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Fish feeding ecology has been shown to vary over a 24-h period in terms of the prey consumed and feeding intensity. Consequently, in order to best determine the interspecific feeding associations within a fish community, examination of the diet at multiple times over a 24-h period is often necessary. We examined the diel feeding ecology of three fish species that were numerically dominant in a Lake Ontario embayment during summer. The diet of each of the three species, young-of-year Pumpkinseed Lepomis gibbosus, Golden Shiner Notemigonus crysoleucas, and Brook Silverside Labidesthes sicculus, was distinct with no significant overlap in diet composition occurring within any of the 4-h time intervals. The diet composition of each species suggested that Brook Silverside were feeding at the surface (terrestrial invertebrates and aquatic surface dwelling hemipterans), whereas young-of-year Pumpkinseed (amphipods) and Golden Shiner (tipulids) were feeding on different benthic prey. Differences in feeding periodicity were most pronounced for young-of-year Pumpkinseed. Our findings provide valuable insights on interspecific feeding associations among these three fish species during summer in a Lake Ontario embayment.

Thirty-six Brook Silversides, Labidesthes sicculus, and 15 Golden Silversides, Labidesthes vanhyningi, collected from the Ouachita and Red River drainage basins of Arkansas and Oklahoma, U.S.A., were examined for parasites. Six (17%) of the L. sicculus and 3 (20%) of the L. vanhyningi were infected with Dermocystidium sp., 1 (7%) L. vanhyningi harbored an immature tapeworm, Proteocephalus sp., and 1 (7%) L. vanhyningi was infected with the copepod Ergasilus funduli. We document new host records for all 3 parasites as well as 2 new state records for Dermocystidium sp. and E. funduli.

Great Lakes coastal wetlands provide a critical habitat for many fish species throughout their life cycles. Once home to one of the largest wetland complexes in the Great Lakes, coastal wetlands in the Huron–Erie Corridor (HEC) have decreased dramatically since the early 1900s. We characterized the nearshore fish communities at three different wetland complexes in the HEC using electrofishing, seines, and fyke nets. Species richness was highest in the Detroit River (63), followed by the St. Clair Delta (56), and Western Lake Erie (47). The nearshore fish communities in the Detroit River and St. Clair Delta consisted primarily of shiners, bluntnose minnow, centrarchids, and brook silverside, while the Western Lake Erie sites consisted of high proportions of non-native taxa including common carp, gizzard shad, goldfish, and white perch. Species richness estimates using individual-based rarefaction curves were higher when using electrofishing data compared to fyke nets or seine hauls at each wetland. Twelve fish species were captured exclusively during electrofishing assessments, while one species was captured exclusively in fyke nets, and none exclusively during seine hauls. Western Lake Erie wetlands were more indicative of degraded systems with lower species richness, lower proportion of turbidity intolerant species, and increased abundance of non-native taxa. This work highlights the importance of coastal wetlands in the HEC by capturing 69 different fish species utilizing these wetlands to fulfill life history requirements and provides insight when selecting gears to sample nearshore littoral areas.

The Mississippi Silverside, Menidia audens, was first encountered in Kentucky Reservoir, the most downstream reservoir on the mainstem Tennessee River, in 1991. Over the next 19 years, it invaded all nine mainstem reservoirs, consisting of 1049 river km, and two tributary reservoirs, at an average rate of 55 km per year. This species was first encountered in Barkley Reservoir, the lowermost reservoir of the Cumberland River, in 1990, and has since established populations throughout at least 402 river km of the mainstem Cumberland River. Following the first record of M. audens in an unimpounded section of a Tennessee River tributary during 1998, 1048 sites were sampled throughout the Tennessee River system and this species was documented in only eight additional unimpounded tributaries, indicating aversion to lotic systems. Following the invasion of Tennessee River reservoirs by M. audens, mean abundance of the Brook Silverside, Labidesthes sicculus, linearly decreased with time. Electrofishing catch per u...

The Mississippi silverside (Menidia audens), now common throughout the Tennessee-Tombigbee Waterway (TTW) in Mississippi, apparently invaded this highly modified system from the Tennessee River, concurrent with TTW construction (1972–1985). Subsequent decline in distribution and abundance of the native brook silverside (Labidesthes sicculus) led to speculation that dietary competition with M. audens might be occurring. Therefore, diet data from sympatric and allopatric collections of the two silversides at several sites in TTW were analyzed using multivariate statistics and null models to test for significant dietary differences, overlap and niche shifts potentially attributable to habitat alteration. Diet overlap between the two silversides at sites of co-occurrence was greater than expected under the null model. Moreover, intraspecific food habits did not differ between individuals occurring in sympatry and those occurring in allopatry for either silverside. Thus, significant portions of their ...

Most studies that have examined mercury (Hg) contamination of fish have focused on game species feeding near the top of the food web, while studies that examine forage fish that feed near the base of the food web are rare. We conducted a survey of Hg contamination in three species of forage fish, brook silverside (Labidesthes sicculus), threadfin shad (Dorosoma petenense) and gizzard shad (Dorosoma cepedianum), from Caddo Lake, Texas, USA and found species-specific differences in Hg concentrations. We examined total length, age, trophic position (determined using delta15N), and growth rate of forage fish as factors that could have influenced within- and between-species differences in Hg concentration. Total length and age were the best predictors of within-species differences in Hg concentration. Between-species differences in Hg concentrations were most strongly influenced by trophic position.

We compared small-mesh (4-mm) fyke netting and boat electrofishing for sampling a littoral fish assemblage in Muskegon Lake, Michigan. We hypothesized that fyke netting selects for small-bodied fishes and electrofishing selects for large-bodied fishes. Three sites were sampled during May (2004 and 2005), July (2005 only), and September (2004 and 2005). We found that the species composition of captured fish differed considerably between fyke netting and electrofishing based on nonmetric multidimensional scaling (NMDS). Species strongly associated with fyke netting (based on NMDS and relative abundance) included the brook silverside Labidesthes sicculus, banded killifish Fundulus diaphanus, round goby Neogobius melanostomus, mimic shiner Notropis volucellus, and bluntnose minnow Pimephales notatus, whereas species associated with electrofishing included the Chinook salmon Oncorhynchus tshawytscha, catostomids (Moxostoma spp. and Catostomus spp.), freshwater drum Aplodinotus grunniens, walleye Sande...

Two atherinid species, Labidesthes sicculus (brook silverside) and Menidia beryllina (inland silverside), often co-occur in North American reservoirs. Menidia beryllina is a superior competitor for zooplankton and has displaced Labidesthes in a number of reservoir habitats. In Lake Texoma (Oklahoma-Texas), Labidesthes was thought extirpated from the reservoir after introduction of Menidia in the 1950s, but several recent populations were discovered in down-lake coves with established marinas. Artificial lighting from marinas might benefit Labidesthes by attracting terrestrial insects in these habitats. We conducted a field experiment to test effects of artificial lighting and abundance of Menidia on growth and diet of Labidesthes. Dry weight of Labidesthes at the end of our experiment was significantly higher in artificially lit treatments than in dark treatments, but there was no significant effect of Menidia abundance on weight of Labidesthes. We concluded this effect was attributed to greater availability of dipterans, which dominated the diet of Labidesthes, under artificial lights. Whereas Menidia is a more efficient planktivore than Labidesthes, increased abundance of dipterans near marinas likely promotes the coexistence of these 2 species. RESUMEN—Dos especies Atero ´nidos, Labidesthes sicculus y Menidia beryllina (charal de marea), suelen co- ocurrir en los embalses norteamericanos. Menidia beryllina es un competidor superior para zooplancton

Estimates of caloric density and associated variation were generated for several common species of fish prey in the lower Mississippi River. Estimates were derived for eight common fishes including gizzard shad (Dorosoma cepedianum), threadfin shad (D. petenense), blue catfish (Ictalurus furcatus), flathead catfish (Pylodictis olivaris), brook silverside (Labidesthes sicculus), freshwater drum (Aplodinotus grunniens), white bass (Morone chrysops), and bluegill (Lepomis macrochirus) and for two decapod species, the giant river prawn (Macrobrachium ohioni) and a Procambarus crayfish species. Generated values for gizzard shad and bluegill were comparable to literature values; values for the other fishes and the two decapods have not been reported previously. Seasonal trends in caloric density were evident for blue catfish and gizzard shad. Though caloric content peaked at different times of the year for each species, values were consistently most variable during spring for both species.

The range of brook silverside (Labidesthes sicculus) extends from Minnesota eastward to southern Quebec, and south through New York, Texas, and Florida. The species is found in the St. Lawrence and Richelieu Rivers in Quebec, and the Allegheny and St. Lawrence River drainages, Mohawk and Hudson Rivers in New York. We found brook silverside for the first time in four of the five basins of Lake Champlain, over a range of 150 km, in 1998. Several individuals were collected at each site, indicating that the species is established in the lake. The route of introduction of brook silverside is unclear; they could have entered the lake from the Mohawk River via the Champlain Canal at the south end or from the Richelieu River via the Chambly Canal at the north end. This finding extends the range of brook silverside by approximately 88 km, into Lake Champlain in western Vermont.

Thirty-eight taxa of young-of-the-year fishes were collected with a beach seine and plankton nets in Mitchell Bay, a shallow, densely vegetated embayment on Lake St. Clair, from April to October, 1983, 1984, and 1990. The ecosystem of the bay and adjacent land has been altered by agricultural, industrial, and recreational development for more than a century. Although taxa were numerous, most species were rare or uncommon in collections. The assemblage of larval fish consisted primarily of brook silverside (Labidesthes sicculus), pumpkinseed (Lepomis gibbosus), spottail shiner (Notropis hudsonius), emerald shiner (Notropis atherinoides), alewife (Alosa pseudoharengus), and gizzard shad (Dorosoma cepedianum). Many species were distributed in or near submerged macrophytes at the shore. The species most abundant were pumpkinseed, which reached peak density (11 931 young of the year/100 m3) in late June 1990, and brook silverside (1363 young of the year/100 m3) in late June 1984.

This study compared susceptibilities of the inland silverside Menidia beryllina and the brook silverside Labidesthes sicculus to capture by largemouth bass Micropterus salmoides. Largemouth bass were stocked into a pond containing known quantities of the silversides. Several days later the pond was drained and the remaining silversides were collected. We recovered substantially lower proportions of inland silverside than of brook silverside in two trials. In addition, smaller inland silverside in trial 1 and smaller individuals of both species in trial 2 were recovered in substantially lower proportions than larger fish. We concluded that the inland silverside is more susceptible to capture by largemouth bass than the brook silverside, and that smaller individuals of both species are more susceptible than larger individuals.

Common names: Waccamaw silverside. Conservation status: Listed as threatened by U.S. Fish & Wildlife Service (1987). Identification: Freshwater, lacustrine derivative of the allopatric Menidia beryllina. Long, slender-bodied atherinid (body depth 7–8 times in SL) reaching maximum length of 84 mm. D1 III–VI; D2 7–11; A 19 (17–21); vertebrae 42–45; lateral scales 44–50. Overall silvery to translucent, with melanophores lining the posterior edge of dorsal, lateral scales. Scales poorly developed and deciduous. This species is not sexually dimorphic, with the exception of pre-spawning females being slightly more robust than males. Drawing by E.F. Menhinick. Distribution: One of three endemic fishes in Lake Waccamaw, Columbus County, North Carolina (Hubbs & Raney 1946, Frey 1951). Specimens have been collected occasionally in the headwaters of the Waccamaw River, just below the Lake Waccamaw dam during periods of high water (Shute et al. 1981). These specimens were likely washed over the dam during high flows and do not represent an isolated, reproducing population. Abundance: Very common – one of most abundant species in Lake Waccamaw. Habitat and ecology: Found in large schools near the surface in open water areas, typically above sandy bottoms and areas with little vegetation. Diet consists mainly of zooplankton, especially cladocerans. Minor food sources include ostracods and aquatic insects (Davis & Louder 1969). Menidia extensa is one of the most important forage species in the lake (Rohde et al. 1994). Reproduction: The following life history information is taken primarily from Davis & Louder (1969). Spawning occurs from March through July, which is marked by a large migration from open waters to vegetated near-shore spawning grounds. No parental care is exhibited. Best described as an annual species – most individuals die after spawning and do not live into their second year. Individuals become sexually mature at approximately 30 mm SL (Shute 1980). Threats: The shoreline of Lake Waccamaw is becoming densely developed. Homes and cottages cover nearly three-fourths of the shoreline while the remaining one-fourth lies within Lake Waccamaw State Park. Coincident to this development is the potential for increase in nutrient loading in the lake (Shute 1997). Nutrient loading increases the potential for wide-scale algal blooms and corresponding eutrophication. Because M. extensa has an annual life cycle, it is susceptible to rapid extinction given reproductive failure for even a single year. Additionally, the recent invasion of the lake by the brook silverside (Labidesthes sicculus), is of concern (Moser et al. 1998). The potential for negative interactions between these two atherinids is unknown; early indications are that there is some habitat segregation (Rohde unpubl.). Conservation actions: The U.S. Fish and Wildlife Service recovery plan (1993) calls for protection of critical habitat, research to determine the specific habitat requirements of all life stages, and bi-annual monitoring of the population as well as water and habitat quality monitoring. Research is also being conducted on captive propagation of this species.

Age 0 fishes were collected to determine occurrence, relative abundance and species composition at three sites in River Canard, Ontario in spring-autumn, 1994-1995. This small lowland river (mean annual discharge, 3.2 m3 s-1) has variable flow during fish spawning and early nursery periods, high suspended particulate load, and sparse rooted vegetation and other physical cover. Forty-two taxa (12 families; 24,544 specimens) collected with beach seines and a plankton net represented a wide range of reproductive strategies and a diverse taxocene. Gizzard Shad Dorosoma cepedianum (67% of total catch), Orangespotted Sunfish Lepomis humilis (8%), and Brook Silverside Labidesthes sicculus (6%) were the most abundant species. Environmental conditions were such that fish attained autumnal lengths comparable to species in various systems throughout the ecoregion.

Le mode de reproduction de L.s. a ete examine sur le terrain, en observant les œufs recoltes chez des femelles lors de la saison de ponte. L'ultrastructure des spermatozoides a ete etudiee

Species associations among 48 fish species of the Kiamichi River, a large tributary of Red River in SE Oklahoma, were examined using factor analysis of abundance data for 131 collection localities. Collections with high scores for Factors II and III (Steelcolor Shiner and Brook Silverside Groups) were concentrated in upper portions of the drainage, although certain species of both groups were rather widely distributed over the drainage. Collections with high scores for Factor I (White Bass Group) were primarily restricted to the mainstream of the lower Kiamichi River; those with high scores for Factors V and VI (Silvery Minnow and Golden Shiner Groups) were concentrated in tributaries of the lower Kiamichi. Excepting two species restricted to the lower Kiamichi, the species of Factor IV (Green Sunfish Group) were widely distributed over the drainage. In general, occurrence in the lower Kiamichi was positively correlated with westward distribution of the species into prairie environments of Oklaho...

Since 1900, major changes have occurred in the assemblage of small littoral-zone fishes (maximum total length

Brook silverside (Labidesthes sicculus) eggs, larvae, and juveniles were collected with a plankton net from the Peace River, Florida. Eggs had two or three attachment filaments (mode = 2) and a mean diameter of 1.2 mm. Oil globules were present in the yolk, and decreased from a mean of 22 after fertilization to one by the late embryo stage. Recently hatched protolarvae ranged from 4.7 to 5.6 mm total length and had six to seven and 28 to 31 postanal myomeres. The ratio of preanal length to total length increased as the anus migrated posteriorly during the metalarval phase; preanal myomere counts increased while postanal counts decreased. Pectoral anlages were present at hatching. By 8.0 mm, the base of the second dorsal and anal fins began to develop, and fin ray anlages were present in the caudal fin. Pelvic fin anlages appeared by 10.3 mm and all median fin rays were visible by 11.3 mm. The first dorsal fin developed between 11.3 and 15.5 mm. Metalarvae transformed into juveniles between 15.5 a...

The brook silverside (Labidesthes sicculus) was the only atherinid species found in Lake Texorna, Oklahoma, from 1944 to 1953. Inland silversides (Menidia beryllina) were first collected in Lake Texoma in 1953 and had completely replaced Labidesthes by 1955. We conducted comparative studies of feeding mechanics and feeding efficiencies of Labidesthes and Menidia to see if there was a competitive differential between species that could have been a factor in the replacement of Labidesthes by Menidia. Menidia has a protrusible and tube-shaped mouth that is more successful capturing evasive copepod prey than the v-notched mouth of Labidesthes. While both species have similar feeding rates for slow-swimming daphnids, Menidia has higher feeding rates than Labidesthes for cyclopoid and calanoid copepods. Menidia's use of copepod prey is a competitive advantage over Labidesthes in laboratory competition experiments. We hypothesize the same advantage was an important factor in displacing Labidesthes from Lake Texoma.Key words: planktivory, Labidesthes sicculus, Menidia beryllina, Lake Texoma

Whole body concentrations of Cd, Cr, Cu, Fe, and Zn were determined for samples of chain pickerel (Esox niger), bluegill (Lepomis macrochirus), blueback herring (Alosa aestivalis), brook silverside (Labidesthes sicculus), and golden shiner (Notemigonus crysoleucas) from a 1,120-hectare impoundment near Aiken, South Carolina. Species differences in mean concentrations were found for all five elements. Frequency distributions of 23 species-element groupings were compared to the normal, lognormal, Weibull, and exponential distributions. The lognormal, normal, Weibull, and exponential distributions had the best fit to 57, 17, 26, and 0 percent of the species-element groupings, respectively. Four of the 23 species-element groupings departed significantly from all four of the distributions, primarily as a result of strong positive skewness. All species for which Cd and Cr were studied exhibited significant positive skewness, while skewness was less pronounced for concentrations of Cu, Fe, and Zn. Most ...

On June 4, 1974, three brook silversides, Labidesthes sicculus, were collected by electrofishing near the mouth of the Dead River, a tributary of Lake Superior at Marquette, Michigan. This is the first record of the species in the Lake Superior watershed and it may be that the species has only recently established itself in the area.

Life history calculations for Lake Texoma Menidia beryllina (Cope) show that female fecundity is size-dependent with egg numbers ranging up to ca. 2000 eggs per female per day of a 3-month breeding period. During that time female growth cannot be demonstrated and extensive mortality results in virtually no adults surviving to spawn a 2nd year. Growth is density-dependent and reproduction can occur if youngof-the-year achieve minimum spawning size before water temperatures exceed the maximum breeding limit of ca. 30 C. INTRODUCTION Detailed life-history summaries are available for few fishes, especially for small species with short life spans. Substantial background information is available on feeding and reproduction that can facilitate life-history calculations for Menidia beryllina (Cope) inhabitating Lake Texoma. Most of the published reports on Menidia in Lake Texoma reference the Mississippi silverside (Menidia audens); however, Chernoff et al. (1981) demonstrate extensive integration with the tidewater silverside (Menidia beryllina). I agree with their conclusion that the two morphs are conspecific and use the latter name to comply with scientific name priority. Lake Texoma was formed by Denison Dam in 1942 and filled to power pool level in 1945. At this level, the lake has a surface area of 36,000 ha and a shoreline of 933 km (Patten et al., 1975). When first filled, Lake Texoma had dense populations of the brook silverside (Labidesthes sicculus). The first reported collection of Menidia in Lake Texoma was in 1953 (Riggs and Bonn, 1959). By 1955 Menidia had attained population densities equivalent to those of Labidesthes in earlier years. It seems apparent that Menidia were inadvertently released into Lake Texoma in the early 1950s from an unknown source. This hypothesis of introduction is supported by the first known occurrence of Menidia in Oklahoma in 1949 (Moore and Cross, 1950) and by the absence of Menidia at inland locations in Texas prior to 1950 (Bonn and Kemp, 1952). Tilton and White (1964) demonstrate and document a spread of tidewater silversides in the Colorado River Basin in Texas. The Lake Texoma stock of Menidia was the source of the silversides stocked into Clear Lake, California (Carl D. Riggs, pers. comm.). Food habit studies by Saunders (1959), Elston and Bachen (1976) and R. Drenner (pers. comm.) have shown that the Lake Texoma stock of Menidia feeds extensively on copepods, cladocerans and chironomids. Elston and Brachen (1976) reported they feed mostly during daylight hours (0700-2000 hr) in August and they suggested a 1-hr stomach retention time. If so, they have ca. 14 daily feedings. If those feedings average only 1 % of total biomass, a daily ingestation of 14% of the biomass occurs. Observations during May, June and July 1980 (the Lake Texoma breeding period) suggest more nighttime feeding by Menidia (Michael Bleakley, pers. comm.).