Monday, November 26, 2007

Sea Floor Spreading

What is sea floor spreading? Sea-floor spreading is the process by which new sea floor is formed as it moves away from spreading centers in mid-ocean ridges.

What are some of the major land forms that are created from plate movement? Trenches, Mid-Ocean Ridges, Mountains & Volcanoes.

How were the Mariana Islands formed? The Mariana Islands were formed by volcanoes.

What evidence exists today that the plates are still moving and that the islands are ancient volcanoes? Plate Tectonics! The earth beneath our feet is not dead; it is constantly moving, driven by forces deep in its core. Nor is the planet's crust all of one piece; it is composed of numerous plates, which are moving steadily in relation to one another. This movement is responsible for all manner of phenomena, including earthquakes, volcanoes, and the formation of mountains. All these ideas, and many more, are encompassed in the concept of plate tectonics, which is the name for a branch of geologic and geophysical study and for a powerful theory that unites a vast array of ideas. Plate tectonics works hand in hand with several other striking concepts and discoveries, including continental drift and the many changes in Earth's magnetic field that have taken place over its history. No wonder, then, that this idea, developed in the 1960s but based on years of research that preceded that era, is described as "the unifying theory of geology."

What is an atoll? An atoll is a coral reef that develops as a ring around a central lagoon.

Why are atolls mainly found on the Pacific? Because atoll formation requires coral reef building, atolls are limited to tropical waters. Atolls are most commonly found in the Pacific and Indian Oceans.


Wednesday, November 14, 2007

Fish of the Marianas Waters

CN: Mahi Mahi SN: Coryphaenidae Hippurus

CN: Bluespine Unicornfish or Tataga SN: Naso Unicornis

CN: Atulai SN: Selar Crumenophthalmus

CN: Bluefin Trevally SN: Caranx Melampygus

CN: Malabar Trevally or Eiei SN: Carangoides Malabaricus

CN: Parrotfish or Palakse SN: Cheilinus Digraammus

CN: Red Snapper or Onaga SN: Lutjanus Campechanus

CN: Rudderfish or Guilie SN: Centrolophus Niger

CN: Skipjack Tuna SN: Katsuwonus Pelamis

CN: Snapper or Gindai SN: Pristipomoides Zonatus

CN: Tagafi - Red Phase or Red Bass SN: Lutjanus Bohar

CN: Two-spot Red Snapper or Tagafi SN: Lutjanus Bohar

CN: Mutibar Goatfish or Satmoneti SN: Parupeneus Multifasciatus

CN: Striped Surgeonfish SN: Acanthurus Lineatus

CN: Star Puffer SN: Arothron Stellatus

CN: Lattice Soldierfish SN: Myripristis Violacea

CN: Sabre Squirrelfish SN: Sargocentron Spiniferum

CN: Orangespine Unicornfish SN: Naso Lituratus

CN: Manta Ray SN: Manta Birostris

CN: Great White Shark SN: Carcharodon Carcharias


FORUM TOPIC (Chapter 1, Page 21)

Critical Thinking – Question 2

In Chapter 1 it was explained that the statement “There are mermaids in the ocean” is not a valid scientific hypothesis. Can the same be said of the statement “There are no mermaids in the ocean”? Why?

Yes, I believe that the same can be said of the statement “There are no mermaids in the ocean” as the statement “There are mermaids in the ocean” because neither statement is testable.

I grew up being told beautiful stories of mermaids in the ocean therefore I believe that because marine biologists could not prove that there are no mermaids in the ocean does not mean that mermaids do not exist.

On the other hand, marine biologists may state that the statement “There are mermaids in the ocean” is a testable hypothesis since they have searched for a mermaid without success. A testable hypothesis is one that at least potentially can be proved false. In this case, they can prove that there are no mermaids in the ocean because they have not found a single mermaid.

SEE FORUMS (Chapter 3, Page 69)

Critical Thinking - Question 2

Just for the fun of it, someone in Beaufort, South Carolina, throws a message in a bottle into the sea. Some time later, someone in Perth, on the west coast of Australia, finds the bottle. Referring to Figure 3.20 and fold-out map of this book, can you trace the path the bottle probably took?

The path the bottle probably took started from the warm currents of the Gulf Stream to the cold Canary Current where the winds would then take it to the Antarctic Circumpolar Current to where it was found in Perth, on the west coast of Australia.

This is very interesting. This reminds me a lot of one of my favorite shows; “Message In A Bottle” stars Kevin Kostner.

Tuesday, November 13, 2007

SEE FORUMS (Chapter 8, Page 179) - Questions

Question 1.

The only living representatives of a very ancient group is the hagfishes and lampreys (jawless fishes). Why do you suppose these jawless fishes do not live in our waters?

Question 2.

A Marine Biologist from Fish & Wildlife collected a deep-water female shark containing 20 eggs from our waters for the first time and did a detailed study on it. Do you think that the Marine Biologist will conclude that this shark species, although new, belong to the family of sharks already present in our waters? Would it be possible that this new female shark mated with one of our male sharks? Please explain your answers.

Question 3.

Parrot fish is one of the favorite fish of the local people. What are the advantages and disadvantages should parrot fish have an equal number of males as females present in our waters?

Thursday, November 8, 2007

SEE FORUMS (Chapter 8, Page 179)

Critical Thinking - Question 3
Individuals of some species of bony fishes change sex, some to maintain more males than females, others more females than males. What are the advantages and disadvantages of each situation? Are there any advantages and disadvantages in having an equal number of males and females?
In the deep sea finding a mate can be difficult – even harder than finding food therefore being able to change from a male to a female or a female to a male is advantageous for these types of fishes because there would be an increase in reproduction. Deep-sea fishes that are hermaphrodites guarantee the ability to breed. In at least some species of anemone fishes (Amphiprion), all individuals begin as males. Each sea anemone is inhabited by a single large female that mates only with a large, dominant male. If the female disappear or is experimentally removed, her mate changes into a female and the largest of the non-breeding males becomes the new dominant male. Males of some wrasses form harems of many females. If the male disappears, the largest dominant female immediately begins to act like a male and within a relatively short period of time changes color and transforms into one that is capable of producing sperm. A variation of hermaphroditism among fishes is sex reversal, or sequential hermaphroditism, in which individuals begin life as males but change to females (protandry), or females change into males (protogyny). These changes are controlled by sex hormones but triggered by social cues such as the absence of a dominant male. I believe that there are neither advantages nor disadvantages in having an equal number of males and females since protandry and protogyny are present within these fishes. The way I understand it, we will never run out of fishes that are hermaphrodites.

SEE FORUMS (Chapter 8, Page 179)

Critical Thinking - Question 2

A deep-water shark, new to science, is collected for the first time. The specimen is studied in detail, but its stomach is empty. How could you get a rough idea of its feeding habits? The specimen is a female, and its reproductive tract is found to contain 20 eggs. Can you tell the type of development characteristics of this species?

I think one can get a rough idea of an unidentified deep-water shark's feeding habits by studying the feeding habits of other known sharks. In addition, sharks possess movable powerful jaws that have rows of numerous sharp, often triangular teeth, therefore, if the unidentified deep-water shark possess any of these features, then we can assume that their feeding habits would be the same as the sharks known today.
Yes, it is possible to tell the development characteristic of the unidentified deep-water female shark by studying the 20 eggs found in its reproductive tract. Since the eggs were found in the reproductive tract of the unidentified deep-water shark then this shark could be ovoviviparous, which are cartilaginous fishes that retains eggs inside their reproductive tract for additional protection and gives birth to live young.

SEE FORUMS (Chapter 8, Page 179)

Critical Thinking - Question 1

Hagfishes and lampreys are the only living representatives of a very ancient group. Why do you suppose there are still some of these jawless fishes around?

I suppose hagfishes and lampreys (jawless fishes) are still living today because of the simplicity of their way of life. Hagfishes feed mostly on dead or dying fishes while lampreys attach to other fishes and suck their blood or feed on bottom invertebrates. Both jawless fishes do not require much effort for survival.