BIOL 111 Lecture Notes - Lecture 18: Salamander, Move, External Fertilization

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: All

Document Summary

1998: 2nd species found in indonesian fish market. Nowadays: coelacanth are now known to be alive. Has a single skeletal = unique movement of the fins. Estivate in mud during drought periods waiting for the rain to come back. Devonian droughts (400 mya: shallow inland seas, swamps and ponds, low dissolved oxygen there is a lot more oxygen in the air, promoting the movement out of the water to the land. Increased competition in water: crowding in small pools. No vertebrate predators on land (not yet) Differences between land and water as relevant to life. Stability of temperature (water is temperature-stable because it can maintain temperature) Amount of uv radiation (more uv radiation on land) Air has higher concentration of oxygen than water. Gases diffuse faster in air than water. Multiple respiratory surfaces depending on the species external gills, lungs, trachae, etc. Lobe-finned fishes: 2 ventral pockets formed off esophagus, used as a supplemental respiratory device.