In this article we will discuss about the examples of vertebrate chordates. The first vertebrates were fishlike. Fishes are aquatic, gill-breathing vertebrates that usually have fins and skin covered with scales. The larval form of a modern-day lamprey, which looks like a lancelet, may resemble the first vertebrates- it has the three chordate characteristics (like the tunicate larva), as well [...]
Phylum Hemichordata has been divided into following four classes: Class 1. Enteropneusta: 1. Commonly known as "acorn" or "tongue worms". 2. Solitary and burrowing worm-like marine animals. 3. Body consists of proboscis, collar and trunk; collar without tentaculated arms. 4. Alimentary canal straight; mouth and anus at opposite ends. 5. Numerous pairs of U-shaped gill-slits. 6. Two pairs of hepatic [...]
The following points highlight the five main representative types of hemichordata. The types are: 1. Saccoglossus (=Dolichoglossus) 2. Ptychodera 3. Cephalodiscus 4. Atubaria 5. Rhabdopleura. Type # 1. Saccoglossus (=Dolichoglossus): Saccoglossus (Fig. 3.1) is a typical enteropneust very much similar to Balanoglossus in habits, habitat and structure. It is a marine, slender soft- bodied tongue worm living in spirally twisted [...]