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 a type of invertebrate found in marine or ocean environments. Common echinoderms include the sea star, sea urchin, sand dollar and sea cucumber. Most echinoderms have arms or spines that radiate from the center of their body. The central body contains their organs, such as mouth for â¦ [Read more...]