Jasmine Jeannis
Lock Haven University
Biology240
March 30th, 2017
An Overview of Phylum Echinodermata
Introduction
Overview: Echinoderms are found at every ocean depth. They are abundant in the biotioc desert of the deep sea, as well as shallower oceans. Echinoderms are the second largest group of phyla, after the chordates. Echinoderms are also the largest phylum that has no freshwater or terrestrial representatives. The value of echinoderms is in the ossified skeletons which are a huge contribution to many limestone formations. They were also the most used species in the regenerative research. The phylum echindermata is one of the first phylum that was discovered and named. In the ancestral taxonomy, Echinodermata has the fewest synampomrophies…show more content… Major Features
Reproduction of Echinoderms:
Asexual reproduction for echinoderms occurs in various ways including regeneration, budding, and amictic parthenogenesis. The method of fission is used by some species of echinoderms. This particular species of starfish has been able to clone their population because of temporary stressful conditions. In fact, the echinoderms fission is analogized with the fragmentation of meteorites. The most infrequent form of asexual reproduction is amictic parthenogenesis. (Mladenov 1995)
For most species, reproduction occurs by free-spawning. Free-spawning is where male and female release gametes around the same time and fertilization would occur in a water column. There are some species that differ with their ways of sexual reproduction. For example, Intraovarian brooders such as Leptosynapta must fertilize internally (Hyman 1955). Factors such as water temperature and light are known to impact the reproductive cycle in terms. Because of their various ways to reproduce, scientist believe this why echinoderms inhabit such a large geographical area and maintain a high population density.
Regeneration of…show more content… Some are carnivores while others are herbivores. The carnivores take advantage of the suction of their tube feet to pry open muscles, scallops, clams, etc. After opening the bivalve, the stomach will exit through their mouth, release enzymes and then begin to digest its prey inside it’s bivalve. When finished, the stomach enters the body again through its mouth. Generally, bivalve creature are ideal including snails and coral even other echinoderms. Other echinoderms are herbivores and feed themselves through the process of filter feeding. This includes but not limited to, scraping algae from rocks, sea urchins, and even capturing plankton (Barnes
