Article © Julian Dignall, uploaded April 01, 2001.
When writing a catfish of the month article, I focus on a facet or set of features that make the individual species in question unique or interesting to the aquarist. Usually these are natural features like behaviour, physical appearance and the like. Among the multitudinous ranks of the genus Corydoras it is hard to find many that stand out. Like many other species in the genus, this month's catfish, which can commonly be found in aquatic retailers' tanks the world over, is a species that does not stand out.
To find a talking point we have to divert from the natural and examine the artificial. Mankind has given this unassuming little catfish the doubtful pleasure of being the most commonly misidentified catfish of all time! As I mentioned, it is commonly found for sale but rarely labelled correctly. Almost always labelled as Corydoras julii or simply as the "Julii Cory", that it is not. C. julii is a valid scientific name, but for a different species.
If you examine them closely these two species have only really a passing resemblance. That said, the three line Cory, like many other species of Corydoras, is quite variable in terms of colour patterning. Compare the picture on the left and the one above - both are C. trilineatus. The fish above displays bold reticulated (wavy) lines, particularly around the head area. Now look at the image on the left, the pattern is not as well defined although the lines are still present. There are two features you should look for when attempting to tell the species apart. Firstly Corydoras julii tends to have a more broken mid-body lateral stripe. The top image on this page shows a very bold strongly defined line which is a good example although, again, the image to the left is less well defined. In C. julii the stripe is almost a collection of spots running along the body. Maybe more significant is the patterning on the fishes head. This is most easily compared if you look at the fish head-on (see image below). C. julii has distinct spots and no reticulated lines whereas C. trilineatus always shows at least some of these wavy lines.
So, there you have it - a tale of two corys. The history of this great misidentification I am less sure of. Most likely the first species imported was indeed C. julii from Brazil. The more recent opening up of South America, in terms if export by air, allowed species from other countries (specifically Peru in this case) to replace certain species with others in the marketplace.
To a degree, older literature is to blame, although if you look at quite a few really old aquarium books from the middle of the last century you are often surprised by a picture of the real C. julii. Enough about C. julii - it's hogging this spotlight which should be on C. trilineatus. The bottom picture in this article I took this morning to go with this article. It shows (from left to right). Corydoras similis, C. trilineatus and C. gossei. This particular C. trilineatus is special and has a story to tell.
During a tropical fish collection expedition into the area down river from Iquitos, Peru, we chanced across a local hut literally in the middle of nowhere. Nothing remarkable about that, this was a common occurrence, but within a small girl was ill with fever. Her somewhat anxious father asked the leader of our party as we passed if we could help in any way. We gave him some paracetomol to ease the girl's condition. It was all we could do, but the father was very grateful. Espying our various nets and buckets he correctly guessed we were collecting fish and rushed off to soon return with a small plastic bucket. Within it were a number of Corydoras which he had collected to sell onto exporters or their agents. He gave us these with his thanks. The specific three line Cory you see here was in that bucket.
Copyright information for the images used in this article can be found on the species' full Cat-eLog page.
|Cat-eLog Data Sheet
|Corydoras (lineage 9) trilineatus Cope, 1872
|Three Line Cory
Leopard Cory, Panzerwels (Germany), Three Stripe Cory, Trestribet Pansermalle (Denmark)
|Tributary of Río Ambyiacu, Peru.
|Corydoras dubius, Corydoras episcopi, Corydoras trilineatus
|kor ee doh rass (lineage nine). - try lin knee ah tuss
|61mm or 2.4" SL. Find near, nearer or same sized spp.
|Probably the most misidentified fish commonly found in aquatic retailers who incorrectly sell it as C. julii. The true C. julii is such a rare import that sheer numbers mean you are unlikely to really encounter this Brazilian fish. C. julii is similar to the more spotted forms of C. trilineatus but has no trace of any reticulated colour patterning at all and is entirely covered with small, distinct spots. It's mid-lateral black stripe is fainter and does not reach as far towards the fishes head as in C. trilineatus. This species was described in 1872 with a couple of paragraphs of text and drawings which do not clearly show coloration. The author notes, "Light straw-colored, brownish above, a yellowish lateral band with rather faint brown margin above and below, and blackish median line. A very black spot on the ends of the soft dorsal rays; tail deeply forked, with five vertical bands; anal spotted. Some longitudinal lines on the side of the face".
|South America: Central Amazon River basin; Peruvian Amazon and coastal drainages of Suriname.
Amazon, Upper Amazon, Marañón, Ucayali (click on these areas to find other species found there)
Amazon, Upper Amazon, Ampiyacu (click on these areas to find other species found there)
Amazon, Upper Amazon, Marañón, Pastaza (click on these areas to find other species found there)
Amazon, Middle Amazon (Solimoes), Purus, Macapá (click on these areas to find other species found there)
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|IUCN Red List Category
|Least Concern, range map and more is available on the IUCN species page. Last assessed 2020.
|5.8 - 7.2
|16.0-25.0°C or 60.8-77°F (Show species within this range)
|A hardy species that will tolerate most water conditions found within a reasonably maintained aquarium.
|Sinking pellets and frozen bloodworm are ideal although all prepared foods that reach the bottom are accepted. User data.
|Sandy or small rounded gravel is required to ensure the fishes barbels are not damaged in the search for food. Some plants should be used to provide shade and a sense of security.
|This commonly encountered Corydoras is a perfect community tank citizen.
|Should be kept in a shoal of at least six individuals. This, along with the presence of some mid water shoaling species, will increase the confidence of the fish in a community tank environment.
|The fish appears to prefer clean, soft water and should be conditioned in such an environment. pH and temperature seem less important but a drop in temperature may induce spawning. The eggs hatch after four to five days. The eggs are very susceptible to fungus and best removed, treated and the fry allow to hatch in a very controlled environment. The young can be raised on newly hatched brineshrimp again vigilance in respect of water quality is paramount.
|There are 18 breeding reports, read them all here.
|Proceedings of the Academy of Natural Sciences of Philadelphia v. 23, pp 281, Pl. 6 (figs. 2a-c).
|There are 354 registered keepers, view all "my cats" data.
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|More on Corydoras (lineage 9) trilineatus
|Look up Corydoras (lineage 9) trilineatus on AquaticRepublic.com
|Look up Corydoras (lineage 9) trilineatus on Fishbase
|Look up Corydoras (lineage 9) trilineatus on Encyclopedia of Life
|Look up Corydoras (lineage 9) trilineatus on Global Biodiversity Information Facility
|LFS label creator
|2023 Jan 12 05:18 (species record created: 2001 Apr 01 11:22)
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