Introduction:
Colenterata and Ctenophora are two phyla of marine organisms that exhibit differences in their anatomical features and reproductive strategies. While Colenterata is an obsolete term that includes cnidarians, Ctenophora refers to comb jellies. In this comparison, we will focus on the characteristics of Ctenophora that distinguish it from Colenterata.

Hollow tentacles around the mouth:
In Ctenophora, the tentacles around the mouth are solid and not hollow. These tentacles are used for capturing prey and are lined with specialized cells called colloblasts. Colloblasts secrete a sticky substance that immobilizes the prey, allowing the ctenophore to bring it towards its mouth for ingestion. In contrast, cnidarians, a group of organisms within Colenterata, possess hollow tentacles that contain stinging cells called cnidocytes.

Stinging cells in epidermis and gastrodermis:
Cnidarians, including organisms like jellyfish and sea anemones, possess stinging cells called cnidocytes in both their epidermis (outer layer) and gastrodermis (inner layer). These cnidocytes contain specialized organelles called nematocysts, which are used for defense and capturing prey. In contrast, Ctenophora lacks stinging cells in their tissues and relies on colloblasts for capturing prey.

Polymorphism and metagenesis:
Polymorphism refers to the existence of multiple distinct forms within a species or group. Ctenophora exhibits polymorphism, meaning that different individuals within the same species can have different body forms and characteristics. For example, some ctenophores have long tentacles while others have short ones. Additionally, some species of ctenophores undergo metagenesis, which involves alternating between sexual and asexual reproductive phases. This allows for the production of genetically diverse offspring through sexual reproduction and rapid population growth through asexual reproduction.

Sexual reproduction:
Ctenophores primarily reproduce sexually. During sexual reproduction, eggs and sperm are released into the water, where fertilization takes place externally. The resulting zygotes develop into larvae, which eventually grow into adult ctenophores. This reproductive strategy allows for genetic variation and adaptation to changing environmental conditions.

In conclusion, in comparison to Colenterata (specifically cnidarians), Ctenophora (comb jellies) differ in various aspects such as the presence of hollow tentacles around the mouth, absence of stinging cells in their tissues, polymorphism, and metagenesis. Ctenophores primarily rely on colloblasts for prey capture and exhibit a diverse range of body forms within their species. They reproduce sexually through external fertilization, ensuring genetic diversity and adaptation.