The present work analyzes the involvement of telencephalon of goldfish in spatial strategies, using a procedure analogue to the hole-board task. With this aim, goldfish with sham operation or telencephalon ablation were trained to find a baited feeder within a twenty-five feeder matrix, which maintained stable spatial relationships relative to five peripheral landmarks. After training, differen...

We investigated the differences in the expression of the neurohormones kisspeptin (Kiss) and gonadotropin-inhibitory hormone (GnIH) and cytochrome P450 aromatase (P450arom), gonadotropin hormones (GTHs), and sex steroids in the goldfish Carassius auratus exposed to light-emitting diodes (LEDs). The expression levels of Kiss1, Kiss2, G-protein-coupled receptor 54 (GPR54), GTHs, GnIH, and P450aro...

Twin-tail goldfish possess a bifurcated caudal axial skeleton. The scarcity of this trait in nature suggests that a rare mutation, which drastically altered the mechanisms underlying axial skeleton formation, may have occurred during goldfish domestication. However, little is known about the molecular development of twin-tail goldfish. Here we show that the bifurcated caudal skeleton arises fro...

BACKGROUND Large volumes of lymph can be collected from the eye-sacs of bubble-eye goldfish. We attempted to induce vitellogenin (Vtg) in the eye-sac lymph of bubble-eye goldfish and develop a method for visualizing Vtg incorporation by zebrafish oocytes using FITC-labeling. METHODS Estrogen efficiently induced Vtg in the eye-sac lymph of goldfish. After FITC-labeled Vtg was prepared, it was ...

An external pinkish growing mass that emerged from the right nostril of an adult goldfish Carassius auratus L. was evaluated by means of light microscopy and immunohistochemistry. The neoplasm presented a well-developed fibrovascular stroma associated with solid cell nests and a large number of Flexner-Wintersteiner rosettes. Myelinated fibres were observed around them. Neoplastic cells showed ...

Goldfish in a warm environment can cause a small drop in the temperature of their environment by pressing a lever. The fish regulate the temperature of their environment, keeping the temperature between 33.5 degrees and 36.5 degrees C most of the time.

The issue we address is whether an animal knows or understands the significance of learning. We constructed an animal's own conceptualization via resolving a paradox underlying the process of learning. We found a kind of self-similar pattern in the behavior of goldfish resolving a paradoxical experimental problem. The pattern can be considered as a solution to the paradox in the experiment. An ...

Members of the Notch gene family are thought to be involved in the regulation of cell fate decisions in a variety of embryonic tissues, particularly in the developing central nervous system (CNS) in Drosophila and vertebrates. In goldfish the CNS continues to develop and add neurons well into adulthood and has the capacity to regenerate new neurons. Using probes derived from Xenopus Notch to sc...

Although the importance of kisspeptin in the pituitary is firmly established, the signaling mechanisms for the pituitary actions of kisspeptin are still largely unknown. Somatolactin (SL), a member of the growth hormone (GH)/prolactin (PRL) family, is a pituitary hormone with pleiotropic functions in fish, but its regulation by kisspeptin has not been examined. To investigate the functional rol...

Goldfish (Family Cyprinidae, Carassius auratus) and killifish (Family Cyprinodontidae, Fundulus heteroclitus) were acclimated to 10, 20 and 35 °C for 4 weeks. The thermal acclimation of C-start (escape swimming) performance and the physiological properties of fast twitch muscle fibres that underlie it were investigated in these species at the molecular (myosin isoform expression), biochemic...