Cnidaria

Kunidaria is a huge gate made up of some of the most beautiful salt and freshwater creatures, genuine jellyfish, box jellyfish, coral and sea anemone, and hydra. Kunidaria is a very diverse group of animals, but there are some characteristics that bind them. Most Kunidaria are double embryos. In other words, they consist only of two layers of cells. The outer layer is called the ectoderm or the epidermis, and the inner layer is called the endoderm or the gastrointestinal tract.

Cnidaria and Ctenophora are strains with the most basic branches of special sensory organs. Kunidaria is radially symmetric and has sensors and ganglion neurons and neural networks in which their processes are interspersed in two layers of epithelial cells (Watanabe, Fujisawa, and Holstein, 2009). The sensory structure that forms part of the epidermis is on the doors of all animals. Conidia neurons do not aggregate to form the central nervous system or ganglion, which is why neural networks are considered to be the simplest nervous system (Sarnat & Netsky, 2002). In gnathing, the sensory structure consists of naked sensory neurons whose dendrites are formed by modified cilia (Jacobs et al., 2007). Sensory organs are individual sensory neurons, or a small population of sensory neurons, and usually function in either light detection, mechanical perception, or chemical perception (Jacobs et al., 2007). Jacobs et al

Neurons are present in Ctenophora, Cnidaria and Bilateria, but not in Placozoa and Porifera ... In the clade consisting of Ctenophora and Knydaria and Bilateria, nerves may appear independently. Alternatively, if the origin of the nerve is only one, use Placozoa alone (if Porifera is a sister group of all other animals), use Placozoa and Porifera (Ctenophora all other animals Sister group). - Dan et al. 2014 Pisani et al. (2015) Placozoa was also placed in a position to show multiple acquisitions and / or loss of the nervous system, but the authors did not consider this classification in their role evolution argument. Of course, their papers focus on phylogenetic relationships, but regardless of Placozoa their statements about the evolution of the nervous system are not enough. Their placement of Placozoa is also their conclusion, a recent paper on ion channel evolution (Liebeskind et al.