I have a modest aquarium. Modest in size, much diminished in content. I had once stocked it with all kinds of fish – Asian barbs (Cyprinidae) and loaches (Botiidae), South American corydoras (Callichthyidae) and tetras (Characidae). Unfortunately, aquarium fish are very delicate creatures, short-lived and prone to mysterious afflictions. I am cautious when it comes to buying them. Experience has taught me to avoid those which are extremely gentle (like the goldfish, incapable of defending itself, and best raised alone) or too hostile (the fiercely territorial African cichlids).
This made a bit of research mandatory before every purchase. I would check out aspects of fish behaviour crucial to their survival in an aquarium – territoriality, aggression, schooling habits, food requirements and hardiness. I even maintained notes about the different species I introduced into my tank, from the humble black neon tetra (Hyphessobrycon herbertaxelrodi) to the rare Denison barb (Sahyadria denisonii). The irony of the entire exercise lies in the fact that of all the specimens I raised, the lone and longest surviving one happens to be an ‘undocumented’ suckermouth catfish (of the family Loricariidae).
My brother wanted a fish that would keep the aquarium clean, and one fine day, he bought this little beast from the pet shop. It was around the length of my index finger, and extremely shy. I had a pot inside the tank where it took up residence. More than two years down the line, it has grown into a formidable creature, bigger than my hand. Loricariidae, the family name, is derived from the Roman word Lorica for body armour – a reference to the prehistoric appearance of these freshwater catfishes from tropical Central and South America.
The other characteristic is the suckermouth, located below the head (like a shark’s mouth). Suckermouth catfishes use it to attach themselves to the substratum and feed on detritus. I may not know which species of Loricariidae my specimen belongs to but I do know that it is an adaptable creature, having overcome its shy demeanor (without abandoning caution) and anatomical constraints. Whenever I drop fish feed into the tank, it swims upside down to skim it off the surface. That might explain its longevity.
Image Attribution: The image above is sourced from Wikimedia Commons and based on an illustration from the book ‘Expédition dans les parties centrales de l’Amérique du Sud, de Rio de Janeiro à Lima et de Lima au Para’, documenting the species discovered by an expedition under the command of the French naturalist, Francis de Laporte de Castelnau (1810-1880). The explorers charted the territory along the watershed between the Amazon and the La Plata systems, from Rio de Janeiro in the east to Lima in the west, before heading north to the state of Para on the Atlantic.