African cichlid fishes have repeatedly evolved highly specialized modes of feeding through adaptations of their oral jaws. Here, we explore the molecular genetic basis of the opening and closing lever mechanisms of the cichlid lower jaw, which have traditionally been used to describe the mechanics of feeding behavior in bony fishes. Quantitative genetic analyses demonstrate that the opening and...

The evolution of cone opsin genes is characterized by a dynamic process of gene birth and death through gene duplication and loss. However, the forces governing the retention and death of opsin genes are poorly understood. African cichlid fishes have a range of ecologies, differing in habitat and foraging style, which make them ideal for examining the selective forces acting on the opsin gene f...

The conservation of data deficient species is often hampered by inaccurate species delimitation. The galaxiid fishes Aplochiton zebra and Aplochiton taeniatus are endemic to Patagonia (and for A. zebra the Falkland Islands), where they are threatened by invasive salmonids. Conservation of Aplochiton is complicated because species identification is hampered by the presence of resident as well as...

Anesthesia reduces the handling process duration and prevent fish injuries. The anesthetic effect ideal concentrations of eugenol tricaine methanesulfonate (MS-222) were tested for pearl cichlid (Geophagus brasiliensis) juveniles with an average weight 4.4 g in water at 24ºC. criterion determining optimal dose considered induction time one minute. Experiment 1 25, 75, 150 300 mg L-1 eugenol. be...

Abstract Optimally foraging animals should minimise time spent in order to perform other fitness-enhancing activities. The ruminants’ more efficient digestive system, requiring lower volumes of forage, is predicted provide an advantage over hindgut fermenters with respect effort, but this may be offset by their need for higher quality forage. We contrasted the activity two similarly-sized, synt...

1. Zebra mussels aggregate to form dense colonies where, depending on the flow rate, individuals in different vertical locations within the colony may experience restricted food availability. 2. Using P-labelled Chlamydomonas angulosa, we found ingestion rates of individual mussels located at the surface to exceed those in the bottom of a 6 cm thick colony by up to 75%. 3. Higher velocities (10...

Teleost fishes have become important models for studying the evolution of the genetic mechanisms of development. A key resource for comparative genomics and positional cloning are large-insert libraries constructed in bacterial artificial chromosomes. We have constructed bacterial artificial chromosome libraries for two species of teleost fish that are important models for the study of developm...

The Cape mountain zebra (Equus zebra) has recovered from near extinction over more than eight decades. While their numbers have increased, populations remain isolated with low genetic diversity. With 75 new being founded and 4800 extant animals, conservation management strategies are implemented to mitigate risk of losses in diversity reproductive fitness. One objective is identify characterist...

using probiotics can control pathogens by a variety of mechanisms. probiotics can promote growth performance and have, therefore, become increasingly important in the aquaculture industry. convict cichlid belongs to the family of cichlidae and is known for its rapid development in laboratory conditions and is suitable for behavioral examinations. the aim of this study was to evaluate the effect...

Bioinvasions are a major cause of biodiversity and ecosystem changes. The rapid range expansion of the invasive quagga mussel (Dreissena rostriformis bugensis) causing a dominance shift from zebra mussels (Dreissena polymorpha) to quagga mussels, may alter the risk of secondary poisoning to predators. Mussel samples were collected from various water bodies in the Netherlands, divided into size ...