Its a bit long, however it would be appreciated if some of you stomatopod addicts could proof read it (or some of it) and verify i havnt made any mistakes. Its not done yet, but i think its getting close.
Also, If Roy Caldwell reads this, could you tell me what the date is on your site (for citing purposes).
Stomatopoda
Stomatopods are predatory crustaceans that range in size (among species) from approximately 1cm to 36cm. They go by multiple common names including manits shrimp, thumb splitter, and prawn killer. They belong to the Kingdom Animalia, Phylum Arthropoda, Class Crustacea, Subclass Malacostraca and the order Stomatopoda (international wildlife encyclopedia). They are mainly found in tropical or subtropical marine environments. Stomatopods are highly predetorial and are equipped to lake down prey with a pair of limbs called raptorial appendages.
Members of the of the order stomatopoda appear to be a cross between a shrimp and a Prey Mantis (refer to figure 3). There are eight pairs of limbs that arise from the thorax (The thorax is the segment between the head and abdomen of an animal). Above the thorax segmentation are five pairs of limbs called maxillipeds. These limbs are used primarily for hunting and feeding. The second pair of maxillipeds is drastically larger then the other pairs and is called the raptorial appendage. These limbs are the main weapon of the mantis shrimp and are very powerful despite the small size of the stomatopod. The raptorial appendages in some larger species has been tested and estimated to be equivalent the force of a .22 caliber bullet (Specifically Hemisquilla ensigera and Odontodactylus scyllaruscan). Some stomatopods are capable of striking prey in less then 8 milliseconds. In comparison, this is about 50 times faster then the speed of a blink of a human eye. Stomatopods are then unofficially divided into two main subgroups called “spearers†and “smashers†based on the appearance of their raptorial appendage. In “smashersâ€Â, the raptorial appendage appears to be the shape of a club (refer to figure 2), while “speares†posess a pointed and barbed limb that is easily capable of slicing through soft bodied prey such as fish (refer to figure 1). A stomatopod’s spear, depending on species, may poses between 2 and 20 barbs. If a stomatopod has damaged raptorial appendages, or looses them (or one) altogether, it is able to regenerate it after approximately four successive molts. On the back of the stomatopod (parallel to the maxillipeds) is a large shield like section of a stomatopods exoskeleton called the carapace. The carpace is relatively short and makes up for less then one third of a stomatopods body (not including claudal region). Underneath the thorax, stomatopods posess three pairs of legs called pereiopods. These limbs are also referred to as “walking legsâ€Â. These limbs are used for walking across the sea floor, swimming as well as sifting and digging in sand. Heading towards the tail, five pairs of pleopods are located. The pleopods are biramous and branch into two. On these two branches are the stomatopods filamentous gills. The telson and the uropod form a lobster like tail that is able to protect stomatopods.
There are 17 existing families in this order as well as three species that are extinct. The families are: Alainosquillidae, Bathysquillidae, Coronididae, Erythrosquillidae, Eurysquillidae, Gonodactylidae, Hemisquillidae, Indosquillidae, Lysiosquillidae, Nannosquillidae, Odontodactylidae, Parasquillidae, Protosquillidae, Pseudosquillidae, Squillidae, Takuidae and Tetrasquillidae. In this essay the family Gonodactylidae will be used as a representative of smashers and the family Lysiosquillina will be used as a representative of spearers. There are approximately 450 species found in this order.
Compared to other crustaceans and other animals in general, stomatopods are fairly advanced. Marine biologist (University of Queensland, Australia), Dr. Justin Marshall once stated that†Mantis shrimp have the world’s most complex vision system.†Stomatopods have hexocular vision and are able to seer other spectrums of light that humans cannot including infra-red, ultra-violet as well as some species being able to see polarized light. Hexocualr vision is when an organism has three different focal points in each eye. Humans in comparison only have binocular vision or two focal points in each eye. This allows them to be very effective hunters due to their accuracy in judging distance between themselves and prey. Each eye is located on a stock that is capable of a wide range of motion. Stomatopods have up to 16 different visual pigments in their eyes compared to the three that humans have (red blue and yellow).
Stomatopods live primarily in habitats that suit their type of raptorial appendage. Spearers generally live holes dug in soft substrates such as sand (refer to figure 4), while smashers are commonly found in rock crevices on coral reefs (refer to figure 5). Smashers are often far more aggressive when it comes to defending their crevice. Crevices in coral reefs are hard to come by so smashers will aggressively defend then, while smashers will just seek out new burrows in substrate. A spearers burrow may be up to approximately 33 ft long and posess several entrances. Stomatopods live primarily in tropical of subtropical waters, however species of the super family Bathysquilloidea live in outer shelf habitats up to depths of 1500m.
Stomatopods are sexually dimorphic and the sexes can be fairly easily distinguished by their exterior anatomy. Male stomatopods poses a long and slender pair of penes (penis like organ) that are located at the base of the last set of peraeopods. Females lack penes and poses gonopores which is a slit. Gonopores are located between the first and second pair of paraeopods. Males also have lager raptorial appendages and telsons then females.
The majority of stomatopods are solitary and only encounter each other when breeding or during territorial disputes. Breeding is achieves by inserting the males penes into the females gonopores and excreting sperm. Mating is achieve by the pair positioning themselves underside to underside. Fertilization is internal and occurs when eggs are laid and pass through the gonopores and the stored sperm. After breeding, the males will leave the female. The family Lysiosquillids is an exception to this however. In this family, after breeding, the pair becomes monogomus and stays with each other for the rest of their lives. This could be up to twenty years before one of their deaths. In this situation, the male acts as the provider and gathers food while the female says with the eggs in which she has formed into a ball using exhudate that the female excreates from her ventral thorax. Once the female clumps the eggs into a ball, the female will either carry the egg mass with her maxillipeds or attach it to her crevice (homes) wall. In monogomus pairs, the female does not eat while attending the egg mass. The eggs hatch in one to three weeks. The eggs go through four main stages of development. They are in sequential order: antizoeae, erichthaus, pseudozoea and then the alima stage. Families containing larger species such as Lysiosquillae have more developed offspring that is born after going through the first couple stages of development.
Stomatopods are common in tropical and subtropical marine waters throughout the world. Scientists are able to determine the health of the world’s oceans by estimating the number of stomatopods present in a given area. Stomatopod populations will decline prior too many other species if pollution rises. Stomatopods of the family squilla are available as a commercial food source. This gives scientists a good indicator of the pollution levels in areas of the ocean and allows them to act prior to the pollution becoming a true problem. Depending on species, stomatopods are generally diurnal, nocturnal or crepuscular (dawn and dusk). When resting in their burrow, it is not uncommon to find the entrance blocked deliberately either with rocks of the stomatopod’s tail. Smashers primarily hunt hard bodied prey such as crabs, snail or mollusks, while spearers prefer to hunt soft bodies prey such as fish. This is because of their raptorial appendages. Smashers are able to use their “club†to break open hard bodied prey, while spearers are not. The blow of a smashers club is able to cripple and eventually kill hard bodied prey. This makes spearers have to prey on soft bodies foods such as fish. Spearers catch potentially fast moving fish by lying in wait in their burrow then ambushing it as it passes over head. Smashers on the other hand have to leave their burrow to catch hard bodied prey. After catching the prey, smashers then drag it back to their burrow to consume.
The stomatopod species Lysiosquillina maculate (commonly called Zebra mantis shrimp due to its colour pattern) is considered to be one of the largest of stomatopods growing to a maximum of approximately 15 inches and is a “spearerâ€Â. Both male and female Lysiosquillina maculate show distinct altering bands on their dorsal abdomens (refer to figure 6). Females tend to have a more orange appearance. Adult species of the family Lysiosquillina can be distinguished from other families partly by the presence of submedian teeth located on the telson. Stomatopod species range in a variety of colours from brown to yellow to purple. Different species usually have different colour patterns that are unique to their species. Lysiosquillina maculate are found in the Indo-Pacific region from Hawaii and Galapagos to East Africa. In the wild they inhabit “U†shaped burrows in which they wait in ambush for soft bodied prey like fish to pass over head. Like other “spearers,†Lysiosquillina maculate live in burrows dug into soft substrates such as sand or mud. Lysiosquillina maculate live in intertidal regions where the sand bed could be exposed to air or submerged up to 10 meters. Adult Lysiosquillina maculate form monogamous pairs. In comparison to Lysiosquillina maculate, Gonodactylaceus falcatus is a “smasher†who inhabits dead branching coral heads as well as other crevices in solid rock. Similar to Lysiosquillina maculate, Gonodactylaceus falcatus inhabits intertidal zones where water could be meters above the sea substrate or have the sand bed exposed to air during low tide. Gonodactylaceus falcatus inhabits between French Polynesia and the red sea. They have also been introduced by humans to Hawaii and surrounding areas. Scientists believe this species only reproduces twice a year. Members of the genus Gonodactylaceus have an absence of spines on their dactylus. Dactylus is the club some stomatopods. The genus Gonodactylaceus only contains “smashers.â€Â
References
Ahyong, S., Lowry, J. (2001). Stomatopoda: Families. Version 1: 1Retreived November 10, 2008 from. http://www.crustacea.net
Bertler, J. (2007). Colour Vision and Communication in Aquatic Environments. Retrieved December 27, 2008 from http://ilc00f.facbacs.uq.edu.au/VTHRC/ecovis/stomatopods.htm
Caldwell, R., Fox, H. (Date). Secrets of the Stomatopod: An Underwater Research Adventure. Retrieved November 10, 2008 from http://www.ucmp.berkeley.edu/aquarius/index.html
Carlton, J., DeFelice, R.,Eldredge, L. (2001). A Guide book of introduced marine species to Hawaii: Hawaii biological survey 2001.
http://www2.bishopmuseum.org/HBS/invertguide/species/gonodactylus_falcatus.htm
Englemann,J., Hegner,W. (1968). Invertebrate Zoology: Second Edition. New York.
Fitzgerald, K. (2004). Grzimek’s Animal life Encyclopedia (Volume 2 pp164-175). Detroit: Gale Cengage Learning
International Wildlife Encyclopedia: Third Edition (Volume 11 pp. 1551-1552). New York: Marshall Cavendish Corporation.
Manning, R. (1995). Stomatopods., 828-831.
Poore, G. (2004).Marine Decapod Crustacea of Southern Australia: A guide to Identicacation. Australia: CSIRO Publishing.
Yi, K. (2001). Squillia Empusa. Retrieved December 27, 2008 from
http://animaldiversity.ummz.umich.edu/site/accounts/information/Squilla_empusa.html.
Also, If Roy Caldwell reads this, could you tell me what the date is on your site (for citing purposes).
Stomatopoda
Stomatopods are predatory crustaceans that range in size (among species) from approximately 1cm to 36cm. They go by multiple common names including manits shrimp, thumb splitter, and prawn killer. They belong to the Kingdom Animalia, Phylum Arthropoda, Class Crustacea, Subclass Malacostraca and the order Stomatopoda (international wildlife encyclopedia). They are mainly found in tropical or subtropical marine environments. Stomatopods are highly predetorial and are equipped to lake down prey with a pair of limbs called raptorial appendages.
Members of the of the order stomatopoda appear to be a cross between a shrimp and a Prey Mantis (refer to figure 3). There are eight pairs of limbs that arise from the thorax (The thorax is the segment between the head and abdomen of an animal). Above the thorax segmentation are five pairs of limbs called maxillipeds. These limbs are used primarily for hunting and feeding. The second pair of maxillipeds is drastically larger then the other pairs and is called the raptorial appendage. These limbs are the main weapon of the mantis shrimp and are very powerful despite the small size of the stomatopod. The raptorial appendages in some larger species has been tested and estimated to be equivalent the force of a .22 caliber bullet (Specifically Hemisquilla ensigera and Odontodactylus scyllaruscan). Some stomatopods are capable of striking prey in less then 8 milliseconds. In comparison, this is about 50 times faster then the speed of a blink of a human eye. Stomatopods are then unofficially divided into two main subgroups called “spearers†and “smashers†based on the appearance of their raptorial appendage. In “smashersâ€Â, the raptorial appendage appears to be the shape of a club (refer to figure 2), while “speares†posess a pointed and barbed limb that is easily capable of slicing through soft bodied prey such as fish (refer to figure 1). A stomatopod’s spear, depending on species, may poses between 2 and 20 barbs. If a stomatopod has damaged raptorial appendages, or looses them (or one) altogether, it is able to regenerate it after approximately four successive molts. On the back of the stomatopod (parallel to the maxillipeds) is a large shield like section of a stomatopods exoskeleton called the carapace. The carpace is relatively short and makes up for less then one third of a stomatopods body (not including claudal region). Underneath the thorax, stomatopods posess three pairs of legs called pereiopods. These limbs are also referred to as “walking legsâ€Â. These limbs are used for walking across the sea floor, swimming as well as sifting and digging in sand. Heading towards the tail, five pairs of pleopods are located. The pleopods are biramous and branch into two. On these two branches are the stomatopods filamentous gills. The telson and the uropod form a lobster like tail that is able to protect stomatopods.
There are 17 existing families in this order as well as three species that are extinct. The families are: Alainosquillidae, Bathysquillidae, Coronididae, Erythrosquillidae, Eurysquillidae, Gonodactylidae, Hemisquillidae, Indosquillidae, Lysiosquillidae, Nannosquillidae, Odontodactylidae, Parasquillidae, Protosquillidae, Pseudosquillidae, Squillidae, Takuidae and Tetrasquillidae. In this essay the family Gonodactylidae will be used as a representative of smashers and the family Lysiosquillina will be used as a representative of spearers. There are approximately 450 species found in this order.
Compared to other crustaceans and other animals in general, stomatopods are fairly advanced. Marine biologist (University of Queensland, Australia), Dr. Justin Marshall once stated that†Mantis shrimp have the world’s most complex vision system.†Stomatopods have hexocular vision and are able to seer other spectrums of light that humans cannot including infra-red, ultra-violet as well as some species being able to see polarized light. Hexocualr vision is when an organism has three different focal points in each eye. Humans in comparison only have binocular vision or two focal points in each eye. This allows them to be very effective hunters due to their accuracy in judging distance between themselves and prey. Each eye is located on a stock that is capable of a wide range of motion. Stomatopods have up to 16 different visual pigments in their eyes compared to the three that humans have (red blue and yellow).
Stomatopods live primarily in habitats that suit their type of raptorial appendage. Spearers generally live holes dug in soft substrates such as sand (refer to figure 4), while smashers are commonly found in rock crevices on coral reefs (refer to figure 5). Smashers are often far more aggressive when it comes to defending their crevice. Crevices in coral reefs are hard to come by so smashers will aggressively defend then, while smashers will just seek out new burrows in substrate. A spearers burrow may be up to approximately 33 ft long and posess several entrances. Stomatopods live primarily in tropical of subtropical waters, however species of the super family Bathysquilloidea live in outer shelf habitats up to depths of 1500m.
Stomatopods are sexually dimorphic and the sexes can be fairly easily distinguished by their exterior anatomy. Male stomatopods poses a long and slender pair of penes (penis like organ) that are located at the base of the last set of peraeopods. Females lack penes and poses gonopores which is a slit. Gonopores are located between the first and second pair of paraeopods. Males also have lager raptorial appendages and telsons then females.
The majority of stomatopods are solitary and only encounter each other when breeding or during territorial disputes. Breeding is achieves by inserting the males penes into the females gonopores and excreting sperm. Mating is achieve by the pair positioning themselves underside to underside. Fertilization is internal and occurs when eggs are laid and pass through the gonopores and the stored sperm. After breeding, the males will leave the female. The family Lysiosquillids is an exception to this however. In this family, after breeding, the pair becomes monogomus and stays with each other for the rest of their lives. This could be up to twenty years before one of their deaths. In this situation, the male acts as the provider and gathers food while the female says with the eggs in which she has formed into a ball using exhudate that the female excreates from her ventral thorax. Once the female clumps the eggs into a ball, the female will either carry the egg mass with her maxillipeds or attach it to her crevice (homes) wall. In monogomus pairs, the female does not eat while attending the egg mass. The eggs hatch in one to three weeks. The eggs go through four main stages of development. They are in sequential order: antizoeae, erichthaus, pseudozoea and then the alima stage. Families containing larger species such as Lysiosquillae have more developed offspring that is born after going through the first couple stages of development.
Stomatopods are common in tropical and subtropical marine waters throughout the world. Scientists are able to determine the health of the world’s oceans by estimating the number of stomatopods present in a given area. Stomatopod populations will decline prior too many other species if pollution rises. Stomatopods of the family squilla are available as a commercial food source. This gives scientists a good indicator of the pollution levels in areas of the ocean and allows them to act prior to the pollution becoming a true problem. Depending on species, stomatopods are generally diurnal, nocturnal or crepuscular (dawn and dusk). When resting in their burrow, it is not uncommon to find the entrance blocked deliberately either with rocks of the stomatopod’s tail. Smashers primarily hunt hard bodied prey such as crabs, snail or mollusks, while spearers prefer to hunt soft bodies prey such as fish. This is because of their raptorial appendages. Smashers are able to use their “club†to break open hard bodied prey, while spearers are not. The blow of a smashers club is able to cripple and eventually kill hard bodied prey. This makes spearers have to prey on soft bodies foods such as fish. Spearers catch potentially fast moving fish by lying in wait in their burrow then ambushing it as it passes over head. Smashers on the other hand have to leave their burrow to catch hard bodied prey. After catching the prey, smashers then drag it back to their burrow to consume.
The stomatopod species Lysiosquillina maculate (commonly called Zebra mantis shrimp due to its colour pattern) is considered to be one of the largest of stomatopods growing to a maximum of approximately 15 inches and is a “spearerâ€Â. Both male and female Lysiosquillina maculate show distinct altering bands on their dorsal abdomens (refer to figure 6). Females tend to have a more orange appearance. Adult species of the family Lysiosquillina can be distinguished from other families partly by the presence of submedian teeth located on the telson. Stomatopod species range in a variety of colours from brown to yellow to purple. Different species usually have different colour patterns that are unique to their species. Lysiosquillina maculate are found in the Indo-Pacific region from Hawaii and Galapagos to East Africa. In the wild they inhabit “U†shaped burrows in which they wait in ambush for soft bodied prey like fish to pass over head. Like other “spearers,†Lysiosquillina maculate live in burrows dug into soft substrates such as sand or mud. Lysiosquillina maculate live in intertidal regions where the sand bed could be exposed to air or submerged up to 10 meters. Adult Lysiosquillina maculate form monogamous pairs. In comparison to Lysiosquillina maculate, Gonodactylaceus falcatus is a “smasher†who inhabits dead branching coral heads as well as other crevices in solid rock. Similar to Lysiosquillina maculate, Gonodactylaceus falcatus inhabits intertidal zones where water could be meters above the sea substrate or have the sand bed exposed to air during low tide. Gonodactylaceus falcatus inhabits between French Polynesia and the red sea. They have also been introduced by humans to Hawaii and surrounding areas. Scientists believe this species only reproduces twice a year. Members of the genus Gonodactylaceus have an absence of spines on their dactylus. Dactylus is the club some stomatopods. The genus Gonodactylaceus only contains “smashers.â€Â
References
Ahyong, S., Lowry, J. (2001). Stomatopoda: Families. Version 1: 1Retreived November 10, 2008 from. http://www.crustacea.net
Bertler, J. (2007). Colour Vision and Communication in Aquatic Environments. Retrieved December 27, 2008 from http://ilc00f.facbacs.uq.edu.au/VTHRC/ecovis/stomatopods.htm
Caldwell, R., Fox, H. (Date). Secrets of the Stomatopod: An Underwater Research Adventure. Retrieved November 10, 2008 from http://www.ucmp.berkeley.edu/aquarius/index.html
Carlton, J., DeFelice, R.,Eldredge, L. (2001). A Guide book of introduced marine species to Hawaii: Hawaii biological survey 2001.
http://www2.bishopmuseum.org/HBS/invertguide/species/gonodactylus_falcatus.htm
Englemann,J., Hegner,W. (1968). Invertebrate Zoology: Second Edition. New York.
Fitzgerald, K. (2004). Grzimek’s Animal life Encyclopedia (Volume 2 pp164-175). Detroit: Gale Cengage Learning
International Wildlife Encyclopedia: Third Edition (Volume 11 pp. 1551-1552). New York: Marshall Cavendish Corporation.
Manning, R. (1995). Stomatopods., 828-831.
Poore, G. (2004).Marine Decapod Crustacea of Southern Australia: A guide to Identicacation. Australia: CSIRO Publishing.
Yi, K. (2001). Squillia Empusa. Retrieved December 27, 2008 from
http://animaldiversity.ummz.umich.edu/site/accounts/information/Squilla_empusa.html.
