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

Difference between algae and protozoans, Q. What is the fundamental differe...

Q. What is the fundamental difference between algae and protozoans? The basic difference between algae and protozoans is the fact that algae are photosynthetic autotrophs while

Acute myocardial infarction with haemodynamic deterioration, Acute Myocardi...

Acute Myocardial Infarction with Haemodynamic Deterioration :  These patients may require urgent insertion of intra aortic balloon pump (IABP) followed by PTCA or surgery. 50 per

How are the male gametes of gymnosperms formed, Q. How are the male gametes...

Q. How are the male gametes of gymnosperms formed? What is the relationship between the pollen grains and the concept of alternation of generations? In the male strobiles (cone

Nonsurgical retreatment -secondary endodontic ttt, Nonsurgical retreatment ...

Nonsurgical retreatment (secondary endodontic ttt ) -Is the main difference between primary endodontic disease versus post treatment disease is the need to Regain access to

What is the life cycle of the schistosome, What is the life cycle of the sc...

What is the life cycle of the schistosome? Male and female adult schistosomes live in blood vessels of the human intestines. The females release eggs that trespass the vessel w

What is the molecular formula of glucose, Q. What is the molecular formula ...

Q. What is the molecular formula of glucose? How can its structural formula be explained? The molecular formula of glucose is C 6 H 12 O 6 . Structurally glucose is a hexago

Explain precautions for estimation of reducing sugar, Explain Precautions f...

Explain Precautions for Estimation of Reducing Sugar by Fehling Soxhlet Method? 1. Clamp the burette so that the tip of the burette is exactly above the mouth of the conical fl

Interspecific sterility, In interspecific sterility, the failure in mating ...

In interspecific sterility, the failure in mating occurs because of inability of the sperm to reach the egg in animals and the pollen to reach ovules in plants. In plailts interspe

Explain about force-gated channel, At 1:00AM, Neuron A is at rest with memb...

At 1:00AM, Neuron A is at rest with membrane potential equal to -70 millivolts; it is producing no action potentials.  The threshold for an action potential in neuron A is -55 mill

Of which substances is chromatin made, Of which substances is chromatin mad...

Of which substances is chromatin made? Chromatin is made of DNA molecules associated to proteins known as histones. Cell Nucleus Review - Image Diversity: chromatin

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