There are few things as contentious in biology and taxonomy as the subject of what defines a species and what is a new species respectively. Gargs are believed to consist of two different taxiforms; Gargus Keenrussians as seen in Keen 1 and Gargus Monumenta as seen in Monuments of Mars.
Evidence against speciation:
- Basic morphology is similar, both species share the characteristic double motile eye stalks.
- Both forms are dangerous and toxic to the touch, the poison used being almost identical.
- Both species are carnivourus and survive by consuming Martian plantlife, especially phytozooforms such as pat-pat.
Evidence for speciation:
- Morphology is appreciably different; Gargus K are green with highly visible teeth and red eyes. Gargus M. conversely are red with green eyes and almost never show their teeth unless eating.
- Both species utilize different manners of attack and defense; While Gargus K. are capable of completely disembowleing an opponent and devouring them, Gargus M. refuses to use its teeth in either attack or defense, prefering its poisonus skin as a deterrent. This makes them vulnerable to attack by heroes. Also, Gargus K. is capable of quite a turn of speed when charging, whilst Gargus M. prefers to walk sideways, crablike and is incapable at moving at more than walking pace.
- While both species are carnivorus, Gargus K survive on Mars widdershin face, where they mainly prey on pat-pat and even small Yorps. Gargus M. are found only on the turnwise face of Mars, where large plant and animal life is rare, they consume much smaller organisims.
- Different behaviour; While Gargus K. actively seek out food supplies and violently charge intruders, especially dominant males, Gargus M. prefers aimless rambling, often just moving back and forth pointlessly.
- Different size. In the comparative illustrations it can be seen that while Gargus K. are approximately slightly taller than the height of an 8 year old child, Gagus M., despit their sparse diet, are about as tall as a grown man.
Given these points of evidence, it is proposed that Gargus K. and Gargus M. are seperate species. Some however believe in the existence of a third taxiform, as quoted by RocketJess:
"Of course, it is very often overlooked that there is in fact a third species of garg: the Altairian Cave Garg (gargus altairius). Having evolved completely underground, it has unusually large eyes, to the point that the eyestalks cannot support them properly and they tend to be next to the garg's body rather than held above it. They also have the most curious (and quite frankly rather stupid) defence mechanism of shooting their eyeballs at potential threats. The actual effectiveness of rendering themselves half-blind in the dark caves with a potential enemy approaching is questionable at least, and it is fortunate for the garg that they have very fast regenerative abilities."