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A Great Cat. . . Fish: Aspidoras eurycephalus
By Patrick Miller
Finding my catch
I purchase most of my fish at Grand Valley aquarium Club (GVAC) meetings, auctions or other club’s events. Most of the fish that I buy are ones that are on my list of wanted fish and they have a tank waiting for them or at least I can make space for them. It is not often that I see a fish that I decide that I must have and don’t have it on my list of wanted fish. However, at the spring 2007 GVAC auction I found a bag of fish that I decided ‘I must have.’ Well, actually, there were many bags of Aspidoras eurycephalus and each bag had 5 fry in them. It was love at first sight with this little fish. Aspidoras eurycephalus is not a large fish but can make a big impact on your tank.
About the fish
This little cat fish not only looks great with a silvery base and brownish black markings coving the entire body except for the stomach area but it can be a lot of fun to watch especially if excited with a few black worms or in the mood to spawn. The Aspidoras catfish are not large fish and this little guy is no exception.
If you haven’t seen an Aspidoras species fish think of a Corydoras but on slimfast. Aspidoras eurycephalus is much more slender than Corydoras, with females being fatter in the belly and a little larger than males. Total adult length of this fish is about 2” with females being a little longer and more robust than males. Female coloration may also be a little more washed out than the males but overall it may be difficult for someone to sex if they have never seen this species or if they are young fish.
These little fish are fast growers and at 2-3 months of age should be about ¾-1” in length. The little fry that I purchased in the spring of 2007 were this size and started producing eggs at the beginning of October 2007. They could not have been more than 12 months old if even that age.
Name game
But before we get into the care and breeding of this little fish lets look at some background information. This little fish was first described in 1976 by Nijssen and Isbrücker and has not been renamed or moved to another genus and therefore there are no synonyms for this fish. In other words you will not have to wonder what other names people are selling this fish as.
The
name Aspidoras comes from Greek.
Aspidoras: From the Greek aspis, meaning shield and doras, meaning skin; in
reference to the bony plates. This specific epithet refers to the specimen's
broad(eurys=broad) head(kephale=head).
1
Aspidoras differ from Corydoras in Aspidoras
posses a duel fontanel bone structure in the skull whereas Corydoras have only
the one larger fontanel.
2 Aspidoras
also have very small eyes along with the girth/length of the Aspidoras
species being smaller than the Corydoras as a whole.
Native habitat
Their native range is the Upper Tocantins River basin which is located in South Central Brazil. Because of the topography of the Upper Tocantins River Basin, the river has a noticeable current. This is the tropics and average high air temperatures for the river basin ranges from 72deg F near the headwaters near Anapolis (3000ft above sea level) in the Brazilian Highlands to 95deg F at Peixe (820ft above sea level) about 350 miles down river.
Captive care
Aspidoras eurycephalus is a catfish and like most, not all catfish, they tend to spend almost all of their time at the bottom of the tank. For a group of these fish, 5-8, I would suggest a tank size of 20L or larger, my group of five fish were kept in a 29 gallon tank. This fish will do better in a group and my original group did well and doubled in number in a tank with knife livebearers and cherry red shrimp. The more bottom space you provide the happier your fish will be and since they are bottom dwellers the tank does not need to be very deep. However, covers should be used as when spawning they tend to be right at the surface of the water and can easily jump out in their excitement if there isn’t a cover.
I use hang on the back power filters for their current creating ability in nearly all of my tanks. For maintaining this fish you really want to have a filter that creates a current. As mentioned previously this is a river fish and in my experience will do better in a tank that has at least a moderate amount of current. Sponge filters have their place but not in an adult Aspidoras tank if you want to see this fish’s best behavior.
Under gravel filters have their place but like the sponge filters but, in my opinion, not if you want the best tank set up for A. eurycephalus. The reason for staying away from under gravel filters is the substrate material. A. eurycephalus being a catfish will dig around in the top layer of substrate looking for food. Larger substrate material needed for under gravel filters is to large for this small fish to rout through and this can cause damage to its barbels and lead to infections . This leaves internal power filters, canister filters or hang on the back power filters as my choice for being the best filter types for keeping A. eurycephalus.
As mentioned above you will want to keep your substrate material small, round and smooth. Sand works well for this fish as it will give them material that they can dig around in for food without the possibility of them getting wounded while digging6. For my tanks I use a mix of particles from sand up to 3mm in size. While this fish will do some digging in my experience it will not dig more than about a centimeter deep so you can use a dirt substrate with sand over the top if you are an aquarist who has planted tanks.
This is a fish that can be much more active at night and so it is best to provide it cover in the form of caves and pieces of wood. They will also benefit from a heavily planted tank as it will provide them with many more hiding places and allow you to see much more activity during the day.
My tank temperature for these fish is kept between 71deg F to 80deg F. but this fish will do well in water up through the low 80’s. Large rapid fluctuations should be avoided as in their native habitat they do not occur. However, lowering the water temperature a few degrees can help bring on spawning.
Feeding
Aspidoras seem to enjoy eating most foods offered to them. Like most fish their diet should be varied. While they will accept flake and pellet food willingly and well formulated flakes or pellets can be the staple of their diet they will do much better if they are given live or frozen foods. My fish received my standard diet for maintaining fish of Bio-pureTM frozen bloodworms and daphnia in the morning and a rotation of different types of flakes in the evening. If you are keeping these fish in a community set up then you will want to make sure that food gets to the bottom of the tank. You will notice that these little guys will actively go after food but they tend to wait for it to get to the bottom of the tank. Feeding one meal at night or supplementing feeding a few times a week with a night feeding of sinking pellets will also help ensure they get the food they need.
Spawning
With how easily these little guys spawn it’s a wonder why they are not more common in the hobby. It seems that all you need to do for these little guys to spawn is to stick them in water and add food.
Most fish of this genus spawn during the wet season when temperatures a slightly cooler and I was expecting them to start laying eggs after a month or so of conditioning. I started the conditioning at the end of September by adding a third meal of black worms to their feeding schedule every other day. This third meal was usually given just before the lights went out. To my surprise I found my fist eggs at the beginning of the second week of this schedule of feeding.
Aspidoras eurycephalus spawn in the same way as most fish in the subfamily Corydoradinae . The eggs are small, white and they are very adhesive. The fish will stick these eggs to almost any surface. My experience was that 90% of the time they put the eggs in an area that received a strong current and was close to the water line. After a few months of producing eggs their favorite spot to place their eggs became the outflow of the Penguin Bio Wheel filter. Eggs were stacked sometimes two thick in masses of up to 40 eggs. This was also the reason for many of their untimely deaths as they did a good job of jumping out of the 1-1/2” gap in the cover that allowed for the filter.
Spawning behavior started just before the lights went out and eggs were laid within a few hours after that in the darkness. My temperature for spawning started out at 76deg F, which was lower than the summer high in the tank of 80deg F and fell over the next few months to about 72deg F by the end of April when eggs stopped appearing. At 76deg F the eggs take about 72 hours to hatch. I became so good at timing their hatches I was able to watch many of them hatch out. Unfortunately, I was unable to get any good film of them hatching as they seemed to wait until I turned off the lights to hatch.
I left the first few batches of eggs in the tank with the parents, some knife livebearers, some Xiphophorus birchmanni that had also breed in the tank and cherry red shrimp. This was a mistake as the adult X. birchmanni really liked the eggs and the X. birchmanni fry were large enough, at about 1”, to eat the A. eurycephalus fry that did hatch. Also the A. eurycephalus fry need an environment where they can lay on the bottom and not move around a lot for the first few days after hatching so that they can absorb their yoke sack. If you have lots of snails, as I did in that tank, they can catch and eat the fry.
How I spawned the fish
The method that I used to produce good batches of fry were; first to remove the X. birchmanni from the tank so that the eggs would not be eaten. Second I set up a 2 gallon egg tank that had a heater and air stone in it. Third I set up a 10 gallon fry tank which contained no substrate, had two caves, a heater and a sponge filter. The temperature on these tanks was set to 76deg F, the same as the adult’s tank. I would look for eggs in the morning before work. If the eggs were on a plant I cut the leaf and put it into the egg tank. If the eggs were on the glass I took a razor blade and scraped them off into a net and moved them into the egg tank. A note of caution here, you do not want to touch the eggs if at all possible. Touching them usually means that they will develop fungus and die. Scrapping the eggs right into a net and transporting them to the egg tank in the net solves this problem.
I did not use any chemicals in the egg tank because I did not need them and I do not like to use chemicals. Changing the water in between the batches of eggs and covering the tank to keep light out was enough to get most eggs hatched. After 2-3 days of the fry being in the egg tank and not being feed I removed them and placed them into the grow out tank. I then put fresh de-chlorinated water in to the egg tank and added another batch of eggs to hatch out.
For feeding of the fry I used Hikari First BitesTM for the first few days and then moved to crushed flakes and frozen daphnia alternating the feedings of crushed flake and daphnia. You should find that your fry will grow quickly on 3-4 feeding per day with good water changes. Within 2-3 weeks of feeding, you can move the fry to a community tank that contains small fish or leave them in the grow out tank. I found it best to add them to a tank with a couple larger adult A. eurycephalus. As long as you do water changes and feed them very well they should be ready for sale or trade after about 10-12 weeks.
A final note on spawning this fish: It is possible, and probably common, to have these fish spawn in a community tank and to get the fry to survive. In the adult A. eurycephalus tank I left the knife livebearers and the cherry shrimp. Since I did not try to remove all of the eggs that were produced by the adult A. eurycephalus some eggs were left to hatch and the fry left to fend for themselves. Of all the eggs that hatched in the adult’s tank between 7 fry did survive to adulthood and thrived along with their parents. The point of this note is that you do not need to take every step that I did just to get these fish to breed successfully you will just end up with many more fish to sell off or give away.
Conclusion
Aspidoras eurycephalus is a great little catfish. Not only do they stay small, have interesting behaviors, look cool and go great in a peaceful community tank but they are also a good little fish to try your luck with breeding. I highly recommend these little fish for anyone who is looking to find a catfish.
After a year of keeping these fish I am still not sure why these little fish are not in every pet store but they should be.
Sources
1. Planetcatfish.com http://www.planetcatfish.com/catelog/species.php?species_id=811
2. http://www.scotcat.com/factsheets/aspidoras_sp_c125.htm
fishbase.org
Encarta.msm.com http://encarta.msn.com/map_701516017/tocantins.htmlc
www.wunderground.com