PETER B. MCINTYRE is a junior biology concentrator at Harvard College. He wrote this article for Microbiology of Soil and Water, taught by Professor Ralph Mitchell. Mr. McIntyre currently studies social behavior related to air breathing in South American catfish in the laboratory of Professor Karel Liem. He plans to pursue a career in ecological research, focusing on aquatic ecosystem dynamics....

Sport-fish introductions are now recognized as an important cause of amphibian decline, but few researchers have quantified the demographic responses of amphibians to current options in fisheries management designed to minimize effects on sensitive amphibians. Demographic analyses with mark-recapture data allow researchers to assess the relative importance of survival, local recruitment, and mi...

Rapidly evolving systems offer the chance to observe genetic and phenotypic change in real time. We exploit a well-characterized introduction of cichlid fish into Lake Malawi National Park to document a short history of habitat colonization and the evolution of genes and colour pattern. In the early 1960s, a fish exporter introduced individuals of Cynotilapia afra to a single site (Mitande Poin...

—The flathead catfish Pylodictis olivaris is a large predatory fish that has been introduced widely beyond its indigenous range to the detriment of many native fish communities. It disperses rapidly within and among river systems, but its potential to use saltwater or brackish waters for migration and exploitation of marine prey resources is unknown. We evaluated the salinity tolerance of juven...

The flathead catfish Pylodictis olivaris is a large piscivore that is native to the Mississippi and Rio Grande river drainages but that has been widely introduced across the United States. River ecologists and fisheries managers are concerned about introduced flathead catfish populations because of the negative impacts on native fish communities or imperiled species associated with direct preda...

In view of the bad convergence performance and low precision of standard artificial fish swarm algorithm in the water quality properties identification, this paper put forward an improved identification model based on adaptive parameters optimization. Firstly, it optimized the immune cloning and selection algorithm (ICSA) in periodic mutation operator and selection operator. Then it introduced ...

In this paper, the suspension control of a Robot Fish with two 2-DOF pectoral fins, a caudal fin and a volume regulator is introduced. Because the diving depth of the robot fish is related to its volume and the hydrodynamic forces acting on its body, the suspension control is implemented by regulating the attack angle of pectoral fins and the volume of the robot fish body. The attack angle of p...

Empirical studies suggest that most exotic species have fewer parasite species in their introduced range relative to their native range. However, it is less clear how, ecologically, the loss of parasite species translates into a measurable advantage for invaders relative to native species in the new community. We compared parasitism at three levels (species richness, abundance and impact) for a...