I.D: A. gibbiceps vs. A. roraime

[FishSoup]

Hey there guys, was wondering about A. gibbiceps and A. roraime: are they separate species, or simply different colour forms of A. gibbiceps?

I was observing my pair of wild-caught A. gibbiceps "Santa Izabel", when i realised that the female has the vertical markings on her caudal fin which i read online separate A. roraime from A. gibbiceps. Some other websites however state that A.roraime is simply just a variant of A. gibbiceps.

Both the fish show the barring on the chest and belly that serve as the diagnostic feature of A. gibbiceps

Anyone here can enlighten me?

 

[Mike Wise]

Whether or not A. gibbiceps & A. roraimae are different species depends on who you ask. Römer and Staeck consider them as 1 species. Kullander and Koslowski believe that they are different species. Whichever they are, they are closely related.

A. gibbiceps was poorly described by Meinken in 1969. He based the name (gibbiceps = gibbous head) on a poorly preserved male, whose head was unnaturally swollen. His type series also included a specimen of A. paucisquamis.

Two forms of A. gibbiceps are found near the main channel of the Rio Negro. In one, the male's caudal fin has stripes that parallel the bony rays in the caudal fin. In the other form, from the lower Rio Branco, the caudal fin shows cross bands in the caudal fin.

A. roraimae was described by Kullander in 1980 from some females and juveniles from the upper Rio Branco near Boa Vista. At the time, there was suspicion that the type material might be a population of A. gibbiceps. Staeck collected some males near Boa Vista that he concluded were A. gibbicep. Stawikowski also collected some specimens upstream of Boa Vista, in the Guyana part of the Rio Branco headwaters. These fish show obvious differences to A. gibbiceps:

Dorsal fin: A. gibbiceps males have high anterior dorsal spines and moderately extended dorsal fin lappets. A. roraimae males have much lower anterior dorsal spines and a serrated dorsal fin with barely extended lappets.

Lateral band: A. gibbiceps has a lateral band that extends into the base of the caudal fin. A. roraimae has a lateral band that ends before the base of the caudal fin. It is separated from an irregular dark blotch on the base of the caudal fin by a small light colored area.

Diagonal bars: The diagonal bars below the lateral band on A. gibbiceps are broad and occur where the vertical bars would appear on most apistos. These bars often split into 2 diagonal stripes, but there is always a wider interstitial area between groups of stripes that are equivalent to where the interstitial area between vertical bars occur. On A. roraimae, there are no diagonal bars, only diagonal stripes. These stripes occur not only where the vertical bars normally occur, but also in the area between the bars. Koslowski (2002) wrote (trans.), "I am not certain if these differences are enough to call them different species, but in other species-groups it is sufficient to separate different forms."

 

[FishSoup]

I see... using the other diagnostic traits, i think the female is indeed A. gibbiceps :biggrin: i was wondering why they alone of my 4 apisto pairs have not bred, and was worried they were different species. Thanks Mike

 

[Mike Wise]

A. gibbiceps has always had a reputation for being a problematic breeder. Some breeders find it moderately simple; others impossible. I sometimes wonder if it depends on where (type of water) the fish come from.

 

[FishSoup]

Just a week after i posted this question, the female gibbiceps spawned! :biggrin:

Maybe if i post more questions about all my apisto pairs here they'll all start spawning too?!! haha