Green Terrors

Last updated: 2012-05-02 — Created: 2011-09-04

Today we’ll be talking about the green terror. There are actually two species that share the trade name: the false green terror (Andinoacara rivulatus), which is what you will typically find in the stores, and the original/true green terror (Andinoacara stalsbergi), which is much harder to find and may require a special order from Peru to obtain. A third species (Andinoacara aequinoctalis) has been proposed as the goldsaum, suggesting there may be a separation between the orange-tailed and white-tailed varieties of the false green terror.

I’ve read that a shortage of the original several years ago meant the false GT was found to take its place, which has since become what we now see in stores and know as the GT, however incorrect this naming may be. Nowadays, obtaining the true GT is quite a challenge. I’ve been told that an order quantity of 100+ would be required for it to be worth the trip to get some, but I was also warned that “nobody buys these fish”. Now, I’d like to think this has more to do with higher availability of this false species that has stolen the name, but perhaps the gold seam variety is much more attractive to today’s fish hobbyist who prefers the orange, green and brown hues all on the same fish. In my opinion, the iridescent spots on a dull body of the true GT sure do outshine the dull spots on an iridescent body of the false GT, so I’d like to believe that the prettier fish has been shafted because of its lesser availability. Still, having never once seen a true GT in a fish store to date, it is very hard to compare the two just from pictures scattered around the Internet. If I can procure some, I will attempt to settle this argument at a later date. For now, however, I will have to settle with observing just the false GT.

I talked with the proprietor of one of my LFSs about his experiences with breeding GTs. He told me he’d spawned them and observed variety of tail seam colours within the same spawn, ranging from white to yellow to bright orange. Curious to see if there’s any sort of correlation between the tail colours on parents and their offspring, I’d like to mate a pair and see if I can figure out a pattern. Since you don’t as often see the white-tailed variety, I’ve opted to focus on these instead of the orange. I’ve found myself a large male and two females as breeding stock. It could be that these fish breed true (i.e. all of their offspring come out white-tailed), suggesting the white and orange are indeed separate species or that a recessive gene exists within the same species for the less-common white seam. It could also be that the offspring have a variety of colours between individuals, as my fish store friend describes, suggesting a hybrid of two species, incompletely-/co-dominant genes or variable expressivity/penetrance of the genes. For now, I’m just growing out the trio in hopes they mature and two pair up, but I hope my questions will be answered in the coming months.

February 28th, 2012 – There hasn’t been a huge amount of progress with the false GTs. Initially, I had all three cohabiting, but the females fought, so I separated one and put her with other fish. It’s been difficult to accelerate their growth since the remaining female has ceased eating and won’t shake an insidious internal infection, while the male has issues with hole-in-the-head disease. Despite treatment attempts – isolation, medication, salt, increased heat and pristine water – the symptoms persist in both fish. Even with the forehead craters and the occasional trail of white stringy poop, the male’s appetite is still voracious, however, so I decided to reunite him with the other female to see what would happen. This female has a lame right pectoral fin and tattered dorsal and pectoral fins, so I wasn’t sure she’d be accepted, but after a couple of days in the same tank, there were signs of chewed lips and darkened blacks, suggesting the two fish have paired and may spawn presently. As mentioned, I will look to see if this pair produces fry that all have white-seam tails as well.

May 2nd, 2012 – I got the internal infection under control and the two remaining GTs have been steadily packing on weight. It looks like the first round of eggs has been laid by the female. The male shows little interest in guarding the nest and has no sign of having dropped his junk the way the female has, so we’ll see if the eggs were fertilized at all. The first round is usually just a trial run anyway, so no big loss this time.

After some serious issues with hole-in-the-head, I’ve determined I can’t keep this species alive in my tanks, so I will leave this experiment be for now. If someone else feels like taking it on, please do share your results!


Posted in Fish Profiles | Leave a comment

Experiment: Growth Rates of Fish

Last updated: 2012-01-13 — Created: 2012-01-13

A comment posted yesterday reminded me of an experiment a friend of mine did once that I’ve been meaning to repeat. I will have to procure a proper apparatus, but I at least want to share the concept to get the ball rolling.

The hypothesis is that water changes are much more important to rapid fish growth than frequent feeding. I will have to cite this, but it’s said that fish excrete hormones that build up in the water and stunt growth, which is a natural defence for keeping fish small in crowded spaces. When fish have more open swimming spaces, they tend to grow faster. Have you noticed how fish at a store may appear to stay the same size for a long time, but really start to grow once you get them home into your own tanks?

My friend’s experiment involved just two tanks:

  1. heavy feeding with light water changes, and
  2. light feeding with heavy water changes.

I would propose doing the experiment and include a control group as well:

  1. heavy feeding with normal water changes
  2. normal feeding with normal water changes
  3. normal feeding with heavy water changes

Temperature can affect metabolic rate. Similar to how pond fish or frogs hibernate through the winter with their metabolic rates slowing to almost nil, organisms in warmer environments will have accelerated biological processes and life cycles – disease will be fought and food processed faster, parasites will die off more quickly and fish will become more aggressive. For this reason, identical heaters should be set to the exact same temperature, verified with (perhaps multiple) accurate thermometers.

The tanks should be exactly the same: the same volume with the same filtration rate and method, same lid and lighting (probably none), etc. Filters should be stocked with new, yet fully-cycled media and all rinsed out on the same schedule. Tanks should be located next to each other to minimise any differences due to external light sources, draught, evaporation, ambient temperature, etc. Visual barriers will be kept between tanks to ensure no macho stuff happens between tanks 1 & 2 and 2 & 3.  Fish stocking should be identical, ideally all from the same spawn, grown out for a small time, then equally divided amongst the tanks. Basically, anything and everything should be done to ensure that the only two variables are: a) the amount of food added, and b) the volume of water changed.

Food types and amounts should be consistent, so some measure of a “dose” of food would need to be established. This “dose”, as well as its frequency and the frequency and volume of water changes would have to be chosen such that “heavy feedings” do not lead to wasted food and/or toxic water parameters, while “heavy water changes” don’t lead to shocked fish. Nitrate measurements could be taken periodically to ensure these choices are reasonable.

I would propose the following definitions as a starting point:

  • heavy feeding = “a dose of food, twice daily”
  • normal feeding = “a dose of food, every other day”
  • heavy water changes = “50% of water volume, twice weekly”
  • normal water changes = “25% of water volume, bi-weekly”

This means that tank #1 gets 4 times more food and tank #3 gets 8 times more water changed than tank #2. Observation between the three tanks would show how these two factors can affect fish growth over time. It is predicted that fish in tank #1 will show only a moderate increase in growth over those in tank #2, where fish in tank #3 will show a significant one.

Updates to follow once I decide to perform the experiment.

Posted in Fish Health | Leave a comment

Welcome to my blog!

Some notes and guidelines for this blog:
–> Posts will be brought to the top of the feed whenever they are updated with new information, so re-read old posts if you see them jump the queue. I’m working on adding updated & created dates to each entry.
–> Some of my pre-formatted text sections seem to be magically losing their line breaks, so please let me know if you find one of these sections in a post and I will fix it.
–> Fish are friends, not food!
–> Fries are chips, not fish! (Baby fish are fry, plural)
–> Common names of species are printed in lowercase, unless they incorporate a proper noun, in which case only the proper noun is capitalised. (NOTE: Older posts are still being revised to fix this. Thanks Zed!)
–> Scientific/Latin names are italicised with a capital on the genus and lowercase for the species name. Genus names can be reduced to just their first letter if they have been spelt out in full once already.
–> This blog does its best to conform to the rules of the international flavour of English that is used in English-speaking countries other than the United States. All posts are written in international/UK/non-US/the Queen’s English. I’m Canadian; that’s how I roll.
–> Plurals of Latin loanwords have been preserved: medium becomes media, not mediums; aquarium becomes aquaria, not aquariums; data is treated as the plural of datum; et cetera.
–> Apostrophes should never, ever, ever (EVER!) be used to indicate plural, so EBJDs, not EBJD’s.
–> The contents of this blog represent original work. All pictures were photographed personally (or used with permission of their respective owners and cited appropriately), while the text represents many months of personal research, experience, and chatting with other aquarists. Everything is happily shared with you, but is here for informational and educational purposes only. Please do use, link to and learn from the this blog, and share it with your friends, however, stealing or reposting is just not good karma, and I will be forced  to hunt you if you do! Just sayin’.
–> Found something helpful? Have a story to share? Disagree with everything I’ve written? I’d love to hear from you. Please comment, comment, comment!
–> …However, if you’re posting comments for the world to see, please do so using full sentences and proper punctuation. I will not feel badly about editing out messenger shorthand and other such atrocities.
Posted in Uncategorized

EBJDs – Electric Blue Jack Dempseys!

Last updated: 2012-03-12 — Created: 2010-09-08

There’s a quick mention of breeding EBJDs in the February 2012 Freshwater Q & A section (page 6) of Aquarium Fish International magazine. Check it out!

If anyone has had the opportunity to see one of these stunning Rocio octofasciata fish in real life, s/he’ll agree that few other cichlids come even close to the wow-factor that these maintain. In hopes of producing some EBJD offspring, I’ve started to grow out one male EBJD and three female regular JDs.


Jack Dempseys can be sexed the same way as most cichlids – males have the typical long, pointed fins where females have shorter, rounded ones. In addition though, female JDs have a blue spangling on their cheeks, as can be seen from the above photo, where the males just have the underlying body colour.

This large male was in Big Al’s Scarborough and has a gorgeous, almost electric blue appearance. However, he is indeed a standard JD with the standard underlying dark body colour. You can also see here the lack of blue spangling on his cheek, as compared to the female in the previous photo.


Theories of whether the electric blue variant is a natural colour morph or has been hybridised are abound and have been hotly debated. I’ve talked to a gentleman who has worked in ornamental fish wholesale, saying to have seen many EBJDs that possessed traits more like a Cuban cichlid (Nandopsis tetracanthus) than a Jack Dempsey during his tenure. Others have claimed that the EBJD also has part Haitian cichlid (Nandopsis haitiensis) in it. It could be that many generations of out-crossing to regular JDs has aligned and stabilised the EBJD genes. However, until someone actually repeats the hybridisation and provides actual photographic proof of the process (a good start is here), I’m sticking with the natural colour morph theory. After all, it’s just as likely (if not more likely) that a natural colour morph EBJD was hybridised to a Cuban cichlid to produce these Cuban-looking EBJDs. I do not believe that  a regular JD was hybridised to a Cuban cichlid to arrive at the EBJD we now know and love! The topmost photo in this post shows one of my EBJD males next to a JD female and it leaves no question in my mind that EBJDs are just a variant with albino-like mutation. Red pigment in this fish is limited regardless, so this explains the yellow eyes instead of red. So, with this said for the sake of exploring the possibilities, let’s continue…

EBJDs are the result of a semi-lethal recessive gene mutation that reduces the typical  pigmentation of the fish, giving rise to the truly-sweet electric-blue colouration. They are a natural variant, however, they aren’t found in the wild because the weaker blue fry do not survive. The double-dose of the blue gene causes the EBJD to grow much more slowly and become a tad less nasty than its wild-type counterpart. As a result, blue fry must be carefully separated from their black brothers and sisters and raised in isolation in order to survive. This was originally done by a fellow named Hector Luzardo in 1985. Slower growth also means that while your EBJD and JD juveniles may be the same size when you purchase them, they will be of radically different sizes within a few months. You will probably have to give your original EBJD some lead time to grow before getting him/her a mate.

To further complicate the issue, the inherent weakness of the EBJD means that if two EBJDs are mated together directly, while they will indeed produce 100% EBJD offspring, these offspring will be so weak, the pairing will almost surely also result in 100% dead offspring. So, how do we obtain blue offspring if we can’t use the blue fish to do it, you may ask? The answer lies in making use of blue-gene carriers, as was originally done when these fish were first discovered. The fish that carry the gene, but look like regular ol’ Jack Dempseys, are known as BGJDs, blue-gene Jack Dempseys.

The Recipe:

 eb = the electric-blue gene
 JD = the wild-type gene
 JD/JD = WTJD - A regular/ordinary/wild-type JD
 JD/eb = BGJD - A blue-gene JD (looks like a wild-type JD)
 eb/eb = EBJD - An electric-blue JD

So, at the locus that controls electric-blue colouration:

  • A wild-type JD has two copies of the wild-type gene and no blue genes.
  • A blue-gene JD has one copy of the wild-type gene and one copy of the blue gene (but looks exactly the same as the wild-type JD)
  • An electric-blue JD has two copies of the blue gene and no wild-type genes.

Ideally, we would just be able to randomly put two Jack Dempseys together and have them mate to produce some electric-blue offspring, as Mr. Luzardo did, however, the chances of this are pretty slim, and it would involve more time and tank space than the average aquarist would typically have. So, we must rely on other means. The first step is to out-cross our EBJD in order to preserve the blue gene, but allow stronger genes to be used in creating future generations. It doesn’t matter which parent is which colour, however, since a lot of male cichlids are known to be more temperamental and beat up their mistresses, I have opted to use a blue male and regular females. I would much rather replace and re-grow a $7 JD than a $48 EBJD should anything go awry. I’ve seen both males and females in stores, so perhaps I will reverse the colours in the future, once I’ve acquired more experience.

Please note: The projections suggested below are completely theoretical – reality is rarely so exact. Genetics may do its part to produce a ratio as is described, however, unpredicted gene interactions, male growth superiority, bad environmental conditions, bacteria, disease, competition for food, sibling cannibalism, fish defects, etc. all can skew these numbers.

Step 1:

Mate: Outcross EBJD to WTJD 

  x |   JD  |   JD  |
 eb | JD/eb | JD/eb |
 eb | JD/eb | JD/eb |

100% BGJDs (look like wild-type JDs)

Now that we have a spawn containing all blue-gene carriers, the next step involves a number of options, each with major benefits and drawbacks. While it is unknown whether all EBJDs out there descend from the same pair or not, we do know that there is an inherent lack of vigour in the blue offspring. Whether this is due to inbreeding depression caused by inheriting multiple identical copies of certain bad genes, or whether it’s just something about the double-dose of blue that makes the fish weak by nature, is unknown. Regardless, we can’t do anything about the blue fish being weaker, but there are some things we can do to ensure all of the other genes involved are as varied and strong as is possible. If we know there’s a weakness in the blue fish, our goal should be to ensure that we select non-blue fish that are totally unrelated and share no common ancestry. Do this by purchasing only one fish from each store/chain/hobbyist and ensure that they don’t use the same supplier as other places you shop. Obviously, selecting siblings from the same tank in the same store from the same supplier is no way to go about obtaining genetic variety! Now, on to creating the actual EBJDs…

Step 2:

Option 1: Inbreed

Mate: BGJD to BGJD, brother to sister

  x |   JD  |   eb  |
 JD | JD/JD | JD/eb |
 eb | JD/eb | eb/eb |

25% WTJDs
50% BGJDs (look like wild-type JDs)
25% EBJDs

Pro: Cheapest - only one EBJD involved, used in one spawn.
Pro: Brothers and sisters are about the same size.
Pro: No risk of losing expensive EBJDs.
Con: Wild-type offspring will be mixed with blue-gene carriers.
Con: Least genetic variety (inbreeding is worse than back-crossing).
Option 2: Back-cross

Mate: BGJD to EBJD, father to daughter or mother to son

  x |   JD  |   eb  |
 eb | JD/eb | eb/eb |
 eb | JD/eb | eb/eb |

50% BGJDs (look like wild-type JDs)
50% EBJDs 

Pro: Cheapest - only one EBJD involved, used in two spawns.
Pro: Highest output of EBJD fry possible.
Con: Original parent must be re-introduced to a new mate.
Con: Potential size mismatch with new pair.
Con: Reduced genetic variety from re-use of original parent.

Option 3: Cross with 2nd EBJD. 

Mate: BGJD to unrelated EBJD

  x |   JD  |   eb  |
 eb | JD/eb | eb/eb |
 eb | JD/eb | eb/eb |

50% BGJDs (look like wild-type JDs)
50% EBJDs 

Pro: Highest output of EBJD fry from an adequate genetic base.
Con: Added cost of 2nd EBJD parent.

Option 4: Perform Step 1 with two different sets of parents,
resulting in unrelated spawns A and B (all BGJDs).

Mate: A males to B females, B males to A females

  x |   JD  |   eb  |
 JD | JD/JD | JD/eb |
 eb | JD/eb | eb/eb |

25% WTJDs
50% BGJDs (look like wild-type JDs)
25% EBJDs 

Pro: Most varied genetic base, strongest offspring.
Pro: No risk of losing expensive EBJDs.
Con: Added cost of 2nd EBJD parent.
Con: Wild-type offspring will be mixed with blue-gene carriers.
Con: Must grow out each pair and each spawn in separate tanks!

From my understanding of genetics, these options are in order of least-to-most preferable. I will personally be attempting Option 3, which would be my recommendation to anyone trying this at home. Also, if there’s anything you can do to ensure that your two EBJDs come from as varied a source as possible as well, it should further increase the strength of your line.

Things to Note:

  • Do not mix EBJDs with any kind of aggressive cichlid. They will die!
  • EBJDs have a very high mortality rate and will often die off before they reach about 7 cm in length, especially if stressed. Do what you can to limit this stress!
  • Make small, frequent water changes. If you must remove a large amount of water, replace it slowly, in stages, allowing enough time for the water temperature to stabilise – limit the stress from temperature and chemical changes in the water.
  • Do not mix small & timid EBJDs with large & nasty Jack Dempseys!
  • EBJDs don’t grow as fast, but do grow as big as their wild-type counterparts, up to 25 cm in length. They will start of a pale gold colour and will be fully-blue by the time they reach about 4-5 cm.
  • EBJDs are f#*%ing expensive, so be nice to them! 😛
  • Buy EBJDs as big as you can find them. Having going through five (yes, FIVE!) 3 cm fish at $30-35 apiece, I finally splurged on the larger male pictured above.

As you can see, creating healthy EBJDs requires patience in successfully breeding two generations of fish. Your first EBJDs will be the grandchildren of your original EBJD specimen. This explains why the high cost is usually associated with this glamourous variant!

Random thought: The colours of various fish scales are dependent on cells called chromatophores, including: melanophores (black), xanthophores (yellow), erythrophores (red), iridophores (silver/metallic/iridescent) and leucophores (white). Let’s think about colour theory here for a moment, specifically the additive (light) and subtractive (pigment) colour models. These are the three intersecting circles of primary colours: red-green-blue or cyan-magenta-yellow, respectively. EBJDs, as compared to wild-type JDs are definitely missing most of their black pigment. If we shine white light on the fish and most of its cells that reflect red light are missing and most of its cells that reflect yellow light are missing, what is left? Try opening Photoshop or your favourite application with a colour picker and make your own custom colour. If you start with white in the RGB model, remove some (say 40%) red and then remove some yellow too (yellow is a combination of red and green, so remove equal amounts of each of these, say 60%), what colour do you get?


WHITE (#FFFFFF) – RED (#660000) YELLOW (#999900)(#0066FF)

It would seem that EBJDs have not only reduced amounts of black pigment in their scales, but also don’t produce normal amounts of red and yellow, resulting in a cyan-blue hue. Question: Is there anything on which a fish missing the ability to synthesise certain compounds into coloured pigments might lose out? Is there a beneficial side-effect of creating certain pigments?

Update: I have personally seen what I believe to be both male and female EBJDs in multiple pet shops (“females” were smaller, paler and had shorter, rounded fins as compared to their “male” tankmates), so I do not believe in any sort of sex-linked genes that results in only one gender of these fish. However, after some discussion with other breeders, it would seem that there can be variations in the male-female ratio of blue offspring produced. The exact cause of this is still to be proven, but it’s likely related to water chemistry. The current working theory is that harder/alkaline water produces more males, where softer/acidic water produces more females. The acceptable pH range for these fish seems to vary wildly from one source to the next, but 6.5 to 8.5 seem to be the extremes. Fish eggs in hard water will have a shorter time to be fertilised time than those in soft water. Male (Y-chromosome) sperm are apparently faster, but have a shorter life, while female (X-chromosome) sperm will bring up the rear and stick around a little longer. By putting these two pieces of information together, short fertilization time in alkaline/hard water means more males (all, in extreme cases), while longer fertilization time in acidic/soft water means more females are conceived. Alternatively, with Betta fish, it’s been noted that the age of the parents can affect the sex ratio of the offspring, which is another possibility to test for EBJDs. Younger males mated to older females (hence mother to son) produce more male offspring, where younger females mated to older males (hence father to daughter) produce more females.

More Tidbits:

  • It’s been suggested that the blue-gene JDs (that are apparently indistinguishable from their wild-type brothers and sisters) in fact are distinguishable once they reach a certain size. By looking at the underlying body colour, particularly in the forehead area, BGJDs apparently have a magenta hue to them, where wild-type JDs are a darker grey.
  • Skeletal deformities are common with this fish, which apparently onset during the 2-4 cm size range. These deformities may be caused by poor water quality, bacteria or bad diet.
  • As a preventative measure during the formative months for these fish, one must ensure their diet contains sufficient calcium, as well as phosphorus, which is required for proper calcium absorption. The gills can absorb calcium from the water from a concentration of 5 ppm, but phosphorus needs to be ingested. The best source of these elements is skeletal, so try to ensure some fish meal or bone-containing organisms are fed to your fish. Magnesium must also be present, though most foods will contain adequate amounts.
  • I’ve been advised to raise fry in soft water for as long as possible, until the fish are at least 4-5 cm in length. It is when the fish has fully blue and no longer shows any golden blotches that you can relax a bit, as most deformities will show up by this time if they are going to.
  • Eye problems are inherent in these fish, so keep your popeye medication handy just in case something flares up. My older specimen had cloudy eyes for the duration of his stay with me and the younger one has developed a haemorrhaging inside his eyeball, making his entire pupil look red instead of black. Gross!

Questions to Answer:

  1. What is the ideal pH/water hardness to produce a 1:1 sex ratio of EBJDs.
  2. Does the choice of crossing options in Step 2 affect the strength of the offspring?
  3. Does the age of the parents in relation to each other affect the sex ratio of offspring?
  4. Does the age of the parents affect the number of EBJD offspring?
  5. What causes deformities in the EBJD offspring?

March 8, 2011 – Experiment rebooted. After losing my old JD to age/bloat and my young one to an eye infection, I recently found EBJD #8 at my local PJ’s for a great price. He’s smaller than I would have usually bought, but bigger than the ones that went belly-up on me previously, so it’s going to work out, I hope. I think I will name him something mean, so this way he can’t die. The only question is, will big mama take to him all right?

Shown below are EBJD #8, my female JDs and a Cuban I got for reference.

September 12th, 2011 – After losing another EBJD male today, I’m putting this experiment on hold indefinitely. Perhaps when I have larger tanks, UV sterilisation and better filtration in place, I’ll try again, but it’s getting way too expensive losing these fish repeatedly to warrant continuing for the time being!

March 12th, 2012 – Experiment rebooted…again. I was in a store yesterday, where I had a bunch of unclaimed credit, and they had a number of small EBJDs available at a pretty good price: $50/3. So, here I go again! I’m going to grow this trio out a bit in an isolation bucket within my angelfish tank, before releasing them into the community. I’m hoping that the larger volume of water and lower aggression levels will help prevent any health issues this time around. *crosses fingers*

December 15th, 2012 – Out of EBJDs…again. I give up…for now. 😦

November 5th, 2013 – Found this lively EBJD male for just $38 at a really nice size. He’s taken to my last female, so I’m going to give it one last ditch effort. With both fish mature already, the grow-out phase can be skipped, so I hope it’s just a matter of conditioning and letting them get to work!
20131105-JD pair

For more info:

Posted in Genetics | 6 Comments

Vieja Dismantled!

To follow-up my post titled The Word of the Day is Vieja!, here is an update of how the species have been reorganised. It also looks like a lot of the species names are moving away from the -um (singular)/-a (plural) endings and opting for the -us (singular and plural) ending instead. Makes life a little easier. According to FishBase, the following former-Vieja species have been reallocated to the following genera as of September, 2011:

  • “Cichlasoma”:
    1. C. tuyrensis
    2. C. ufermanni
  • Paraneetroplus:
    1. P. argenteus
    2. P. bifasciatus
    3. P. breidohri
    4. P. fenestratus
    5. P. guttulatus
    6. P. hartwegi
    7. P. maculicauda
    8. P. melanurus/synspilus
    9. P. regani
    10. P. zonatus
  • Theraps:
    1. T. godmanni
    2. T. heterospilus
    3. T. intermedius
    4. T. microphthalmus

According to the Cichlid Room Companion, things look a little different:

  • Chuco:
    1. Ch. godmanni
    2. Ch. intermedium
    3. Ch. microphthalmus
  • “Cichlasoma”:
    1. C. tuyrensis
  • Paratheraps:
    1. P. bifasciatus
    2. P. breidohri
    3. P. fenestratus
    4. P. guttulatus
    5. P. hartwegi
    6. P. melanurus/synspilus
    7. P. zonatus
  • Vieja:
    1. V. argentea
    2. V. heterospilus
    3. V. maculicauda
    4. V. regani
    5. V. ufermanni


Posted in Fish Profiles | 3 Comments

Convicts & Honduran Red Points

This was somewhat of an accidental side project which came into being when my “female” Honduran red point was thrown in my main tank with a bunch of female pink convicts and turned out to be a male instead. It all started when I read a post from Finatics on PriceNetwork that talked about these fish that were similar to, but much nicer than regular convicts. Curious, I had to go see what all the fuss was about. I so I ran out to see them and Mike was able to point out one that was swimming in the midst of a bunch of regular Black convicts. Lo and behold, the fish was much nicer, showing a lovely red hue in its tail and a more pronounced blue around the gills. We both thought it was a female, but it’s possible to make this mistake when they’re young and males show a few iridescent scales that look like the start of a female’s typical orange belly colour. I brought “her” home and “she” ended up making babies with a female pink convict, so definitely a male!

Male Honduran Red Point (Amatitlania siquia)

Male Black Convict (Amatitlania nigrofasciata)

Since the HRP x pink convict pair bred in my main display tank, I wasn’t able to rescue the whole spawn, but did grab a handful of the survivors and grew them out. All fry displayed the darker colour of the HRP, showing that dad did not have any form of leucistic genes present and was therefore a true black HRP. Some were given to some friends, but I saved a few for myself and raised them up. After a few months and them reaching maturity, I found I had only two left, one male and one female. This particular hybridisation is usually given the name “blue convict” owing to the fact that they are much more iridescent from the HRP genes, but still look like regular ol’ convicts. The female in particular had some righteous colouring, stunning blues & yellows and an almost barred orange when ready to breed…

Blue “Convicts” (Amatitlania siquia x A. nigrofasciata hybrid)

With just one of each gender left, I decided I had to experiment. I back-crossed the female with her father to keep her pretty colours, but breed out the convict resulting in a touch of pink convict added to HRPs. The male was crossed with an unrelated pink convict (one of the marble-less offspring from my light marble pairing) to attempt to produce a “white HRP”. I don’t know if a naturally-occurring leucistic version of the HRP exists, but I’ve heard that those that are floating around have a much paler complexion as compared to pink convict. I’ve also seen some really pale pink convict in a local PJ’s, so I decided I’d try for myself to see what happens when a touch of HRP is added to pink convict.

Experiment 1: HRP x (HRP x Pink Con) Back-Cross

Above you can see the blue “convict” mother and the HRP father tending to their fry, born somewhere around the 20th of December, 2010. Again, these hybrids will be roughly 1/4 pink convict and 3/4 HRP, with the male HRP being the father of both the fry and their mother.

Fry after a couple of weeks are doing well and appear to be all dark in colour, as expected. It will be interesting to see if any of them have any marked differences in colour at all, favouring either their HRP or convict ancestry.

April 5th, 2011 HRP x (HRP x pink)/”blue” fry at 4 months old. Only seven left, but looking good! 🙂

September 5th, 2011 – No survivors remain.

Experiment 2: (HRP x Pink Con) x Pink Con Cross

This experiment will attempt to produce some white “HRPs”, pulling the leucistic genes from the pink convict and the pretty iridescent colours from the HRP. Granted, leucism does reduce the overall colouration of the fish, but we’ll see what happens, as iridescent scales are more about shininess than colour. I’m predicting something similar to what happens with a platinum angelfish, where there is no colour, but more iridescence, leading to a fish that is more white than pink. Following this analogy, pink convict would be the same as blushing angelfish, where less iridescence allows the colour of the underlying organs showing through, giving the fish a pink hue.

Above you can see the difference between a blushing and a platinum angelfish, which are what I’m hypothesising the analogues to pink convict and white “HRPs” are. Also shown are the blue “convict” male and the pink convict female tending to their eggs, which hatched around the 27th of December, 2010.

January 8th, 2011 – Even after only a couple of weeks, some fry are showing a distinct difference in colour. A quick count revealed an interesting discovery; the colours have not be inherited in a completely Mendelian fashion as one might predict. Now, this may be a result of them being too young to accurately separate into the “blue” and “white” buckets properly. However, since hybrids express their genes in uncontrolled and unpredictable ways, the favouring of the more abundant pink convict genes in this case wouldn’t be unusual. Counts were 79 total, 32 blue (40.5%), 47 white (59.5%).

April 5th, 2011FAIL! After the (HRP x pink) x pink/”white” batch was allowed to grow out for a few months, I found that the colours came out a complete swampwater mess! Despite the two pink females used to produce these fry being all-pink visually, their offspring inherited marble genes somehow, which supports the variable expressivity of the marble gene theory. Out of the 38 fish counted, 22 were marbled (57.9%) and 16 black (42.1%), with seven of these black appearing really intensely-coloured and the remaining nine being more subdued. Welcome to the world of hybrids! The seven “darkies” have been saved for further observation and the rest released into other tanks as lunch.

September 5th, 2011 – Just one (HRP x pink) x pink dark female remains at this point. I may mate her back to her great-grandfather (the HRP) at some point down the road, but chances are I’ll just pull the plug on this particular experiment. Hope it has been insightful.

Revised: 2012-01-17
Posted in Genetics | 24 Comments

Latin Lesson

We’ve all seen those hard-to-pronounce scientific (Latin) names for fish, and in this post I want to explore their usage a little. I’ve often seen names that end with -um, -us, -a, -ae, -i, -is, -es and so on, and never known whether they’re plural or singular or how to properly flip them or even pronounce them properly. Of course, you can’t just add an ‘s’ to the end like in English, so I was curious to figure out the ‘rules’.

For fish names, I found that if the fish is named for a person, the name will typically take on the same gender as that person,  -ae to honour females and -i to honour males. Most other fish names will refer to some apparent character or descriptive trait of the fish, or where the fish was discovered. These names typically end in -is (meaning “of”), -es (masculine or feminine), -us (masculine), -a (neuter). These endings are all the plural form and refer to the group of fish that represent the species, or two or more of the species. If referring to a single fish the rules are the same as for Latin adjectives, which follow the same pattern as the nominative (aka subjective) case. These rules do not necessarily apply if the fish name is derived directly from Greek words or is an acronym. For example, Cryptoheros sajica is an abbreviation of Salvador Jimenez Canossa, so the singular/plural case is ambiguous (but if anyone wants to name a fish for me, I think gredasti has a nice exotic-sounding ring to it! Ah?)

To sum up…


“I’d like a…”
“I have one…”


“May I have some…”
“I have a pair of…”
1st declination,



2nd declination,



2nd declination,



3rd declination,
masculine/feminine (unused)
3rd declination,
neuter (unused)
4th declination,



4th declination,
neuter (unused)
-u -ua
5th declination,



A description meaning “of…”



Interesting note:

The letters V, J and W did not exist originally in Latin. U and V were considered to be the same letter, classically. When the vowels U or I were to be pronounced as consonants, they were written as V or J, respectively. W developed as a letter from sounds best approximated as vv (or maybe uu?). Perhaps as a consequence, it’s interesting how this letter w is “double you” in English, but “double vee”  in French (doo-blah-veh) and Spanish.

Some examples…

-a/-ae endings:

(In some contexts, the suffix -ae is given a long i sound: “eye”, but is most correctly given  a long e sound: “ee”. A long a sound is incorrect: “eh”)

  • arrow cichlid: One Amphilophus sagitta, many A. sagittae – “arrow”
  • red terror: One ‘Cichlasoma’ festa, many ‘C.’ festae – In honour of Dr. Enrico Festa
  • Myrna’s cichlid: One Cryptoheros myrna, many C. myrnae – In honour of Myrna Lopez Sanchez

-us/-i endings:

(note that a single i is pronounced long: “eye”,  while a double i is pronounced as a long e followed by a long i: “ee-eye”)

  • keyhole: One Cleithracara maronius, many C. maronii – From the Maroni River
  • (true) green terror: One Andinoacara stalsbergus, many A. stalsbergi – In honour of Alf Stalsberg
  • wolf cichlid: One Parachromis dovius, many P. dovii – In honour of Captain Dow (there’s no w in Latin!)
  • black diamond: One Paratilapia pollenus, many P. polleni

-um/-a endings:

  • convict: One Amatitlania nigrofasciatum, many A. nigrofasciata – “black-barred”
  • Jack Dempsey: One Rocio octofasciatum, many R. octofasciata – “eight-striped”
  • redhead: One Vieja synspilum, many V. synspila – “fused-spotted”
  • two-band: One Vieja bifasciatum, many V. bifasciata – “two-barred”

-us/-us endings:

Singular and plural forms are identical.

  • midas: Amphilophus citrinellus – “lemon-coloured”
  • red devil: Amphilophus labiatus – “big lips”
  • false green terror: Andinoacara rivulatus – “provided with small brooks”
  • Mayan cichlid: ‘Cichlasoma’ urophthalmus – “tail of the eye” (caudal spot)
  • (blue/grey/true) Texas cichlid: Herichthys cyanoguttatus – “cyan-speckled”
  • (false) severum (plural severa): Heros efasciatus – “no stripes”
  • (frue) severum (plural severa): Heros severus – “serious, severe”

-es/-es endings:

Singular and plural forms are identical.

  • sieve cichlid: ‘Cichlasoma’ grammodes – “linked with lines”
  • triangle cichlid: Uaru amphiacanthoides

-e/-is endings:

  • red-stripe eartheater: One Geophagus surinamense, many Geophagus surinamensis – “of  Suriname”
  • emerald/chocolate cichlid: one Hypselecara temporale, many Hypselecara temporalis – “of this world/of time” 
  • moga cichlid: one Hypsophrys nicaraguense, many H. nicaraguensis – “of Nicaragua”
  • green pearlscale cichlid: one Herichthys carpinte, many H. carpintis – “of Carpenter’s Lagoon”
  • jaguar cichlid: one Parachromis managuense, many P. managuensis – “of Lake Managua” in Nicaragua.

And for more information than you care to know…

Typically, words in English that are borrowed from Latin and Greek (loanwords) have irregular plurals:

  • Words that end in -ma are made plural with -mata
    • dogma -> dogmata
    • schema -> schemata
    • stigma -> stigmata
  • Words that end in -us are made plural with -i or -uses or -era
    • alumnus -> alumni (masculine, neuter)
    • cactus -> cacti
    • census -> censuses
    • fungus -> fungi
    • genus -> genera
    • hippopotamus -> hippopotami
    • octopus -> octopodes (from Greek, not Latin)
    • platypus -> platypodes (from Greek, not Latin) or platypus
    • radius -> radii
    • syllabus -> syllabi
    • virus -> viruses  (there is no known Latin plural for virus)
  • Words that end in -um are made plural with -a
    • addendum -> addenda
    • agendum -> agenda
    • bacterium -> bacteria
    • candelabrum -> candelabra
    • consortium -> consortia
    • datum -> data
    • forum -> fora
    • maximum -> maxima
    • medium -> media
    • memorandum -> memoranda
    • millennium -> millennia
    • minimum -> minima
    • podium -> podia
    • quantum -> quanta
    • stadium -> stadia
    • symposium -> symposia
  • Words that end in -a are made plural with -ae
    • alga -> algae
    • larva -> larvae
    • pupa -> pupae
    • alumna -> alumnae (feminine)
    • antenna -> antennae
    • formula -> formulae
    • nebula -> nebulae
    • persona -> personae
  • Some words that end in -x are made plural with -ces
    • appendix -> appendices
    • index -> indices
    • matrix ->matrices
    • process -> processes (included because of possible same pronunciation)
    • radix -> radices
    • vertex -> vertices
  • Words that end in -is are made plural with -es
    • axis -> axes
    • basis -> bases
    • crisis -> crises
  • Words that end in -on are made plural with -a
    • automaton -> automata
    • criterion -> criteria
    • phenomenon -> phenomena
    • tetrahedron -> tetrahedra

Yay Latin! Now I have to go update my stock list!


Revised: 2012-01-17
Posted in Random/Useful Information | Leave a comment