Spawning Otothyropsis piribebuy.
Steven Chester 2017
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I consider myself an all-round fish breeder, over the years I have specialised in the husbandry, maintenance and breeding of Dwarf cichlids and Characins, however I have also bred numerous other groups of fish including plenty of the Corydoradinae. These were however my only experience with catfish and during the early months of 2017 I planned to expand my experience with other genus of catfish and set out with the aim of maintaining and hopefully spawning either a Otocinclus species or a species of whiptail catfish, I was not fussed which and it was more a case of which came my way first!
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During the spring Preston and District aquarist society auction I chanced upon a fish simply labelled as ‘Black Oto’s’ I took a chance and bought ten individuals, these were newly imported wild fish, a good size but in average condition, they would need some work to condition them for breeding but I already had a plan in place. Firstly, I needed to know what species I had and to find some details on their habitat, range and preferred parameters. My first port of call was my bookshelf and armed with the Baensch Catfish Atlas, a back catalogue of ‘Cat Chat’ magazines and also several other older books on catfish. It quickly became apparent that my ‘Black Oto’s’ were not written about, the closest match I found was either an Histonotus species or the fish known as LG2 which had a trade name of ‘Otocinclus ‘Negros’! this sounded promising and a online contact via social media put me onto the name Otothyropsis piribebuy, from then on the information came thick and fast, a online search found the Scientific description of the species, from there I found that the Type locality of this recently (2011) described species was the Rio piribebuy, a smaller tributary of the Rio Manduvira which in turn feeds into the larger Rio Paraguay. Using the town of Eusebio Ayala which is located nearby I could excess weather reports online and figure out temperature fluctuations and also seasonal changes which may help me with the maintenance and breeding of this species.
As I said earlier I was already planning on acquiring a species of either Otocinclus or a Whiptail catfish of some description, and had made some tanks available for when I did find some, the tank in question is one of the larger tanks in my fishroom, I have four tanks measuring 40x24x18” high and holding around 250litres each, they are connected together on a system utilising a sump of aprox 500litres, this system of 1500 litres and a large biological filter provides very stable water quality and parameters. The water source to my home comes from the Welsh mountains and is very pure rainwater which runs from inert slate mountains and is pumped directly to my home in Cheshire, England. The water from my tap averages PH7 and a conductivity of 50-75us/cm, KH and GH both barely measure 1 degrees, it is ran through a sediment and carbon filter (HMA) and stored in a large 700litre vat where it is warmed to 26c before use. The low conductivity of my water usually sees the PH drop to around 6 once it has been in my tanks for a week or so due to the low buffering capacity. The tank used for the Otothyropsis was an upper tank at eye level and had not been cleaned of algae for quite a while in anticipation of the intended inhabitants, the visibility into the tank was restricted by a growth of soft green algae and all panels were similar, the fish were added as the sole inhabitants of this tank and were given some Oak branches to sit and rest upon, these branches were collected from the ground underneath a oak tree in a non-polluted area, they were dry and took several days to soak and sink, a point worth noting is that they were covered with Lichen, it proved to be a very good food source for the Otothyropsis! As an alternate food source, I also offered a few slices of cucumber weighed down with aquarium lead.
Only 24 hours after purchase and acclimatisation of the new fish my choices of food items were proven to be correct, the Otothyropsis had an insatiable appetite for the algae in the tank, considering the low numbers in such a large tank I was shocked at how quickly the fish cleaned the tank of algae, within 48 hours every glass panel in the 40x24x18 aquarium was spotless, they had devoured two slices of cucumber and appeared to be searching constantly for food, the added oak branches provided not only a resting place but also a secondary food source, the wood started to fungus after several days submerged, the lichen also started to soften and the Otothyropsis obviously delighted in rasping the surface of the wood.
Water changes were performed weekly with the 500litre sump being draining to waste and refilled with clean water of the parameters mentioned earlier, the fish began to show signs of sexing and the females were obviously ripening and coming into breeding condition, the size difference of the males and females was staggering, the females were twice as wide as the much slimmer males. After two weeks of conditioning I decided to setup a dedicated spawning tank for these fish and to try and reproduce them, the date was 23/04/17. The breeding tank was much smaller and measured 24x13x10” I have 36 of these 40litre tanks and they house all my smaller species that I am intending to breed. The tank was cleaned and a thin layer of sand added, several fresh oak branches were placed into the tank, these were snapped to make a tight fit and ran across the tank from the upper corner to low down, close to the substrate, a couple of large Red oak leaves were added. The tank was filled with freshwater with parameters of PH7, Conductivity 60us/cm, Temp 26c, filtration was taken care of using a weighted sponge filter, finally a small 10w powerhead was added and it was hoped that the freshwater and increased movement would be enough to trigger a spawning in this species. The fish were added late at night after a quick acclimatisation and the fish room lights were turned off to allow them to settle.
My routine is to spend an hour feeding and observing my fish before work so my alarm is set for 6am, I leave for work at 7.15am so I generally have an hour to feed my fish and do any other small jobs before leaving for work. New projects are always amongst the first to be checked out and on the morning of the 24/04/17 I headed straight for the Otothyropsis tank, mainly to check that they had settled ok, I wasn’t expecting breeding behaviour so soon but the fish proved me wrong, I could observe eggs on the front panel and to my delight saw almost all of the ten inhabitants active within the tank, they were fast and agile and similar in mating behaviour to Corydoras, it seemed that the males were hunting females and coaxing them to breed, several times I witnessed a male approach a female, he worked his way infront of her whilst still attached to the front glass using his mouth, he then bent his body into a U shape and offered himself to the female who was situated below him, the female would swim up into the curve of the males body, a few seconds later a single egg was laid on the glass and chasing activity started again, it was difficult to observe if all fish were involved in spawning, I witnessed two females spawn in separate locations but could not say that all ten were involved despite all ten being increasingly active throughout the tank. The eggs were fairly large at around 2mm and were laid haphazardly throughout the tank, the front pane was the preferred site but I could also observe eggs laid on the wood, leaves and also the plastic weighted base of the sponge filter. Egg numbers (Visible) were around 60-70 and development within the egg could be observed within eight hours, 36-48 hours after spawning the fry hatched from the egg membrane and used the yolk sac for the next few days, by day 5 (29/04/2017) the fry were developed enough to search for their first foods, this was supplied in the form of newly hatched artemia, powdered fry food and also the natural fauna on the wood and leaves, the fry grow rapidly and were perfect miniture replicas of their parents within a month or so.
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The Otothyropsis proved to be extremely easy to breed, after the initial excitement of the first spawn it became a daily occurrence to see spawning behaviour and eggs at various stages of development, the tank quickly filled with fry of all ages and at the age of 12 weeks the oldest fish were large enough to separate and move onto new homes. I would highly recommend this interesting species, for me they were extremely easy to maintain and condition for breeding, the reproduction of this species is almost trouble free and the offspring grow quickly without any major obstacles in feeding. The fish were distributed within my local fishclub and I have had reports from two people that the F1 offspring are currently breeding for their new owners, at the time of writing this it would make the F1 generation seven months old at the very latest, potentially six months old to sexual maturity!
I hope that this report may help others in their quest to maintain and breed this beautiful and interesting little catfish, I am certainly becoming converted to the more obscure and rarely spawned South American catfish!
