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How many gill slits do fish have?
Just like all other animals, fish need oxygen to survive. Because they live in water, they have evolved gills which enable them to remove dissolved oxygen from water. Most fish have four gills on both sides of their head. Sharks and other more primitive fish may have five or more gill slits.
What are the lines on a fish called?
Cirri are not sensory organs. Most fish have a structure called the lateral line that runs the length of the body—from just behind the head to the caudal peduncle (Fig. 4.31). The lateral line is used to help fishes sense vibrations in the water.
How many fins does a fish have?
There are five main fins on a fish that are commonly described in fish Identification. Dorsal fins are located on the back or on the top of the fish, and aid the fish in sharp turns or stops, and assist the fish in rolling.
How many layers does a fish heart have?
The fish heart has four chambers: sinus venosus, atrium, ventricle, and bulbus arteriosus (conus arteriosus in elasmobranchs).
Do fish have alveoli?
Today I found out how fish gills work. These fantastic little organs allow the fish to absorb oxygen from the water and use it for energy. Gills work on the same principle as lungs. In the lungs, there are small sacs called alveoli that are approximately 70% capillaries.
Do fish have limbs?
The ribs attach to the spine and there are no limbs or limb girdles. The main external features of the fish, the fins, are composed of either bony or soft spines called rays which, with the exception of the caudal fins, have no direct connection with the spine.
Do all fish have scales?
Do all fishes have scales? No. Many species of fishes lack scales. All the clingfishes (family Gobiesocidae) for example, are scaleless.
What are the two layers of the skin of fish?
The skin of fish is made up of two distinct layers, viz. an outermost layer, the epidermis and an inner layer dermis or corium. The epidermis originates from ectoderm and the dermis derives from mesoderm layer (Fig. 3.1). 1. The Epidermis layer of skin in fishes:
Do animals on the Mid-Atlantic Ridge Live at the same depth?
Although the scientists discovered new species during their trips, they also established that most of the animals on the Mid-Atlantic Ridge also live at the same depths on the continental slopes around the edges of the oceans.
Do sea mounts and ridges mean more marine life on land?
The scientists, from the University of Aberdeen and the Institute of Marine Research in Norway, say marine life gets sparser the deeper and further one gets from land, but that sea mounts and ridges have been considered to be areas of the mid-ocean where marine life is plentiful.
What are the different types of scales found in fish?
(ii) Cycloid scales found in Burbot and soft-rayed fishes. (iii) Rhombic or diamond shaped scales, common among gars and sturgeons. (iv) Ctenoid scales, characteristics of spiny-rayed bony fishes (Acanthopterygii). Scales may also be classified as placoid or non-placoid. Three basic types of non-placoid scales are — cosmoid, ganoid and bony-ridge.