Corydoras similis
A"Tail spot tank catfish"
Corydoras similis was described by Hieronimus in1991. Before its description this catfish was already available in the trade and it became known as Corydoras spec. described "violet". As only Hieronimus this Corydoras in the magazine for fish news (Jg.1; No.1 described) it got the name Corydoras similis. Hieronimus states the holotype location as being from Brazil, from an influx to the Rio Madeira near the city of Ariqumes. Hieronimus also states that Corydoras similis and Corydoras ourastigma are from the same area, the Rio Branco catchment area in the Brazilian federal state Roraima. The federal state Rondonia reaches to the border with Bolivia and the federal state Roraima borders on Venezuela and Guyana, approx. 900 km between the two locations! Since the location of the Holotype is decisive, this second location detail is doubtful.
The name similis comes from the Latin and means as much as "similar". In turn, this refers to the coloring which is very similar to Corydoras ourastigma. The difference between the two catfishes which are both striking are clearly visible, the shape of the head of Corydoras similis is part of the tank kept catfishes with a round, short, muzzle and Corydoras ourastigma belong to the representatives of the group with a long muzzle. Corydoras imitator and Corydoras adolfoi are another well know couple that share the same colour characteristics and the same differences.
In Corydoras similis the tail root spot is very conspicuous, ranging from deep blue through violet to purple depending on the incidence of light, there are many small covering the whole body making it a very attractive Corydoras. The fins are transparent, only the first hard rays with sand-coloured to bright brown dots. It is often being described as a "tail spot tank catfishes" (Hieronimus 1990)
There are also other species belonging to this tail root spot group.
Corydoras caudimaculatus, different from Corydoras similis by a black tail root spot delimiting clearly
Corydoras guapore, a tank catfish of a little egg-shaped shape swimming more in the middle water layers
Corydoras ourastigma, a manner with a long muzzle.
C 66 (Evers, 1999; This Corydoras doesn't lie DATZ 52/1 in the shape for any saddle nose like C. ourastigma between C. ourastigma and C. similis), (stretched than C. similis but no-one)
My eight Corydoras similis, three females and five males, were already in good condition when purchased. They were put into a tank measuring 60cm x 30cm x 30cm, in water the same as they were used to, which was imperfect condition. Two small Anubia, sticks and two big smooth stones were added to the tank furnishings and offered the tank catfishes hiding-place possibilities and also resting places. The aquarium receives indirectly ambient light.
Two weeks after arriving they started to perform in the Corydoras way and started to produce eggs. The first measuring results yielded a pH value of 6.8 and a complete hardness of 8° dH at a water temperature of 25° Celsius.
All 19 eggs were deposited in the flow area of the filter where it lay. They were larger in comparison to the white eggs of Corydoras aeneus. 16 catfish larvae hatched out after four days, their yolk sac was used up after further three days and they coped with Artemia-Naupli eaten freshly without problems after I had moved the larvae into a separate rearing bowl. I then moved the small Corydoras into a 15 litre aquarium. A further change is then carried out when they reach a size of 1 cm.
Many small spots cover the whole body of the catfish; the primary body colour at this time is now a bright yellow. As the growth increases the colour of the young already starts to resemble that of their parents. When they are 2cm they are Corydoras similis completely.
At this size the Corydoras similis are moved into a 60 litre aquarium, in which they remain till a size is reached where one can sell them on. At approximately 2 cm one already recognizes clearly the beautiful characteristics of the adults ice blue spot at the tail root. These catfishes grow very speedily with good, varied feeding and partial water changes. The breeding and rearing of this Corydoras was good to gain experience and when trying other tank catfishes should reduce any problems. The final piece of information I have about this catfish is, when two females have provided eggs, usually one or the other would spawn on average once per week. The numbers of eggs laid were between 40-60 eggs per female, with one or two eggs always in the female ventral fin bag. Also after turning the lights off spawning wasn't interrupted.
