EL ANIMAL QUE HA SALVADO MÁS VIDAS HUMANAS./HORSESHOE CRAB

EL ANIMAL QUE HA SALVADO MÁS VIDAS HUMANAS.

No es ni el fiel perro, ni el leal caballo, ni la valiente paloma mensajera, sino la especie más antigua del planeta: el cangrejo herradura.

Es muy posible que, si alguna vez te han puesto una inyección, le debas la vida al cangrejo herradura  (Limulus polyphemus). La industria farmacéutica utiliza un extracto de su sangre, el lisado de amebocito del Límilus o LAL, para probar fármacos, vacunas y aparatos médicos, como los riñones artificiales, y comprobar que no hay microbios. No existe ninguna otra prueba tan sencilla y fiable.

Los cangrejos herradura viven en zonas costeras de poca profundidad que suelen estar contaminadas. Un litro de esta agua de mar pude contener fácilmente miles de millones de bacterias tóxicas. Los cangrejos herradura carecen de sistema inmunitario, por lo que no pueden desarrollar anticuerpos para combatir las infecciones. Sin embargo, su sangre contiene un elemento milagroso que se coagula alrededor de los agentes invasores y los disuelve: es lo que se utiliza en la producción del LAL, Para descubrir si algo destinado a un uso médico está contaminado o no, solo hay que exponerlo a un poco de LAL: si no coagula, está limpio.

A diferencia de los seres humanos, la sangre de los cangrejos herradura no tiene hemoglobina, que se vale del hierro para transportar oxígeno, sinohemocianina, que utiliza el cobre. Y eso explica que su sangre sea azul. Un litro vale unos 15.000 dólares estadounidenses.

"Ordeñando" cangrejos

Para conseguirla, no se mata a los cangrejos herradura, sino que se les "ordeña". Se pescan manualmente hasta un millar de ellos cada semana, desde barcas con rastrillos para moluscos, y se transportan aún vivos al laboratorio. Aunque se les extrae un 30% de su volumen sanguíneo, se recuperan rápidamente y se devuelven al agua. Se sangra a los cangrejos una vez al año, se congela y se deshidrata la sangre y, entonces, se envía a todo el mundo.

Cangrejos que no son cangrejos

En realidad, los cangrejos herradura no son cangrejos. Ni siquiera son crustáceos. Se parecen más a las garrapatas, los escorpiones y las arañas y son el último superviviente del orden, antaño numeroso, de los Xiphosura ("Cola de espada"). Habitan la costa atlántica de América y los mares del sudeste asiático desde el Ordovícico, hace 445 millones de años, y no han cambiado en todo este tiempo, que equivale al 75 por ciento de todo el tiempo transcurrido desde que apareciera la vida en el planeta, unos 200 millones de años antes de la aparición de los dinosaurios. No está mal para algo que parece un ratón de ordenador de diseño o un sombrerito de latón.

Si han sobrevivido durante tanto tiempo es, en parte, gracias a sus conchas lisas y curvadas. A los depredadores les cuesta mucho darles la vuelta para exponer el blando abdomen, aunque los nativos americanos solían utilizarlas para achicar el agua de las canoas.

Los cangrejos "salvadores"

Además de lo extraordinario de su sangre -ahora sabemos que también permite detectar la meningitis y el cáncer-, los cangrejos herradura pueden soportar el calor y el frío extremos y pasar un año sin comer.

Por si fuera poco, tienen diez ojos. Lo más curioso es que el Polifemo, el cíclope de la mitología griega cuyo nombre llevan, solo tenía uno.

               HORSESHOE CRAB

The horseshoe crab   is one of the oldest living things that exist in the   Earth . They inhabit our planet from 250 million years ago, long before the   dinosaurs . Are authentic   living fossils   that are slowly disappearing. It is a chelicerate of Merostomata class. Despite its name, this species is closer to spiders than to crabs, with which unrelated.

Their habitat

These strange creatures live in shallow muddy waters of   North Atlantic . They live in water but once a year, in the mating season, invade some coasts of North America . There females lay eggs in the   sand between the rocks.

So they are moist and protected from aquatic predators, they were the only animals living in the   Earth   when they appeared. Today this method has been left with a little older, and  Seagulls   feed on them.

Its characteristics

They measure about 50 inches, roughly the length of a human foot. Rocks seem to have a shell, hard, dark brown. They are not really crabs are more closely related to ticks,   spiders  and scorpions.

The so-called horseshoe crab, although   crab   has little, as his species is closest to arachnids which the crabs, it's all a living fossil because they have an estimated 450 million years old.

It has a body divided into three lobes divided by longitudinal grooves and ventral legs of emerging appendices and compound eyes. Their habits are unknown.

Pharmacological properties

It also has substances that detects harmful substances produced by   bacteria . Are equivalent to our   WBCs . And it is precisely these pharmaceutical substances used to detect possible   infectious bacteria in   drugs   which are applied via   Intravenous   and so if they test positive discard.

So far, this method has not been able to reproduce in the laboratory and the alternative method is injecting a   rabbit   and see if an infection develops.

Formerly used in agriculture as fertilizer. Today used as bait to fish in the pharmaceutical industry and their blood having unique properties is used. It is colorless or   blue   greenish, as it is loaded or not oxygen. This is because instead of iron to form hemoglobin for oxygen has copper forming keyhole.

Its true blue blood

Horseshoe crabs are a wonder of nature, for several reasons. One is one of the oldest living things on the planet, above even the dinosaurs, and the other is that its blue blood has utility as diverse and curious as to find ways of life outside the planet, or currently and study, combat the effects of   AIDS .

His colorless blood turns blue when exposed to air for its high copper content, and is a treasure for medicine and science because they contain several compounds that are a treasure for both pharmacological research and scientific applications.

Its peculiar blood cells contains about calls   amibocites , they react to a bacterial infection, in fact, if one of these crabs is injured at sea, the blood becomes solid preventing the entry of microorganisms and thus avoiding infection very quickly. Thus, it appears that the enzymes in your blood seem to be the secret that has survived millions of years.

The study of the properties of your blood emerged in the 50s, when scientists discovered that the blood clotted in contact withthe Salmonellay the Ecoli, have since been tested with it thousands of drugs and antibiotics we use every day, and is currently developing an enzyme that inhibits the effects of   AIDS , so curiously should be grateful to these strange looking animals for their contribution to our welfare and sure many drugs that have ingested to our recovery in a simple flu or infection.

No less interesting use of blood, is studying NASA, and is none other than the search for life on other planets. The process is as follows, to draw blood, enzymes are removed, dry and frozen and then the instrument incorporates a spatial measurement expressly designed for this purpose, which causes blood to be transformed into contact yellow a form of microscopic life in space. Another novel use of the blood of this animal is a rapid test for detection of possible infections in astronauts for immediate treatment.

The extract is obtained directly from horseshoe crab and once bleeding is returned to the sea.

His disappearance

These fascinating prehistoric animals are disappearing. Slowly but steadily.

A recent study by the Geological Survey of   USA   points decline guilty of climate change is happening on our planet since the end of the Ice Age and is accelerating emissions of greenhouse gases we emit humans.

However, previous studies claim that overfishing and catches for drug also contribute greatly to its demise.

Crab populations have declined since used as bait to catch whelks and snails. Consequently, some predators of horseshoe crabs are also rare as the Red Knot and Atlantic loggerhead turtle.

The negative part of the business is the market that becomes precious liquid. To draw blood, heart crab is punctured, and about 100 milliliters are extracted. The value of a liter in the market is 12,000   Euros   ($ 15,000), and this business generates in the US alone, 50 million a year.

Incidentally, during extraction, 15% of the animals die, the rest is returned to the sea .

@RdzgCarlos   With a Creative Commons Licence International 4.0