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- Thread starter cambo01
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So what "difference in head shape" are you referring to? Because based on my reference I'd say your first pic was retros and your second was a palmas polli. However, that's just based on what I can see in the pics provided. But here's what stood out to me from fishbase:
retropinnis:
"Dorsal surface of the body is gray or brown colored, well separated from the ventral surface, which is yellowish (Ref. 46852). Reticulated pattern on dorsal side with olive-colored spots (Ref. 41580); also lower jaw with black spots, which separates it from Polypterus palmas (Ref. 44841, 46861). The pectoral fin, yellow at its base, with a black spot on the distal side (Ref. 41580, 51884, 56367). Other fins have brown spots (Ref. 41580)." - So I'd check for a black spot on the distal (back) side of the pectoral fins. Maybe that will make it easier to tell.
palmas polli:
"Dorsal surface and flanks with large black blotches, forming a dense reticulate pattern, ventral surface uniform pale (Ref. 28149). The fleshy base of the pectoral fin with a large grey to black spot (Ref. 28149, Ref. 46409). Dorsal fin spotted, pectoral fin with a striped pattern in some specimens, pelvic fin pale and anal fin sometimes slightly colored (Ref. 28149)."
So based on the pale ventral surface, grey spot on the proximal side of the pectoral fin, and stripes on the pectoral fin, I'd say your second pic was a palmas polli. Whereas your first pic shows 2 fish with yellow bellies, black spots on the lower jaw, and yellow pectoral fin bases indicating retropinnis. I pay little attention to how dark the pattern on the back is though, since it tends to vary with genetics, health, and tank conditions. But again, I am curious what you're specifically looking for in the "head shape". You might be able to teach me something! I don't quite have as many upper-jaw bichirs as you do, but I do currently have 4 species of upper jaws and I have had 2 more in the past. So I'm not exactly out of my element here.
retropinnis:
"Dorsal surface of the body is gray or brown colored, well separated from the ventral surface, which is yellowish (Ref. 46852). Reticulated pattern on dorsal side with olive-colored spots (Ref. 41580); also lower jaw with black spots, which separates it from Polypterus palmas (Ref. 44841, 46861). The pectoral fin, yellow at its base, with a black spot on the distal side (Ref. 41580, 51884, 56367). Other fins have brown spots (Ref. 41580)." - So I'd check for a black spot on the distal (back) side of the pectoral fins. Maybe that will make it easier to tell.
palmas polli:
"Dorsal surface and flanks with large black blotches, forming a dense reticulate pattern, ventral surface uniform pale (Ref. 28149). The fleshy base of the pectoral fin with a large grey to black spot (Ref. 28149, Ref. 46409). Dorsal fin spotted, pectoral fin with a striped pattern in some specimens, pelvic fin pale and anal fin sometimes slightly colored (Ref. 28149)."
So based on the pale ventral surface, grey spot on the proximal side of the pectoral fin, and stripes on the pectoral fin, I'd say your second pic was a palmas polli. Whereas your first pic shows 2 fish with yellow bellies, black spots on the lower jaw, and yellow pectoral fin bases indicating retropinnis. I pay little attention to how dark the pattern on the back is though, since it tends to vary with genetics, health, and tank conditions. But again, I am curious what you're specifically looking for in the "head shape". You might be able to teach me something! I don't quite have as many upper-jaw bichirs as you do, but I do currently have 4 species of upper jaws and I have had 2 more in the past. So I'm not exactly out of my element here.
I dont think fishbase is 100% accurate all the time. What I heard they base their studies on only the specimens they caught, and I dont think they have that many retros since they are so rare.
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Uh...they don't do that. They pull the information from other sources. Primarily books. I actually left those references in the quotes I posted. On the site they're links that bring you to the exact source.
example:
Hanssens, M.M., G.G. Teugels and D.F.E. Thys Van den Audenaerde, 1995. Subspecies in the Polypterus palmas complex (Brachiopterygii; Polypteridae) from West and Central Africa. Copeia 1995(3):694-705.
example:
Hanssens, M.M., G.G. Teugels and D.F.E. Thys Van den Audenaerde, 1995. Subspecies in the Polypterus palmas complex (Brachiopterygii; Polypteridae) from West and Central Africa. Copeia 1995(3):694-705.
Have fun with your new bichir man!C'mon M4ttSyke, you're not even going to tell me how you came to that conclusion? Just "it's face looks like a retro"?
Head shape:
For retropinnis, the headshape is more like a weeksii and the body is very slender and elongated.
Palmas polli, the head shape is similar to a senegal bichir and their bodies become very thick.
Also, for retropinnis, a KEY factor is their olive green whereas palmas polli give off either a lime green or a dark green pattern.
if you actually look at the pectoral fin bases in my 1st pic showing my two fishes, you can see that the base is actually black and green. Also another key factor for palmas polli is their "large black blotches" which is easily distinctable in my 1st pic. The darkness of the pattern is KEY to identify a bichir. Substrate can affect it, sure. But for palmas polli. Once it settles in, it becomes the color that I have now.
here's a comparison of stressed and not stressed:
Stressed palmas polli:
Not Stressed:
If you also look at the pictures, Palmas polli has 4-6 sharp Dorsal fins whereas Retropinnis has 6-7 rounded dorsal fins.
Well I don't think I can offer too much more than I have, so I'm gonna let it go and default to you guys. I'll just have to be a quiet skeptic. polypterus.info states that their head doesn't resemble a weeksii, but I found the thread from last year where you were asking the same question on this forum and the people here told you what you told me. It's just odd that all of the literature I've come across would lead to another identification, or just make it more ambiguous. Also, I found a taxonomic key from the museum of natural history, but all of the pics posted in this thread have properties of both species. If only they gave more info....
However I have seen a number of accounts stating that the retros tend to be more slender. I'll have to snap a pic of my fish sometime so we can dispute its species. When I first purchased it, it looked very much like your retro (thin, green), and was way more pale and green than your stressed polli pic, but now it's definitely thickened (as have all of my bichirs) and is darker. However it went from a transparent tank at the wholesaler to my black gravel so I guess I've seen it at both extremes.
However I have seen a number of accounts stating that the retros tend to be more slender. I'll have to snap a pic of my fish sometime so we can dispute its species. When I first purchased it, it looked very much like your retro (thin, green), and was way more pale and green than your stressed polli pic, but now it's definitely thickened (as have all of my bichirs) and is darker. However it went from a transparent tank at the wholesaler to my black gravel so I guess I've seen it at both extremes.
again, when it comes to those websites, those are very inaccurate because when it comes to polypterus. there is not much information given.
Retropinnis doesn't get darker than mine is. Retros are known to be "zaire green" and olive green, mixed in with a bit of yellow. The only upper jaws that can be established as "black" is ornatipinnis and palmas polli. Palmas Palmas and palmas buettikoferi do have some black in it but yellow and gold dominate the fish respectively. Mokelembembe does have some black as well but its more of a very very dark purple. If you need me to take pics of all of my bichirs and show them to you to give off a strong, quick distinction of each fish, that's fine with me.
