Pirate Perch Aphredoderus Sayanus Research Articles

Two Novel Myxozoans from Pirate Perch Aphredoderus sayanus (Gilliams, 1824) in the Upper Mississippi River, Including the First North American Species of Hennegoides Lom, Tonguthai, & Dyková, 1991

The pirate perch Aphredoderus sayanus is a relatively small fish species found in rivers throughout much of the eastern United States. Due to their cryptic nature, relatively little is known regarding their parasite fauna. A survey of pirate perch from the upper Mississippi River revealed 2 novel myxozoans. Hennegoides flockae n. sp. was observed in heavily infected gills where the lamellae featured irregular expansion by bulbous myxozoan polysporic plasmodia, typically affecting the middle to distal half of the filaments. When severe, infection of sequential filaments was such that the filaments were fused, forming what appeared as multicystic/lobular parasitic aggregates subdivided by fine epithelial cords. The total myxospore length of Hennegoides flockae was 35.4-46.4 (41.3 ± 3.3) and the spore body, asymmetrically ovoid in valvular view, was 15.4-18.7 (17.0 ± 0.7) × 7.1-8.7 (7.9 ± 0.4). Henneguya marcquenskiae n. sp. was observed in the liver with plasmodia present randomly and infrequently in the hepatocellular parenchyma. The total myxospore length for Henneguya marcquenskiae was 39.5-55.9 (48.4 ± 4.2), with the spore body being lanceolate, 13.9-16.5 (15.4 ± 0.7) × 7.1-9.0 (8.3 ± 0.5). Phylogenetic analysis of the SSU rRNA gene placed both Hennegoides flockae and Henneguya marcquenskiae as sisters to each other in a clade containing other Myxozoans known to infect the gills of esocids, percids, and centrarchids. These parasites represent the first reports of Henneguya and Hennegoides from pirate perch, with the latter being the first report of this genus outside of the Asian continent.

Is the Pirate Really a Ghost? Evidence for Generalized Chemical Camouflage in an Aquatic Predator, Pirate PerchAphredoderus sayanus

Camouflage occupies a central role in arsenals of both predators and prey and invokes visions of organisms possessing specific characteristics or altering their shape, color, or behavior to blend into the visual background or confound identification. However, many organisms use modalities other than vision. Chemical communication is particularly important in aquatic systems, and chemicals cues are used by a broad array of colonizing organisms to recognize and avoid risky habitats. Here we describe a habitat selection experiment with aquatic beetles and summarize results of 11 experiments involving colonizing beetles and ovipositing tree frogs that provide evidence that pirate perch Aphredoderus sayanus are chemically camouflaged with respect to a diverse array of prey organisms. We believe this to be the first example of a predator possessing a generalized chemical camouflage effective against a broad array of prey organisms, and we suggest that it may constitute a novel weapon in the predator-prey arms race.

Patterns of Habitat Use among Vegetation‐Dwelling Littoral Fishes in the Atchafalaya River Basin, Louisiana

AbstractInformation regarding the relative value of different aquatic macrophytes as fish habitat is lacking for large floodplain river systems, such as the Atchafalaya River basin in south‐central Louisiana. We made seasonal comparisons of fish (total length, <100 mm) density, diversity, and biomass and physicochemistry among submersed hydrilla Hydrilla verticillata, emergent bulltongue Sagittaria lancifolia, and floating water hyacinth Eichhornia crassipes. In addition, we examined the influence of habitat structure and physicochemistry on fish assemblage composition and density. Although there were no seasonal differences in fish biomass among plant types, hydrilla consistently supported the greatest fish density and diversity across seasons. While hydrilla and water hyacinth fish density changed little among seasons, density in bulltongue was higher during low water. Of the 12 most common fish species, the pirate perch Aphredoderus sayanus and yellow bullhead Ameiurus natalis showed no consistent pattern of habitat use. However, the densities of golden topminnow Fundulus chrysotus, bluegill Lepomis macrochirus, warmouth L. gulosus, redear sunfish L. microlophus, and pugnose minnow Opsopoeodus emiliae were highest in hydrilla, whereas the density of bantam sunfish L. symmetricus was highest in water hyacinth. A seasonally variable pattern was found for western mosquitofish Gambusia affinis, redspotted sunfish L. miniatus, sailfin molly Poecilia latipinna (higher in bulltongue), and least killifish Heterandria formosa (lower in water hyacinth). Overall, littoral fish distributions reflected responses to several spatially and temporally variable environmental factors (e.g., water quality, plant complexity, and seasonal depth changes). We suggest that the consistently high fish density and diversity in hydrilla across seasons were related to an optimization of favorable water quality (particularly dissolved oxygen [DO]), architectural complexity, and biovolume. However, during low water, as hydrilla and water hyacinth canopies became very dense and water hyacinth DO levels remained low, bulltongue was more heavily used by several species, presumably because of a more favorable combination of DO, complexity, and particularly depth.

Characteristics of Woody Cover Used by Brown Madtoms and Pirate Perch in Coastal Plain Streams

We measured or described microhabitat characteristics of woody debris accumulations (i.e., structural complexity, cavity space, stein diameter, suspended and benthic leaves, depth, inside and outside flow, undercut bank, and lateral position) found in headwater coastal plain streams of central Louisiana. Debris characteristics at sites used as diurnal cover by adult brown madtoms Noturus phaeus and pirate perch Aphredoderus sayanus were compared with characteristics at unoccupied debris sites. Woody debris used by brown madtoms was characterized as having greater cavity space, structural complexity, and suspended leaves. Additionally, brown madtoms more frequently occupied debris areas located beneath undercut banks or next to areas of high flow. Of all the habitat variables, undercut bank and cavity space showed the strongest relationship with the presence of brown madtoms in woody debris. Brown madtoms demonstrated no significant difference in use of debris characteristics between small (34–83 mm TL), medium (84–101 mm TL), and large (102–140 mm TL) size-groups. Relative to unoccupied sites, pirate perch more frequently occupied sites with benthic leaves and leaves suspended within the debris. Debris in deep water with undercut banks and slow inside flows were also used more by this species regardless of its size-group. The structural complexity of debris at sites occupied by large and medium size pirate perch (59–95 mm TL) was significantly greater than that at unoccupied sites and at sites occupied by small pirate perch (27–58 mm TL). Overall, submerged debris tended to have specific physical characteristics that acted as important determinants in diurnal habitat use of these two structure-associated fishes.