Echinoderms (scientific name Echinodermata) are a major group of only marine animals. The name comes from the Greek word for "spiny skin". There are about 7,000 species found usually on the sea floor in every marine habitat from the intertidal zone to the ocean depths (Marine Education Society of Australasia 1999-2015). They occur in various habitats from the intertidal zone down to the bottom of the deep sea trenches and from sand to rubble to coral reefs and in cold and tropical seas. Some echinoderms are carnivorous, others are detritus foragers or planktonic feeders. Reproduction is carried out by the release of sperm and eggs into the water. Echinoderms can regenerate missing limbs, arms, spines - even intestines. Some brittle stars and sea stars can reproduce asexually by breaking a ray or arm or by deliberately splitting the body in half. Echinoderms are protected …show more content…
Sea cucumbers are football shaped creatures that lay on their side at the bottom of the ocean. They have five rows of tube feet running lengthwise. Its mouth is surrounded by tentacles that are really tubed feet. Unlike sea stars, the vascular system is not filled with sea water. Instead, sea cucumbers use a special body fluid. Sea cucumbers eat plankton and other organic matter. Some position themselves in a current that brings a steady supply of food, and spend hours there. The tentacles open up and collect food in the current. The sea cucumber brings each tentacle to its mouth to eat, while the other tentacles go on collecting food. Other sea cucumbers feed by sifting through sand using their tentacles (Missouri Botanical Garden, 2002). The feather stars and sea cucumbers are mainly filter feeders, catching whatever they can find floating in the ocean currents (Coral Reef Life on Sea and Sky, 1998-2016). Some sea cucumbers can secrete a sticky glue-like substance as a defense mechanism. (Oceanic Research Group,
Fox, R. 2001. Invertebrate Anatomy OnLine: Artemia Franciscana. Lander University. http://webs.lander.edu/rsfox/invertebrates/artemia.html, retrieved February 13, 2011.
T. californicus is found from Alaska to Baja in small, shallow tidepools and tidal flats in the upper spray zone where they cannot avoid the full effect of visible and ultraviolet (UV) radiation. Individuals assemble in areas of lower radiation at midday, yet have no preference to the intensity of light at dawn and dusk (Hartline and Macmillan 1995). These tiny arthropods inhabit all types of marine sediments from sand to fine mud and ooze. Along with plankton, T. californicus eats microscopic algae, protists, bacteria, diatoms, algae and microbes (McGroarty 1958). When the concentrations of the species in their habitats are high, T. californicus will turn to cannibalism for a food source. The nautilus eye present in the species is rich with fatty acids and provides a good food source for the animal.
Cephalopods are known to be exceptionally intelligent by invertebrate standards and in some respects even rival “higher” vertebrates. These animals have many highly evolved sensory and processing organs that allow them to gain a greater understanding of their environment and their place within it. Due to their advanced structures, many of which are analogous to vertebrate structures, and abilities they have been widely studied. Their methods of learning have been of prime interest and many experiments have been conducted to determine the different ways in which octopuses can learn. From these experiments four main kinds of learning have been identified in octopuses: associative learning, special learning,
The barnacles not only live and reproduce inside the host crab, but they control it. The tendrils attached to the nerves produce substances that change the crab’s endocrine system. This leads to the crab’s body absorbing its own Y-organ. The Y-organ instructs the crab to molt or grow. The crab’s androgenic gland is also degenerated. The androgenic gland controls sex differentiation. At this point, the crab is unable to grow, molt, regenerate lost limbs and it is infertile. When the barnacle inhabits a male crab, the changes feminize him. The male crab will resemble and act like a female. He may even perform a female mating dance. After all this has taken place, the host crab will take care of the parasitic eggs. The crab acts as if the eggs are its own. At the right time, the crab will climb up onto a high rock, and tend to the egg pouch, as it would do in its own reproductive cycle. When the generous number of eggs are ready to hatch, the crab will bob up and down in the water to release them. The crab will then mix the floating eggs with it’s claw to set them on their way. These larvae will usually find new hosts, which continues this
The outer layer of a reef consists of living animals, or polyps, of coral. Single-celled algae called zooxanthellae live within the coral polyps, and a skeleton containing filamentous green algae surrounds them. The photosynthetic zooxanthellae and green algae transfer food energy directly to the coral polyps, while acquiring scarce nutrients from the coral. The numerous micro habitats of coral reefs and the high biological productivity support a great diversity of other life.
Sabellaria cementarium belongs to the phylum Annelids and is an invertebrate polychaete species. They are found in small clumps at the rocky bottoms of the sea floor where they use the rich source of natural phytoplankton as their primary diet (Qian and Chia, 1990). The tube-like worms can behave social and form extensive reefs or independently build hollow tubes in to the sandstone (pawlik and Chia, 1991). Embryos form a polar lobe that is absorbed in to the blastomeres at the end of division. Larval development and movement follows shortly after the 14-15 hour fertilization period where spiral cleaving of the fertilized oocytes appears (Render, 1983). Much is still not known about the invertebrate worm in their natural niche.
Scorpaenidae are mostly marine fish,very few found in fresh and brackish water. The family have around around 45 different genera and 380 different species. They are mostly found in the India Ocean and the Pacific Ocean. Most of them lives in coral, tropical reefs and shallow waters, warmer areas. Not all of the family fish lives in the shallow water, small portion of the Scorpaenidae live deep as around 7,000 feet. Just like most of the coral reef fish are, Scorpaenidae have camouflaged body. Their characteristic reflects their name, they have sharp spine that can sting other organisms. Their spine are covered with venomous mucus just like how some other kind of fish are covered with the venomous mucus. Their body are covered with scales. Generally speaking, the Scorpaenidae family fish have different number of spines over the course of the body. Most known type pf Scorpaenidae are lionfish and scorpionfish. Lionfish have preorbital bone with 3 spines, spines and third below the diagonal; , big mouth, end position, oblique fissure. Mandible, vomer and jaw bone with villiform teeth group. Gill openings are wide, tetrabranchiate membranes without the isthmus, pre-opercular margin with 5 spines. Body are ctenoid scales, round head. On the side, there are about eight to nine dorsal fin, fin spines and rays of an anal fin; five to six pectoral fins, they are large, round, and are branched from the upper fin rays. There are about one to five pelvic, sub thoracic; caudal fin rounded truncate. Reef stonefish are extremely camouflaged, they could look exactly like a rock when hiding for predation. The spines of Scorpaenidae are hard and rough, some of their fin spines have poison, can cause serious pain, swells and fatal wounds. Some of ...
Crustaceans belong to the Arthropoda Phylum, which includes critters like ants, spiders, and centipedes. I know! Crazy to think that a delicious crab is in the same group as a spider! But they share similar characteristics. For starters, members of the Arthropoda Phylum do not have a backbone like you and me, so they are called __invertebrates__. And, as mentioned earlier, their skeleton is external, which is referred to as an __exoskeleton__.
In the coral reef habitat, food consumption is based on sunlight. The sunlight gives food to the plants, bacteria and algae, which is eaten by the plant eaters or herbivores, such as parrotfishes. The bigger carnivores, such as the Whitetip Reef Shark, in the ecosystem then eat those fishes along with the bacteria and plankton in the water. On the other hand, the deep sea is based on dead animal bodies or waste, shown in the fake whale carcass in the deep sea exhibit. Organisms of the deep sea feed on waste because sunlight does not have the ability to reach that deep in the ocean. Nektons are the fishes that feed on the waste produced by the epipelagic zone.
It has arms which extend from a central disk and has a knobby body surface. Using these physical characteristics, we would classify the starfish into the Kingdom Animalia, phylum Echinodermata, and class Asteroidea. The second organism is a species of bird. Again using the dichotomous key, we find that this organism has a regular body shape.
When sea cucumbers were threatened, some of them can discharge sticky threads to trap their enemies while others can mutilate their own bodies as a defense mechanism. They will aggressively contract their muscles and throw away some of their internal organs out of their anus. Then, the lost organs are quickly regenerated.
Soft corals are very widespread among the Great Barrier Reef and other Indo-Pacific coral reefs. On the Great Barrier Reef they may cover up to 37% of the reef area (Bastidas, et. al, 2001). Even though soft corals are abundant on the Great Barrier Reef they have been overshadowed by the study of hard corals. Very little research has been conducted on them, yet they are just as fascinating as their hard coral neighbors. The main purpose of this paper is to explain why evolution has made it possible for soft corals to reproduce both sexually and asexually. To do this I will first introduce soft corals, then explain the types of reproduction soft corals are capable of, and finally explain why evolution has made it possible for soft corals to reproduce both sexually and asexually, using numerous studies to support my claims. Most of the information on this topic was very species specific, but this paper will explain the reproductive evolution of soft corals in a broader array that will pertain to the scientific order Alcyonacea, or all types of soft corals.
Crustacea is a large subphylum of Arthropoda, consisting of almost 52 000 described species, including animals like crabs, lobsters, shrimp and barnacles. The majority of these are aquatic, living in marine or fresh water environments, though some have adapted to living on land like some crabs and woodlice. Most crustaceans are relatively small, though there are some exceptions. All of them have a hard, strong exoskeleton, divided into two parts, which has to be shed in order to allow the animal itself to grow. They have a large circulation system, where blood is pumped around the body by the heart. Only some crustaceans have sexes separate, and those that are usually mate seasonally and lay eggs. The study of Crustacea is called carcinology.
Porifera is the most simplistic phylum under the kingdom Animalia. The sponges have no tissue layers, but instead an interior and exterior layer with a gelatinous middle layer that separates the two. They are the only phylum with asymmetrical symmetry. Throughout the advancing phyla it will be shown this trait is lost. Porifera lacks a proper digestive system, but a canal system allows the sponges to filter feed. Along the inside of a sponge, flagella pump water through the sponge’s body. This process brings in oxygen and other small organisms and then flows out the top of the sponge, the osculum, removing waste by diffusion. Sponges lack a circulatory system, as does many of the first couple of phyla. A coinciding factor could be their small size. A nervous system is also missing, but very basic nerve cells within the pores sense the water currents. Gas exchange occurs through these pores. Reproduction in sponges can be asexual by budding, gammation, or fragmentation. Some sponges can also have sexual reproduction occur as an egg gets released and fertilized in the open water by free floating sperm. After this stage they cling onto rock and begin their sessile, basic, life....
Soft corals such as sea fingers and sea whips, are soft and bendable and often resemble plants or trees. These corals do not have stony skeletons, but instead grow wood-like cores for suppor...