Camponotus anderseni
Encyclopedia
Camponotus anderseni is a species of mangrove ant
found in northern Australia
. There is little known about the ant species, Camponotus anderseni, because it is a relatively new discovery.
, an online database reviewed by scientists and authenticated by “expert curators”, gives a detailed description of this mysterious ant through the peer-reviewed series, Memoirs of the American Entomological Institute. The Camponotus anderseni is light brown and glossy. Like any arthropod
, its body contains three sections. The first part is called the prosoma
while the middle part is called the mesosoma
, and the posterior part is called the metasoma
. The dorsum
, or posterior side, of the mesosoma on Camponotus anderseni is flattened. It also has distinct metanotum on the posterior of the thorax
. It is lacking erect setae under its head, and its body is slightly raised on the tibiae, or fourth joint of each leg. Its eyes elongate looking outward, nearer to the mandibles than the vertex
. It is dimorphic, meaning there are two separate forms based on class. In major workers, the clypeus
is depressed and finely punctate. The anterior margin is convex. In minor workers, the clypeus is wide, and the anterior margin is convex and projecting.
of Western Australia
. According to recent studies, C. anderseni are the only species of ant known to live in the twigs of these trees, and recent studies showed that approximately 81% of the ant nests in the canopy of the mangrove tree Sonneratia alba were occupied by Camponotus anderseni. The remaining nests were inhabited by three species of Tapinoma
, two species of Crematogaster
, Monomorium floricola, and Tetraponera punctulata.
in Darwin, Australia. They studied Camponotus anderseni in a series of experiments to determine varying carbon dioxide and oxygen levels in nests. During inundation, a soldier sacrifices himself to block the entrance hole with a its head which effectively prevents flooding inside the nest. Once this occurs, the area can be very crowded, with the ants and coccids filling up to half the volume, and the conditions in the nests during a flood become hypercapnic and hypoxic.
Each nest has only one entrance, and the opening is only about 1.56mm in diameter. The diameter of the galleries is only approximately 2.31 mm. During normal conditions with open nests, the oxygen depletion is substantial in the part of the nest most distant from the opening, and in a 120 mm long nest the oxygen concentration can be as low as 15.7%. During simulated inundation, in which the nest entrances were blocked, the oxygen concentration dropped to less than 0.5% after one hour. After opening the nest entrance, the oxygen concentration increased again, but for a 100 mm long nest it took nearly 20 minutes before the concentration was back to the normal depressed level.
The dilemma faced by C. anderseni is to avoid drowning without suffering anoxia or hypercapnia, and they show a remarkable ability to adapt to the extreme conditions in the mangrove and exploit a niche where the density of other ants is insignificant. By adapting to these hostel situations, mangrove ants have developed the ability to switch to anaerobic respiration. This was proven by the observed oxygen and carbon dioxide levels. Oxygen uptake in the nests eventually stopped, but the carbon dioxide production continued. This indicates high levels of anaerobic respiration.
A similar study was conducted by Nielsen and other associates with another Australian mangrove ant, Polyrhachis sokolova
. This mangrove species has been known to use the front four legs as oars and the back two legs as rudders in order to swim back to the nest directly before inundation. At this point, the ants retreat into their nest in the mud, which creates an air pocket and blocks out the incoming tide. The question was again raised about the ant’s source of air, and the study on carbon dioxide levels in the nests of Polyrhachis sokolova was conducted. The experiment concluded with results similar to the study of Camponotus anderseni nests with evidence that the ants had achieved anerobic respiration.
Camponotus anderseni and the study involving this species have made significant contributions to the scientific community. This study alongside the study on Polyrhachis sokolova has supplied the only published work explaining the unique ability for mangrove ants to breathe anaerobically. Before these studies, there was no notable explanation among scientists for many ant species surviving in mangrove inundations.
of Camponotus anderseni were regularly observed gnawing small cavities in the green terminal shoots of Sonneratia trees, and this species occupied all of the examined terminal nest-cavities. It was thereby concluded that all ant galleries in Sonneratia branches are founded by this species. However the densities of these ants in Sonneratia trees differs greatly even in close vicinities because of the remote characteristics of these trees. The base of the Sonneratia trees is usually surrounded by sea water. Therefore, each tree functions as an island. After the queens have landed and lost their wings, they have very limited capacity for dispersal to neighboring trees.
One of the most remarkable observations in this study is that queens and workers of Camponotus anderseni were never
found in the same nest cavity. No queens were found in any of the 225 dissected nest
chambers containing C. anderseni. In an additional 400 nests collected from other areas, queens were only found in the soft green shoot
s at the terminal ends of the branches of Sonneratia and were never together with workers. In the older nest chambers, workers were always present, regardless of the umber of brood
and alate
s. Furthermore, it was not possible the find an egg-laying queen in the main nest chambers of nests. Many believe that the only plausible explanation for the observed demographic variation in the nests of Camponotus anderseni is to assume that the species has some form of thelytokous parthenogenesis, which is known from only very few species. This hypothesis is currently being tested with DNA
micro satellite markers.
, several began to fight. This indicates that nests represent separate colonies
.
. More important for this species is the possibility of being washed away by the tide, waves or heavy rainstorms. Large nest cavities require very long hollowed twigs, which break easily during strong winds, potentially resulting in the ants being washed away. Larger cavities in thicker branches require the ants to excavate
hard wood, which did not seem to be the case for this species. A more serious problem is the coccids, which primarily require cavities with a thin wall. Finally, a large cavity with several entrances and a large volume of air is much more difficult to keep waterproof during flooding.
which has lead scientists to believe that these ants rely on another food source. Due to the high numbers of coccids, their main food source is most likely honeydew
. Honeydew is defined as a saccharine deposit secreted by aphids or scale insects. Very little is known about the dispersion of coccids to new chambers. It seems unlikely that the new queens transport coccids during nuptial flights, because no coccids are ever found in chambers less than 6 weeks old.
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
found in northern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. There is little known about the ant species, Camponotus anderseni, because it is a relatively new discovery.
Description
The Encyclopedia of LifeEncyclopedia of Life
The Encyclopedia of Life is a free, online collaborative encyclopedia intended to document all of the 1.9 million living species known to science. It is compiled from existing databases and from contributions by experts and non-experts throughout the world...
, an online database reviewed by scientists and authenticated by “expert curators”, gives a detailed description of this mysterious ant through the peer-reviewed series, Memoirs of the American Entomological Institute. The Camponotus anderseni is light brown and glossy. Like any arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
, its body contains three sections. The first part is called the prosoma
Cephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...
while the middle part is called the mesosoma
Mesosoma
The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings....
, and the posterior part is called the metasoma
Metasoma
The metasoma is the posterior part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the mesosoma. In insects, it contains most of the digestive tract, respiratory system, and circulatory system, and the apical segments are typically...
. The dorsum
Dorsum (anatomy)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
, or posterior side, of the mesosoma on Camponotus anderseni is flattened. It also has distinct metanotum on the posterior of the thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
. It is lacking erect setae under its head, and its body is slightly raised on the tibiae, or fourth joint of each leg. Its eyes elongate looking outward, nearer to the mandibles than the vertex
Vertex
Vertex may refer to:-Mathematics:*Vertex , an angle point of any shape or angle*Vertex , a node in a graph*Vertex , a local extreme point of curvature...
. It is dimorphic, meaning there are two separate forms based on class. In major workers, the clypeus
Clypeus
The clypeus is one of the sclerites that makes up the "face" of an arthropod.In insects, the clypeus delimits the lower margin of the face, with the labrum articulated along the ventral margin of the clypeus. The mandibles bracket the labrum, but do not touch the clypeus. The dorsal margin of the...
is depressed and finely punctate. The anterior margin is convex. In minor workers, the clypeus is wide, and the anterior margin is convex and projecting.
Taxonomy
The Encyclopedia of Life also gives a taxonomic description of Camponotus anderseni. However, the species C. anderseni has not been cataloged because it is a relatively new discovery.Geography
The Camponotus anderseni has only been found in the mangroves of northern Australia. It is found exclusively in twigs of the mangrove tree Sonneratia alba. These trees can be found in the Kimberly region in the North TerritoryNorthern Territory
The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...
of Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. According to recent studies, C. anderseni are the only species of ant known to live in the twigs of these trees, and recent studies showed that approximately 81% of the ant nests in the canopy of the mangrove tree Sonneratia alba were occupied by Camponotus anderseni. The remaining nests were inhabited by three species of Tapinoma
Tapinoma
Tapinoma is a genus of ants that belongs to the ant subfamily Dolichoderinae. There are 63 described species.The origin of the scientific name is interesting. Tapinoma is derived from the Finnish spirit god Tapio hence the common name ghost ant. Melanocephalum is derived from the two Greek words...
, two species of Crematogaster
Crematogaster
Crematogaster is an ecologically diverse genus of ants found worldwide, which are characterised by a distinctive heart-shaped gaster , which gives one of their common names, Valentine Ant. It is the only genus of the tribus Crematogastrini. Most of species are arboreal...
, Monomorium floricola, and Tetraponera punctulata.
Flooding in the Mangroves
Some select species of ant in the Australian mangroves because the advantage of living in a mangrove is less competition from other ants. Unfortunately, this is because the mangrove is considered to be highly undesirable by most ant species due to the two daily inundations. However, all mangrove ants have a remarkable ability that allows them to survive these floods which would otherwise exterminate all ant colonies in a single tidal wave. All of these ants use some method to create a sealed pocket of air to protect from any water gathering inside the nest. To avoid drowning during high tide, some ants escape to higher parts of the trees, whereas others hide in air-filled cavities in the mangrove trees or in air pockets in the mangrove mud. These retreats have limited air volumes, and they are therefore subject to extreme changes in the oxygen and carbon dioxide concentrations. This creates a problem when there are limited oxygen levels for large colonies.Study of Oxygen Deprivation in Nests
This problem was studied by a group of professors from the Department of Biological Science in the University of Aarhus, Denmark and the School of Science at Charles Darwin UniversityCharles Darwin University
Charles Darwin University is an Australian public university with about 20,000 students in 2007.The University offers a wide range of Higher Education degrees and Vocational Education and Training courses with flexible study options, including part-time, external and online.CDU has campuses in the...
in Darwin, Australia. They studied Camponotus anderseni in a series of experiments to determine varying carbon dioxide and oxygen levels in nests. During inundation, a soldier sacrifices himself to block the entrance hole with a its head which effectively prevents flooding inside the nest. Once this occurs, the area can be very crowded, with the ants and coccids filling up to half the volume, and the conditions in the nests during a flood become hypercapnic and hypoxic.
Each nest has only one entrance, and the opening is only about 1.56mm in diameter. The diameter of the galleries is only approximately 2.31 mm. During normal conditions with open nests, the oxygen depletion is substantial in the part of the nest most distant from the opening, and in a 120 mm long nest the oxygen concentration can be as low as 15.7%. During simulated inundation, in which the nest entrances were blocked, the oxygen concentration dropped to less than 0.5% after one hour. After opening the nest entrance, the oxygen concentration increased again, but for a 100 mm long nest it took nearly 20 minutes before the concentration was back to the normal depressed level.
The dilemma faced by C. anderseni is to avoid drowning without suffering anoxia or hypercapnia, and they show a remarkable ability to adapt to the extreme conditions in the mangrove and exploit a niche where the density of other ants is insignificant. By adapting to these hostel situations, mangrove ants have developed the ability to switch to anaerobic respiration. This was proven by the observed oxygen and carbon dioxide levels. Oxygen uptake in the nests eventually stopped, but the carbon dioxide production continued. This indicates high levels of anaerobic respiration.
A similar study was conducted by Nielsen and other associates with another Australian mangrove ant, Polyrhachis sokolova
Polyrhachis sokolova
Polyrhachis sokolova is a species of ant recently discovered to be capable of surviving tidal inundations.Researchers at the James Cook University gained attention in 2006 after finding and reporting this behavior. Polyrhachis sokolova nests in mud in mangrove swamps, regularly inundated by rising...
. This mangrove species has been known to use the front four legs as oars and the back two legs as rudders in order to swim back to the nest directly before inundation. At this point, the ants retreat into their nest in the mud, which creates an air pocket and blocks out the incoming tide. The question was again raised about the ant’s source of air, and the study on carbon dioxide levels in the nests of Polyrhachis sokolova was conducted. The experiment concluded with results similar to the study of Camponotus anderseni nests with evidence that the ants had achieved anerobic respiration.
Camponotus anderseni and the study involving this species have made significant contributions to the scientific community. This study alongside the study on Polyrhachis sokolova has supplied the only published work explaining the unique ability for mangrove ants to breathe anaerobically. Before these studies, there was no notable explanation among scientists for many ant species surviving in mangrove inundations.
Queens and Workers
In another experiment by Morgens Gissel Nielsen, colonies of Componotus aderseni were observed and behaviors were recorded. New queensQueen ant
A queen ant is an adult, reproducing female ant in an ant colony; generally she will be the mother of all the other ants in that colony. Some female ants do not need to mate to produce offspring, reproducing through asexual parthenogenesis or cloning and all of those offspring will be female.Ant...
of Camponotus anderseni were regularly observed gnawing small cavities in the green terminal shoots of Sonneratia trees, and this species occupied all of the examined terminal nest-cavities. It was thereby concluded that all ant galleries in Sonneratia branches are founded by this species. However the densities of these ants in Sonneratia trees differs greatly even in close vicinities because of the remote characteristics of these trees. The base of the Sonneratia trees is usually surrounded by sea water. Therefore, each tree functions as an island. After the queens have landed and lost their wings, they have very limited capacity for dispersal to neighboring trees.
One of the most remarkable observations in this study is that queens and workers of Camponotus anderseni were never
found in the same nest cavity. No queens were found in any of the 225 dissected nest
Ant colony
An ant colony is an underground lair where ants live, eat and mate. Colonies consist of a series of underground chambers, connected to each other and the surface of the earth by small tunnels. There are rooms for nurseries, food storage, and mating...
chambers containing C. anderseni. In an additional 400 nests collected from other areas, queens were only found in the soft green shoot
Shoot
Shoots are new plant growth, they can include stems, flowering stems with flower buds, and leaves. The new growth from seed germination that grows upward is a shoot where leaves will develop...
s at the terminal ends of the branches of Sonneratia and were never together with workers. In the older nest chambers, workers were always present, regardless of the umber of brood
Brood
Brood may refer to:* Brood, a collective term for offspring* Brooding, the incubation of bird eggs by their parents* Brood , the young of a beehive*Brood: to think deeply about something, often in a dark or melancholy manner....
and alate
Alate
An alate is a winged reproductive of a social insect . Alate females are typically those destined to become queens , whereas alate males are occasionally referred to as "drones"...
s. Furthermore, it was not possible the find an egg-laying queen in the main nest chambers of nests. Many believe that the only plausible explanation for the observed demographic variation in the nests of Camponotus anderseni is to assume that the species has some form of thelytokous parthenogenesis, which is known from only very few species. This hypothesis is currently being tested with DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
micro satellite markers.
Behavior
Camponotus anderseni workers of neighboring nests are known to be highly aggressive to each other. This was observed in a careful study from the University of Aarhus by watching neighboring ants in their environment as well as in a laboratory. When ants from different nests were placed together in a Petri dishPetri dish
A Petri dish is a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells or small moss plants. It was named after German bacteriologist Julius Richard Petri, who invented it when working as an assistant to Robert Koch...
, several began to fight. This indicates that nests represent separate colonies
Ant colony
An ant colony is an underground lair where ants live, eat and mate. Colonies consist of a series of underground chambers, connected to each other and the surface of the earth by small tunnels. There are rooms for nurseries, food storage, and mating...
.
Colony Size
Because each nest represents a separate colony, there are exceptionally small colonies, which are a clear adaptation to the high degree of environmental variability. A large colony requires either many small nest chambers or a few larger ones. The exchange between the many small chambers will increase the time the workers spend outside the nests and therefore also the degree of predationPredation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
. More important for this species is the possibility of being washed away by the tide, waves or heavy rainstorms. Large nest cavities require very long hollowed twigs, which break easily during strong winds, potentially resulting in the ants being washed away. Larger cavities in thicker branches require the ants to excavate
Excavate
The excavates are a major kingdom of unicellular eukaryotes, often known as Excavata. The phylogenetic category Excavata, proposed by Cavalier-Smith in 2002, contains a variety of free-living and symbiotic forms, and also includes some important parasites of humans.-Characteristics:Many excavates...
hard wood, which did not seem to be the case for this species. A more serious problem is the coccids, which primarily require cavities with a thin wall. Finally, a large cavity with several entrances and a large volume of air is much more difficult to keep waterproof during flooding.
Diet
Camponotus anderseni are rarely seen foragingForaging
- Definitions and significance of foraging behavior :Foraging is the act of searching for and exploiting food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce...
which has lead scientists to believe that these ants rely on another food source. Due to the high numbers of coccids, their main food source is most likely honeydew
Honeydew (secretion)
Honeydew is a sugar-rich sticky liquid, secreted by aphids and some scale insects as they feed on plant sap. When their mouthpart penetrates the phloem, the sugary, high-pressure liquid is forced out of the gut's terminal opening. Honeydew is particularly common as a secretion in the Hemipteran...
. Honeydew is defined as a saccharine deposit secreted by aphids or scale insects. Very little is known about the dispersion of coccids to new chambers. It seems unlikely that the new queens transport coccids during nuptial flights, because no coccids are ever found in chambers less than 6 weeks old.