Pirate perch

Abstract: Larval fishes were collected with light traps and iehthyoplankton nets for two consecutive years during spring and early summer in the channel and floodplain (tupelo and oak forest) of the Cache River, Arkansas. A total of 8,113 individuals were collected between the greas. Twenty-eight species were confirmed, but total number of taxa, including genus and family level groupings, was 35. Pirate perch (Aphredoderus sayanus) was the most abundant species, with 21% of the total catch consisting of this fish. Percidae (darters) was the dominant family, comprising at least seven species and accounting for 57% of the total numbers of fish collected. The families Cyprinidae and Centrarchidae were also common. Specimens that could not be identified to species made up nearly 56% of the eatch. Species richness was similar among the three habitats probably due to hydraulic mixing, but individuals in the families Centrarchidae, Cyprinidae, and Percidae were more abundant in tupelo and oak habitats than in channel for net and light trap catches. Mean catch of total individuals in nets and light traps was greater in floodplain habitats than in the channel, particularly during spring 1989. Large catches in spring 1989 corresponded to higher water levels that expanded the aquatic/oak forest transition zone compared to lower water levels in 1988. Thus, late winter and spring floods that inundate the oak forest appear to be a major factor in regulating abundance of larval fishes in this bottomland hardwood wetland.

Abstract: The food habits (1,773 individuals) and the distribution (2,056 individuals) of 9 families, 26 genera, and 32 species of fishes, were determined for Tuckahoe Creek, a lower piedmont tributary of the James River, Virginia. These species represent 41% of the freshwater fishes known for the entire river basin. Five species accounted for 69% of the collection:Etheostoma nigrum (20%),Lepomis macrochirus (18%),Hybopsis leptocephala (15%),Notropis cornutus (11%), andAphredoderus sayanus (5%). Within the upper twothirds of the creek there was a trend for the number of species to increase in a downstream direction. Stomach contents of 273L. macrochirus were mainly insects (65%) and crustaceans (29%). Tendipedids and copepods were particularly important food items although the bluegill consumed a wide variety of animal forms. The selection was a probable reflection of the general availability of potential food. Young fish (0 and 1 age-groups) fed more often on microcrustaceans and dipteran larvae while older fish consumed a higher percentage of coleopterans and hymenopterans. Analysis of stomach contents of other centrarchids showed significant differences. Hemipterans dominated the diet ofCentrarchus macropterus and were important food items forChaenobryttus gulosus. Entomostracans formed the bulk of the diet ofEnneacanthus gloriosus and decapods were eaten primarily byC. gulosus. The largest percentage of coleopterans was taken byLepomis auritus. The cyprinids were represented by all types of feeders.Notropis cornutus was a true omnivore (feeding equally on plant and animal matter) andH. leptocephala selected a diet primarily of plant material. Dipteran larvae dominated the diet of the percid,E. nigrum (78% of total items) and the pirate perch,A. sayanus (53%).Gambusia affinis fed mainly on Hemiptera (34%). The catostomids consumed predominantly microscopic plants. Specimens ofEsox niger less than 74 mm SL ate insects more often (48% as opposed to 16% in larger fish), whereas larger specimens fed on fishes (63% as opposed to 30% in the smaller forms).

Abstract: 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 ...

Abstract: 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-pre...