Coxal glands, Biology

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.

Posted Date: 2/4/2013 4:27:30 AM | Location : United States







Related Discussions:- Coxal glands, Assignment Help, Ask Question on Coxal glands, Get Answer, Expert's Help, Coxal glands Discussions

Write discussion on Coxal glands
Your posts are moderated
Related Questions
Define the Phosphorus - The Macromineral? The body contains about 620 g (20 moles) of phosphorus. Of this 87% is present in bones. It is thus more widely distributed in the bod

What are the factors that limit our ability to fully classify and understand microbial diversity and what implications do these challenges have for environmental and health managem

Q. Which Of the substances is chromatin made? Chromatin is made of the DNA molecules associated to proteins known as histones.

Define Mineralizations and formation of new bone? Vitamin D plays a role in the synthesis of a prominent non collage nous protein, osteocalcin, a vitamin K- dependent protein f

Quality control of feedstuffs Quality control is essential at all stages in the production of compound feed so that animals could get wholesome balanced and nutritious feed. Th

Explain about the Thiamin - Vitamin B or aneurin? Thiamin is one of the earliest recognized vitamins. The chemical structure of thiamine was established by Williams in 1936. Th

State about the blood ocular barriers of the eye? Blood Ocular Barrier: All vascular beds of the eye are highly permeable to lipoid soluble substances (oxygen, carbon dio

Give definitions of atomic number and atomic mass and how they relate to protons, neutrons, and electrons in neutral atoms?

Explain the Hydrophobic Grid Membrane Filter (HGMF)? It is also used to enumerate microorganisms from a variety of food samples. By using this method, organisms as few as 10 ce

Why could a disease be more serious in a population with a low genetic diversity? A population with a low genetic diversity could be more expected to be wiped out by a disease