Chondrichthyes: Characteristics, Classification and Examples

image of Chondrichthyes

The word ‘chndrichthyes’ came from Greek word ‘chondr’ meaning cartilage and ‘ichthys’ meaning fish. Chondrichthyes include all the cartilaginous fishes that contain cartilaginous skeletons. All the representatives of this group have jaws and paired fins with paired nares. The body is covered with placoid scales. Their body growth range from 10 cm (finless sleeper ray) … Read more

Cephalaspidomorphi : Characteristics and Examples

Image of Cephalaspidomorphi Characyeristics and Examples

Fish is a cold-blooded aquatic vertebrate organism which makes the most diverse and largest taxonomic group. It contains the following four taxonomic classes: Myxini Cephalaspidomorphi Elasmobranchiomorphi, and Osteichthyes. Cephalaspidomorphi (Hagfishes and Lampreys) The class Cephalaspidomorphi is named after the Greek word kephale = head + aspidos = blade or shield + morphe = form. This … Read more

Fisheries: Bangladesh Perspective

The term “fisheries” is widely used. Fisheries generally refer to the cultivation and breeding of edible and marketable fish. However, in the broadest sense, it also includes the exploitation of many other aquatic animals besides fish. The prudent exploitation of fish, shrimps, crabs, and various types of mollusks such as oysters, dolphins, and whales for … Read more

Ecological Classification of Fishes

Ecological classification of fishes

According to E.O. Wilson, there are 1.7 million species in the world. At present, this number is considered a small part of the world’s biodiversity. There are 751,000 species of insects known worldwide, including 112,000 species of Lepidoptera, 103,000 species of Hymenoptera, and 290,000 species of Coleoptera. There are also 290,000 beetle species. On the … Read more

Fish: Definition and Characteristics

Fish Definition & Characteristics

Fish is a primitive jawed vertebrate animal (Phylum: Chordata). They are cool-blooded aquatic animals that breathe and move with the help of fins. Fish originated in the Ordovician period and spread in the Devonian period. That is why Devonian is called the golden age of fish. The study of fish is called Ichthyology. Fish are … Read more