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

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

amphisbaenian Amphisbaenia (called amphisbaenians or worm lizards) is a group of usually legless squamates, 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

Squamata Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species ...

. 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 mice). Numerically, beetles, ants, and spiders compose the majority of their diet; however, ants, insect larvae, beetles, crickets, grasshoppers, and termites 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 relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

from eastern

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

and the island of

Trinidad Trinidad is the larger and more populous of the two major islands of Trinidad and Tobago. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is often referred to as the southernmos ...

through the entire Amazon Basin to northern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. ''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 co ...

of epididymal

spermatozoa A spermatozoon (; also spelled spermatozoön; ; ) is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromos ...

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 In medicine, a catheter (/ˈkæθətər/) is a thin tubing (material), tube made from m ...

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 many animals including humans. It is a cap-like structure derived from the Golgi apparatus. In placental mammals the acrosome ...

, a moderately long midpiece, columnar mitochondria, 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 Nucl ...

, and a

fibrous Fiber or fibre (from la, fibra, links=no) is a #Natural fibers, natural or Fiber#Artificial fibers, artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The stronge ...

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 Kingdom ...

Lizards of South America Lizards of the Caribbean Reptiles of Bolivia Reptiles 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