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Vertebrate Natural History

FORS2355 Vertebrate Natural History Lab 1: Hagfish/Lamprey Date: August 23, 2021 Due Date: August 30, 2021 Vertebrate Diversity Phylogenetic relationships Hagfish and Lamprey fishes are jawless fishes, while other fishes possess a jaw. Each branch is represented by different traits. MIGHT BE ON TEST Figure 1.4 Phylogenetic relationships of extant vertebrates. This tree depicts the probable relationships among the major groups of extant vertebrates and is the phylogeny we follow in this book. Phylogenetic terminology assigns names to the lineages originating at each branch point. This process produces a nested series of groups, starting with the most inclusive. For example, Gnathostomata includes all vertebrate animals that have jaws. Because the lineages are nested, it is correct to say,for example, that mammals are both gnathostomes and osteichthyans. Hagfishes: Class: Myxini Order: Myxiniformes Family: Myxinidae Characteristics: No vertebrae and jawless (Agnathan) of head region on tongue to branchial pou General Ecology: Inhabit colder waters of deep-sea; marine Worldwide distribution except poles. Generally, scavengers; locate food via olfaction Lateral mucus glands important for predatory defense. o Watch Mucus Video 0 Watch Predatory Defense Video Elongate; eel-like (up to 0.5m/1.6ft) Pinkish; pinkish/brown Thick barbels Rudimentary eyes Scaleless Exton gl Duundo