....................................................................................................................... 5 INTRODUCTION .............................................................................................................. 6 METHODS FOR SPAWNING THE ENDANGERED MOHAVE TUI CHUB IN AQUARIA .........................................................................................

Fish otolith and water chemistry were assessed in the Grand Canyon reach of the Colorado River and its tributaries. Aqueous strontium and selenium (in ratio to calcium) and carbon stable isotopic ratios were identified as markers with excellent potential to track the provenance and movements of the endangered humpback chub Gila cypha. Although otolith dC and Sr/Ca varied proportionately to wate...

The chub is a freshwater fish of the family Cyprinidae, which is widely distributed throughout Europe. Prior to 2001 there were no reports of chub being present in Ireland. In 2001 and again in 2004 it was reported that an angler had caught chub in a section of the River Inny. On neither occasion were live specimens retained for authentication. In 2005 a number of live, angler-caught chub from ...

Two 6-wk trials were conducted in 28-m2 earthen ponds to compare the efficacy of the arroyo chub, Gila orcutti, to the mosquitofish, Gambusia affinis, as a biological control agent for mosquitoes and a possible replacement for the mosquitofish in sensitive watersheds of southern California. The mosquitofish population growth rate was 1.73 times greater than the arroyo chub population growth rat...

Caudal-fin-based swimming is the primary form of locomotion in most fishes. As a result, many species have developed specializations to enhance performance during steady swimming. Specializations that enable high swimming speeds to be maintained for long periods of time include: a streamlined body, high-aspect-ratio (winglike) caudal fin, a shallow caudal peduncle, and high proportions of slow-...

—Yaqui topminnow Poeciliopsis occidentalis sonoriensis and Yaqui chub Gila purpurea, two federally endangered fishes from the Rio Yaqui basin (Arizona, USA, and Sonora, Mexico), were propagated by various methods. Propagation of Yaqui topminnow was attempted in aquaria and wading pools; the greatest number of offspring was produced in 556-L, plastic wading pools. We added substrate, artificial ...

Conservation biologists rely heavily on taxonomy to set the scope for biological monitoring and recovery planning of rare or threatened species. Yet, taxonomic boundaries are seldom evaluated as falsifiable hypotheses that can be statistically tested. Here, we examine species boundaries in leatherside chub (Teleostei, Cyprinidae), an imperiled desert fish native to the Bonneville Basin and uppe...

Toxicity tests using standard effluent test procedures described by the U.S. Environmental Protection Agency were conducted with Ceriodaphnia dubia, fathead minnows (Pimephales promelas), and seven threatened and endangered (listed) fish species from four families: (1) Acipenseridae: shortnose sturgeon (Acipenser brevirostrum); (2) Catostomidae; razorback sucker (Xyrauchen texanus); (3) Cyprini...

The Colorado River drainage basin is home to a diverse but imperiled fish fauna; one putative challenge facing natives is competition with nonnatives. We examined fishes from Colorado River tributaries to address the following questions: Do natives and nonnatives from the same trophic guild consume the same prey items? Will a given species alter its behavior when presented with different prey t...

Population genetic structures of the mackerel (Scomber scombrus) and chub mackerel (Scomber japonicus) were studied in the Mediterranean Sea. Fragments of 272 bp (S. scomber) and 387 bp (S. japonicus) of the 5'-end of the mitochondrial control region were sequenced from spawning individuals collected off the coasts of Greece, Italy, Spain, and Portugal. High levels of mitochondrial control regi...