith annuli were more distinguishable than pectoral spine annuli and were validated for age-1–4 channel catfish. Therefore, we recommend using otoliths to estimate the age of channel catfish.
Article
Continuous direct current (DC) and pulsed DC (PDC) of varying frequency and pulse period are commonly used to immobilize and collect crappies Pomoxis spp. in freshwater. However, little information is available about the minimum electrical-setting thresholds required for immobilization or how the settings relate to incidence of injury. We investigated the effect of increasing power densities on the immobilization and injury of black crappies P. nigromaculatus (average total length = 154 mm) treated with DC and various PDC settings. Forced swimming toward the electrodes was observed in black crappies exposed to DC, but that was less apparent for PDC. The minimum peak power densities required to immobilize black crappies ranged from 0.10 to 6.5 mW/cm3 and depended on pulse frequency and period. The incidence of hemorrhaging ranged from 0% to 50% and that of spinal damage from 9% to 45%. However, the severity of injury also depended on pulse frequency and period. No fish suffered mortality at or below the immobilization thresholds, but mortality ranged from 0% to 15% at settings above the thresholds. Mortality was observed with PDC settings of 15 Hz only. Fish that were tetanized following electrical treatment were more prone to injury than those that exhibited narcosis.
Article
A length-categorization system was developed to assess structure of fish stocks with greater precision than is possible using Proportional Stock Density (PSD). Three new size categories - preferred, memorable, and trophy - were developed to accompany previously established stock and quality lengths. Like minimum stock and quality lengths, minimum lengths for the new categories are defined as percentage lengths of the all-tackle, world-record fish. Length ranges from or near which minimum stock, quality, preferred, memorable, and trophy lengths should be selected were computed for all freshwater fish species having a world-record length listed by the International Game Fish Association in 1982. Minimum lengths corresponding to each of the five size categories are proposed for several species. By arraying samples of fish population data or angler catch data according to the five size-group categories, a length-frequency distribution can be easily assessed and verbalized. Relative Stock Density (RSD) or models for catch rates also can be developed to set management objectives that are easily understandable, yet reflect recruitment, mortality, and growth functions of fish populations and communities. Desirable percentages and catch rates for size-group categories may differ among individual waters or geographic regions depending upon management objectives and the capacity to produce the species of interest.
Article
Fish size and electrical waveforms have frequently been associated with variation in electrofishing effectiveness. Under controlled laboratory conditions, we measured the electrical power required by five electrical waveforms to immobilize eight fish species of diverse sizes and shapes. Fish size was indexed by total body length, surface area, volume, and weight; shape was indexed by the ratio of body length to body depth. Our objectives were to identify immobilization thresholds, elucidate the descriptors of fish size that were best associated with those immobilization thresholds, and determine whether the vulnerability of a species relative to other species remained constant across electrical treatments. The results confirmed that fish size is a key variable controlling the immobilization threshold and further suggested that the size descriptor best related to immobilization is fish volume. The peak power needed to immobilize fish decreased rapidly with increasing fish volume in small fish but decreased slowly for fish larger than 75–100 cm. Furthermore, when we controlled for size and shape, different waveforms did not favor particular species, possibly because of the overwhelming effect of body size. Many of the immobilization inconsistencies previously attributed to species might simply represent the effect of disparities in body size.
Article
The razorback sucker, Xyrauchen texanus, in the middle Green River (U.S.A.) has been described as a static population consisting of old individuals that will eventually disappear through attrition. Capture data between 1980 and 1992 indicated a constant length frequency despite a slow but positive growth rate of individual fish. Abundance and survival estimates indicated that the population of razorback sucker in the middle Green River is precariously low but dynamic. Although high variation existed among survival estimates, no significant decrease in the population between 1982 and 1992 could be detected. The low level of recruitment occurring in the razorback sucker population of the middle Green River was related to high-flow years, indicating that floodplain habitats may be necessary for survival of the species. La probación de Xyrauchen texanus en el río “Middle Green” (EEUU) ha sido descrita como estática consistiendo en individuos viejos que eventaulmente van a desaparecer por atrición. Los datos de captura entre 1980 y 1992 indicaron una frecuencia de tallas constante a pesar de una tasa de crecimiento individual lenta pero positiva para los peces. Las estimaciones de abundancia y supervivencia indicaron que la población de Xyrauchen texanus del río “Middle Green” es precariamente baja pero dinámica. Si bien existió una alta variación entre las estimaciones de supervivencia, no se puedo detectar un decremento poblacional significativo entre 1982 y 1992. Los bajos niveles de reclutamiento que ocurren en la población de Xyrauchen texanus fue relacionada con años de grandes caudales lo que indica que los hábitats de las planicies de inundación son necesarios para la supervivencia de la especie.
Biological characteristics and seasonal use of Blue Sucker in the James River, South Dakota. South Dakota Department of Game, Fish and Parks, State Wildlife Grant
  • T Carlson
  • B Schall
  • D Lucchesi
Carlson, T., B. Schall, and D. Lucchesi. 2021. Biological characteristics and seasonal use of Blue Sucker in the James River, South Dakota. South Dakota Department of Game, Fish and Parks, State Wildlife Grant, Project T-86-R-1, Performance Report, Pierre.
Movement, habitat use, and population dynamics of Blue Sucker in the southern Great Plains. Doctoral dissertation
  • J J Dyer
Dyer, J. J. 2018. Movement, habitat use, and population dynamics of Blue Sucker in the southern Great Plains. Doctoral dissertation. Oklahoma State University, Stillwater.
Three-year summary age and growth report for Blue Sucker
  • S Labay
  • J Kral
  • S Stukel
LaBay, S., J. Kral, and S. Stukel. 2008. Three-year summary age and growth report for Blue Sucker. South Dakota Department of Game, Fish and Parks, Yankton.
Inland fisheries management in North America
  • K. L. Pope
  • S. E. Lochmann
  • M. K. Young