Cycleptus Elongatus Research Articles

Demographics, Reproductive Characteristics, and Genetic Connectivity of Blue Suckers (Cycleptus elongatus) in a Large Tributary

Demographics, Reproductive Characteristics, and Genetic Connectivity of Blue Suckers (Cycleptus elongatus) in a Large Tributary

Mesohabitat and macroecological correlates for blue sucker (Cycleptus elongatus) occurrence in regulated rivers

AbstractBlue sucker (Cycleptus elongatus) populations occur in the Mississippi River and Gulf of Mexico drainages of North America and are negatively affected by habitat fragmentation and flow regime alteration caused by dams. During fish assemblage surveys in August of 2022, we collected five juvenile blue suckers (312–428 mm total length) in the Angelina River upstream of Sam Rayburn Reservoir in East Texas (46,335 ha surface area) where the occurrence of the species was previously unconfirmed. Given this unexpected finding, we (1) analyzed mesohabitat associations to compare habitats we sampled with reports in the literature and (2) reviewed blue sucker occurrences in state, national, and global databases across historical (1950–1980) and contemporary (1981–2022) time periods to assess occurrence across gradients of habitat fragmentation and streamflow regulation. The blue sucker population in the Angelina River upstream of Sam Rayburn Reservoir was previously unconfirmed but is within the native range. Mesohabitats occupied by blue suckers were consistent with literature reports, including fast velocity, shallow depth, and coarse substrates. The low degree of regulation (19% of natural runoff stored by upstream reservoirs) and a high degree of habitat connectivity (287 rkm of unfragmented mainstem habitat) for the Angelina River upstream of Sam Rayburn Reservoir matched range‐wide patterns of persistence within relatively intact (unfragmented and unregulated) or remnant (fragmented but unregulated) riverscapes. Our review reveals that blue sucker populations might persist (1) in remnant river fragments where local habitat conditions are appropriate and (2) where effects of habitat fragmentation and flow regulation are not coupled.

Mismatch between temperature and discharge disrupts spawning cues in a fluvial specialist, blue sucker Cycleptus elongatus

AbstractSeasonal movements cued by environmental variables are a critical component of riverine fish life history. Life‐history events for species such as blue sucker Cycleptus elongatus are likely cued by discharge and temperature and may be disrupted if those life‐history events and environmental regimes are mismatched. However, this effect may be dependent upon the habitat occupied when environmental cues are received by individuals. We tracked telemetered blue sucker in the Colorado River, Texas, USA, from 2015 to 2017 and modelled the relative effects of discharge, temperature and habitat structure on seasonal movement patterns. Tagged fish varied in their propensity to move, although most returned to their original tagging locations. Decreasing temperatures and increasing discharge resulted in increased seasonal movements. Temperature and discharge had the largest effect on movement behaviour, but the magnitude of movements was largely dependent on the year. Temperatures between 12 and 19°C and discharges between 10 and 240 m3s−1 resulted in greater probabilities of spawning movements. Spawning was most probable in 2015 and reduced or halted in 2016 and 2017. Future climate scenarios suggest North America will experience increased drought, warmer temperatures and more variable weather patterns. These future scenarios could negatively impact blue sucker by disrupting environmental cues and habitat availability for seasonal life‐history events. Our results suggest temperature and discharge are critical cues for the species, but that their combined effect is largely dependent on the occupied habitat.

Development and Application of a Size Structure Index for Blue Sucker

AbstractBlue Sucker Cycleptus elongatus is a species of concern across much of its native range due to population fragmentation and habitat loss. A primary 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 = 59 cm, and trophy = 74 cm. We estimated mean values for PSDs using a Bayesian 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 structures except for the James River. The length categories that we derived from the values for PSD should provide an additional tool for evaluating spatial and temporal changes in the size structure of Blue Sucker populations when monitoring the status of this species of concern.

New data on Henneguya postexilis Minchew, 1977, a parasite of channel catfish Ictalurus punctatus, with notes on resolution of molecular markers for myxozoan phylogeny.

Previous morphological and histological data are supplemented with molecular and ultrastructural data for a Henneguya sp. isolated from farm-raised channel catfish Ictalurus punctatus in Mississippi, USA. Myxospores were cryptic, encapsulated within a thin layer of epithelium in the gill lamellae with spore measurements consistent with the original description of Henneguya postexilis Minchew, 1977. Myxospores were 42.7-49.1 µm in total length with spore bodies 12.1-17.2 × 3.6-4.8 × 2.9-3 µm. Polar capsules were of unequal length, with the longer capsule being 4.4-6.7 × 1.1-1.6 µm and the shorter capsule being 4.4-6.4 × 1.1-1.6 µm. Polar tubules had 6-8 turns. Caudal processes were 25.7-38.1 µm in length. Spores were encapsulated in a thin layer of epithelium in the gill lamellae. Molecular data from the most commonly used markers for myxozoan identification and phylogeny, partial 18S small subunit ribosomal gene (SSU), partial 28S large subunit ribosomal gene (LSU), and elongation factor 2 (EF2) were generated for H. postexilis. Additionally, novel data for LSU and EF2 were generated for archived myxozoan specimens from farm-raised catfish (H. mississippiensis, H. ictaluri, H. exilis, H. adiposa, H. sutherlandi, H. bulbosus, Unicauda fimbrethilae), as well as archived specimens from wild fish (H. laseeae [from Pylodictis olivaris], Hennegoides flockae [from Aphredoderus sayanus], Myxobolus cloutmani [from Cycleptus elongatus]. These include the first EF2 sequence data for the genera Hennegoides and Unicauda. Phylogenetic analyses using these data placed H. postexilis in well supported clades with other ictalurid-infecting Henneguya species. Phylogenetic signal assessments on these analyses suggest that while SSU provided the greatest phylogenetic signal, LSU yielded comparable signal, supporting previous work implying this region may be underutilised in reconstructing myxobolid phylogenies.

A NEW SPECIES OF MYXOBOLUS (CNIDARIA: MYXOSPOREA: MYXOBOLIDAE) FROM THE BLUE SUCKER, CYCLEPTUS ELONGATUS (LESUEUR) (CYPRINIFORMES: CATOSTOMIDAE: CYCLEPTINAE), FROM ARKANSAS.

During 9-10 February 2018 and 21-22 February 2020, 7 adult Blue Suckers, Cycleptus elongatus, were collected by hoop nets from the Red River, Little River County (n = 3), and the Black River, Lawrence County (n = 4), Arkansas, and their gills, gallbladders, fins, integument, other major organs, and musculature were examined for myxozoans. All 7 (100%) were infected with an unknown species of gill-infecting Myxobolus sp. Twenty formalin-fixed plasmodia (cysts) of Myxobolus cloutmani n. sp. were elliptoidal, 407 μm long × 270 μm wide. Formalin-fixed myxospores were orbicular to broadly elliptoidal, 8.7 μm long × 7.8 μm wide. Two polar capsules were pyriform and subequal in size, extending over halfway in the myxospore. The larger polar capsule was 5.5 μm long × 3.1 μm wide, while the shorter was 5.1 × 2.9 μm. A coiled polar filament possessed 5 or 6 coils. The myxospore was 3.7 μm thick in sutural view, with a distinct sutural ridge. Qualitative and quantitative morphological data were from formalin-fixed as well as ethanol-preserved spores, while molecular data consisted of a 2,010 base pair sequence of the partial 18S ribosomal RNA gene and a 2,502 base pair sequence of the partial 28S ribosomal RNA gene. Phylogenetic analysis grouped M. cloutmani n. sp. with the other catostomid-infecting myxobolids. This is the first myxozoan reported from C. elongatus.

Comparison of Four Hard Structures Including Otoliths for Estimating Age in Blue Suckers

AbstractThe Blue Sucker Cycleptus elongatus is an imperiled North American catostomid in need of management and protection. No hard structures are validated for aging this species, but past studies focused on somatic structures such as fin rays and scales. Calculated parameters (mortality, recruitment, growth) that inform management decisions are directly influenced by the accuracy and precision of the hard structure used to estimate age. We identify the most precise and credible structure with which to age Blue Suckers while also completing the first in‐depth investigation of their otoliths. We collected Blue Suckers (n = 168) from the lower Wabash River and compared ages estimated from scales, opercles, pectoral fin rays, and lapillus otoliths but were unsuccessful in estimating ages from cleithra. We identified structure bias between all structures and found scales (n = 67; maximum = 11 years, mean = 8.2 years) and opercles (n = 65; maximum = 15 years, mean = 8.3 years) to be substantially less precise than pectoral fin rays and lapillus otoliths. We found that otoliths (n = 128; maximum = 42 years, mean = 13.5 years) were more precise than fin rays (n = 167; maximum = 20 years, mean = 9.6 years) and yielded a much higher range of ages. We could not identify any range of ages or total lengths in which (nonlethal) fin ray age could be accurately corrected to (lethal) otolith age. Thin‐sectioned otoliths are the gold standard for aging most fishes, including numerous age‐validated catostomids, and the credibility of Blue Sucker otolith age estimates was additionally supported by a strong correlation between whole lapillus mass and estimated age (R2 = 0.89). Overall, evidence indicates that Blue Sucker lapillus otoliths yield more precise and credible age estimates than other hard structures.

Blue sucker habitat use in a regulated Texas river: implications for conservation and restoration

Species conservation requires a clear understanding of habitat availability and subsequent use of those habitats. In cases where species declines have occurred and gone undetected by conservation managers, habitat alteration, fragmentation, and loss are often the largest contributors. River fragmentation often results in altered flow regimes, subsequently impacting the availability of riverine habitats. Blue sucker (Cycleptus elongatus) is associated with riffle and run habitat, which is especially impacted when river flows are altered. The goal of this research was to identify the extent of blue sucker habitat and mobility of the species in the Colorado River, Texas. To understand habitat selection and use, blue suckers (N = 49) were surgically implanted with telemetry tags. During 2015–2017, thirty-eight attempts were completed to relocate individuals. Optimized hotspot analysis identified three river reaches critical for blue suckers that accounted for 20% of the study area. Blue suckers used these locations year-round including during spawning. Habitats used by blue sucker were composed of gravel, cobble, boulder, and bedrock typically in riffle and run habitat. Mobility, as measured by home range size, increased as riffle density decreased. Larger home ranges were presumably necessary to find habitat to complete aspects of their life history. Results of this study suggest suitable habitats are limited throughout the fragmented riverscape. Conservation action in the form of habitat construction or increased stream connectivity through barrier mitigation could have positive impacts on the future of blue suckers in the lower Colorado River, Texas.

Ontogenetic shifts in mesohabitat use of young-of-year Rio Grande blue sucker in the big bend region of the Rio Grande

Alteration of flow regimes by anthropogenic activities is one of the primary environmental problems in riverine systems. Understanding how hydrologic conditions can affect ontogenetic habitat shifts of imperiled fishes is important in order to develop conservation and management strategies for each life-history stage. We examined relationships between the abundance of young-of-the-year (YOY) Rio Grande Blue Sucker and various abiotic variables in the Trans-Pecos region of the Rio Grande in Texas, USA. We used open N-mixture modeling to better understand the factors affecting ontogenetic habitat shifts of the imperiled aridland river fish. In addition, we examined differences in Rio Grande Blue Sucker total length among three mesohabitat types (pool, riffle, and run). The results of open N-mixture modeling suggested that as pool area increased, the abundance of YOY Rio Grande Blue Sucker increased. Total length of YOY Rio Grande Blue Sucker also significantly differed among the three mesohabitat types. The total lengths of YOY Rio Grande Blue Sucker in pool habitats were lower than in other mesohabitats, suggesting that YOY Rio Grande Blue Sucker undergo ontogenetic habitat shifts into greater current velocity habitats as they grow. The habitat associations we documented support the growing body of research emphasizing the importance of maintaining sufficient and appropriately timed flows to avoid prolonged low flows that limit habitat availability for native fish species during sensitive life stages in the Rio Grande and other aridland rivers.

Seasonal movements and tributary-specific fidelity of blue sucker Cycleptus elongatus in a Southern Plains riverscape.

This study used acoustic telemetry and a multistate Cormack-Jolly-Seber model to determine the seasonal movement patterns of blue sucker Cycleptus elongatus from 2015 to 2017. Several hypotheses were ranked using AICc , and it was determined that the movement patterns of blue suckers in a mainstem reach below a hydropower dam (i.e., tailwater) differed from those of blue suckers tagged in the major tributaries (perennial with stream order >3). This study estimated a low probability (≤0.13) blue suckers would leave the tailwater reach at any time during the study. Conversely, blue suckers tagged in the major tributaries had a high probability (≥0.88) of leaving after the spawning season (February-May). Blue suckers tagged in the major tributaries displayed a high probability (0.83) of returning to the tributaries in the spawning season of 2016 when discharges were high. Blue suckers also had a higher probability of fidelity to the tributary where they were tagged (0.65) rather than straying to different tributaries (0.18). The majority of tagged blue suckers that strayed selected the only undammed tributary in the study area. In 2017, spring discharges were low, and the probability of blue suckers returning to any major tributary was low (0.19), with little difference in the probability of displaying site fidelity (0.10) vs. straying (0.09).

Trends in River Discharge and Water Temperature Cue Spawning Movements of Blue Sucker, Cycleptus elongatus, in an Impounded Great Plains River

Riverine fishes are sensitive to human-induced changes to their ecosystems and have experienced substantial declines in the past century. The presence and operation of dams modifies natural flow regimes thereby disrupting cues that signal migration and negatively influencing habitats critical to riverine fishes. Blue Suckers (Cycleptus elongatus) make large annual movements, require large and unfragmented reaches of river, and may be sensitive to modifications of cues that initiate migration. We assessed the influence of individual and abiotic factors on home ranges and movements of 62 transmittered Blue Suckers from 2006–2014 in the Missouri River upstream of Fort Peck Reservoir in Montana. Populations in this area are disjunct from those downstream and are influenced by upstream dam regulation. Blue Suckers used large expanses of river with overall home ranges ∼88 river kilometers, but these home ranges were about two times smaller than reported elsewhere. Increasing discharge and water temperature were associated with movement rate and movement probability and cued spawning movements of Blue Suckers. Movement rates increased with discharge to peak and decreased thereafter. Surprisingly, movement rate and probability were highest at the lowest water temperatures we observed (∼1–5°C) unlike previous studies in other systems when peak movement occurred at ≥10°C. Blue Suckers aggregated and showed interannual fidelity to several locations during spawning. Aggregation and fidelity suggest that optimal spawning areas, which exist in tributaries, may be limited within our study area. Our results support evidence that riverine fishes require natural trends in discharge and water temperature, including occasional flood pulses and connectivity among seasonal habitats. The Upper Missouri River retains pseudo-natural discharge and temperature regimes that elicit responses of Blue Sucker to environmental cues, but other rivers may not. Preserving or restoring these features, and entire riverscapes, would maintain natural environmental cues and habitats required by riverine fishes to complete their life histories.

Observations on Habitat Use of Age-0 Rio Grande Blue Sucker (Cycleptus sp. cf. elongatus)

During April 2018, we collected 23 age-0 (33–55 mm total length) Rio Grande Blue Sucker (Cycleptus sp. cf. elongatus) from 3 locations in the Rio Grande near the confluence with the Rio Conchos where the species is rarely reported. Age-0 Rio Grande Blue Suckers occurred in habitats ranging from 6 to 81 cm deep, with current velocities ranging from 0 to 1.03 m/s over silt, sand, gravel, cobble, and bedrock substrates. There was limited evidence for greater detection in slower-velocity habitats with bedrock, silt, and sand substrates, but the habitats we sampled were not unique from habitats sampled in a previous year-round study reporting only a single individual. We conclude that our sampling occurred shortly after successful recruitment, and that age-0 Rio Grande Blue Suckers use a wide variety of habitats.

Intensive Sampling Reveals Underreported Use of Great-River Tributaries by Large-River Fishes in Missouri

Large tributaries may help sustain large-river fish populations by mitigating fish-habitat losses within the highly modified great rivers of the Mississippi River basin. These tributaries are likely most beneficial for fish species specializing on non-degraded large-river habitat for some portion of their life histories. Few great-river tributaries, however, have been surveyed using methods that comprehensively target all fish species, resulting in uncertainty or bias in the reported composition of many tributary fish assemblages. We report important distributional records, including 23 new accounts, for 12 large-river specialist fishes in Missouri—Alosa alabamae (Alabama Shad), Cycleptus elongatus (Blue Sucker), Pimephales vigilax (Bullhead Minnow), Notropis wickliffi (Channel Shiner), Polyodon spathula (Paddlefish), Hybognathus placitus (Plains Minnow), N. blennius (River Shiner), Macrhybopsis hyostoma (Shoal Chub), Scaphirhynchus platorynchus (Shovelnose Sturgeon), M. storeriana (Silver Chub), Ichthyomyzon unicuspis (Silver Lamprey), and Alosa chrysochloris (Skipjack Herring)—following 38 comprehensive fish surveys in tributaries of the Missouri and Mississippi rivers. New accounts collectively demonstrate tributaries support more large-river specialists than historically documented and thus may be currently undervalued sources of habitat for large-river fishes.

Habitat Alterations and Fish Assemblage Structure in the Missouri River System, USA: is Ecomorphology an Explanation?

Sampling was conducted over a two-year period to determine if fish body morphology (as indicated by the Fineness Ratio (FR), an index of fish streamlining) and habitat alterations can interact to influence fish assemblage structure in three human-altered segments of the Missouri River. It was hypothesized that segments with more variability in depths, velocities, and substrates would have a fish assemblage characterized by more diversity in streamlining. Conversely, it was hypothesized that fish assemblages in more altered river segments would exhibit less diversity in streamlining, i.e., less variability from optimal values because of more uniform habitat conditions. In faster more uniform habitats, fewer variations from optimal streamlining would be adaptive. The three flowing segments studied encompassed the mouth of the Yellowstone River (YSS; moderately altered), the area below Garrison Dam, North Dakota (GOS; below dam-highly altered) and the segment from St. Joseph to Kansas City, Missouri (SKS; channelized-highly altered). The three segments exhibited greatly different fish assemblages. Small native minnows (Cyprinidae), particularly flathead chub (Platygobio gracilis), and deep-bodied suckers, such as bigmouth buffalo (Ictiobus cyprinellus), were common in the YSS. The GOS was dominated by the dorsally compressed fathead minnow (Pimephales promelas). Emerald shiner (Notropis atherinoides) and gizzard shad (Dorosoma cepedianum) dominated the fish assemblage in the SKS. When FR and physical conditions were analyzed across all habitat types, the least altered, more natural YSS was characterized by higher diversity of FR and higher variability in velocity and depth than the most altered SKS. Results for the GOS were more difficult to interpret. The fish assemblage in the highly channelized SKS exhibited the weighted mean FR that was closest to the optimal 4.5 value (FR = 4.42) with the smallest deviation from optimal (0.08). The highest mean and highest maximum current velocity use in the three segments was found for species such as sicklefin chub (Macrhybopsis meeki), sturgeon chub (Macrhybopsis gelida), and blue sucker (Cycleptus elongatus), that were nearly optimally streamlined. Deep-bodied species with FRs typically below 3.5, such as Ictiobus spp., river carpsucker (Carpiodes carpio), and centrarchids, tended to exhibit the lowest mean and lowest maximum current velocity use in the three segments . Results of this study can be useful in helping to understand fish assemblage composition in relation to river alterations in various geographical areas. Because the fineness ratio is only a simple index of streamlining and does not account for other anatomical (e.g., fins) and behavioral aspects of fishes, more studies on different species are needed to develop a stronger understanding of how fish cope with the current. Because of the complexity of interacting natural and human-caused factors affecting these highly altered large river systems, fish streamlining is only one of several factors that may influence the observed fish community structure of a large river system. Streamlining deserves consideration, however, for inclusion in more complex models explaining and predicting fish community structure in large rivers.

Comparison of the Precision of Age Estimates Generated from Fin Rays, Scales, and Otoliths of Blue Sucker

Abstract Evaluating the precision of age estimates generated by different readers and different calcified structures is an important part of generating reliable estimations of growth, recruitment, and mortality for fish populations. Understanding the potential loss of precision associated with using structures harvested without sacrificing individuals, such as scales or fin rays, is particularly important when working with imperiled species, such as Cycleptus elongatus (Blue Sucker). We collected otoliths (lapilli), scales, and the first fin rays of the dorsal, anal, pelvic, and pectoral fins of 9 Blue Suckers. We generated age estimates from each structure by both experienced (n = 5) and novice (n = 4) readers. We found that, independent of the structure used to generate the age estimates, the mean coefficient of variation (CV) of experienced readers was approximately 29% lower than that of novice readers. Further, the mean CV of age estimates generated from pectoral-fin rays, pelvic-fin rays, and scales...

Relative Abundance, Movements, and Habitat Use of Southeastern Blue Sucker Cycleptus meridionalis in the Lower Pearl River, Louisiana

Abstract The southeastern blue sucker population in the lower Pearl River that runs through Louisiana has been impacted historically by numerous natural and anthropogenic habitat alterations, with collection records indicating a significant population decline in this system over recent decades. Electrofishing surveys, radio telemetry, and bathymetry and habitat mapping were used to examine relative abundance, movements, and habitat associations of southeastern blue sucker in the lower Pearl River. Relative abundance of southeastern blue sucker was lower relative to other large benthic Pearl River species. Radio telemetry surveys indicated southeastern blue suckers exhibited small home ranges, limited movements, and strong associations with upstream outside edges of deep bends that were characterized by gravel substrates and woody debris. Increased consideration for elevating southeastern blue sucker conservation status in the lower Pearl River system may be warranted given their high habitat specificity, ...

Blue Sucker Summer Utilization Distributions and Inter-annual Fidelity to Summering Habitats

Blue Sucker Summer Utilization Distributions and Inter-annual Fidelity to Summering Habitats

Habitat use and population characteristics of potentially spawning shovelnose sturgeonScaphirhynchus platorynchus(Rafinesque, 1820), blue sucker (Cycleptus elongatus(Lesueur, 1817), and associated species in the lower Wisconsin River, USA

Summary 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 electrofished 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 homing 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, 500–2400 g weight, and 5–20 years of age, whereas spawning blue sucker ranged from 495 to 822 mm total length, 900–5100 g weight, and 5–34 years of age, although age estimates were uncertain. Females were significantly larger than males for both species although there was overlap. Growth in length was negligible for tagged and recaptured presumably spawning shovelnose sturgeon and low (3.5 mm/y) for blue sucker, suggesting that nearly all growth may have occurred prior to maturity and that fish may have matured at a wide range of sizes.

Archaeological data suggest broader early historic distribution for blue sucker (Cycleptus elongatus, Actinopterygii, Catostomidae) in New Mexico

Zooarchaeological data are increasingly important for establishing late Holocene conservation baselines for species of concern. The blue sucker (Cycleptus elongatus) is experiencing range reduction and is endangered in the State of New Mexico. The early historic (ca. AD 1540) distribution of blue sucker is poorly understood, and the extent of habitat loss is unclear. In 1961, two blue sucker skeletal elements were recovered from a late prehistoric/early historic archaeological site in northern New Mexico called Rainbow House (LA 217). Those remains suggest that the past range of blue sucker was larger; however, since that publication, little consideration has been given to the past presence of this species in the Upper Rio Grande. New zooarchaeological data from a site in northern New Mexico called Ponsipa (LA 297) have revealed the presence of multiple blue sucker skeletal elements. Additionally, a review of site reports and regional archaeological journal publications increased the abundance of blue sucker elements found at Rainbow House and added three archaeological sites where blue sucker has been reported in the region. Collectively, this information suggests a broader pre-impoundment distribution for blue sucker than previously recognized and can help establish a new baseline for their conservation or restoration in New Mexico.

Biology, Spawning, and Movements ofCycleptus meridionalisin the Lower Alabama River, Alabama

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.