Medusa vs. aguamala vs. aguaviva
Even though 'medusa', 'aguamala', and 'aguaviva' in Spanish all refer to species of jellyfish, these terms can vary depending on the region and the cultural context.
Medusa
'Medusa' is a standard, scientific term for 'jellyfish' and it is universally understood across different Spanish-speaking countries.
Las medusas son animales marinos muy comunes.
(Jellyfish are very common marine animals.)
La picadura de una medusa puede ser extremadamente dolorosa.
(The sting of a jellyfish can be extremely painful.)
Aguamala
'Aguamala' directly translates to 'bad water'. It is used colloquially and generally in countries like Mexico and Cuba to refer to venomous jellyfish.
En las playas Mexicanas, se ven aguamalas en ciertas estaciones del año.
(On Mexican beaches, you see jellyfish during certain seasons of the year.)
Una picadura de aguamala causa una sensación de quemadura.
(A jellyfish sting causes a burning sensation.)
Aguaviva
'Aguaviva' translates literally to 'living water'. This word is more commonly used in Spain, Argentina, Venezuela, and other South American nations. It's a general term for all types of jellyfish.
Tienes que tener cuidado en el agua porque hay aguavivas.
(You have to be careful in the water because there are jellyfish.)
La costa de Valencia suele tener aguavivas durante los meses de verano.
(The coast of Valencia usually has jellyfish during summer months.)
Summary
While all three words 'medusa', 'aguamala' and 'aguaviva' refer to various species of jellyfishes in Spanish. The term ‘medusa’ is a standard term understood universally across various Spanish-speaking countries; the term ‘aguamala’ which directly translates to ‘bad water’ is colloquially used in countries like Mexico and Cuba referring to more venomous species of jellyfishes. Finally, the term ‘aquaviva’, literally translating to ‘living water’, is more commonly used in Spain, Argentina, Venezuela and other South American nations as a general term for all types of jellyfishes.