Cortisol is recognized as a physiological indicator of stress in fish. However, this hormone typically measured plasma samples. In study, cortisol content was evaluated for the first time scales tropical tuna. The sample included 20 skipjack tuna (Katsuwonus pelamis) and 25 yellowfin (Thunnus albacares) collected Atlantic (the Gulf Guinea off Ivory Coast) Indian Ocean (off Reunion Island), thei...

Structural complexity on coral reefs has been shown to positively influence several measures of biodiversity, and is thus an important ecological variable. The dominant field method used by reef scientists to measure structural complexity is the chain-and-tape method, which produces a measure of rugosity calculated as the ratio of contour–following vs. straight distance between two points on th...

Tagging or marking small laboratory-bred fish species is not an easy task. This also holds for the zebrafish, Danio rerio, which is widely used throughout the world as a model organism for genetics, developmental biology, etc. We present a simple marking technique based on scale regeneration. A comparative morphological study of various types of zebrafish scales indeed shows that regenerated sc...

The name Pethia melanomaculata (Deraniyagala) is available for the Sri Lankan fish previously referred to P. ticto, being distinguished from its Indian congeners by the combination of the following characters; having ½4/1/3½ scales in transverse line on body; body depth 32.4-41.5% of standard length (SL); head length (HL) 26.1-29.2% of SL; snout length 25.3-35.6% of HL; eye diameter 24.4-31.9% ...

Biodiversity and nature values in anthropogenic landscapes often depend on land use practices and management. Evaluations of the association between management and biodiversity remain, however, comparatively scarce, especially in aquatic systems. Furthermore, studies also tend to focus on a limited set of organism groups at the local scale, whereas a multi-group approach at the landscape scale ...

Pethia longicauda, a new cyprinid fish, is described from Hiranyakeshi River, Krishna drainage, Maharashtra, India. It can be distinguished from congeners based on a combination of characters including: a long caudal peduncle, incomplete lateral line, absence of barbels, upper lip thick and fleshy, distinct lateral fold on snout, 22-24 scales in lateral series, 5-6 lateral-line pored scales, ni...

Knowledge of the structure-property-function relationships of dermal scales of armoured fish could enable pathways to improved bioinspired human body armour, and may provide clues to the evolutionary origins of mineralized tissues. Here, we present a multiscale experimental and computational approach that reveals the materials design principles present within individual ganoid scales from the '...