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

Ecology, In what manner is the ecosystem concept useful in the study of env...

In what manner is the ecosystem concept useful in the study of environment

What is monera, What is monera? One of the 5 main kingdoms contains bac...

What is monera? One of the 5 main kingdoms contains bacteria and blue/green algae. Does NOT have a cell membrane, or in other words, is made of prokaryotic cells. Actually,

What is classic blalock-taussig bt shunt in shunt operations, What is Class...

What is Classic Blalock-Taussig BT Shunt in Shunt Operations ? Subclavian artery, which arises from innominate artery, is anastomosed to pulmonary artery. In a patient with lef

Reasons for increasing popularity of dental implants, Q. Reasons for increa...

Q. Reasons for increasing popularity of dental implants? There are various reasons for increased popularity of dental implants. With the rapid development and evolution of impl

Peste des petits ruminants (ppr), Peste des petits ruminants (PPR) is an a...

Peste des petits ruminants (PPR) is an acute, highly contagious viral disease of goats and sheep caused by peste des petits ruminants (PPR) virus which belongs to the genus Morbil

Define the roller drying (drum drying) method, Define the Roller Drying (Dr...

Define the Roller Drying (Drum drying) Method? One of the important techniques for drying liquid food products is the roller drier. Like spray drying, roller drying can only be

What does a two-direction arrow show in a chemical equation, What does a tw...

What does a two-direction arrow show in a chemical equation? The oxygen atoms share two pairs of electrons, as every atom needs two more electrons to fill the orbitals of its o

What are the frequencies of dominant and recessive allele, In a population ...

In a population of 200, 90 are homozygous dominant, 40 are heterozygotes, and 70 are homozygous recessive for a particular trait. What do you expect the frequencies of the dominant

Explain the procedure for morphological study of fungi, Explain the Procedu...

Explain the Procedure for Morphological Study of Fungi? Now carry out the exercise, following the steps enumerated herewith: 1. Prepare a humid chamber by placing two-three

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