''Amphisbaena alba'', also known as the red worm lizard or less commonly as the white or white-bellied worm lizard, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

amphisbaenian Amphisbaenia (called amphisbaenians or worm lizards) is a group of typically legless lizards, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As ...

in the reptilian

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Squamata Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest Order (biology), order of reptiles; most members of which are commonly known as Lizard, lizards, with the group also including Snake, snakes. With over 11,991 species, it i ...

. Despite the large geographic range that this species covers, little is known about its ecology due to its secretive habits. ''A. alba'' has a diverse diet ranging from plant material to small vertebrates (such as lizards and their eggs, snakes, mice, and other rodents). Numerically, beetles, ants, and spiders compose the majority of their diet; however, ants, insect larvae, beetles, cockroaches, hemipterans, mole crickets, crickets, grasshoppers, termites, spiders, scorpions, pseudoscorpions, and annelids are ingested to satisfy a larger volume. The females are somewhat larger than the males, and can reach over 80 cm, which is quite large for an amphisbaenian. They are known to bury themselves in leafcutter ant nests and hide in the ants' garbage dump areas to avoid irritating the ants into attacking, and to bury themselves to avoid predation in general.

Geographic range

It occurs in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

from eastern

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

and the island of

Trinidad Trinidad is the larger, more populous island of the Republic of Trinidad and Tobago, the country. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is the southernmost island in ...

through the entire

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

to northern

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. ''Amphisbaena alba'' has the largest geographic range of all the amphisbaenians.

Reproduction

Reproduction for this species occurs in the dry season of its geographical area. Some evidence suggests that this species exploits the living space of the leaf-cutting ant and may even use the nests of these ants to deposit its eggs. ''A. alba'' lays the greatest number of eggs at a time (8–16) in comparison to other amphisbaenians, which is possibly due to its large body size. There is no sexual dimorphism in regard to snout-vent length, meristic, or morphometric characters for ''A. alba'' most likely due to functional constraints related to their burrowing nature. The

ultrastructure Ultrastructure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope. This traditionally meant the resolution and magnification range of a c ...

of epididymal

spermatozoa A spermatozoon (; also spelled spermatozoön; : spermatozoa; ) is a motile sperm cell (biology), cell produced by male animals relying on internal fertilization. A spermatozoon is a moving form of the ploidy, haploid cell (biology), cell that is ...

has been studied for ''A. alba''. Mature spermatozoa are

filiform Filiform, thread or filament like, can refer to: * Filiform, a common term used in botany to describe a thread-like shape *Filiform, or filiform catheter, a medical device whose component parts or segments are all cylindrical and more or less un ...

and are characterized by features such as a depression in the transverse section of the

acrosome The acrosome is an organelle that develops over the anterior (front) half of the head in the spermatozoa (sperm cells) of humans and many other animals. It is a cap-like structure derived from the Golgi apparatus. In placental mammals, the acroso ...

, a moderately long midpiece, columnar

mitochondria A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is us ...

, an elongated

nucleus Nucleus (: nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucleu ...

, and a

fibrous Fiber (spelled fibre in British English; from ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often inco ...

sheath in the midpiece. Epidermal glands are located in the cloacal region of ''A. alba'' and are most likely used for reproduction and marking territory. The openings of the glands are plugged with a solid, holocrine secretion that is removed when it moves through tunnels and leaves a secretion trail.

Erythrocyte characteristics

The stages of ultrastructural changes of organelles in developing erythroid cells are similar to the developmental changes in other vertebrate groups. The greatest difference is the periodical transverse alignment of hemoglobin molecules in the organelle matrix of the hemosomes. The transformation of the erythroid cell organelles for hemoglobin biosynthesis occurs slowly. This is due to the low metabolic rate of ''A. alba'' which is a result of the hypoxic environment where it lives.

Defensive tactics

When ''Amphisbaena alba'' assumes a defensive posture it bends its body into the shape of a horseshoe and raises both the head and the tail. The tail is made of tough collagen bundles that allows the tail to absorb mechanical pressure from a bite. The body of ''A. alba'' is also covered with a flexible armor which makes other areas resistant to bites as well.

References

External links

* {{Taxonbar, from=Q1290784

alba ''Alba'' ( , ) is the Scottish Gaelic name for Scotland. It is also, in English-language historiography, used to refer to the polity of Picts and Scots united in the ninth century as the Kingdom of Alba, until it developed into the Kingd ...

Lizards of the Caribbean Reptiles of Bolivia Amphisbaenians of Brazil Reptiles of Colombia Reptiles of Ecuador Reptiles of French Guiana Reptiles of Guyana Reptiles of Panama Reptiles of Paraguay Reptiles of Suriname Reptiles of Trinidad and Tobago Reptiles of Venezuela Fauna of the Amazon Fauna of the Pantanal Reptiles described in 1758 Taxa named by Carl Linnaeus