Coxal glands, Biology

Assignment Help:

Coxal Glands

There is a pair of coxal glands, in almost all the segments in Onychophora (Peripatus). Developmentally; in every segment a hollow follicle or somite arises and in the trunk region, they become divided in dorsal and ventrolateral portions. The ventrolateral portion grows into the appendages and its cavity makes the end sac of the coxal gland. The end sac opens by a ciliated canal, the coelomostome, into acoiled excretory canal. The terminal portion of the canal is enlarged to form a vesicle or bladder. So the coxal glands are derived from coelomoducts. In arthropods there is a likeness in the formation of coxal glands from coelomoducts and the creation of gonads and their ducts.

In crustaceans they are found in third and sixth segments and they are suitably. named depending upon the site of their opening to outside. The one located at the base of the third segment opens at the base of the antenna, therefore called antennal gland. The one located in the sixth segment opens at the base of the second maxilla, and is termed as maxillary gland. Antennal gland is present in the larval forms of Ostracoda, Copepoda, Branchiopoda, Branchiura, Cirripedia and lower Malacostraca but TP the adults of these groups have maxillary glands. The adult amphipod and decapod crustaceans comprise antennal glands. Mysidacea, a primitive group of crustaceans have both of the antennal and maxillary glands functional. Most arachnids have a pair of coxal glands opening in the sixth segment, opening at the base of third pair of walking legs. In Limulus, there are four pairs of coxal glands.


Related Discussions:- Coxal glands

What do you know about tricuspid stenosis, Q. What do you know about Tricus...

Q. What do you know about Tricuspid stenosis? It is rare disease, with rheumatic etiology seen in 90 per cent of cases. In patients with rheumatic mitral stenosis only 3-5 per

What do you understand by coelenteron, What do you understand by Coelentero...

What do you understand by Coelenteron? The name given to internal cavity of the cnidarians. This is an incomplete gut with just one opening, the mouth. Food to be digested and

Classification of environmental disasters, The Environmental Disasters Are ...

The Environmental Disasters Are Classified Into Two Major Categories: 1.      Natural Disasters like Earthquakes, Tsunami, Landslides, Cyclones, Floods, and Droughts Etc. 2.

Ulcerative enteritis (quail disease), Ulcerative enteritis (quail disease) ...

Ulcerative enteritis (quail disease) Ulcerative enteritis, caused by Clostridium colinum, is found in chicken, quails, pheasants, turkeys and some other birds. Clostridial or

.ecology, describe between native and non-native species from the Otay rive...

describe between native and non-native species from the Otay river valley

What do you understand by flagella, What do you understand by Flagella. ...

What do you understand by Flagella. A cellular hairlike locomotory structure which comprise an extension of the plasma membrane surrounding a 9+2 organization of microtubules.

Geology LAB, Can you guys help with my homework assignment for Geology?

Can you guys help with my homework assignment for Geology?

Define components of total parenteral nutrition, Define Components of Total...

Define Components of Total parenteral nutrition? Glucose: Initiated at the rate of 6 mg/kg/min and increased upto 12-1.4 mg/kg/min, but care to be taken to prevent hyperglyce

Diagnosis, D i a g no s i s Diagnosis, the key for successful ma...

D i a g no s i s Diagnosis, the key for successful management of the disease problem, refers to identification of the cause of a disease. The process of diagnosis requir

What are called transactions, What are called Transactions? The grouped...

What are called Transactions? The grouped SQL statements are known as Transactions (or) A transaction is a collection of actions embused with ACID properties.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd