The Ayyalon Cave ( he, מערת איילון) is a large limestone cave near

Ramla Ramla or Ramle ( he, רַמְלָה, ''Ramlā''; ar, الرملة, ''ar-Ramleh'') is a city in the Central District of Israel. Today, Ramle is one of Israel's mixed cities, with both a significant Jewish and Arab populations. The city was f ...

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

in which new species of

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

were discovered in April 2006.The Hebrew University Press release announcing the discovery
/ref> It has been studied for its complex

food web A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Another name for food web is consumer-resource system. Ecologists can broadly lump all life forms into one ...

, which survived for millions of years without light or organic food coming in from the surface, being based solely on a type of bacterium which feeds on sulfur which serves as the only organic matter available for the next higher level of organisms to feed on. The cave has offered an ecological refuge for species whose relatives living at the surface have been wiped out by climatic changes and catastrophic events over millions of years, and offers a unique sample for the study of long-term ecological changes in the area. The cave is not accessible to the public. Only a small number of researchers are allowed to enter.

Name

In scientific literature the cave is known as the Ayyalon Cave. In the press it might be spelled as "Ayalon Cave", and has also been dubbed "the Noah's Ark cave", as it offered animal species a survival niche and it is located in the "land of the Bible".

History

The cave was discovered in 2006 when a small opening was discerned in a quarry near Ramla.

Description

The cave, deep, extends including its branches, which makes it the third-largest limestone cave in Israel. According to Professor

Amos Frumkin Amos Frumkin is an Israeli geologist and speleologist. Frumkin (עמוס פרומקין; born in 1953) is a professor of geology at the Hebrew University of Jerusalem. Frumkin was born in Tel Aviv, Israel, in 1953. His expertise is the geology ...

of the

Hebrew University The Hebrew University of Jerusalem (HUJI; he, הַאוּנִיבֶרְסִיטָה הַעִבְרִית בִּירוּשָׁלַיִם) is a public research university based in Jerusalem, Israel. Co-founded by Albert Einstein and Dr. Chaim Weiz ...

, the cave is unique in that a thick layer of

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Chalk ...

left it impermeable to any water coming from the surface.

Ecosystem

Photosynthesis-free food chain

As the cave was completely cut off from the outside environment, it sustained an independent

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

; this ecosystem relied for an

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...

source neither on

sunlight Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...

and

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

, nor on an external source of

organic compounds In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The s ...

. Rather, energy was extracted by

chemoautotrophic A Chemotroph is an organism that obtains energy by the oxidation of electron donors in their environments. These molecules can be organic ( chemoorganotrophs) or inorganic (chemolithotrophs). The chemotroph designation is in contrast to phototro ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

, living in a film on top of the water of an underground lake. These bacteria produce energy by

oxidizing Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...

the

sulfide Sulfide (British English also sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to chemical compounds lar ...

compounds in the water, and derive organic compounds using

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

from the air. These compounds form the basis of the cave's ecosystem. The temperature and salt content of the cave's water indicates that it originates from sources deep underground. Although this cave is part of an

aquifer An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...

fed by rain falling in the mountains to the east, which happens to be one of the main potable water sources for

and the

Palestinian territories The Palestinian territories are the two regions of the former British Mandate for Palestine that have been militarily occupied by Israel since the Six-Day War of 1967, namely: the West Bank (including East Jerusalem) and the Gaza Strip. The I ...

, chemically more complex sources can create local pockets with very specific water composition.

New species

Researchers announced that they have so far discovered eight species previously unknown to science, all without eyes, comprising four aquatic

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

species and four other species of terrestrial crustaceans and

springtail Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called Ento ...

s. They added that the crustaceans included two seawater and two fresh water species, this diversity giving hope that it might help better understand the water history of the region. Unfortunately, a species of eyeless

troglobitic A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves. These are separate from species that mainly live in above-ground habitats but are also able to live u ...

scorpion representing a

taxonomic family Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order (biology), order and genus. A family may be divided into subfamily, subfamilies, which are intermediate r ...

previously unknown to science, has been discovered only a decade or so after its extinction. This was probably caused by overpumping of the

ground water Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...

, which has led the underground lake to shrink, and with it the food supply to dwindle. The ten specimen found dead in the cave are exceptionally well preserved and allowed the conclusion that they used a motion detecting organ situated on their abdomen for orientation. The species was given the name Akrav israchanani, from the

Hebrew Hebrew (; ; ) is a Northwest Semitic language of the Afroasiatic language family. Historically, it is one of the spoken languages of the Israelites and their longest-surviving descendants, the Jews and Samaritans. It was largely preserved ...

word for scorpion, "akrav", and honouring the researchers who identified it, Israel Naaman and Hanan Dimentman.

References

External links

National Geographic
* {{Caves in Israel Caves of Israel Limestone caves Ramla