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Starfish shows an alimentary canal extending from oral to aboral side. It shows the following parts. 1. Mouth: It is present on the oral surface. It shows sphincter muscles. It is capable of great expansion and redution. 2. Oesophagus: Mouth leads into short oesophagus. This leads into stomach.…
The body wall of star fish consists of 1. Epidermis 2. Dermis 3. Muscles and 4. Coelomic epithelium. 1. Epidermis The epidermis is made by ciliated columnar epithelium. It secretes a thin layer of cuticle. The cuticle and epidermis will cover the tube feet, pedicellariae and dermal branchiae.…
Introduction Star fish or Sea star is common echinoderm in the sea water. Its Zoological name is Asterias rubens. It belongs to, Phylum: Echinodermata Sub Phylum: Asterozoa Class: Stelleroidea Sub Class: Asteroidea Order: Forcipulata The genus Asterias is represented by 100 species, Eg: 1) A. rubens (North European…
Jacob Klein (1734) first used the term Echinodermata for sea urchins. Linnaeus in 1758 placed Asterias, Echinus and Holothuria under Mollusca. Lamarck (1801) included these animals in the order Echinoderm of the Class Radiata. In 1847 Leuckart gave phylum rank to the Echinodermata. The Echinoderms are spiny skinned animals. They…
The excretory system of Unio includes a pair of kidneys (organs of Bojanus) a pericardial gland (Keber's organ). The kidneys include the coelomic cavities. Organ of Bojanus: These are present below pericardium on either side of the venacava. Each kidney has two parts. The ventral part is brown,…
GENERAL CHARACTERS & CLASSIFICATION OF MOLLUSCA Introduction: Mollusca includes soft bodied animals. It was first applied by Ariistotle to the cuttle-fish of the Aegean Se. The Moiluscans are soft bodied, triploblastic coelomate & bilaterally symmetrical animals. There are about 10,000 living species. It is the second biggest phylum of the…
Pila is a unisexual animal. Males and females are separate. Male is smaller than female. Male will show penis at the end of vas deferens. Male Reproductive System It shows testis, vas deferens and penis. 1. Testis: Only one testis is present. It is present in the…
In pila a big kidney will work as an excretory organ. It is called organ of Bojanus. It is present on the left side. It opens to the exterior. It has two chambers. One is on the right anterior side and the second one is at the left posterior…
The blood vascular system cf Pila includes sinuses and blood vessels. This system contains Blood Heart, Pericardium Arteries Veins Sinuses 1. Blood It is liquid tissue. It contains plasma and amoeboid cells. It is bluish liquid. In the plasma "haemocyanin" is dissolved. The amoeboid cells will work as…
Pila is an amphibian. It shows many sense organs. They are ospharadium, eyes, statocyst and tentacles 1. Ospharadium Near the left pseudepipodium attached to the pulmonary sac a leaf like ospharadium is present. It is leaf like. It is 6 to 7 mm. in length. It isbipectinate. It bears a…
Pila shows a well-developed nervous system. This nervous system will show 5 pairs of ganglia, the connectives and commisures and nerves. 1. NERVE GANGLIC Cerebral ganglia Pedal ganglia Visceral ganglia Pleural ganglia Supra and infra intestinal ganglia. On the dorso-lateral sides of the buccal mass cerebral ganglia…
Pila is a amphibian. When it is in water, it will perform branchial respiration with the help of gill. When it is on land it will perform pulmonary respiration with the help of pulmonary chamber. Branchial Respiration: When pila is in water it will perform respiration with gill…
In the digestive system of pila a long coiled alimentary canal and digestive glands are present. The alimentary canal will show the following parts. 1) Mouth: At the anterior end of the head mouth is present. It opens into buccal cavity. 2) Buccal cavity: Its walls are made…
Pila lives in fresh water ponds, rice fields etc. It is an amphibious form. It belongs to Phylum: Mollusca Class: Gastropoda Sub-class: Prosobranchiata Order: Mesogastropoda. SHELL Shell of Pila is a single piece and hence it is called univalvia. It protects the body of the animal. The…
"Aristotle" recognised many Cephalopods and Gastropods. In 1650 "Johnson" coined the word "Mollusca". "Linnaeus" included "Mollusca" in the phylum "Verms". In 1790 Cuvier laid the foundation for modern classification of Mollusca. In 1818 "de Blainville" proposed "Bivahlia" name. In 1821 "Gold fuss" proposed the name "Pelecypoda". In 1862 "Bronn" proposed…
Character Endocrine Gland Exocrine Gland i. Definition The glands whose secretions are always inside the body are called endocrine glands. The glands whose secretions come out of the body are called exocrine glands. ii. Secretions Hormones Enzymes and other than hormones iii. Passage of secretions Travel through blood Never released…
