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

Enzymology, Ethylene glycol is a poison that causes about fifty deaths a ye...

Ethylene glycol is a poison that causes about fifty deaths a year in the United States. Treating people who have drunk ethylene glycol with massive doses of ethanol can save their

Describe technique operation prosthetic valve endocarditis, Describe the Te...

Describe the Technique of Operation in prosthetic valve endocarditis? The operative principle is drainage of abscess, removal of debris and valve rep or replacement to reverse

Different modes of nutrition, Explain different modes nutrition like Autotr...

Explain different modes nutrition like Autotroph,hetrotroph,saprotroph,holozoic

Limiting factor - ecosystem, Limiting Factor - Ecosystem In all ecosys...

Limiting Factor - Ecosystem In all ecosystems one factor, usually abiotic, limits the growth of organisms and is therefore called a limiting factor. The limiting factor is one

Recombinent DNA, any interesting information about recombinent DNA

any interesting information about recombinent DNA

Name the process in that substances carry across membrane, Substances which...

Substances which are insoluble in a membrane are carried across membrane with concentration gradient by means of a carrier molecule in a process termed as: a) Diffusion. b)

What are the main functions of saliva, Q. What is the approximate pH of the...

Q. What is the approximate pH of the salivary secretion? Is it an acid or basic fluid? What are the main functions of saliva? The saliva pH is approximately 6.8 it is therefore

Phylem protozoa, how does these phylem parasites????

how does these phylem parasites????

What is the importance of vitamin C, Importance of Vitamin c Vitamin C ...

Importance of Vitamin c Vitamin C is involved in redox processes in the organisms. It is possible, that vitamin C exerts its physiological function as a redox  substance in com

Manifestations of hypertension, Manifestations of Hypertension • Renal ...

Manifestations of Hypertension • Renal Failure • Left Ventricular Failure • Myocardial Infarction • Cerebral Haemorrhage

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