Marine life individuals per square meter and accounting for about 80% of all individual animals on earth, their diversity of life cycles, and their presence at various trophic levels point at an important role in many ecosystems. Echinoderms (Greek for "spiny skin") is a phylum which contains only marine invertebrates. The adults are recognizable by their radial symmetry (usually five-point) and include starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7000 living species, making it the second-largest
Jaliscan spiny pocket mouse Jaliscan spiny pocket mouse The Jaliscan spiny pocket mouse ("Heteromys spectabilis") is a species of heteromyid rodent endemic to Mexico. The specific name "spectabilis" means "striking", and refers to the animal's relatively bright coloration. It was formerly placed in the genus "Liomys", which is now recognized to be paraphyletic and has been subsumed into "Heteromys". The Jaliscan spiny pocket mouse is a relatively large member of its genus, measuring in head-body length, with a tail about the same length again. Adult males weigh about on average, while females are significantly smaller, weighing on average. The fur is reddish brown over