[canlax]

Hi All,

I currently have 2 L. Caeruleus both fairly large (5" and thick). The tank is understocked so that may explain it but the larger of the two has been exhibiting some very aggressive and dominating behaviours. Seeing as they are generally regarded to have a calmer temperament I am wondering if it is a possibility I have a hybrid. Reasons being:

1) Two egg spots on the aggressor's anal fin
2) Rather than a bright 'electric' yellow he has a dirtier look (is this a sign of age?)
3) Territorial/aggressive behaviour

I would appreciate some input on this, and maybe some general observations of how to distinguish a yellow lab hybrid vs. the real thing. In my research I have found that a lot of people unawarely purchase hybrids because they do not know the difference.

I have tried to give some good caves and split the tank into 'sections' for lines of sight. I am planning on adding another 6 juvenile L. Caeruleus to the tank however am a little hesitant at the moment given the above. Do you think this would help or worsen my situation? Are there advantages/disadvantages to adding juveniles rather than mature tank mates with respect to aggression?

Current stock:
2 L. Caeruleus, unknown sex
1 Aulonocara Rubescens, male
1 Dragonblood Peacock, male
8 Juvenile C. Moorii, unknown sex

No other issues with the above set up at the moment anyways. Tank is 55 gallon. Once I add the 6 L. Caeruleus I will consider my tank fully stocked. Just so this thread doesn't go off course I am aware of size potential for C. Moorii but given their slow rate of growth it isn't a major concern of mine at the moment. Once I finish the basement I will get a big home for them!

 

[GTZ]

Their behavior is likely due to there being only 2 in the tank.
Egg spots vary and have no bearing (as far as I know) on whether the fish is a hybrid or not.
Arguably, the most common hybrid labs are crossed with red zebras, these are often missing the black dorsal, pelvic and anal fin stripes.
The larger labs dirtier look is likely part of his or her dominance in the tank.

 

[pack-rat]

I'm still a novice, but I have added juvies (1 to 1.5 inches) to my tank of young adults (2.5 to 3.5 inches) without issues. My tank is heavily stocked now and everybody chases everybody else now and then, but nobody gets hurt, so I think I am ok. I have 4 species in a 75G tank.

My yellow labs range in quality (judging by the black markings) and it seems to me that the likely hybrids are more aggressive. I have I think 3 males in a group of 6 fish, which also complicates things. I am making plans now to remove the 2 males with poor markings.

Since your labs are both large, and you didn't mention anything about spawning, I would suppose you have two males. You could try to confirm this through venting. Anyway, you could remove one of these fish, although it might not be necessary if you can add several females and give enough rock cover. My multiple males spar and chase, but there are no injuries, and I've had several successful spawns.

 

[canlax]

Since your labs are both large, and you didn't mention anything about spawning, I would suppose you have two males. You could try to confirm this through venting.

You make a good point. I haven't had the pair long enough to confirm if they have spawned as I inherited the tank from someone leaving the hobby and he didn't provide this information. I have never vented a fish before so am a little unsure about grabbing the fish, any tips? I have a friend who is experienced with cichlids I may need to have him come over for a crash course on venting.

With that said I probably will take my chances in adding additional labs to hopefully distribute aggression.

 

[pack-rat]

As I said, I'm still a novice myself. I have tried to vent my fish once or twice but couldn't see the male/female difference. That was a few months ago and maybe it would be easier now that they are bigger, but I think I have pegged the sexually mature males through behavior (of course watching them spawn is a dead giveaway!).

In my opinion, adding additional labs is not a bad idea. If you also want to establish the sex of your current fish you should read the article on venting. Supposedly it is not that difficult once you get the hang of it.

http://www.cichlid-forum.com/articles/gender.php

Good luck!