Keeping fish in pairs/harems

[OrionN]

Don't believe information you read on Royal Gramma. These fish are protogynous hermaphrodites. It is easy to get a harem of them. They should be easy to breed. The only reason why breeders do not bred the normal RG because it is too cheap wild caught.
I keep harem of them for years and they spawned in my tank. After about 5 years, when the male got really old, the largest female change sex and killed him. This was in a 420 gal tank. He was not able to hide from the new male.

One word of caution. To keep fish in harems and pairs the male have to be in optimal shape and HEALTHY in order to suppress other females from change sex.
It is MY OPINION that the reason why multiple males do not developed in my tank is because of the way I feed my fish. I also put large mirror on my tank to stimulate the males. I believe that territorial dispute is common, and is the fact of life. Male must be able to defend their territory. Weaken male will be replace. To this end, I put up large mirror on my tank to simulate territorial dispute which is natural in nature.

 

[OrionN]

In my tank, the male is in the back and female in front. The Males are more purple and less yellow. Also male with much longer pelvic fins. The male purple to yellow ratio is about 2/1. The female purple to yellow ratio is about 1/2. This is in fully developed male. This color ration does not come on overnight.

Pictures from Live Aquaria which clearly show morphological differences between male and female
Fairly new male, notice the purple and yellow ration is not any where near my male, however we can clearly see the lenght of the pelvic fins are clearly longer when compare to the female in picture below
Young Male

Female

 

[Silly clownfish]

Thank you for all of the great ideas and detailed responses. @Orion - you are one of my reef2reef heroes and the inspiration behind me pairing my cherub angels

I leaning toward a couple of blennies, Royal gramma and still thinking a pair of flame hawks. One pair at a time, introducing in QT with dividers, etc. so if anyone needs to be separated it will be easier.

Or maybe wrasses instead of RG.

 

[Griev]

I also focused on groups of fish in my 200.

As for fish that would work in a smaller tank, I've got 4 blackcap basslets (related to Royal Grammas) and they're a hoot. Tons of personality and always opening their mouths at each other.

A pair of gencanthus, like spot breast angelfish is also an option in a 75.

Anthias might be hard, since you should really keep them in a group of 6+ (I have 12) imo to avoid them getting picked off one by one.

 

[OrionN]

Thank you for all of the great ideas and detailed responses. @Orion - you are one of my reef2reef heroes and the inspiration behind me pairing my cherub angels

I leaning toward a couple of blennies, Royal gramma and still thinking a pair of flame hawks. One pair at a time, introducing in QT with dividers, etc. so if anyone needs to be separated it will be easier.

Or maybe wrasses instead of RG.

I never keep CB Royal Gramma. WC RG only eat frozen food and live food. It is difficult to give RG good enough frozen food to keep them well color. Most of the time, RG coloration will fade as they stay in our tank. I went into great trouble to keep mine well fed with good frozen and raw food. I use chopped live oyster a lot, and fish roe. I can get access to fresh fish roe which I save to feed my tank. I think these are pack full not vitamins and nutrients.

 

[Zionas]

Dwarf angels have different social structures, if given the opportunity most prefer harems of 3+ individuals.

Just going off of FishBase, the species that are confirmed to prefer monogamy seem to be (obligate monogamous):

(1) Cherub (which you already have a pair of)
(2) Japanese Pygmy (Interruptus)
(3) Potter’s (only available CB through Biota)
(4) Half-Black
(5) Lemonpeel (read in another study)

These species (again going off of FishBase) are OK in both pairs and harems (selectively / optionally monogamous):
(1) Yellow (False Lemonpeel)
(2) Bicolor
(3) Multi-Bar
(4) Purple-Masked (Venusta)
(5) Narcosis (I guess not many have one)
(6) Keyhole (FishBase says harems but an old book by Rudie Kuiter says they form both pairs and harems)

The rest naturally prefer harems, or are unknown. Of course pairing is possible and I’ve seen people with Centropyge pairs work out over several years, but it seems like relatively few species naturally prefer pairing over 1 male and 2+ females if there’s the possibility of forming a harem. I would like to see studies over the course of 10+ years for pairs of the species that naturally prefer harems more.

There is a user on here who’s had his wild caught Joculator pair for 8 years and counting, and maybe Sanjay Joshi’s Joculator pair he’s had for about this long or longer. Also had a guy who had a pair of Fireballs (Brazilian Flameback) for over a decade. But not sure if these are cases where the owners got lucky or the fish themselves are flexible despite what the sources say. Dave Botwin (o2manyfish) I believe had a pair of Golden (Aurantia) for over a decade, and several people have kept pairs of the Paracentropyge (Multifasciata and Venusta).

I never heard of anyone with a Flame Angel, Coral Beauty or any of the more “common” haremic species (in theory) keeping just a pair for many years, but I wouldn’t be surprised if they exist and I just don’t know about it.

Pairing vs harem forming also depends on population density and coral growth, from what I gathered. So some of the species I mentioned could be considered “obligate” monogamous, while others are facultative / flexible.


The common Bangaii and PJ Cardinals are also examples of a fish many keep in groups, but are functionally monogamous with age. They only spawn in pairs and don’t change sex.


Flame Hawkfish and Longnose Hawkfish are protogynous hermaphrodites and are obligate monogamous (other Hawkfish are haremic).

Not sure about Chrysiptera damsels (if they can change sex) but my understanding is that “pairs” are really just FWBs that come together when spawning but otherwise don’t stick around each other much. So this is a MAYBE as far as I see.

Orchid Dottybacks, many have successfully kept in pairs but I prefer Basslets. I heard with a spawning pair, however, the males tend to die a lot earlier than the females because they exhaust themselves spawning and taking care of the eggs.

Blennies I believe don’t change sex and I don’t know how to sex them.

People have kept Matted Filefish in pairs and I think there’s a way to sex them by the growth of their bristles, but I have no idea. They don’t change sex.

Maybe a pair of Chalk Basslets? They occupy a slightly different niche than the Grammas and are more open-water than the Grammas, so I guess less conflict over territory.



Are you considering any larger fish to keep singly?

@Silly clownfish

And leave room for a larger fish or a pair of slightly larger fish. You don’t seem to stock overly heavily, so I believe this could be a decent way to go about it.

Not sure about pairs of some Wrasses as there are instances of male and female spawning but the female ends up changing into a second male. So, a MAYBE.


I like @Griev Genicanthus pair suggestion if you want a pair of larger fish (but I’d make them your only larger fish). They will complement your Centropyge pair well. Some other “medium” sized Angels, Poma Lab’s Red Sea Angel gets to 6” max, maybe smaller if grown from a juvenile and not something commonly seen in tanks. Singapore Angels (Chaetodontoplus mesoleuceus) also don’t get big but wild ones can be a bit fragile. What else? I don’t think Tangs are your thing.

Marine Betta is a cool fish, but not sure how to pair / sex them and I don’t believe they change sex. Not overly active, more of a reclusive fish so I worry wild ones are still regularly caught with cyanide or anesthetics. You would want to wait for one or maybe a pair of CB ones from Biota.

So you could end up with something like this:
(2) Cherub Angels (already have them)
(2) Royal Grammas
(2) Flame Hawkfish
(2) Chalk Basslet / Matted Filefish / Blenny of your choice
(2) Genicanthus sp (Spotbreast, Watanabei, Bellus) OR Marine Betta OR Singapore Angelfish OR Red Sea Angelfish or some combination of 2 different larger fish

Let me know what you think.

I didn’t mention a pair of Shrimp Gobies and a Pistol Shrimp because of the Flame Hawks and I would hate the possibility of any bottom dwellers getting dive bombed by the Hawks. And the Hawks are more out and about than many Shrimp / Goby combos.

 

[Zionas]

@Griev How do your 4 Black Caps get along? What do you think is the male to female ratio of them?

I like the Genicanthus idea. A pair of Bellus, Watanabei or Spotbreast. Maybe Lamarck’s but I don’t know if they usually get larger or maybe a bit more aggressive.

 

[Griev]

@Griev How do your 4 Black Caps get along? What do you think is the male to female ratio of them?

I like the Genicanthus idea. A pair of Bellus, Watanabei or Spotbreast. Maybe Lamarck’s but I don’t know if they usually get larger or maybe a bit more aggressive.

They're very social. I think I have two males and two females, it's pretty hard to tell. The females tend to hang out with the biggest male on one side and the other male is typically by himself on the other side. They'll sometimes visit each others sides to spit sand from far above or to open their mouths at each other, but never fight. Probably because there's a clear size difference.

I've got 4 Watanabe and 3 spot breasts in my 200. I love the Watanabe, but they get what can only be described as zoomies and love to race around the tank to show off, they'd probably fell cramped. The Spot Breasts are much calmer by comparison, stay a little smaller too. No experience with Lamarck (because I've read they're more likely to eat zoa's/lps) or Bellus.

 

[Zionas]

@Griev The Black Caps sound hilarious. It looks like you have a male that took both females and the other male just kinda hangs there. How long have you had them for?

Are the Genicanthus angels your only larger fish? 7 sounds like quite a group. I guess there’s only 1 male and the remaining 6 are females? I wonder if you had any trouble with disease, swim bladder issues or getting them to eat everything.

I like your suggestion of a pair of Swallowtail Angels for OP’s setup.

 

[Griev]

I've had the Black caps together about a year and a half so far. I've actually been thinking about adding a few more.

The biggest fish in my tank is a huge Foxface. He's super chill and an excellent dither fish. Then I've got a small tang gang (2x purple, 1x Achilles), then the 7 Angels.

They're definitely sensitive fish and I've lost a few during QT to viral issues and infections likely due to rough handling during capture. It's worth paying extra for these fish to be either conditioned or fully QTed from the vendor.

I've actually got two male Watanabes, and the rest are all female. My build thread has more details, but my situation is unique and I don't think I've ever seen another 'sub-male' Watanabe in captivity.

 

[Silly clownfish]

More good ideas, just when I thought I had it all planned out . I have a not very local LFS ordering in a couple of small flame hawks for the next pair. Depending when they come in, with my quarantine protocol, it will likely be the end of the year before I go for a third pair (some basslet), then a couple of blennies. I’ll probably change my mind a dozen more times.

Yes, I am currently planning on just 4 pairs of smaller fish. I could be convinced to add one bigger fish, would probably look at a single one spot foxface. I think a pair of genicanthus would be too big in a 75g

Other option for a bigger fish pair - I have thought of moving my spotcintus clown from my other tank and getting her a new mate (I believe her previous mate jumped), but am concerned a pair of them would be too aggressive in a community 75. She regularly tells me to get my hand out of her tank.

And no pistol shrimp - the tank is in the living room and I don’t want to hear the clicking.

 

[Zionas]

@Silly clownfish I like the idea of a OSFF as a larger fish over the Clarkiis. So basically:

(2) Cherub Angels
(2) Basslets
(2) Flame Hawks
(2) Blennies of some kind
(1) One Spot Foxface

Do you have many corals? Just curious.

 

[Silly clownfish]

Yep, that is my current plan.

Not a lot of corals, and nothing delicate some umbrella leathers (tan and line green), hairy green mushrooms, frogspawn euphyllia, Orange Eye Leptastrea, some miscellaneous mushrooms, and some anthelia. My previous OSFF only ever bothered zoas - I think mainly to get algae off the rock. I’m not a zoa fan, so not an issue.

Thanks for all of the great advice!

 

[Zionas]

@Silly clownfish Sounds like a good plan to me. As for the Blennies, which genus would you be most interested in? You mentioned the Lawnmowers so I assume Salarias, and maybe Ecsenius.

Maybe a pair of Starry Blennies? More colorful than the Lawnmowers but the Lawnmowers are being captive bred. Same personality if that’s what you’re in for.

Are you locked on the Royal Grammas or a Gramma species for a pair of Basslets? The easiest route would be a captive bred pair of Royal Grammas, or if you’re willing to spend more, a captive bred pair of Black Caps. I believe Biota is also doing the Brazilian Grammas.

 

[Silly clownfish]

I’m not locked on either the blennie type or basslet type.

For blennies, it seems some varieties are easier to pair than others. So I am leaning toward tailspot (escenius) or bicolor.I’m not sure if tailspot would be easier just because it is smaller and they can go live at opposite ends of the tank if they don’t pair up.

For basslet, I am thinking CB Royal grammas.

 

[Zionas]

@Silly clownfish That sounds like a decent way to go. CB Royal Grammas and a pair of (likely) Ecsenius blennies. The Tailspots are pretty small to begin with, so I’m not sure if you get one 1.5 inches or so how old the fish is. Maybe see what Biota has on offer too.

 

[Largeangels]

A little over 3 weeks. Left is the dominant one. Been getting along really well so far. Will be keeping a
very close eye on them.

 

[Zionas]

Hi, any updates? Hope all’s going well. @Silly clownfish

 

[Doctorgori]

FWIW
I have/had groups of Carribean blue darts (4)
Chalk bass (3) Royal grammas (4) masked gobies(3-4) Seahorses (4) …

Assorted species of Carribean “red” cardinals; which actually would kill each other but (sort of) managed by mixing species… it worked for a few years until it didn't

 

[Zionas]

@Doctorgori Hi there. How long did your Chalk Bass and Royal Grammas live / how old are they now if you have them?

I wonder which species those red Cardinals were. Since there’s no way for the average person to sex them, I believe you might have had more than 1 male or several males. Not sure. I do know the Apogon Maculatus (Flame Cardinal) gets fairly large for a Cardinal. I think the problem is that many people have Cardinals as a schooling fish, when they actually prefer pairs as adults.