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

What are the so-called good and bad cholesterol, What are the so-called "go...

What are the so-called "good" and "bad" cholesterol? Lipoproteins are complexes made of lipids (triglycerides and cholesterol) and proteins. The lipoproteins present dissimilar

What is the difference between spermatids and sperm cells, What is the diff...

What is the difference between spermatids and sperm cells? What is the name of the transformation of spermatids into sperm cells? Sperm cells (the male gametes) are matured spe

Deficiency diseases-calcium deficiency (hypocalcicosis), Calcium  deficien...

Calcium  deficiency (hypocalcicosis) Calcium deficiency or hypocalciosis is a sporadic condition occurring in a particular group of animals causing osteodystrophy. Aetiol

Which are the more abundant ribosomes in secretory cells, Which are the mor...

Which are the more abundant ribosomes in secretory cells - the free cytoplasmic ribosomes or those associated with the rough endoplasmic reticulum? Free cytoplasmic ribosomes

Illustrate the tyndallisation, Q. Illustrate the tyndallisation? John T...

Q. Illustrate the tyndallisation? John Tyndall devised a process of sterilisation by steaming for a few minutes at 100 o C on 3-4 successive operations separated by 24 hour in

Explain infectious proteins, Infectious proteins are present in: 1.Gemin...

Infectious proteins are present in: 1.Gemini viruses 2.Prions 3.Viroids 4.Satellite viruses Prions

Define the nutrient requirements during trauma, Define the Nutrient Require...

Define the Nutrient Requirements during Trauma? Nutritional assessment of the trauma patient is done to determine energy and protein requirements. Basal energy requirements are

Protection of protein meals or bypass protein, Protection of protein meals ...

Protection of protein meals or bypass protein The protein of oil cakes, having higher protein degradability, such as groundnut cake, mustard cake are utilized in the rumen les

Define about the column chromatography, Define about the Column chromatogra...

Define about the Column chromatography? In column chromatography, a tube is filled with the material constituting the stationary phase, plus a solvent (mobile phase). The gener

What are the positions of actin and myosin molecules, What are the position...

What are the positions of actin and myosin molecules in the sarcomere before and during the muscle contraction? Schematically actin filaments attached perpendicularly to both s

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