Bronze Corydoras vs Otocinclus

The same axes for both animals, taken from the same care guides, so this is a like-for-like comparison rather than two articles written months apart. Neither animal is the right answer on its own — the question is which one fits the space, the budget and the routine you actually have.

Freshwater Fish
Bronze Corydoras
Corydoras aeneus
Difficulty
Beginner
Lifespan
5-10 years
Adult size
6-7 cm (2.5-3 in)
Minimum space
75 L (20 US gal)
Company
Must be kept in at least 6
Daily time
Low-moderate (daily feed, weekly water changes)
Running cost
Low
Habitat
Aquarium 75L+ / 20gal+
Diet
Omnivore (bottom-feeder)
Suits you if
Beginners wanting an active bottom-dweller. Peaceful community aquariums. Keepers using sand substrate
Watch out for
Keeping fewer than 6 (they are social). Sharp gravel eroding their barbels. Assuming they survive on leftovers

Full Bronze Corydoras guide

Freshwater Fish
Otocinclus
Otocinclus vittatus
Difficulty
Intermediate
Lifespan
3-5 years
Adult size
3-5 cm (1.5-2 in)
Minimum space
75 L (20 US gal)
Company
Must be kept in at least 6
Daily time
Moderate (daily feed, stable mature tank)
Running cost
Low-Medium
Habitat
Aquarium 75L+ / 20gal+ (mature)
Diet
Herbivore (algae/biofilm grazer)
Suits you if
Mature, algae-rich planted tanks. Nano and peaceful community setups. Keepers wanting safe algae control on plants
Watch out for
Adding to a new tank with no algae/biofilm. Buying thin, starved, hollow-bellied stock. Keeping fewer than 6 (they shoal)

Full Otocinclus guide

How to read this

Every row is filled from the same field of the same care guide for both animals, so nothing here is cherry-picked to favour one of them.

Minimum space is the figure from each species' housing guidance, converted to one unit. It is a floor, not a target.

What this does not tell you: your experience, your household, your climate, or which animal you will actually enjoy. Difficulty is our judgement, not a measurement. Read both full guides before deciding — and if the honest answer is neither, that is a good outcome too.