The members of Protochordata are divided into three subphyla based on their notochord, Subphylum Cephalochordata, Subphylum Urochordata, and Subphylum Hemichordata. Habits and Habitats: Members of Hemichordata generally live inside the burrow made in sand or mud in the solitary or colonial states. Members of subphylum Urochordata may be a sedentary or free-swimming line in the … Read more
Characteristics Features of Subphylum Cephalochordata: They are marine and found in all around the world but present in abundance in warmer sea in shallow coastal areas. Most of the time in the day they present inside the tubular sand burrows with keeping the anterior part outside of the burrows and remaining part inside the burrow. … Read more
In subphylum Cephaochordata we can see all the fundamental three characteristics of phylum Chordata and we list below those characters and how they present in the members of subphylum Cephaochordata and at last, we will discuss the Systematic Position of Cephaochordata. Dorsal Hollow Nervecord: In Cephaochordata the nerve cord present on the dorsal side of … Read more
Cephalochordate shows similarity with different Non-chordate groups of animals like Mollusca, Annelida, Echinodermata in various features but there are strong differences also present between them. Cephalochordate shows all fundamental features of phylum Chordata in simple form and Cephaochordata are much closer to Chordata as compared to Non-Chordata. Affinities of Cephaochordata with Hemichordata: Hemichordata have several … Read more
Cephalochordata is a subphylum placed under phylum Chordata but the Chordata features in them are very simple and they show great similarity with some Non-chordate groups of animals. Cephalochordata shows similarity with many groups of Non-chordate animals but we only discuss the important Non-chordate group with which Cephalochordata shows strong affinities. Cephalochordata also shows great … Read more
Primitive Features of Subphylum Cephaochordata: Branchiostoma represent primitive members of phylum Chordata so all the Chordata features present in them are very simple. Assymetrical arrangments of different organs in Branchiostoma shows it ancestry of modern Chordata, the assymetrical body are much similar to the Echinodermata which represents that the are very near to Chordata as … Read more
Cephalochordate has all the basic Chordata characters but in a simple form, we will discuss all the characteristic features of subphylum Cephaochordata. They are Marine: Members of subphylum Cephaochordata live in marine environments, they present in shallow water as well as in the deep ocean. But they prefer shallow coastal areas and the warmer ocean. … Read more
What is Branchiostoma (=Amphioxus): They are marine fish-like animals, due to the presence of all the three fundamental Chordate characters they are considered as Chordata and placed under Subphylum Chephalochordata. On external appearance, they look like lances so they are also popular as ‘lancelet’ or ‘lancet’. In Branchiostoma the notochord is present up to the … Read more
In Branchiostoma nervous system is very simple with a dorsal nerve cord, nerves, sense organs but there is no well-developed brain in Branchiostoma. Central Nervous System of Branchiostoma: Branchiostoma does not have a proper brain, the hollow dorsal nerve cord or neural tube represents the central nervous system in Branchiostoma. In Branchiostoma the notochord extends … Read more
In Branchiostoma primary excretion occur through nephridia, the nephridia in Branchiostoma is ectodermal in origin. In higher Chordate primary excretory organ is kidneys and it is mesodermal origin but in the case of Branchiostoma, it is ectodermal. Protonephridia: On the dorsolateral wall of the pharyngeal region around 100 protonephridia are present on either side of … Read more