- Source: Cephalotes
Cephalotes is a genus of tree-dwelling ant species from the Americas, commonly known as turtle ants. All appear to be gliding ants, with the ability to "parachute" and steer their fall so as to land back on the tree trunk rather than fall to the ground, which is often flooded.
Ecological specialization and evolution of a soldier caste
One of the most important aspects of the genus' social evolution and adaptation is the manner in which their social organization has been shaped by environmental pressures. This is particularly true of the species Cephalotes rohweri, in which an entire soldier class has evolved as a result of highly specialized nest cavity availability.
Because ants within Cephalotes use multiple carved nesting cavities found in the trees upon which they live, a cohort of morphologically specialized soldiers has evolved to defend these nesting cavities. They use their unique plate-like heads to block the entrances to the nests, essentially creating a living door to the nest cavities.
In one particular study, Scott Powell tested the hypothesis that "specialized use of cavities with entrances close to the area of one ant head has selected for a morphologically and behaviorally specialized soldier in Cephalotes." This was accomplished by performing comparative studies between four Cephalotes species, each representing one of the four character states of soldier evolution. Cephalotes was ideal for the study because it is the only genus to contain extant species displaying four levels of major morphological evolution. These character states are:
No soldier present (ancestral)
Soldiers present with simple domed head
Soldiers present with incomplete head-disk
Soldiers present with complete head disk (most advanced)
Another study by Powell examined the process by which environmental factors shape colonial castes within the worker class. However, this study focused more on how colonies adapt their caste systems to ecological factors in their environment.
For the experiment, a species of the genus Cephalotes was used that displayed the highest level of soldier specialization. Three key findings regarding adaptive caste specialization were supported:
Soldiers were best at defending the specific nesting resource found in nature.
Colonies used only certain nests (out of all the available nests), and selected only the nesting sites that would maximize soldier performance.
Soldier performance and limitations had both direct and indirect effects on colony reproduction.
The results of this experiment support the concept that the most specialized soldier phenotype in Cephalotes is a result of adaptation to ecological specialization within a narrow subset of available nests.
Species
= Fossil species
=The fossil record is restricted to the Miocene with species recovered from both Dominican and Mexican ambers. Species were initially described by Gijsbertus Vierbergen and Joachim Scheven (1995) whole placed the species into the genera Cephalotes, Eucryptocerus, Exocryptocerus and Zacryptocerus. All four genera were revised four years later by Maria De Andrade and Cesare Baroni Urbani (1999, who synonymized them under Cephalotes.
The Dominican amber species:
The Mexican amber species:
†Cephalotes maya De Andrade, 1999
†Cephalotes olmecus De Andrade, 1999
†Cephalotes poinari Baroni Urbani, 1999
†Cephalotes ventriosus De Andrade, 1999
See also
Aphantochilus, a genus of crab spiders known to mimic Cephalotes species
References
External links
Media related to Cephalotes at Wikimedia Commons
Kata Kunci Pencarian:
- Cyperus cephalotes
- Agrilus cephalotes
- Serixia cephalotes
- Stenhomalus cephalotes
- Oncideres cephalotes
- Carex cephalotes
- Batrachorhina cephalotes
- Cacia cephalotes
- Obrium cephalotes
- Cleptometopus cephalotes
- Cephalotes
- Atta cephalotes
- Cephalotes pusillus
- Harpalus cephalotes
- Spinoberea cephalotes
- Megalodontes cephalotes
- Serixia cephalotes
- Sophronica cephalotes
- Megachile cephalotes
- Agaricophagus cephalotes
