Tag: cnidaria

Ctenophora is a phylum of animals that live in marine waters worldwide. Their most distinctive feature is the combs, which is groups of cilia they use for swimming. They are the largest animals that swim by means of cilia. Generally, the outer surface bears usually eight comb rows, called as swimming plates, which are used for swimming. Comb plates paddle plates in them are arranged circumferentially like seams in a football. 

Beroe is also known as the mellon jellyfish and is the most common type of species of phylum Ctenophora. Ctenophora is known to have biradial symmetry. Each of the four parts is identical to the opposite side but different from the adjacent side. Cnidoblasts and nematocysts are absent in Ctenophora and are found in cnidarians. 

Ctenophora is a phylum of animals that lives in marine water. Their most distinctive feature is the combs and groups of cilia they use for swimming. They are the largest animals that swim by means of cilia.

Tentacles are the organs which are used to catch the prey. These are present at the opening of the gastrovascular cavity. Colloblasts are a cell type found in ctenophores. They are widespread in the tentacles of these animals and are used to capture prey. These are found in all ctenophores except those of the order Beroida, as they lack tentacles. So, the correct answer is option B.

Jellyfish are the major non-polyp form of the individuals of the phylum Cnidaria. They are free-swimming marine animals consisting of a gelatinous umbrella-shaped bell and trailing tentacles. They do not possess a proper skeleton.
Therefore, the correct answer is option D.

Ctenophora is a phylum of animals that live in marine waters. The outer surface bears usually eight comb rows. This is called as comb plates or swimming-plates, which are used for swimming. Ctenophora lack stinging nematocysts. Lasso cells are kind of defensive and offensive stinging cells. These are found in great numbers in all coelentrates. 

Ctenophora is a phylum of animals that live in marine waters. The outer surface bears usually eight comb rows. This is called as comb plates or swimming-plates, which are used for swimming. Ctenophora lack stinging nematocysts. Lasso cells are kind of defensive and offensive stinging cells. These are found in great numbers in all coelentrates.  The Beroe or Melon jellyfish and flattened species like Cestum belongs to Ctenophora. Ctenoplana is a genus of comb jellies andPleurobrachia is a common genus of Ctenophora.Thus, the correct answer is option D.

• Ctenophora are also known as comb jellies. This is a phylum of animals that lives in marine waters. 
• Many species in this group have the body which is biradially symmetrical. The main axis is oral to aboral (from the mouth to the opposite end). This gives the bilateral form. 
• The tentacles are present around the mouth. These tentacles radiate outwards. This gives the radial form of symmetry. Thus, the type of symmetry is known as biradial symmetry.