The one-trial passive avoidance learning task is commonly used in avian research to explore anatomical, cellular and molecular parameters of learning and memory. Many factors are known to influence the effectiveness and/or duration of such learning events. Combinations of novel odours, such as pyrazine, and aposematic colours, such as brig ht yellow or red, have been shown to induce a long-last...

The characteristic striped appearance of zebras has provoked much speculation about its function and why the pattern has evolved, but experimental evidence is scarce. Here, we demonstrate that a zebra-striped horse model attracts far fewer horseflies (tabanids) than either homogeneous black, brown, grey or white equivalents. Such biting flies are prevalent across Africa and have considerable fi...

Gyrodactylus pisculentus sp. n. is described from the head, body and fins of the northern pipefish, Syngnathus fuscus Storer (Syngnathidae) from the environs of Woods Hole, Massachusetts, USA. The new species is compared with Gyrodactylus shorti and Gyrodactylus syngnathi, species previously recorded from pipefish in the United States and Norway, respectively. Gyrodactylus pisculentus was frequ...

Syngnathid fish (pipefish and seahorses) are unique among teleost fish in that their ovary consists of a rolled sheet with germinal ridge(s) on the dorsal side running along the entire length of the sheet. A distinct difference is seen in the ovarian structure between polygamous Syngnathus pipefish and monogamous seahorses (Hippocampus spp.), the former having one germinal ridge and the latter ...

Measurements of closely related sets of classical and truss dimensions were analyzed to discriminate species of scorpaenidae including the dark banded rockfish, Sebastes inermis, the black rockfish, S. schlegeli, and gobioninae including the striped shiner, Pungtungia herzi, and the slender shiner, Pseudopungtungia tenuicorpa. The measurements of the dimensions were arc sin square root transfor...

Environmental estrogens have been shown to affect populations of aquatic organisms in devastating ways, including feminization of males, alterations in mating behaviors, and disruption of sexual selection. Studies have shown 17α-ethinylestradiol (EE2) exposure to induce female-like secondary sexual traits in male Gulf pipefish, changing how females perceive affected males. We aimed to understan...

In response to movements involving a large part of the visual field, the eyes of vertebrates typically show an optokinetic nystagmus, a response in which both eyes are tightly yoked. Using a comparative approach, this study sets out to establish whether fish with independent spontaneous eye movements show independent optokinetic nystagmus in each eye. Two fish with independent spontaneous eye m...