Visual discrimination abilities in the gray bamboo shark (Chiloscyllium griseum)

Over the last decade, studies examining the cognitive abilities of fish have increased, using a broad range of approaches. One of the foci has been to test the ability of fish to discriminate quantities of items and to determine whether fish can solve tasks solely on the basis of numerical information. This study is the first to investigate this ability in two elasmobranch species. All animals were trained in two-alternative forced-choice visual experiments and then examined in transfer tests, to determine if previously gained knowledge could be applied to new tasks. Results show that the grey bamboo shark (Chiloscyllium griseum) and the ocellate river stingray (Potamotrygon motoro) can discriminate quantities based on numerical information alone, while continuous variables were controlled for. Furthermore, the data indicates that similar magnitudes and limits for quantity discrimination exist as in other animals. However, the high degree of intraspecific variation that was observed as well as the low rate of animals proving to be successful suggest that the ability to discriminate quantities may not be as important to these species as to some other vertebrate and invertebrate species tested so far.

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Irrespective of size, scales, color or body shape, all fish are just fish: object categorization in the gray bamboo shark Chiloscyllium griseum

Animal Cognition ◽

10.1007/s10071-014-0818-0 ◽

2014 ◽

Vol 18 (2) ◽

pp. 497-507 ◽

Cited By ~ 4

Author(s):

V. Schluessel ◽

D. Duengen

Keyword(s):

Body Shape ◽

Object Categorization ◽

Bamboo Shark ◽

Size Scales ◽

Chiloscyllium Griseum

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X-Ray Microanalysis of Nickel and Cobalt Intensified Peroxidase- Antiperoxidase For Verification of Reaction Sites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119168 ◽

1985 ◽

Vol 43 ◽

pp. 468-469

Author(s):

A. Angel ◽

K. Miller ◽

V. Seybold ◽

R. Kriebel

Keyword(s):

Reaction Mechanisms ◽

Visual Discrimination ◽

Osmium Tetroxide ◽

Ultrastructural Level ◽

Microscopic Level ◽

Electron Microscopic Level ◽

Electron Microscopic ◽

X Ray ◽

Insoluble Polymer ◽

Cytochemical Reaction

Localization of specific substances at the ultrastructural level is dependent on the introduction of chemicals which will complex and impart an electron density at specific reaction sites. Peroxidase-antiperoxidase(PAP) methods have been successfully applied at the electron microscopic level. The PAP complex is localized by addition of its substrate, hydrogen peroxide and an electron donor, usually diaminobenzidine(DAB). On oxidation, DAB forms an insoluble polymer which is able to chelate with osmium tetroxide becoming electron dense. Since verification of reactivity is visual, discrimination of reaction product from osmiophillic structures may be difficult. Recently, x-ray microanalysis has been applied to examine cytochemical reaction precipitates, their distribution in tissues, and to study cytochemical reaction mechanisms. For example, immunoreactive sites labelled with gold have been ascertained by means of x-ray microanalysis.

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