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 are the chief complaint and patient expectations, Chief Complaint and ...

Chief Complaint and Patient's Expectations It is extremely vital to know what the patient really wants. 1. The chief complaint should be recorded in patient's own words as f

What are infructescences fruits and pseudofruits, What are infructescences,...

What are infructescences, pseudofruits and parthenocarpic fruits? Infructescences are aggregated fruits created from inflorescences, aggregated flowers. Grape clusters are inst

Explain gastro-intestinal system, Explain G.I. (Gastro-Intestinal) system? ...

Explain G.I. (Gastro-Intestinal) system? A. Skeletal muscles directly control the movement of substances at the entrance of the G.I. system. B. Smooth muscles control the mo

Illustrate the applications of vitamin D, Illustrate the Applications of Vi...

Illustrate the Applications of Vitamin D Vitamin D 2 is mainly used in the preparation of various drug formulations. For the animal feed industry, a mineral stable dry powder

Kinds of hermaphroditism, Kinds of Hermaphroditism Depending upon the...

Kinds of Hermaphroditism Depending upon the timing of maturity of the gonads, hermaphroditism can be of two types 1. Simultaneous hermaphroditism . Both male and female g

What are the indications of implant removal, What are the indications of im...

What are the indications of implant removal? Failed implants need to be removed and the specific indications include: - Severe Perimplant bone loss (> 50 per cent implant le

Nemerteans - regeneration in invertebrates, Nemerteans - Regeneration in In...

Nemerteans - Regeneration in Invertebrates Nemerteans as well possess remarkable regenerative ability, as even a small fragment can regenerate into a complete worm. Nemerteans

Nucleus of a spermatogonia, Plot the amount of DNA in the nucleus of a sper...

Plot the amount of DNA in the nucleus of a spermatogonia from the G1 stage prior to the first meiotic division through the completion of meiosis. Label each of the major stages of

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