Dicrossus maculatus ID confirmation & sexing help

[slimbolen99]

Kinda new at this Dicrossus sp thing, but I am absolutely in love with these little buggers.

I got five, what I believe to be Dicrossus maculatus, from a fish club friend. He thinks he got them from an online vendor listed as wild Dicrossus. I believe them to be maculatus. No other information is available as to their origins, other than they cost him a lot of money, and didn't cost me much at all.

I'd like to get a positive ID on them. I have what I believe to be four females and one male, although one of the "females" may be a sleeper male. They are setup alone in a 75 gallon (48" x 18" footprint), planted tank with driftwood and coconut caves with a larger sand substrate. pH right now is at 6.0. Haven't tested gH or kH yet, but they are probably a little high right now.

Here are a few shots.

Female?

Male?

Sleeper Male?

Thanks everyone!

 

[slimbolen99]

Here is a shot of the tank they are in. I have four coconut shell "huts" if you will with a single 1" diameter hole in them.

 

[briztoon]

Hey slimbolen99. I'm no expert mate, but they look like maculatus to me. In regards to the coconut shells, it's my understanding that maculatus spawn aren't cave spawners, but spawn above the substrate on submerged plant leaves.

 

[slimbolen99]

Thanks Briztoon. I hope we are right...because the fillamentosas are cheaper to get than the maculatus right now.

I guess the next question is, and Mike Wise is going to kill me, do I want to add dithers and make this a true community or should I leave well enough alone and see what happens? My original plan was to add (12)Corydoras loxozonus, and (16) Hyphessobrycon sp. "White Fin" 511 to the tank, trying to keep with the "Columbia Whitewater" theme, but I suppose if I want some fry to survive, that may not be a good idea. It would be nice to have some action in the tank 6" above the substrata...kinda boring up there.

 

[slimbolen99]

Mod, if you could move this to the South America area, that would be great. I don't know why I put it in West Africa.
Thanks!
Bb

 

[wethumbs]

You definitely has at least one male. The 'sleeper male' does look like a male as well. Ventral fins are much longer for the male as compare to the female. One male will dominate the entire tank and mate with all the available females.

Here is a my male

female with fry

Also check out this video on D. maculatus in their natural habitat of Rio Tapajos
http://en.aquanet.tv/

 

[Mike Wise]

Your species ID and sexing are spot on. The females will develop red ventral, which makes them easy to sex. Add whatever fish to the tank you want. I'm not against mixing fish in a community situation, if that is what you want. Breeding will occur. You'll just not get many offspring that way. Briztoon is correct D. maculatus is a secretive spawner, that breed in hidden areas. In this case, they are similar to Nannacara. They don't need caves, but happily use them when available. Otherwise, they uses broadleaf plants and crevasses in wood, etc. Add some small leaves to your tank. This species loves to turn over leaves and check the underside for food.

 

[slimbolen99]

Thanks a lot guys. I would like to keep some fry, but suspect I will be able to steal them if any tetras keep their greedy little mouths away. Good info there on the habitat too. Helps a ton.

 

[gerald]

Note that Wethumb's female has YELLOW pelvic fins, as do the ones in the Rio Tapajos video he linked. I had a pair like his (via Ken Davis), from Santarem near the Tapajos/Amazon confluenece. I'm guessing that Slim's macs (female w/ red pelvics) may be from somewhere else. Since the overall reported range of "maculatus" extends from about 500 miles upstream of Manaus to ~ 600 mi downstream (Ilha de Marajo) there could be multiple species lumped under that name. [Santarem is about 400 mi downstream of Manaus].

 

[slimbolen99]

Gerald, from what I've read, which is very little thus far, but what I've read thus far is that the female's pelvic fins don't turn yellow until the presence of eggs/fry? Obviously, I have no first hand experience, but when/if they do spawn, it will be interesting if the fins do change colors...of course, your idea is as good as anything I've seen. Certainly a possibility.

 

[Apistomaster]

I have only had the type of D. maculatus where the female's fins turned yellow during spawning so at first the red fins threw me until I saw the males. I bought mine from Zach Wilson several years ago.

 

[gerald]

On the Santarem female I had, her pelvics were clear silvery-tan until they turned yellow at spawning. Her anal fin was red-orange before and after spawning (like those in the Tapajos video), but she never showed any red-orange in the pelvics.

Here's a pic of them in a previous thread. She spawned on rocks that I placed on top of a sponge filter inside a plastic container.
http://www.apistogramma.com/forum/s...s-Talk-Dicrossus&p=60999&viewfull=1#post60999

 

[wethumbs]

pelvics were clear silvery-tan until they turned yellow at spawning

Gerald is correct on the pelvics. I picked my female from a dozen or so that ranged from clear to yellow. Yellow pelvics is a characteristic of a mature female. My female pelvics do not turn back to clear silver-tan between spawns. The red pelvics would indicate a different locality. Even the males from the slimbolen's pictures look different in coloration, however, that could be the stronger lighting at his setup as compare to mine.

As for cave spawning for maculatus, my observation is such that they would completely avoid entering a single opening enclosure. I had only seen them peeped into caves from the entrance. Female prefers open area that is hidden, like an open ended PVC. Male has an unique foraging technique in which he uses his pectoral fins and movement from his body to stir up debris in the fine gravels, thus creating a circular 'crater' in the substrate the size of his body. Female does not exhibit such behavior.

Gerald, btw we should trade our F1s in the future.

 

[briztoon]

I think I read over at the Cichlid Room Companion that there are two species of Dicrossus found in the Rio Tapajos; D. maculatus & D. sp. "Tapajos". Yup, I just checked my copy of Cichlid Atlas 1. D. sp. "Tapajos" occurs upstream from the rapids near Sao Luis de Tapajos, while D. maculatus is found in the lower part of the Rio Tapajos around Santarem.

It would be good to see photos of the two species side by side in some ones tank just for comparisons sake.

 

[gerald]

Funny you should ask ... Zack Wilson has the photo you requested. That's Dicrossus sp. "Tapajos" in the back, with three narrow rows of spots rather than two wide rows.

http://www.thedigitalfishroom.com/Photos/maculatusM-10.html

I think the Tapajos maculatus males also have more yellow in the cheeks and a different tail pattern than the "other" macs (the ones with red pelvic females). Does anybody know where the non-Tapajos macs in the trade are collected from?

 

[Mike Wise]

Since the overall reported range of "maculatus" extends from about 500 miles upstream of Manaus to ~ 600 mi downstream (Ilha de Marajo) there could be multiple species lumped under that name. [Santarem is about 400 mi downstream of Manaus].

"Reported range", true, but actual range, false. Reliable reports on the occurrence of D. maculatus indicate a range between the lower Rio Tapajós (near Santarém) and the lower Rio Madeira (near Parantin & Maués). Reports from areas of the Amazon below the Tapajós are from 1865 and are unreliable. Often expeditions placed fish from several collecting localities in the same specimen jars, mixing locations. No reliable reports of the occurrence of Dicrossus exists above the Rio Negro, where both D. foirni and D. filamentosus occur. D. foirni is very similar in appearance to D. maculatus, which may explain the problem.

 

[gerald]

Thanks for clarifying Mike. Based on your info, D. mac's range is really only about 300 - 400 miles along the Amazon from the Rio Madeira confluence downstream to Rio Tapajos confluence. So Agassiz's 1865 reports of D.mac from Rio Solimoes near Tonantins (several hundred miles west of the Madeira/Amazon conflu) and from Ilha de Marajo (hundreds of miles east of Santarem) were due to bad jar labelling?

Also I wasn't aware of that recent paper describing D.foirni (Rio Negro) and D. warzeli (upper Rio Tapajos) until you mentioned the foirni name and I googled it. Here's the link to that paper (no subscription required!):

http://www.uni-muenster.de/imperia/...cr_of_2_dicrossus_-_vert_zool_60__123-138.pdf

... And Kullander's 2011 paper comparing all the Dicrossus species :
http://www.aqua-aquapress.com/pdf/17-2_Dicrossus-foirni.pdf

 

[wethumbs]

It was pointed out that the female from Slimbolen99's post has red pelvic fins. Come to think of it, all filamentosus females have red pelvic fins too.

 

[Mike Wise]

All female D. filamentosus who have matured and become ready to breed have red ventral fins; younger females who haven't come into breeding condition have transparent ventrals.