The term pound-for-pound is often used to compare the value of one thing with that of another in the same category. Comparing, for example, two tins of pitted ripe olives: one weighs 340 g and costs $3.00, while the other weighs 170 g and costs $1.70. The latter, of course, is more expensive, pound-for-pound, as it costs $1.00 per 100 g, while the former costs $0.88 per 100 g.
When used in combat sports, pound-for-pound would refer to the value of a fighter in relation to those of different weight classes. Many boxing fans, for example, are eager to find out who between Floyd Mayweather, Jr. (rated at welterweight) and Manny Pacquiao (rated at light welterweight) is the better boxer, pound-for-pound. But until the two meet in a proposed “catch weight” fight, the issue will remain a question.
When gauging the strength of animals within a class, in relation to their respective body weights, and comparing them with one another, the use of the pound-for-pound basis may also be helpful. So that in some of the specific categories within the animal kingdom, we can determine which particular animal is the strongest, pound-for-pound.
Cat. The strongest animals in this category, pound-for-pound, are the jaguars. Found in Central and South America, a jaguar (binomial name: Panthera onca) normally weighs as much as 211 lb (95 kg). This powerful predator can drag an 800-lb (360-kg) prey in its jaws up a tree or 8 meters to a safe place where it can devour its meal, away from being spotted by other bigger cats (like a tiger or a lion). This means that for every pound (0.45 kg) a jaguar weighs, it is able to drag the equivalent weight of 3.79 lb (1.71 kg), or nearly four times its own body weight.
Bird. The crowned eagles may very well be the strongest animals, pound-for-pound, in this category. Found in Africa south of the Sahara, a crowned eagle (binomial name: Stephanoaetus coronatus) weighs as much as 9.1 lb (4.1 kg). This large, powerful bird of prey can lift a small antelope or a monkey (its favorite prey) that weighs as much as 75 lb (34 kg). This translates to 8-and-a-quarter pounds (3.71 kg) of weight a crowned eagle can carry per pound (0.45 kg) of body weight, or a little more than eight times its own body weight.
Fish. Some anglers contend that the crevalle jacks (binomial name: Caranx hippos) are the strongest animals, pound-for-pound, in this category. At least one claims that he “regularly (has) 7 pound Jacks break 20 pound test.” If this is used as the basis, then a crevalle jack can pull the equivalent weight of 2.86 lb (1.29 kg) for every pound (0.45 kg) of body weight, or almost thrice its own body weight. Crevalle jacks are found in inland waters along the shoreline of the western Atlantic Ocean.
Snake. The anacondas, the largest of all the snakes, are also believed to be, pound-for-pound, the strongest animals in this category. Found in South America, the anaconda (binomial name: Eunectes murinus) can weigh up to 550 lb (247.5 kg) and, though non-venomous, is greatly feared for its ability to squeeze to death a victim weighing the equivalent of four adult humans.
Insect. Many of the relevant information point to the rhinoceros beetles as the strongest animals, pound-for-pound, in this category. These creatures are reported to have the strength of being able to carry the staggering equivalent of 850 times their own body weight, making them virtually the strongest animals, pound-for-pound, on the planet.
1. “Jaguar”, on the Wikipedia – http://en.wikipedia.org/wiki/Jaguar
2. “Birds: Crowned Eagle”, on San Diego Zoo (online) – http://www.sandiegozoo.org/animalbytes/t-crowned_eagle.html
3. “Crowned Eagle”, on the Wikipedia – http://en.wikipedia.org/wiki/Crowned_Hawk-eagle
4. “Crevalle jack”, on the wikipedia – http://en.wikipedia.org/wiki/Crevalle_jack
5. “What is the strongest saltwater fish pound-for-pound?” on Yahoo! Answers – http://answers.yahoo.com/question/index?qid=20090124193053AAgazgO
6. “Anaconda”, on the Wikipedia – http://en.wikipedia.org/wiki/Anaconda
7. “Top 10 Strongest Animals” – Video – http://www.metacafe.com/watch/2190801/top_10_strongest_animals/
8. “Strongest Creature…RHINOCEROS BEETLE”, on Extreme Science (online) – http://www.extremescience.com/StrongestCreature.htm