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

Explain valacyclovir, Valacyclovir (Valtrex) - Valacyclovir is an L-val...

Valacyclovir (Valtrex) - Valacyclovir is an L-valyl ester of acyclovir that is metabolized to acyclovir after oral administration, resultingin higher serum concentrations than

Define the consequences of obesity, Define the Consequences of Obesity? ...

Define the Consequences of Obesity? Obesity has a number of adverse effects and is a risk factor for several problems as highlighted in Figure. It is a risk factor for all caus

Describe class aves in details, Describe Class Aves in details? Class ...

Describe Class Aves in details? Class Aves: The fossil record contains evidence that birds evolved from the reptiles. Birds share anatomical features with Protoavis and Archa

Zoology, differences regarding Tiger Planaria and the Iridescent Phyllodoce...

differences regarding Tiger Planaria and the Iridescent Phyllodoce

Evaluation of health services, CONCEPT AND MEANING OF EVALUATION: Eval...

CONCEPT AND MEANING OF EVALUATION: Evaluation of programmes is critical for measuring various community health services The ultimate reasons for doing evaluation is to ensure

Can you explain bayesian theorem, Q. Can you explain Bayesian Theorem? ...

Q. Can you explain Bayesian Theorem? Bayesian Theorem: The predictive value of a test is related to the incidence of disease in the population. A history of typical angin

Explain scombroid poisoning, Q. Explain scombroid poisoning? Ingestion ...

Q. Explain scombroid poisoning? Ingestion of improperly handled and stored seafood (yellow-fin tuna, skipjack, bonit and mackerel) causes scombroid poisoning. Maitoxin has been

Function of promoter in transcription, Problem 1: How many different ty...

Problem 1: How many different types of RNAs are present? What is the function of Promoter in Transcription? Mention different types of RNAs Discuss function of Promot

Define the food system in space, Define the Food System in space? Mercu...

Define the Food System in space? Mercury (1961-1963) astronauts had to eat bite-sized cubes, freeze dried powders, and semi liquids stuffed in aluminium tubes. For most asbonau

Determine the floor of nose and nasal spine, Floor of nose and Nasal spine ...

Floor of nose and Nasal spine Although variable, the nasal floor is typically situated 5-9mm below the level of inferior turbinates. The inferior piriform rim is used as a guid

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