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

Importance of the glucose blood level for human health, Q. What is the impo...

Q. What is the importance of the glucose blood level for human health? The glucose blood level (glycemia) must be kept normal if it is abnormally low there is not sufficient gl

Modification of trna, Transfer RNA molecules are notable for having general...

Transfer RNA molecules are notable for having generally nucleotides shown in the figure such as 1-methylguanosine (m1G), pseudouridine   (Ψ), dihydrouridine   (D), inosine (I) and

What are retroviruses, What are retroviruses? How do they reproduce and wha...

What are retroviruses? How do they reproduce and what is the role of the enzyme reverse transcriptase? Retroviruses are viruses whose genetic material is RNA. HIV and the virus

Pneumonia, Pneumonia Pneumonia is an inflammatory process in which th...

Pneumonia Pneumonia is an inflammatory process in which there is consolidation in lung caused by exudates filing the alveolar spaces. Gas exchange cannot take place in the c

Determine requirement of trace elements for infant, Determine Requirement o...

Determine Requirement of Trace elements for Infant? Most elements, such as zinc and iodine, hold a major significance in infant nutrition. Zinc is associated with growth while

Is glucose was the only source of fuel, What is the RQ if glucose was the o...

What is the RQ if glucose was the only source of fuel used in metabolism?

Group of the phylum chordata, Q. What is the group of the phylum Chordata t...

Q. What is the group of the phylum Chordata that first colonized the terrestrial environment? From which habitat did they come? Partially aquatic partially terrestrial animals,

Explain the general small size of arthropods, How does the presence of exos...

How does the presence of exoskeleton explain the general small size of arthropods? As they have exoskeleton and periodic ecdysis, the growth of arthropods is limited to avoid t

Determine the categories of sleep disorders, Determine the categories of sl...

Determine the categories of sleep disorders Sleep disorders are generally divided into two major groups: 1) Narcolepsy, which is characterised by excessive sleep or brief in

Deficiency diseases-phosphorus deficiency, Phosphorus deficiency Defici...

Phosphorus deficiency Deficiency of phosphorus is usually primary and is widespread under natural conditions. It is characterized by pica, poor growth, infertility, and osteody

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