Joseph J. Luczkovich

Learn More
We present a graph theoretic model of analysing food web structure called regular equivalence. Regular equivalence is a method for partitioning the species in a food web into "isotrophic classes" that play the same structural roles, even if they are not directly consuming the same prey or if they do not share the same predators. We contrast regular(More)
The field of ecomorphology has a long history with early roots in Europe. In this half of the century the application of ecomorphology to the biology of fishes has developed in the former Soviet Union, Poland and Czechoslovakia, The Netherlands, and in North America. While the specific approaches vary among countries, many North American studies begin by(More)
The goal of an ecomorphological study is to understand the interactions between the morphology of organisms and their ecology. Both the morphology and the ecology presented by an organism are directly or indirectly under the influence of the environmental conditions that the organism experiences and its heritable composition. The development and(More)
In the last fifteen years, ecosystem ecologists have developed a theoretical approach and a set of computational methods called “ecological network analysis” (Ulanowicz, 1986; Kay et al. 1996). Ecological network analysis is based on input/output models of energy or material flows (e.g., carbon compound flows) through a trophic network (e.g., a food web(More)
Ontogenetic increases in mouth size and changes in dentition of percoid fishes may affect the size and species of prey selected, thus influencing the fundamental trophic niche. To examine the influence of oral anatomy on prey selectivity by pinfish, Lagodon rhomboides, and snook, Centropomus undecimalis, two co-occurring percoid fishes with contrasting(More)
—Many fishery biologists that are interested in documenting fish habitat and following the movements and behavior of fishes use acoustic tags. Because over 700 fish species naturally produce lowfrequency, species-specific sounds, these can be used as natural acoustic tags. Passive acoustic approaches (monitoring sound-producing fishes with hydrophones) show(More)
Carboxymethylcellulase (CMCase)-producing obligate anaerobes were isolated from the intestinal tract contents but not the feeding habitat of seagrass-consuming pinfish. Taxonomic characterization of these CMCase-producing strains revealed four taxonomic clusters; three were clostridial and one was of unknown taxonomic affinity. Our results demonstrated that(More)
Assessments of trophic structure through ecological network analysis (ENA) have been done in a wide variety of estuarine and coastal environments. For example, some have used it to compare trophic structures within ecosystems focusing on temporal conditions (Baird and Ulanowicz 1989; Baird et al. 1998) and among ecosystems focusing on spatial conditions(More)
Simultaneous audio and video were recorded of a silver perch Bairdiella chrysoura producing its characteristic drumming sound in the field. The background noise contribution to the total sound pressure level is estimated using sounds that occurred between the pulses of the silver perch sound. This background contribution is subtracted from the total sound(More)