Type specimen of class enteropneusta, Biology

Assignment Help:

Q. Type specimen of class enteropneusta?

Examine the specimen and note the following features:

1. Balanoglossus has a soft, elongated, worm-like body which has a ciliated surface.

2. Body length reaches 10-50 cms and is divided into short conical proboscis, , collar and long trunk.

3. Proboscis is cylindrical, tapering and muscular. Near the base is a proboscis pore which is the opening of the coelom (present within the proboscis) to the exterior.

4: Collar is a short, cylindrical, muscular band enclosing a pair of coelomic cavities (collar coelom). The collar opens by a pair of collar pores on the dorsal ; surface. The rim of the collar encloses the mouth which is permanently open. ,

5. The trunk is superficially ringed and divided into 3 parts (a) anterior branchiogenital part containing genital ridge that carry gonads. This part can , be demarcated from the outside as it has gill-slits but the contents cannot be seen without dissection. (b) hepatic region. (c) the posterior end which is the trunk region.

6. The mouth lies at the base of proboscis and is encircled by the edge of the collar.

7. In the hepatic region are present double rows of hepatic caeca.

8. Alimentary canal is straight and anus is at the end of the trunk. (Sexes are separate and fertilization is external. Development includes a free swimming pelagic larva called tornaria larva.)


Related Discussions:- Type specimen of class enteropneusta

Imaginal discs, Imaginal Discs In the holometabolous larva, there are ...

Imaginal Discs In the holometabolous larva, there are two cell populations: (1) The larval cells that are used for the larval structures and (2) The imaginal disc and th

Effects of plant growth regulators on development, Effects of Plant Growth ...

Effects of Plant Growth Regulators on Development Like animals plants require input of energy from the outside environment to sustain growth and development. But unlike anim

Difference between mussels and octopuses, Q. What is the difference between...

Q. What is the difference between mussels and octopuses regarding their circulatory systems? How does that difference influence the mobility of these animals? Cephalopod mollus

Reproductive mechanisms, Normal 0 false false false EN-...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Investigation of aortic regurgitation by chest x–ray, Q. Investigation of a...

Q. Investigation of aortic regurgitation by Chest X–Ray? Left ventricular dilatation produces cardiomegaly on chest radiograph. Ascending aorta is often prominent. Egg shell ca

Illustrate the structure and functions of aqueous humour, Illustrate the St...

Illustrate the Structure and functions of aqueous humour Aqueous humour is a clear fluid that fills the anterior and posterior chambers of the eye and permeates the vitreous. I

What are blood enzymes, What are blood enzymes? Enzymes are proteins th...

What are blood enzymes? Enzymes are proteins that take out chemical reactions (as opposed to structural enzymes). Most of the detectable enzymes in the blood come from the seve

Define the term - functional magnetic resonance imaging, Define the term - ...

Define the term - Functional magnetic resonance imaging Functional magnetic resonance imaging (fMRI) is a recent development that permits simultaneous measurements of the brain

Agro industrial-oil seed meals as by-pass protein source, Oil Seed Meals as...

Oil Seed Meals as By-pass Protein Source The protein digestion in ruminants encompasses microbial transformation of dietary protein in the rumin. A varying portion of feed pro

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