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 is the need of monitoring and surveillance, What is the need of Monito...

What is the need of Monitoring and Surveillance? Monitoring, we know, is the act of observing something and sometimes keeping a .record of it while surveillance is a repeated s

Explain the principle of nelson-somogyi method, Explain the Principle of Ne...

Explain the Principle of Nelson-Somogyi Method? Glucose is estimated by Nelson-Somogyi method. We begin our study of this method by getting to know the principle involved in th

Illustrate about the ward halstead and luria, Illustrate about the Ward Hal...

Illustrate about the Ward Halstead and Luria The linear approach is best exemplified in the work of A.R. Luria and various collaborators, while the configurational approach is

Explain penicillin allergy, Penicillin allergy Cefazolin is often used ...

Penicillin allergy Cefazolin is often used for prophylaxis in penicillin-allergic patients, but such patients rarely may have allergic reactions to cephalosporins. When allergy

What is the difference between osmosis and diffusion, What is the differenc...

What is the difference between osmosis and diffusion? Osmosis is the occurrence of movement of solvent particles (in general, water) from a region of lower solute concentration

Describe the phylum echinodermata in details, Describe the Phylum Echinoder...

Describe the Phylum Echinodermata in details? The Phylum Echinodermata takes its name from two words of Greek origin: "echino," ; which means "prickle" or "spine," and "derma,"

Explain about crossing over, What is crossing over? How is meiosis related ...

What is crossing over? How is meiosis related to this phenomenon? Linked alleles, for instance, A-b and a-B, form the gametes A-b and a-B that maintain the linkage of the allel

Procaryotes to eucaryotes, PROCARYOTES TO EUCARYOTES Procaryotes are th...

PROCARYOTES TO EUCARYOTES Procaryotes are the simple, unicellular organisms which do not have well defined nucleus, whereas eucaryotes are the complex;multicellular organisms w

How much template dna will you add, You are setting up a PCR reaction. a) T...

You are setting up a PCR reaction. a) The total volume of your reaction is 50 uL. Your stock primer solutions are 25 mM each. You want a final concentration of primer of 1 mM in yo

Define requirements of fat in postoperative nutritional care, Define Requir...

Define Requirements of Fat in Postoperative Nutritional Care Adequate amount of fat is needed to build up and maintain tissue fat reserves. Depending upon the existing health a

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