WebMany hemichordates have a larval stage in their life cycle; the larva is called a tornaria. The hemichordates have remained a general primitive group, at a low level of evolution, closely linked with the echinoderms (e.g., starfish, sea urchins) and sharing with them and the other protochordate groups a sessile (i.e., fixed to a surface) or ... WebThe hemichordates furnish a clue to the link between the chordates in general and the non-chordates, specially the echinoderms in particular. The hemichordates have peculiar anatomical organisation and the free-swimming larva, tornaria, is strikingly similar to the larval stages of some echinoderms. Classification of Phylum Hemichordata:
Hemichordata (Hemichordates) Encyclopedia.com
WebSo, a larval stage must have some evolutionary advantage. It might be that larvae, many of whom burrow, can live in environments where predators struggle to co-exist, or that a mobile larva that can find its own food gets more nutrition than if it had to rely on the finite energy supply of an egg. Web108 Likes, 11 Comments - Greg Pond (@mr_pondweed) on Instagram: "The often elusive and camera shy Phantom Cranefly (Bittacomorpha clavipes) emerged quite early fr..." small hanging wall shelves
Hemichordates: Hemichordata Encyclopedia.com
WebA. have a heart that circulates blood cells with hemoglobin in a closed system. B. have a ventral nerve cord. C. are small fish-like, freshwater animals. D. have a notochord only in their immature stage. E. digest food in a hepatic cecum or liver diverticulum. WebAlso glomerular kidneys are also found in some marine forms. such as myxinoids and sharks. This hints to the Marine origin of chordates. Chordates evolved from some deuterostome ancestor (echinoderms, hemichordates, pogonophorans etc.) as they have similarities in embryonic development, type of coelom and larval. stages. WebPhylum Hemichordata. Examples and Characteristics. The Phylum Hemichordata consists of worm-like organisms collectively known as Hemichordates (currently estimated to have about 130 members). In some literature, Hemichordata is classified as a subphylum of the Phylum Chordata. However, it's a distinct phylum closely related to echinoderms. small happy face emoji