Brazilian gold frog
The Brazilian gold frog ("Brachycephalus didactylus"), also known as Izecksohn's toad or flea-frog, is a very small species of frogs in the family Brachycephalidae. It is endemic to southeastern Brazil and is known from the central part of the state of Rio de Janeiro and from Serra das Torres in extreme southern Espírito Santo. All three English names are misleading or potentially confusing. Many species in the genus "Brachycephalus" are bright yellow-orange, hence the name "Brazilian gold frog", but "B. didactylus" is all brown. "Izecksohn's toad" leads to easy confusion with another species  in the genus, "B. izecksohni", and both names refer to the herpetologist Eugênio Izecksohn. "Flea-frog" or "flea-toad" was historically restricted to "B. didactylus", once placed in its own genus "Psyllophryne" instead of "Brachycephalus", but a second species, "B. hermogenesi", was described in 1998 and two others, "B. pulex" and "B. sulfuratus", have been described since then, bringing it to four species of flea-frogs/toads. Comparison with other small frog species. At in snout–to–vent length, "B. didactylus" is one of the smallest frogs in the world. This species and the roughly similar-sized "Eleutherodactylus iberia" from  Cuba were once regarded as "the" smallest, but several others that are smaller have since been discovered, including the closely related "B. pulex" at , "Stumpffia contumelia" from Madagascar at , and "Paedophryne amauensis" from New Guinea at . Behaviors Though small in size, this little frog is very aggressive. Males of the species will sometimes fight each other by attempting to pull its competitors organs out using it's tongue. These frogs are purely male dominated when it comes to mating. Unlike other frog species, the males do not do flashy dances and use their bright colors to attract mates, they choose  a mate and take them. If two males attempt to breed with the same female, they will fight until one of them is dead. Then the victorious male claims the female and will cling to her back fertilizing her eggs for a time period of three days. Unlike the rest of their very aggressive behaviors, these frogs are excellent fathers. The mother dies as she lays her eggs because her organs excrete while she does it. The male then adopts the behavior of an average frog mother.