Crown of Thorns Starfish

Kingdom: Animalia
Phylum: Echinodermata

Class: Asteroidea

Order: Valvatida

Family: Acanthasteridae

Genus: Acanthaster

Species: A. planci

Phylum Echinodermata: contains about 7000 species and include the starfish, sea urchins, sea cucumbers, brittle stars, and sand dollars

Class Asteroridea: contains all starfish, about 1800 species

Body structure: disk shaped, multiple armed, may have up to 21 arms! heavily spined, grow up to about 35 cm in diameter. usually neutral colours, but can be brightly coloured as well


Digestion: very large stomach, high stomach to body ratio, pulls out its stomach and digests food externally. Quickly eat and swipe away corals and sea urchins, algae, clams, and even each other

Crown of thorns eating coral

Circulatory system: open circulatory system, do not have blood, but use the sea water

Respiration: breath through skin, on the aboral side and near the tube feet where surface area is increased, water vascular system also aids in gas exchange

Excretion: excretion of solid wastes through anus on aboral surface and other wastes through the water vascular system (the tube feet)





WATER VASCULAR SYSTEM: water goes into the madreporite, through the stone canal, to the ring canal, and down one of the radial canal, branch out into the tiny bulbs call the ampullae. During this process, the water acts like the starfish's blood, and gives oxygen, carries wastes, and help the starfish move.

Movement: the crown of thorns starfish uses its tube feet to force water in and then out to create a strong suction, it can then use its muscles to move slowly, inch by inch

Reproduction: the crown of thorns starfish have hermaphroditic reproductive structures called gonads (which are the male and female reproductive structures). Sperm are released into the water (external fertilization) and fertilize the eggs when the water goes into the water vascular system (like sponges)

Teste

Ovary

Symmetry: Asymmetrical, have arms that are not similar, but have the five-point radial symmetry as infants, but eventually more arms grow out

Number of germ layers: The crown of thorns starfish has 3 germ layers (the ectoderm, endoderm, and the mesoderm), or is triploblastic, like all other echinoderms

Other organisms found within this phyla: starfish, sea cucumbers, sea urchins, brittle stars, sand dollars, and sea lilies, and feather stars, these all have similar basic internal structures but have very different external structures and shapes, for example, the reduced arms in the sea cucumber and sea urchin and the brittle stars' long arms

  

Detailed diagram of crown of thorns:

Ecological significance: Does more damage to environment than good. kill off many species of coral, leaving white skeleton behind, the Great Barrier Reef off the coast of Australia was being partially destroyed by these animals, so marine biologists had to inject sodium bisulphate into these creatures, which prove to be fatal to these animals but harmless to the marine environments. These species endanger many other species of coral during massive feeding times in spring. These creatures are becoming more and more common, and the starfish, which were once necessary to keep the numbers of coral in check, is a danger to many areas in the Red Sea, Pacific Ocean, and Indian Ocean.

Deuterostomes or Protostomes: The crown of thorns starfish is a deuterostome, which is due to its embryonic development. Deuterostomes are different from protostomes in the development of the first opening in the blastula, or a more developed stage of the morula. In deuterostomes, the opening becomes the anus and in protostomes the opening becomes the mouth. Deuterostomes contain 4 main phyla, one being the echinoderms and another being chordata, which include all vertebrates.

Other intersting facts:

• The Crown of Thorns Starfish is the 2nd largest starfish in the world, only behind the Sunflower Starfish.
• The Crown of Thorns Starfish can have entire arms filled with their reproductive stuctures
• The ovaries of this starfish can take up a quarter of its body volume and can house 50 million eggs!
• These large starfish can move at 20 km/h at their top speed
• Have toxins called saponins which cause bleeding and severe pain, contained in the spines and break off easily
• These toxins have detergent-like properties and bubble in water
• Can consume 6 square meters of coral a year!

                                                                   Why I love The Crown of Thorns:

One, their spikes fascinate me, I always wonder what it will be like to touch one of them, but of course, I don't want to be poisoned by their detergent toxins. Two, they are very, very large starfish, and large things just simply intrigue me for some odd reason. Third, they come in various colours, from bright red, dark blue, to deep chestnut brown and also have indefinite number of arms (to a certain maximum), and I enjoy seeing an organism, or anything, that's out of the ordinary, and doesn't follow specific rules. Fourth, they look like giant durians, which taste amazing. Last, they throw their stomachs out and digest food externally, what's not to love about that?

Starfish durian

Squid Dissection

Purpose and Goals:

The squid dissection on Friday was an exciting, slimy, and slightly displeasing to the nose (and also a delicious one?). The purpose of said dissection was to fully understand and explore the internal anatomy of a real, (once)-living squid. Some goals I set for myself during the course of the dissection were: to locate and examine the body structures, to relate physical (internal and external) features and characteristics to classroom and textbook material, and to appreciate and gain a deeper understanding/perspective of some simple things in life, such as this simple (delicious) squid. Also, an often excluded and hidden purpose in every dissection, and especially in this one, is to enjoy ourselves. During this dissection, I met (and exceeded?) all of these goals.

Understanding of the biological world:

              

This dissection not only opened my eyes to the details and complexity of some of the simple things we find in everyday life, but also showed me the deeply intricate interactions between these mollusks and the     biological world. The dissection allowed me to see how the squids capture prey, protect themselves, and how they move through their environment from the different structures the squid developed and enhanced over many many generations. These simple, yet exceptionally efficient structure show me the occupation of different niches by the squid, showing me how these organisms interact and contribute to their surrounding environment.

Relation to Class Material:

How is dissecting a squid related to a chapter on squids (mollusks)? Well, for one, they are both about squid. But more importantly, information from actually seeing the squid intertwine with the information in the textbook, such as the features and characteristics, and also the general relation to other mollusks, such as having a coelom and possessing a one-way digestive tract. From the dissection, parts and organs are clearly shown, forming a mental picture of why each part of the squid is there and its function and use. For example, I learned that squid have gills to perform respiration, but have never considered how, but seeing the gills on the sides of the squid's internal organs, I could visualize that the squid could draw in water and bring in O2 from the gills. 

Personal Response:

I found this dissection to be interesting, exciting, and quite amusing. I enjoyed poking pins on the squid and probing around its organs, and feeling how slimy they are. I took note of the body structure of the squid and it fascinated me to realize that these squid could, in fact, squish and squeeze themselves into just about any space possible! I also quite enjoyed playing around with the little guy... poor guy, he didn't deserve to die in the hands of... us. Anyway, the dissection proved again to be a easy to follow step-by-step teamwork project, and it helped me learn and explore not only the inside of a squid, but also the general shape and characteristics of mollusks, and allowed me to glance (even if just a little), in to the entire massive kingdom of animals.

External Anatomy

1. How many arms does your squid have? How many tentacles?
A: The squid has eight arms and two tentacles.


2. Based on the structure of the arms and the tentacles, describe how their differ. What do the arms do and what do the tentacles do?

A: The tentacles are used to capture prey due to their length and the arms are short with suckers which can be specialized for sexual reproduction (production of gametes), used for locomotion, and pushing the prey into its mouth.

3. Draw arrows on the squid to indicate the direction that waters comes out of the funnel and the direction that the squid moves

4. Name two external features that are adaptations for the squid's predatory life. How do these adaptations help the squid?

A: -Suckers on the squids arms help it grab on to any prey and prevent it from escaping

     -The well developed eyes on the squid allow it to seek out its prey and find it before it escapes

5. Do you remember the general traits of mollusks we discussed in lecture? Name two traits that the squid shares with other mollusks.

a. The squid exhibits bilateral symmetry, similar to all other mollusks. This shows the development from simple to more complex organisms.

b. The squid has gills, which are used to breath, like all other mollusks. O2 is extracted through these gills in the process of gas exchange.

Internal Anatomy:

1. The squid has one pair of gills, on on each side of its organs.

2. The ink sac empties through the pen and into the siphon, and sprays predators in time of danger,

3. The function of the pen is to draw the ink out from the ink sac for it to be released into the water. Without the pen, the flow of ink would be uncontrolled (too much) and the ink may spill into the internal cavity or may not be able to shoot the ink out with pressure.

4. Wastes exit the squid from its anus, located above the internal organs, attached to the intestines (solid waste). The nephridia filters the blood of the squid and releases waste also.

Pictures on iPad #3 in album named "Squid dissection Nick"

Annelid Biology Class Dissection--Earthworms (ABCDE)

Purpose and goals of the dissection:

I felt that this dissection was to help us learn and view the different organ systems of the earthworm to get a sense of the complicated structure of it. Even though that the worm is a simple and small organism, the internal organs and behaviour of the worm show the progression towards more advanced species in the world (ie: me) through complex organ development. This showed us the various structures of the worm, helped us identify each of the organs, and really gave us an overview (or deeper view) into (no pun intended) the worm. Overall, I believe the goal of this dissection is to exhibit a deeper understanding of earthworm anatomy, but also a preview of more complex (future) animals.

How it relates to what we are learning in class:

Since we are learning about annelids, and especially earthworms, this dissection made a stronger connection between the two. We were able to see all the different parts of the worm that the textbook told us were there, but never got to view. This allowed me to make a "road map" of the inside of the worm's body, knowing where all the organs are, and how each one is related to the other. I feel this is deeply interwoven with the classroom material. This is very useful in terms of understanding the basic concepts of the phylum Annelida, but also was a great way to practice making connection between knowledge and practical use.

Personal response:

I, personally, really enjoyed this dissection (although I enjoy every lab). I really liked that I had a chance to look at a real worm, and not a diagram on a textbook. I feel that this re-enforced the knowledge of annelids in my mind by making that mental connection between reality and knowledge. I have a sense of how small the organs are, and their respective colouring, location, and their bleeding point (how hard I poke it with the probe before it bleeds). I also saw the whole worm in a three dimensional view, which differed from my knowledge of earthworms. I learned from this that the nephridia are under the digestive tract, and also that the worm is flat on the ventral side, and round on the dorsal side. These little pieces of knowledge strengthens and fills gaps in my overall knowledge of earthworms and lead to a more sturdy and reliable source of information.

Questions:

1. What is the name of the pumping organs of the earthworm?

A: The aortic arches, arranged in parallel near the heart. These five hearts work together to pump blood through the worm's close circulatory system.

2. Trace the parts of the digestive tract through which food passes

A: The digestive system of the earthworm starts at the mouth of the worm, in to the pharynx, down to the esophagus, into the crop and gizzard, and travel through the intestine, and out the anus in excretion.

3. Which parts of the earthworm serve as its brain? How are these parts connected to the rest of the body?

A: The series of ganglia, masses of nerve cells, serve as the earthworms brain with an enlargement in each section. It is connected to the rest of the body by the ventral nerve cord, with a nerve collar just around the pharynx.

4.Which of the parts of the worm's body that you saw are included in the excretory system?

A: The anus passes solid wastes out in the form of feces (or castings). Nephridia, two in each segment, act as primitive bladders to remove wastes from its body fluids and excretes them.

5. How can you find out whether an earthworm eats soil?

A: During the dissection, I saw the worm's digestive tract to be somewhat brown, the colour of soil. Also, the castings of the worm would also contain undigested soil material, giving it the brown colour.

6. Among the earthworm's structural adaptations are its setae. How do you think the earthworm;s setae makes it well developed to its habitat?

A: The setae are hard, minute little spines that the earthworms can dig into the soil, to anchor itself from being dragged out of the ground. This adaptation works best when the setae are dug into the soil, meaning that this adaptation makes the earthworm well developed to its habitat

7. How is the earthworm's digestive system adapted for extracting relatively small amounts of food from large amounts of ingested soil?

A: The gizzard grinds up the soil and passes it on to the intestine to be digested. For this to be efficient, the gizzard and intestine must process much soil to supply the worm with its nutrients. The crop stores soil and will give a constant supply to the gizzard to ensure constant supply of nutrients from large amounts of soil.

8. Your dissection of the earthworm did not go beyond segment 32. What will you observe if you dissect the remainder of the worm to its posterior end?

A: I will be able to see the full intestine, more nephridia, and finally the anus. I will also be able to see the two main blood vessels and the ventral nerve cord.

9. During mating, two earthworms exchange sperm. Fertilization is external, and cocoons are produced from which the young eventually emerge. Refer again to steps 5 and 11. where you located the earthworm's reproductive organs. Use a reference to identify the role of each organ in the reproductive process of the earthworm. Summarize your findings.

A:  Earthworms produce both eggs in the ovaries and sperm in the testes. The sperm is exchanged and received in the seminal receptacles through the sperm grooves. External fertilization occurs after the eggs and sperm have been released. The clitellum acts like a cocoon and wraps the eggs after it slips off the worm.

SOME PICTURES ARE FROM GOOGLE

Zoology Webquest--Photos

Phylum: Porifera
Genus: Gelliodes
Species: fibrosa

Interesting facts:  Feels spongy, jellylike, and is stretchy; introduced species to Hawaii, compete with indigeous species.

Phylum: Porifera
Genus: Gelliodes
Species: fibrosa

Interesting facts: Live in hulls of ships, making it easily introduced to other environments; can reproduce asexually by fragmentation; found in the Philippines, main Hawaiian Islands, and possibly Guam.

Phylum: Porifera
Genus: Zygomycale
Species: parishii

Interesting facts: mainly live in shallow environments; found in Caribbean, Brazil, eastern Pacific at Panama, main Hawaiian Islands, Indo-Malay Region, Australia, and Indian Ocean; usually coloured red or brown

Phylum: Cnidarian

Genus: Chironex

Species: fleckeri

Interesting facts: most complicated cnidarian nervous system; have over 500000 cnidocytes in each tentacles; medusae is cube shaped, have limited memory.

Phylum: Cnidarian

Genus: Physalia

Species: physalis

Interesting facts: not actually a single jellyfish, but a colonial organism made up of zooloids; name comes from 16th century sailing boat; no means of propulsion; float on surface of the water.

Phylum: Cnidarian

Genus: Hydra

Species: oligactis

Interesting facts: grows attached to the stems of water plants, the underside of leaves, submerged twigs, and on the surface of stones; tentacles can extend up to 2.5 cm long (1 inch); can be called brown hydra.

Phylum: Platyhelminthes

Genus: Pseudobiceros

Species: bedfordi

Interesting facts: has two male genitalia, one for injection of sperm to another worm, and one used to "fence" and prevent itself from being fertilized; found in Asia and Africa; has a pale pink underside.

Phylum: Platyhelminthes

Genus: Pseudoceros

Species: dimidiatus

Interesting facts: black stripe on the middle and bright colour around it to warn predators not to eat it; all have a orange margin around the edge; grow up to 8 cm (3 inches) long; cold-blooded

Phylum: Plathyhelminthes

Genus: Taenia

Species: solium

Interesting facts: has a scolex on its head with four suckers to attach to human intestine; infects pigs and humans; can become 2-7 meters long; can have 1000 proglottids, each with 50000 eggs, infection can lead to seizures.