ZOO 2090 Lecture Notes - Lecture 7: Actinopterygii, Aorta, Sarcopterygii

• School: University of Guelph
• Department: Zoology
• Course: ZOO 2090
• Professor: Jinzhong Fu

Document Summary

Many unicellular and some multicellular mucous glands mucus. Mucus prevents entry of foreign materials, likely reduces drag and may include substances toxic to predators. Poisonous glands [stingrays] stratum corneum the primary function of the stratum corneum is to provide protection against desiccation. Derivatives include scales, feathers, hair, claws, etc. fish none or little keratin in epidermis, except for specializations like teeth on lamprey, or the oral disk, or the belly of semi-terrestrial fishes. Dermis scales are made up of bone covered by the thin epidermis scale surface sometimes coated with hard enamel [from epidermis], and a deep layer of dentin [from dermis] Ancient fishes had very well developed dermal scales, forming heavy armour teeth of modern tetrapods are derived from ancient fish scales. Placoid scales [sharks and rays] cosmoid scale [ancient fishes - the most complex scale type] important points of this lecture. Understand the general structure of vertebrate integument. Describe functional variation of the fish integument.