What is the difference between saving an Excel file in .xlsx and in .csv? Would it be better to import into R using .xlsx or .csv?
The phylum Echinodermata, which contains about 6000 species, gets its name from the Greek, literally meaning âspiny skin.â This phylum exists exclusively in the sea and includes sea stars, urchins, brittle stars, and sea cucumbers. They are simple animals, lacking a brain and complex sensing organs.
Echinoderms are invertebrates that have pentaradial symmetry, a spiny skin, a water vascular system, and a simple nervous system. Describe the characteristics of echinodermata. Echinoderms live exclusively in marine systems; they are widely divergent, with over 7,000 known species in the phylum.