Catfish of the Month Right December 2014

Spectracanthicus murinus
Spectracanthicus murinus   Nijssen & Isbrücker, 1987

Article © Matthew Schauer, uploaded May 15, 2015.

To round off the CotM articles of 2014, we have the first article published on from the prolific American fish breeder Matthew Schauer. I had the pleasure of meeting Matt for the first time this year as well and I was delighted to put a face to the username. And not just one of the forum regulars, anyone who keeps an eye our our "Breederboard" league table will be familiar with the username "Nabobmob1" which has been at or around the top of the page for a long time indeed. It's great therefore to see a species introduced that has not only flourished but has bred and been documented here. It's a cool pleco too.

A personal milestone
It seems my fish know the most inconvenient times to spawn and Spectracanthicus murinus was no different. My first spawning occurred the day I was packing to leave for the MASI Spring Fling event in St. Louis. Regardless of the poor timing, I was ecstatic. In my 5 years as an active hobbyist I've spawned over 40 different species, the majority of which have been Loricariidae and corydoradinae, but the Spectracanthicus success was different, special.

I've bred many hobby favourite catfish such as Hypancistrus zebra, Peckoltia compta, many Ancistrus species, all of the "Laser" and most of the pygmy Corys. A wealth of knowledge is available on conditioning, tank set-ups and breeding experiences for many of these fish. However, spawning S. murinus has been a personal highlight. Spectracanthicus is a name few recognize - the genus is made up of only five described species; S. murinus, S. punctatissimus, S. immaculatus, S. tocantinensis and S. zuanoni. The latter three all described in 2014. Seventeen or so L/LDA numbers also exist that are yet to be described, again, most of which are fairly recent discoveries. I am uncertain if the three new fish are descriptions of existing L numbers or totally new discoveries. The information available online for any of these species is very limited and basically consists of a couple of websites reposting the same generic data. The two Spectracanthicus most commonly available are Spectracanthicus punctatissimus and Spectracanthicus sp. L030 but, both are often traded under the synonym Oligancistrus. Unfortunately, L030 and the common name "Peppermint Pleco" are used interchangeably for both species by importers, wholesalers and stores. Don't let that dissuade you from picking up a group of those when available. Both Spectracanthicus punctatissimus and Spectracanthicus sp. L030 are classified as "vulnerable" by the C.A.R.E.S. Preservation Program. You will just have to put in some work when attempting to get a proper identification when you get them home.

Spectracanthicus murinus is a 4.5 inch, modestly coloured fish that can change its base colour from very light grayish yellow to almost jet black depending on tank lighting and mood. When well-conditioned, the fish will have a base colour that is mouse gray which is the meaning of the specific epithet, murinus. The species sports fine white spots and seams of the same colour on the edges of the dorsal and tail fins. The dorsal membrane extends to the first adipose ray like all Baryancistrus. This is a trait shared by all the Spectracanthicus species.

I got my first S. murinus in 2011 when I was occasionally getting fish in through a transshipper. I ordered a box of them because it was a fish I was not familiar with and thought they may be fun to work with. Those fish came in in fantastic health and quickly adjusted to aquarium life. A few months after their arrival, I had a customer make an offer for the entire lot which, I reluctantly accepted with the assumption I could order more. This was not as easy as it sounded. This fish was rarely on the lists I was privy to and the few times they did appear, other things were a priority.

In April 2013 I finally had a chance to bring in another box. These fish were in very rough shape and severely emaciated. Upon arrival I struggled to get them to accept any foods. One by one I lost all but two, and with no real visual sexual dimorphism, I figured I was stuck with a single sex. The remaining two fish were housed in a 20 gallon long (12"x12"x20"/30cm x 30cm x 50cm) along with a trio and some juvenile Ancistrus sp. L180. The tank contained a white sand substrate, three different styled caves and a piece of bogwood. The tank is positioned lengthwise in the rack, the caves and wood stacked into a single structure in the centre on the tank with a vertical sponge filter located behind it. An internal heater kept the tank hovering at 84°F (29°C) and bi-weekly water changes of 30-50% would drop the temp to around 77F (25°C). My water supply is from the Great Lakes and has a PH of 7.2- 7.7, a GH that hovers around 160, a KH around 125, and the TDS generally reads around 160 as well. Though technically these are not ideal parameters for most South American fish, my methods (focus on a healthy diet, good filtration turnover rates and lots of fresh water) have allowed me to be successful with no modification to the tap water. I feed all my fish a wide variety of foods ranging from meat and veggie based pellets, frozen and live foods as well as fresh fruits and vegetables. Spectracanthicus murinus was not picky and once conditioned, accepted all foods offered but preferred foods of high protein.

The first spawning
In early March 2014 my L180 had begun to spawn and I had two batches of fry going in a single cave. It also appeared the Spectracanthicus were fighting for cave space. I initially thought the fish had fully matured and were indeed two males. However, it seemed strange because one of the caves in the tank was unoccupied. I was offering a large burrito styled cave with a flattened end, this was home to the male L180 and fry. So this left the options of a square cave with square end, and a tapered bell style cave. The battle was for the bell and I thought perhaps they prefer this style over others. I added an additional bell on the opposite end of the tank with hopes to end the territory dispute which had become increasingly violent. The two fish would spend most days trying to force each other out of the cave. Once one was evicted it would remain at the mouth of the cave, subjecting itself to tail slaps from the tenant. After a period of time the cave inhabitant would become annoyed with the other fish and would exit the cave. This resulted in a short burst of chasing and head butting until one fish made it to the cave entrance, and the cycle would begin again. I considered at this point separating the two fish but the behavior was not affecting the L180 who was still guarding fry and I thought tampering with the tank would be more disruptive. After a week or so of conflict between the S. murinu, I noticed a change in their behavior. Both fish were now occupying the cave with the male on top doing what I call "the sexy shiver", a behavior witnessed with most pleco species. The "sexy shiver" occurs when the male has the females trapped in the cave and he rapidly flutters his pectoral and anal fins against the female while using his body to force her against the back of the cave. The male kept her trapped for four days in this position.

Finally on April 2nd while preparing to leave for St. Louis, the female exited the cave briefly and quickly backed into position to deposit her eggs. By the next morning, approximately 35 eggs about 3/32" (2.8mm) in diameter could be seen if the male moved just right within the cave. The eggs were a pale yellow to transparent white. The egg mass was a single solid ball which was loosely placed in the back of the cave. The only time the eggs could be seen was when the male was rotating the cluster. I was gone during most of the egg development. But with the particualr style of cave, I'm unsure if it would have been possible to observe or photograph much without excessive disruption.

The eggs hatched five days later, upon my return. The male was positioned in a fashion that left any observation near impossible. The day after the eggs hatched a young fry escaped the cave; Spectracanthicus fry are very small and undeveloped. Literally, an egg with a tail, the eyes and mouth are barely discernable and the young have yet to develop any pigmentation. On April 10th to my surprise, I returned from work to find the male L180 had released his fry and evicted the male Spectracanthicus from his cave. It appeared he was rearing the fry, but too much dismay, the next morning the cave was vacated by both adult fish and was completely empty.

Spectracanthicus murinus
Stillborn Spectracanthicus murinus fry

A second chance
A few weeks later I was already witnessing the courtship ritual occurring again amongst the pair. This time the behavior lasted much longer. I'm uncertain if this is because of the incident with the L180 or the addition of the second bell shaped cave. But unfortunately, an open tank was unavailable, so for the time being the S. murinus would have to cope with their neighbors. On several occasions over the next month I would witness the female backed into the cave with the male doing the "sexy shiver". Each time this occurred it was in a different cave, and each time, the mornings brought an empty cave. On May 19th I was doing my typical evening cave snooping and was delighted to find my second batch of S. murinus eggs had been deposited in the same bell the first batch had been placed. This spawning took place quite rapidly considering the four days of trapping that occurred on the original spawning. This time I wasn't taking any chances. I gently lifted the cave containing the male and eggs and placed it in a large re-circulating hang-on breeding box. I was already seeing the benefits of the fish being located in there, as observations would be much easier. But even then, I was never able to be in the right place at the right time to photograph the male with the eggs.

On May 23rd I found four stillborn fry and the remnants of hatched eggs just outside the cave entrance. Among the dead was one small fry that appeared to have a small hemorrhage in its yolk sac but was still wiggling. I had hopes he would remain alive for further observation of the fish development. Unfortunately over the next 24 hours that fry perished. The next evening the male had vacated the cave after eating the balance of the fry. I'm uncertain what instigated this, in my experiences, an excessively disturbed male will generally eat the eggs, rather than waiting for them to hatch first. Frustrated at my second failure with this species, I returned the male to the tank and contemplated what my next trick would be as I tried to open up an extra tank.

June was a busy month. Most of my livebearers and a few other projects were moved outside for the summer, but for every tank I made available, I quickly filled with another project fish. I was regularly getting in Corys from a fellow breeder that was shutting down his fish room and a home for those became the priority.

Spectracanthicus murinus
Eggs three days after discovery. A few MTS snails were used to assist in egg cleaning

Third time's the charm?
On June 24th I was given another opportunity with these fish. The male was again found in the same bell cave with 35 more eggs. Surprising, because courtship went completely unnoticed. This time I spent several days debating on what approach I would try. It was too late to try and relocate the Ancistrus and my attempt at removing the male with the eggs also failed. I had little option left; the business world's definition of insanity is repeatedly doing the same thing and expecting different results. So, I reluctantly decided to pull the eggs with hopes of hatching them under a gentle tumble. A rearing method I'm generally not very successful with.

The eggs were pulled three days after they were discovered, it was clear the spawn was viable and the fry were developing nicely. Between day four and five the eggs hatched on the 28th and 29th of June. Eight stillborn were removed but, a great majority of the spawn appeared in very good condition. As mentioned earlier, the fry are extremely undeveloped, just a yolk sac with a tail and two tiny black eyes. Once hatched, the air stone was removed and light recirculation was turned on in the breeding box. This was done to prevent the fry from burning excess energy attempting to fight the current so it could be used in development. By the second day slight pigmentation could start to be seen on the top of the head but, judging by the proportion of body to yolk sac I was far from the safe zone with these delicate little guys. A hardwood leaf was placed in the container. This provided cover for the young fry and would provide grazing of the infusoria created by the decomposing leaf when they began feeding.

Spectracanthicus murinus
By the second day slight pigmentation can be seen on the top of the head

Ten fry were lost during the first seven days for reasons unknown. At this point the fry were 8mm (5/8") total length and were getting the gray colour of their parents. A huge difference could be seen in the fry that hatched on the second day. It was clear that a large amount of yolk sac was still remaining and it would be awhile before the fry would be getting their first meal.

By day fourteen the ten remaining fish had full pigmentation and were quite adorable. Mouse grey fry were scooting around the container, but the fry were still quite plump and there was still some time before first foods needed to be offered. On the 21st day, the fry had grown considerably and were now being offered a mix of dried pellet foods.

Spectracanthicus murinus
The fry are seven days old;
the fish on the left is roughly 24 hours younger than the fish on the right.

At the one month mark the fry were approaching 15mm (1/2") and had begun to develop the white spots and seams found in the adults. The spots developed randomly and were quite large in proportion to the body. It was at this point the fry were removed from the container into a "Forty Breeder" (12"x18"x36"/ 30cm x 45cm x 122cm) tank with several other species of similar size. The grow-out tank contained just enough sand to cover the glass bottom, several caves and was littered with driftwood and hardwood leaves, providing lots of places for the assorted fry to hide. Two vertical sponge filters were set up in opposite corners of the aquarium and water changes of 50% were done once to twice weekly. Observation became increasingly difficult as the fry were quite shy. Once a week I would turn the hardscapes just to check their growth and condition.

Growth slowed to a crawl after the first month. 45 days later the fry had grown slightly in mass but very little in length reminding me of the development rates of H. zebra. I've also found the murinus fry development is extremely sensitive. I was traveling a lot in July and in turn tank maintenance was neglected. Once things returned to normal and I went to photograph them, I noticed the fry had begun to develop an up-curl and twist in the pectoral fins. In my experiences this deformity; typically seen in Ancistrus, is more likely a result poor water quality and not necessarily genetics. Because these are F1 fish I have no doubt this is the case. I've doubled my water change frequency. I've had luck correcting this problem in other species when identified early and hope the increased fresh water will again be successful.

I've thoroughly enjoyed my experiences with Spectracanthicus murinus, and look forward to perfecting the spawning and raising of fry. Additionally I plan to try my hand at other Spectracanthicus species. I would encourage everyone to spend a little time with the genus Spectracanthicus, an interesting little fish which deserves to be the topic of more discussions.

Copyright information for the images used in this article can be found on the species' full Cat-eLog page.

Down Cat-eLog Data Sheet
Scientific Name Spectracanthicus murinus  Nijssen & Isbrücker, 1987
Common Name
Type Locality Poça de Pedra, Rio Tapajós, eastern Pará, Brazil.
Etymology Genus: Latin, spectrum = look, apparition + Greek, akantha = thorn. This specific epithet literally means mouse gray (murinus=mouse gray) and refers to its colour.
Down Species Information
Size 64mm or 2.5" SL. Find near, nearer or same sized spp.
Identification Spectracanthicus can be separated from all other loricariids except some Baryancistrus, Parancistrus and an undescribed Hemiancistrus by the presence of the dorsal-fin membrane contacting the adipose-fin spine. It can be separated from Baryancistrus and the Hemiancistrus by having fewer teeth (less than 25 vs. greater than 25) and from Parancistrus by having restricted gill openings. A key to the genus can be found here.

Spectracanthicus murinus is unique among Ancistrini in that it has lost the evertible cheek plates typical of species of Ancistrini.
Down Habitat Information
Distribution South America: Tapajós River basin, Brazil.
Amazon, Lower Amazon, Tapajós (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 2018.
pH 5.5 - 7.5
Temperature 26.0-30.0°C or 78.8-86°F (Show species within this range)
Down Husbandry Information
Feeding Carnivorous. User data.
Breeding Has been bred in captivity and is a cave spawner.
Breeding Reports There is but a single breeding report, read it here.
Down Further Information
Reference Revue française d'Aquariologie Herpétologie v. 13 (no. 4) [for 1986], pp 94, Figs. 1-3.
Registered Keepers There are 14 registered keepers, view all "my cats" data.
Wishlists Love this species? Click the heart to add it to your wish list.
There is but a single wish to keep this species, see who wants what.
Spotters Spotted this species somewhere? Click the binoculars!
There are 13 records of this fish being seen, view them all.
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Last Update 2021 Jan 10 07:53 (species record created: 2015 May 15 13:07)

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