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At least 307 records · Page 17Linked to original sources
USGS2011

Improved method for sectioning pectoral spines of catfish for age determination

A modified low-speed saw provided fast and precise sectioning of catfish pectoral spines for use in aging studies. In one hour, 10–15 spines can be sectioned, the sections mounted, and the annuli counted. Two methods commonly used to section ictalurid pectoral spines are (1) acid decalcification, followed by the use of a razor blade or microtome to slice the softened spines, and (2) cutting hard spines with electric saws. Decalcifying methods are time-consuming, and we had difficulty attaining the proper spine consistency for sectioning when we used decalcification techniques. Electric saws with toothed blades tended to obliterate the first-year annulus at the periphery of the central lumen on spines of channel catfish (Scholl 1968). A low speed saw equipped with two, thin parallel diamond blades was used to section fish fin rays and spines (Shepard and Nichy 1984), but drawbacks are that the preparation is time-consuming and the blades tend to warp. We used a low speed saw with a thick (0.3 mm), single blade for slicing the pectoral spines of brown bullheads ( Ictalurus nebulosus ) with fast, accurate and reproducible results. We also successfully sliced the pectoral spines of channel catfish ( Ictalurus punctatus ) and black bullhead ( Ictalurus melas ). The advantages of this method are: (1) spine sections are clear, with uniform thickness and little tissue damage; (2) no time-consuming procedures are necessary; (3) the original spine remains intact for future sectioning; and (4) the thick, single blade does not warp.

Journal of Freshwater Ecology↗
USGS1991

Effects of submersed macrophytes on dissolved oxygen, pH and temperature under different conditions of wind, tide and bed structure

Seasonal data on diurnal dissolved-oxygen concentration (DO), pH, temperature and chlorophyll-a were collected and species composition and vertical structure of macrophyte beds were analyzed in the tidal Potomac River during the 1987 growing season. The relationships among these variables and physical and climatic factors were analyzed. Elevated surface temperatures, DO and pH were found in macrophyte beds in June and August; surface temperatures were also elevated in the dense Hydrilla verticillata dominated bed in October-November after senescence had begun. Bottom DO, pH and temperature were lower than surface values. Bottom temperatures in vegetated sites were highly variable compared with bottom temperatures in unvegetated sites.

Journal of Freshwater Ecology↗
USGS1991

Crayfish ( Orconectes virilis ) feeding on young lake trout ( Salvelinus namaycush ): effect of rock size

In laboratory studies, we quantified predation rates of crayfish ( Orconectes virilis ) on the eggs and sac fry of lake trout ( Salvelinus namaycush ) and a surrogate species, rainbow trout ( Oncorhynchus mvkiss ), dispersed among different sized substrates (bare bottom, gravel, cobble, large rocks). Predation was most severe when no rocks were present. Feeding rate then decreased as the substrate changed from large rocks to cobble to gravel. Crayfish predation rate did not change with prey type—rainbow trout and lake trout eggs or sac fry. Crayfish foraging in large tanks containing cobble averaged about two eggs or sac fry per day. In most instances, crayfish would have little impact on lake trout egg survival. Only in lake trout spawning grounds with relatively low egg densities, large crayfish populations, and cobble or large rock substrate, would crayfish be expected to have some impact on lake trout egg survival.

Journal of Freshwater Ecology↗
USGS1991

Assessment of the sensitivity of Missouri reservoirs to acidification

We used water quality information from 103 Missouri reservoirs to assess their sensitivity to acidification from acidic atmospheric deposition. Total alkalinity less than 20 mg/L or a Calcite Saturation Index (CSI) of 1.0 or greater were the criteria to classify reservoirs as sensitive to acidification. Most of the reservoirs (83 of 103) would be considered circumneutral, hard water systems with high acid neutralizing capacity. Thirteen reservoirs were sensitive to acidification based on alkalinity or CSI. Four reservoirs with both low alkalinity and high CSI are located in southeast Missouri in areas of igneous rock outcroppings or chert deposits in limestone formations. These reservoirs are small (<40 ha) and have limited watersheds (<600 ha) and site-specific edaphic factors that likely determined their water chemistry. Site-specific factors also influenced water chemistry of acid-sensitive reservoirs that were located in regions expected to yield highly buffered water. No reservoir classified as acid-sensitive presently seems affected by acidification.

Journal of Freshwater Ecology↗
USGS1992

Competition for food between crayfish ( Orconectes virilis ) and the slimy sculpin ( Cottus cognatus )

Interspecific competition for a food resource (fish eggs) was examined in a laboratory setting between two common benthic organisms of the Great Lakes, the slimy sculpin ( Cottus cognatus ) and crayfish ( Orconectes virilis ). In monospecific tests, the median egg predation in aquarium microcosms ranged from 2.5 eggs/d for the sculpin to 3.0 eggs/d for the crayfish. In mixed-species tests, sculpin feeding rates were no different than in the monospecific tests. Feeding rates for crayfish, however, were significantly reduced by the presence of sculpin. In mixed-species treatments in which small refuges were included in the aquaria, crayfish predation of eggs was 50% less than in the monospecific tests, i.e., 1.5 eggs/d, and, crayfish went on 93% fewer excursions outside refuges, spent 94% less time outside refuges, and engaged in 83% fewer feeding bouts than sculpin (P&le; 0.05 for all comparisons). When no refuges were provided, crayfish ceased feeding (0 eggs/d). These results suggest the potential for an asymmetrical competitive interaction in a natural setting in which crayfish may be forced into a suboptimal diet by such an interaction with the slimy sculpin.

Journal of Freshwater Ecology↗
USGS1992

Trace elements in lake sediment, macrozoobenthos, and fish near a coal ash disposal basin

Samples of lake sediment, macrozoobenthos, and fish were collected during 1983 and 1984 near a coal ash disposal basin situated on the western shoreline of Lake Erie. Neutron activation analysis was used to determine if potentially toxic trace elements were present in higher concentrations at stations near the basin than at reference stations a few kilometers away. Of the 29 trace elements examined, arsenic and cobalt were significantly ( p <0.05) more concentrated in sediment nearest the coal ash basin except in spring, when little or no difference was detected. Arsenic and bromine were significantly higher in oligochaetes, and selenium was significantly higher in both oligochaetes and chironomids taken from proximal stations than in those taken from reference stations. Selenium, bromine, cobalt, nickel, and chromium were higher in young-of-the-year brown bullheads taken nearer the disposal basin in fall 1983. Selenium was higher in adult spottail shiners taken at the proximal station in spring 1984, and bromine was higher in yearling white bass from the proximal station in fall 1983 and 1984. None of the trace elements was higher in adult yellow perch or adult brown bullheads at any time. Fewer spottail shiners and yearling white bass were caught close to the disposal basin than far away, which may indicate avoidance by these fish of increased concentrations of trace elements contained within the ash effluent.

Journal of Freshwater Ecology↗
USGS1992

Habitat use by larval fishes in backwater lake of the upper Mississippi River

Light traps were used to sample larval fishes in Lawrence Lake (Pool 8, upper Mississippi River) from late May through mid-August 1990. Catches differed considerably between vegetated sites and an adjacent open-water area and were highly variable among vegetated stations. Sunfishes ( Lepomis spp.) dominated the vegetated sites. Brook silversides ( Labidesthes sicculus ), Cyprinidae and gizzard shad ( Dorosoma cepedianum ) dominated catches at the open-water site. There was no difference in fish use of vegetated habitats near and far from the main channel of the Mississippi River. Taxonomic diversity was greatest at stations with emergent vegetation.

Journal of Freshwater Ecology↗
USGS1993

Reproductive characteristics of a population of the washboard mussel Megalonaias nervosa (Rafinesque 1820) in the upper Mississippi River

We examined monthly and age-specific gametogenic development of the washboard mussel, Megalonaias nervosa , from April 1986 to March 1987 in navigation Pool 10 of the upper Mississippi River. We found M. nervosa to be a late tachytictic breeder. Female marsupia contained eggs or glochidia primarily from August (17°C) through October (9°C). Males were mature from July through October. Most females released their glochidia in October. Only one female was gravid in November (3°C). Most mussels were sexually mature at 8 years of age and then had an estimated average size of 68 mm (shell height). Only 8% of individuals ≤ 4 years of age showed any degree of reproductive development, while > 90% of age 5 and older individuals had recognizable reproductive material present. In host specificity studies, we verified three fish species as hosts for the glochidial stage. Green sunfish ( Lepomis cyanellus ), black bullhead ( Ictalurus melas ), and channel catfish ( Ictalurus punctatus ) produced juveniles after 26–28 days at 17°C. White suckers ( Catastomus commersoni ) and yellow perch ( Perca flavescens ) retained glochidia from 23 up to 26 days, but no juveniles were produced. Glochidia remained attached to common carp ( Cyprinus carpio ) and fathead minnows ( Pimephales promelas ) ≤ 3 days. Channel catfish were retested at 12°C and produced juveniles after 56 days.

Journal of Freshwater Ecology↗
USGS1993

Morphometric differentiation of American shad and white sucker eggs from riverine samples

We developed a statistical method to distinguish the large demersal eggs of American shad from those of white sucker in riverine samples using egg morphometric analysis. Eggs were first screened by total diameter in deionized water according to ranges reported in the published literature. Differences in relative yolk diameter between the two species were then determined statistically from known museum sources. Only those eggs with relative yolk diameters greater than two standard deviations below the mean for white sucker eggs were considered to be American shad eggs. The criteria for American shad eggs were total diameter ≥2.3 nm and relative yolk diameter ≤66%. A partial test of the model showed predicted identity to agree with observed identity for 74 out of 75 shad eggs.

Journal of Freshwater Ecology↗
USGS1993

Crayfish (Orconectes virilis) predation on zebra mussels (Dreissena polymorpha)

In laboratory studies, we quantified predation rates and handling time of crayfish ( Orconectes virilis ) on zebra mussels ( Dreissena polymorpha ) and rainbow trout ( Oncorhynchus mykiss ) eggs. In single prey species tests, crayfish ate zebra mussels at similar rates as they ate rainbow trout eggs. When both prey were present, crayfish preferred rainbow trout eggs. Handling time of mussels was about twice that of rainbow trout eggs, and energetic content of mussels was lower. Therefore, net benefit for foraging on rainbow trout eggs was about three times that of foraging on zebra mussels.

Journal of Freshwater Ecology↗
USGS1993

Spawning activity of paddlefish (Polyodon spathula) in the lower Black River, Wisconsin

We present indirect evidence of successful paddlefish ( Polyodon spathula reproduction in 1989 and 1991 in the lower Black River, Wisconsin, about 5 km upstream of the confluence with the upper Mississippi River. This is the first indication of successful reproduction by paddlefish at the northern end of its range in the central United States. Attempts to document paddlefish Polyodon spathula reproduction by sampling eggs and larvae began in the early 1900s (e.g., Stockard 1907), but the exact timing and location of fish spawning were unknown until the early 1960s. Actual spawning by paddlefish was first observed over gravel bars in the Osage River, Missouri, by Purkett (1961), who then collected eggs and larvae. Paddlefish eggs and larvae have since been collected below dams on the Missouri (Ruelle and Hudson 1977, Unkenholz 1982), Cumberland, and Tennessee Rivers (Pasch et al. 1980, Wall us 1986). However, the spawning areas for most paddlefish populations remain unknown. Because larval paddlefish are rarely sampled, the presence of post-larval and juvenile paddlefish is often interpreted as indirect evidence of successful reproduction. Such evidence has been used in Illinois (Adams 1942), Oklahoma (Houser and Bross 1959), the Missouri River along the Nebraska-South Dakota border (Ruelle and Hudson 1977), Pool 13 of the upper Mississippi River (Gengerke 1978), and Louisiana (Reed et al. 1992) to document successful paddlefish reproduction. We gathered similar evidence from the lower Black River, near La Crosse, Wisconsin. This information is important because Wisconsin represents the northern limit for paddlefish in the central United States (Gengerke 1986) and because attempts to document reproduction by the few remaining localized populations in the state have been unsuccessful (Lyons, In press). Additionally, paddlefish are of special concern in Wisconsin because of low numbers and limited distribution (Johnson 1987). During November 1990, we observed a small paddlefish (about 700 mm total length, TL) in the catch of commercial seine fishermen working in the lower Black River (about 5 km upstream from its confluence with the Mississippi River). On April 15, 1992, commercial fishermen working the same section of the Black River found five small paddlefish (<350 mm TL) in their catch. Additionally, three small paddlefish (about 800 mm TL) were taken on December 28, 1992, during commercial seining operations in the lower Black River. In Pool 13 of the upper Mississippi River, age-1 paddlefish averaged 498 mm fork length (Gengerke 1978), and the growth of paddlefish is faster in backwaters than in the main channel (Rosen 1976, Russell 1986). Therefore, we think that the three 800-mm paddlefish taken on December 28, 1992 were age-1 fish that hatched during spring 1991 near the Lake Onalaska spillway on the lower Black River. We also think that the 700-mm paddlefish observed in November 1990 was an age-1 fish that had hatched in the same area during spring 1989.

Journal of Freshwater Ecology↗
USGS1993

First collection of rudd, Scardinius erythrophthalmus (Cyprinidae), in the New River, West Virginia

We collected the first rudd, Scardinius erythrophthalmus (Cyprinidae), from the New (Kanawha) River drainage, West Virginia. The rudd has now been reported from 12 states (Arkansas, Kansas, Illinois, Massachusetts, Maine, Missouri, New York, Oklahoma, Virginia, Wisconsin, and West Virginia) and several major river systems. The rapid spread of the rudd has apparently been facilitated by bait dealers. Despite its widespread distribution, there have been no investigations of potential interactions with native aquatic fauna.

Journal of Freshwater Ecology↗
USGS1993

Macrohabitat of Sonora Chub ( Gila ditaenia ) in Sycamore Creek, Santa Cruz County, Arizona

Physical characteristics and persistence of macrohabitat used by different life stages of Sonora chub ( Gila ditaenia ) were determined by repeatedly measuring distinct reaches in Sycamore Creek, Santa Cruz County, Arizona, in 1990 and 1991. At the beginning of summer drought, habitats occupied by adult Sonora chub were deeper and larger than areas with only immature fish and unoccupied areas. The medians of maximum depth were 47.0 cm (1990) and 39.7 cm (1991) for habitats with adults, 21.3 cm (1990) and 22.9 cm (1991) for habitats with only immature fish, and 14.6 cm (1990) and 19.7 cm (1991) for unoccupied areas. At the end of summer drought, adults occupied habitats that were deeper and larger, and the percent decrease in area and depth was less than areas containing only immature fish or no fish. The medians of percent decrease in maximum depth were 13% (1990) and 21% (1991) for habitats with adults, 48% (1990) and 41% (1991) for habitats with only immature fish, and 42% (1990) and 33% (1991) for unoccupied areas. By the end of summer drought, habitats with only immature fish were not physically different from unoccupied areas. Loss of total surface area was highest in reaches that contained only immature fish or no fish (range = 36% to 94%). Most Sonora chub lost from evaporating surface waters were immature fish. Ephemeral and unoccupied areas had higher percentages of floating cover and coarser substrates than persistent, occupied areas.

Arizon↗
USGS1993

Energy budget for yearling lake trout, Salvelinus namaycush

Components of the energy budget of yearling lake trout ( Salvelinus namacush ) were derived from data gathered in laboratory growth and metabolism studies; values for energy lost as waste were estimated with previously published equations. Because the total caloric value of food consumed by experimental lake trout was significantly different during the two years in which the studies were done, separate annual energy budgets were formulated. The gross conversion efficiency in yearling lake trout fed ad libitum rations of alewives at 10°C was 26.6% to 41%. The distribution of energy with temperature was similar for each component of the energy budget. Highest conversion efficiencies were observed in fish fed less than ad libitum rations; fish fed an amount of food equivalent to about 4% of their body weight at 10°C had a conversion efficiency of 33% to 45.1%. Physiologically useful energy was 76.1–80.1% of the total energy consumed. Estimated growth for age-I and -II lake fish was near that observed for laboratory fish held at lake temperatures and fed reduced rations.

Journal of Freshwater Ecology↗
USGS1993

A sampling method for conducting relocation studies with freshwater mussels

Low recovery of transplanted mussels often prevents accurate estimates of survival. We developed a method that provided a high recovery of transplanted mussels and allowed for a reliable assessment of mortality. A 3 × 3 m polyvinyl chloride (PVC) pipe grid was secured to the sediment with iron reinforcing bars. The grid was divided into nine 1-m 2 segments and each treatment segment, was stocked with 100 marked mussels. The recovery of mussels after six months exceeded 80% in all but one treatment group.

Journal of Freshwater Ecology↗
USGS1994

Evaluation of the mussel fishery in Wheeler Reservoir, Tennessee River

We evaluated the freshwater mussel fishery on Wheeler Reservoir, a 27,155-hectare mainstream impoundment of the Tennessee River in Alabama. During July 1991 through June 1992, we used a roving creel survey to conduct 285 interviews over 57 weekdays and 12 weekend days. Total harvest during the 12-month survey period was estimated to be 570 metric tons, and included 15 mussel species. The most frequently harvested species were the washboard Megalonaias nervosa. Ohio pigtoe Pleurobema cordatum, and butterfly Ellipsaria lineolata. Harvest peaked in June at 290,414 mussels. Among collection techniques, total estimated effort was highest for divers (71,160 musseler-hours). The total estimated value of the 12-month mussel harvest (in terms of money paid to harvesters) from Wheeler Reservoir was US$2,119,921.

Alabama↗
USGS2011

Diel feeding chronology of six fish species in the Juniata River, Pennsylvania

We examined diel feeding chronology of six fish species in the Juniata River, Pennsylvania. Ephemeropteran nymphs were the major prey of redbreast sunfish ( Lepomis auritus ; 70.5%) and smallmouth bass ( Micropterus dolomieu ; 59.7%) during each of six 4-h intervals over a 24-h period. The main dietary component of mimic shiner ( Notropis volucellus ) was chironomids (42.3%), whereas spotfin shiner ( Cyprinella spiloptera ) mainly ate terrestrial invertebrates (50.2%). Juvenile white sucker ( Catostomus commersoni ) exhibited substantial diel variation in diet composition with some prey taxa composing the entire diet during some 4-h intervals and being completely absent from the diet during other periods. Bluntnose minnow ( Pimephales notatus ) contained mostly detritus (75.5%). Interspecific diel diet overlap (Cγ) was low among the six species except for smallmouth bass-redbreast sunfish (0.735). Mimic shiner ([xbar] = 0.302) had the highest diet overlap with other species and bluntnose minnow ([xbar] = 0.134) had the least similar. Smallmouth bass, redbreast sunfish, white sucker, and spotfin shiner all had diurnal feeding peaks. Peak food consumption of mimic shiner and bluntnose minnow occurred at midnight. Our results indicate that because of diel variation in diet composition and feeding periodicity for these six species, dietary analysis conducted at only one interval would not provide an accurate representation of the diet of these species.

Pennsylvania↗
USGS2011

Preference of redear sunfish on zebra mussels and rams-horn snails

We tested prey preferences of adult (200- to 222-mm long) redear sunfish ( Lepomis microlophus ) on two size classes of zebra mussels ( Dreissena polymorpha ) and two-ridge rams-horns ( Helisoma anceps ) in experimental aquaria. We also tested physical limitations on consuming these mollusks and determined prey bioenergetic profitability. Redear sunfish strongly preferred rams-horns over zebra mussels, but they displayed no size preference for either prey. Ingestion was not physically limited since both prey species up to 15-mm long fit within the pharyngeal gapes of redear sunfish. Rams-horns were more bioenergetically profitable than zebra mussels and ingestion of rams-horn shell fragments was about three times less than zebra mussels. Rams-horns were somewhat more resistant to shell-crushing, but all size ranges of both prey species tested were crushable by redear sunfish. These studies suggested that the redear sunfish should not be considered a panacea for biological control of zebra mussels.

Journal of Freshwater Ecology↗