Friday, January 14, 2011

The Cone Snail by Cody Geidner

                                                                The Cone Snail

(Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Superfamily: Conoidea
Family: Conidea
Subfamily: Coninae
Genus: Conus)

The cone snail is a marine snail that preys on small marine worms and fish, other mollusks and even other cone snails. There are 600 different species of cone snails typically found in warm seas worldwide, most common in the Indonesian-Pacific area most species live near reefs but some live in the sand as well.

The anatomy of a cone snail if that of any other common snail except for one huge detail: the harpoon. This harpoon, formally know as a toxoglossan radula, is a poison filled barb containing tetrodotoxin, a neurotoxin capable of killing humans.
            The smaller snails typically use this barb to hunt small marine worms, but larger ones will actually hunt fish. It is in these species, such as the textile cone snail, that human deaths can occur.
            The harpoon of the snail is hollow and barbed and sits in the snails throat attached to the radula most of time when it is at rest.
            The effect on humans is the fact that like my previous organism that I chose, the Blue ringed Octopus, the cone snail contains venom containing tetrodotoxin that is able to kill you within hours of being bitten or stung. The toxin causes paralysis and loss of vision, and eventually, without help in time, cardiac arrest and death.
            The cone snail, unlike some other gastropods, is not edible and for the most part, serves no purpose in the economy except in the field of pain control. some of the venom of cone snails, in small very diluted forms is starting to be used as a natural, prescription painkiller, one is now on the market available for purchase in Australia.

reproduction in the cone snail has not been widely studied, although it appears most of the species of cone snails have separate sexes and have internal fertilization. egg capsules are attached to a substrate such as a rock or piece of kelp and hatch into either veligers (free swimming larvae) or veliconcha (small versions of cone snails)

Tuesday, January 11, 2011

The Cone Snail (Conus) By: Zachary Kaye

The Cone Snail (Conus) BY ZACHARY KAYE

Introduction: The Conus, or Cone Snail, is classified under the kingdom Animalia, the phylum of mullusca, and the class of gastropoda. Conus is a genus that contains a varied amount of sized snails, ranging from small to large. There are over 3200 species known of the genus conus. Their shell is shaped like a geometric cone, which is where they got their name from. They are all venomous, some being more then others. If you were to get stung by a small conus it would be nothing more then a bee sting. However, the larger and more venomous ones are capable of a very serious sting and have been known to even kill humans. Although they are found in different regions of water, they are most dense in tropical waters.

The snails body anatomy consists of:
1) Proboscis. The proboscis is the cone snail’s hunting tool. This harpoon is loaded with venom that is injected into their pray. The proboscis can extend longer than twice the size of the snail.
2) Siphon. The snail’s siphon is similar to a nose. It is an extendable tube that can be used like a radar and can sense animals around it. It also directs water to the gills to help with respiration.
3) Eye Stalks - Cone snails have a pair of eyes, located on either side of their mouth. It is unknown how well snails can see, however it is certain that the deeper water snails have very limited sight due to the lack of light.
4) Mouth - A cone snail has a huge extendable mouth. The mouth can extend out to eat the pray and once consumed, a muscle brings the mouth back in.
5) Foot - A long muscular foot extends to allow the snail to move along surfaces.

Form and Function: Eating Habits: Cone snails are carnivores, and are predators. They hunt and eat prey such as small fish, mollusk, marine worms, and even other cone snails. Cone Snails are very slow moving, and because of this, use their radula to catch food. Many Cone Snails wait in the sand until prey comes along, and then snatches it in a blink of an eye. It doesn’t only burrow in the sand to hunt, but also to hide and protect itself from its predators. The venom of a few larger species, is powerful enough to kill a human.

Video of Cone Snail catching prey:

Reproduction: The females eggs are fertilized internally by the males sperm. Each one of the egg capsules can contain between 500 and 700 eggs. The capsules are laid under rocks, and very few survive. The few eggs that survive to hatch do so in about 16-17 days. The larvae remain free floating for about 16 days, and then settle onto substrate. At this time they are about 1.5 mm (0.06 in) in length.

Impact on the world/humanity: The largest impact on the world that the cone snail has is the neurotoxins that it produces. They are used to make medicine that treat neuropathic pain. Less then 1% of the 500 species have been studied, and scientist believe that this amazing animal has the potential to treat Parkinson’s disease and depression.

Journal/Article Review:
The summary of this article is that the neurotoxins created by the cone snail have been turned into a pain medicine called Prialt. It is approved by the FDA and is used for neuropathic pain. Some of the neurotoxins made are 1000 times more powerful then morphine. Because our digestive enzymes would break these toxins apart, they are injected directly into our spinal canal.


Thursday, January 6, 2011

Mantis Shrimp (Stomatopods) By: Alek Kanellopoulos

                                                          Mantis Shrimp (Stomatopods)        
                                                             By: Alek Kanellopoulos
                                                                        Figure 1


Mantis shrimp or stomatopods are marine crustaceans. Their phylogenic placement is as follows:

Kingdom – Animalia
Phylum – Arthropoda
Subphylum – Crustacea
Class – Malacostraca
Subclass – Hoplocarida
Order - Stomatopoda

There are around 400 known species of stomatopods today. Although known as “mantis shrimp” they are neither shrimp nor mantids. They get their name solely from the uncanny resemblance they bear to both organisms. Mantis shrimp are fairly large, with lengths of up to 30 centimeters (About one foot), while some as large as 38 centimeters
have been recorded! Mantis shrimp have a truly massive life span of just over 20 years.
                                                                            Figure 2

Mantis shrimp appear in a multitude of colors, often times in beautiful neon arrangements.

                                                                             Figure 3

They are quite common in many sub-tropical and tropical marine habitats, but are poorly understood due to an isolated lifestyle in burrows or holes, only coming out to hunt (YES HUNT) or reproduce. They spend most of their time hiding in rock formations, or creating complex tunnels and passageways in the seabed. The majority of stomatopod species can be found in all tropical and sub-tropical seas, although some do live in temperate oceans. Dubbed “thumb splitters” by many, the mantis shrimps’ most amazing trait is its powerful claws known as raptorial appendages. These claws are some of the fastest striking and most powerful (in relation to size of organism) of any of the marine invertebrates. It is through these claws that the species is separated into two distinct groups: Smashers or spearers.

                                                                           Figure 4

                                                                           Figure 5


The most important aspect to note about the mantis shrimp is its amazing raptorial appendage. Shown above, it is composed of a complex musculature that provides for the amazing amount of force that these animals can create. The appendage shown above is that of a spearer, but the anatomy is much of the same for the smasher except the dactyl is replaced with a type of calcified club. Another fact to know is that mantis shrimp have incredible eyes, which are some of the most photoreceptive of any invertebrate, giving it an innate ability to perceive transparencies in prey, and a multitude of different colors. On top of that the eyes move independently from each other, so at all times the mantis shrimp can see a complete peripheral view of its surroundings.

Form and Function:

The mantis shrimps’ diet consists of crustaceans, worms, fish and even cowries. Unlike most arthropods, mantis shrimp do not generally wait for food to come to them; they go out hunting for their meal. Spearers snatch these pray from the water, while smashers simply smash their shells open with their clubs. Both methods of attack can penetrate, stun, and dismember the prey. Mantis shrimp scurry quickly about their environment looking for food in order to be as efficient as possible. What truly makes hunting possible are these amazing raptorial appendages: The spear, and the club.

Spearers:    Solely have a spiny appendage that is used to stab prey and pull it towards the mantis shrimp. The action is unbelievably fast and generally prey cannot even react to the attack.

Smashers:    In contrast, smashers too possess a spear (rudimentary) but also have a highly advanced club that is used to bludgeon and smash prey apart.

Both types of stomatopod strike rapidly by unfolding and swinging the raptorial claw at the prey, and can often inflict incredible damage on much larger organisms. Primarily in smashers, this attack is phenomenally fast; they can instantly propel their club at a rate of 23 meters per second, which is roughly the acceleration of a .22 caliber bullet. Smashers can strike so rapidly that they actually create a fluid dynamic phenomenon known as “cavitation.” Cavitation occurs when there are two drastically different forces moving in water. The reaction creates an explosion, which generates a strong force and can inflict great damage. This often is the case with fast moving boat propellers, when they cause cavitation.
                                                                           Figure 6

The cavitation reaction produces measurable forces on mantis shrimp prey in addition to the 1,500 Newton force that is caused by the impact of the club. This shockwave is enough without the club to stun or even kill prey. Pound for pound there is not more dangerous predator anywhere in the ocean!

Mantis shrimps reproduce sexually. Sperm from a male travels up the female’s body cavity and fertilizes the eggs of the female. The female then lays eggs, and is left with the job to carry the eggs under her tail until they hatch. In a lifetime, mantis shrimp can have as many as 20 to 30 breeding cycles due to their long life span. Amazingly, male and female come together not only for mating, but also in monogamous long-term relationships lasting around 20 years!

Mantis shrimp has both and mouth and anus and has a one-way digestive tract. Food is taken in through the mouth and expelled through the anus.

Impact On World:

The mantis shrimp is prevalent in Japanese cuisine, often boiled and eaten as a sushi topping, and occasionally raw as sashimi. They are also quite common in Cantonese cuisine. Mantis Shrimp are known to taste more so like lobster than shrimp, and are heard to be quite delicious.
                                                                        Figure 7

Mantis shrimp pose a threat to artificial reef systems, particularly in aquariums, in that they are fervent burrowers. Often times, they will burrow entire canal systems in dead coral, which could have been used for shelter purposes for domestic fish.

Journal Article Review:

Patek, Initials, & Taylor, Initials. (2010). Mantis shrimp bio armor

Patek and Taylor of the Journal of Experimental Biology, studied mantis shrimp and their common sparring habits. They found out that in sparring matches, the mantis shrimp take turns delivering blows to their shield like tail segments, known as telsons. These telsons are incredibly durable, and are able to absorb 70% of the impact from the smasher appendage, much like a punching bag. The strength of the blows is used to establish dominance without resulting in damage between the mantis shrimp and not costing either one their life. They found the durability of the telson is due to heavily mineralized sections of the tail segment.
                                                                        Figure 8

List of References:

Mantis shrimp (stomatopods). (2010, December 9). Retrieved from

Debbie Hauter, Initials. (n.d.). Mantis shrimp - pet or pest. Retrieved from

Patek, Initials, & Taylor, Initials. (2010). Mantis shrimp bio armor