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EDIT: I've added an updated key to the genus Farlowella HERE.

Hi All,

My LFS got a group of about eight Farlowella twig cats. Some are big, maybe 6"+ TL, and others are small, 4"TL. They may be a mix of species, as a couple have shorter snouts than others. Also one of the smaller fish is much more pale in color than the others. (and yet another shorter specimen has a darker color... different species, or just stress/condition?)

Only one fish was positioned with its belly against the glass and it clearly has 3 rows of ventral scutes. I know has three rows, but what else?

Also, what is ideal for temp? I see mariaelenae has a wide range. If that species, would they do okay around 84F-85F with some ?

Thanks, Eric

Here are more photos of the fish with three rows of scutes. There was only one such fish at the store, so I'm not considering buying it. (But it is neat to see by-catch or mixed species groups come in)

It's weird how quickly and fully this fish changes from dark grey to tan and back again. The first time I photographed this fish it was dark tan and almost grey. Later when I caught it and photographed it in a cup it was tan. Then I released it back to the tank and I left, but I then returned to the tank a few minutes later and it was dark and grey again. I was convinced there were at least two fish with 3 rows of scutes. But after picking fish-by-fish through the whole tank... TWICE... there could be only one. I named it... (can you guess?)... Connor MacLeod.

Cheers, Eric

With a tip from @The.Dark.One and Petra Glover, I was directed to the key in Retzer & Page (1997).

• Retzer, M.E. & L.M. Page. (1997). Systematic of the Stick Catfishes, Farlowella Eigenmann & Eigenmann (Pisces, Loricariidae). Proceedings of the Academy of Natural Sciences of Philadelphia, 147: pp. 33-88. Available here: https://www.jstor.org/stable/4065027

From the key, I conclude I saw :
1. b. Median row of abdominal scutes complete (go to trait 4)
4. a. Three rows of abdominal scutes (go to trait 5)
5. a. Four rows of anterior laterial scutes, all rows complete (go to trait 6)
6. a. Snout-mouth length/head length < 0.5 (using pixels, I measured 208/457) (go to trait 7)
7. a. Outer rays of lower caudal fin lobe darkly pigmented to base (go to trait 8 )
8. a. Snout fairly long and narrow = F. mariaelenae

To be sure, I also looked up the descriptions of all new Farlowella species described since Retzer & Page's revision and key in 1997. Here is the list of the more recently described species and why the fish at my LFS can't be them:

• Farlowella altocorpus
  Retzer 2006 (PDF here)
• Farlowella yarigui
  Ballen & Mojica 2014 (PDF here)
• Farlowella gianetii
  Ballen, Pastana & Peixoto 2016 (PDF here)
• Farlowella mitoupibo
  Ballen, Urbano-Bonilla & Zamudio 2016 (PDF here)
• Farlowella azpelicuetae
  Terán, Ballen, Alonso, Aguilera & Mirande 2019 (PDF here)

Farlowella altocorpus, F. azpelicuetae, and F. gianetii also have three ventral rows, but they also all have 5 anterior rows on body, so mine's not them. F. mitoupibo has 3 ventral rows and 4 lateral rows, and is also an Orinoco fish. But that species has an incomplete middle row of ventral plates, so mine's not that. F. yarigui has only two abdominal plate rows, so mine's not that either. I say "mine" but I didn't buy it as they had only one. I have another outlet for the same LFS near my house (20 miles away). I'll take a drive down there and see if they have any in stock.

EDIT: In the next post of this thread (HERE), I've added an updated key which includes all the new Farlowella species described between 1997 and 2019. Those revisions to the key are added in an orange-red color.

Retzer & Page (1997) original KEY TO THE SPECIES OF FARLOWELLA

• 1a. Median row of abdominal scutes incomplete; 2-5 anterior scutes present (Fig. 6b) .......2
  
  • 1b. Median row of abdominal scutes absent (Fig. 6a) or complete (Fig. 6c); 0 – 1 anterior median scutes present .........4
• 2a. Breeding odontodes on side of head long, second row (Fig. 6d) of anterior lateral scutes thickened and forming a smoothly keeled ridge .....9
  
  • 2b. Breeding odontodes on side of head short, second row (Fig. 6d) of anterior lateral scutes flat and smoothly keeled ridge absent ......3
• 3a. Snout-mouth length/pectoral fin length > 1.0 (Fig. 2) .....
  Farlowella platorynchus
  
  
  • 3b. Snout-mouth length/pectoral fin length <0.6 (Fig. 2) ....
    Farlowella colombiensis
• 4a. Three rows of abdominal scutes (Fig. 6c) .....5
  
  • 4b. Two rows of abdominal scutes (Fig. 6a) ....19
• 5a. Four rows of anterior lateral scutes (Fig. 2c), all rows complete (Fig. 6d) ............6
  
  • 5b. Five rows of anterior lateral scutes, middle row may be complete or incomplete (Fig. 6e, f) ....14
• 6a. Snout-mouth length/head length < 0.5 (Fig. 2) .........7
  
  • 6b. Snout-mouth length/head length >= 0.5 (Fig. 2) .....12
• 7a. Outer rays (except outermost ray) of lower caudal fin lobe darkly pigmented to base (Fig. 4, character state 1); breeding male with head and snout almost totally covered with breeding odontodes ......8
  
  • 7b. Outer rays (except outermost ray) of lower caudal fin lobe pigmented only at distal end (Fig. 4, character state 2); breeding male with head and snout not almost totally covered with breeding odontodes ......10
• 8a. Male with small breeding odontodes on head and snout; snout fairly long and narrow .....
  Farlowella mariaelenae
  
  
  • 8b. Male with long breeding odontodes on side of head; snout short and broad .......9
• 9a. In adult male, with body depth less than snout-mouth length (Fig. 2) .......
  Farlowella taphorni
  
  
  • 9b. In adult male, body depth greater than snout-mouth length (Fig. 2) .......
    Farlowella curtirostra
• 10a. Scutes of head and snout lack very dark reticulations ........
  Farlowella paraguayensis
  
  
  • 10b. Scutes of head and snout with very dark reticulations .....11
• 11a. Caudal fin with distinct clear ocellus bar in dark stripes ......
  Farlowella knerii
  
  
  • 11b. Caudal fin lacks distinct clear ocellus bar in dark stripes ......
    Farlowella schreitmuelleri
• 12a. Head and snout of breeding male densely covered with breeding odontodes; males mature at small size (<100 mm); lower body of cleithrum narrow (Fig. 5, character state 0); snout narrow ......
  Farlowella smithi
  
  
  • 12b. Head and snout of breeding male sparsely covered with breeding odontodes; males mature at large size (>125 mm); lower body of cleithrum broad (Fig. 5, character state 2); snout broad .........13
• 13a. Anterior body scutes diamond in shape (Fig. 7, character state 0); caudal peduncle narrow, last few dorsal scutes longer than wide; no breeding odontodes on preorbital ridge (Fig. 3b) ......
  Farlowella reticulata
  
  
  • 13b. Anterior body scutes hexagonal in shape (Fig. 7, character state 1); caudal peduncle broad, last few dorsal scutes wider than long; breeding odontodes on preorbital ridge (Fig. 3b)......
    Farlowella oxyrryncha
    or
    Farlowella hahni
    (see description of F. oxyrryncha)
• 14a. Snout-mouth length/head length <0.5 (Fig. 2)......
  Farlowella jauruensis
  
  
  • 14b. Snout-mouth length/bead length >= 0.5 (Fig. 2) ......15
• 15a. Body depth/pelvic fin length >= 0.86 (Fig. 2) .........
  Farlowella hasemani
  
  
  • 15b. Body depth/pelvic fin length <0.86 (Fig. 2) .............16
• 16a. Pectoral fin length/snout-mouth length <0.62 (Fig. 2) ......
  Farlowella gracilis
  
  
  • 16b. Pectoral fin length/snout-mouth length >0.65 (Fig. 2) ...........17
• 17a. Breeding odontodes not greatly enlarged on lateral scutes; on some individuals first anal and dorsal rays entirely darkly pigmented, other dorsal and anal rays not entirely pigmented ......
  Farlowella nattereri
  
  
  • 17b. Large breeding odontodes on lateral scutes; first anal and dorsal rays never more darkly pigmented than other dorsal and anal rays ......18
• 18a. Snout-mouth length/pectoral fin length <= 1.0 (Fig. 2); pectoral and pelvic fin rays and spines with distinct spots .......
  Farlowella isbruckeri
  
  
  • 18b. Snout-mouth length/pectoral fin length > 1.25 (Fig. 2); pectoral and pelvic fin rays and spines uniformly pigmented, without distinct dark spots ...........
    Farlowella odontotumulus
• 19a. Median abdominal scute at base of pelvic fins (Fig. 6b) ......20
  
  • 19b. No median abdominal scute at base of pelvic fins (Fig. 6a) ......23
• 20a. In adult, lower body of cleithrum narrow, may be in two parts (Fig. 5, character state 1); preorbital ridge and eye elevated over head ......
  Farlowella rugosa
  
  
  • 20b. In adult, lower body of cleithrum broad or very broad (Fig. 5, character states 2, 3); only eye elevated over head (Fig. 3) .......21
• 21a. Body of cleithrum very broad (Fig. 5. character state 3) ......
  Farlowella henriquei
  
  
  • 21b. Body of cleithrum broad (Fig. 5, character state 2) .....22
• 22a. In adult, snout-mouth length < 3.0 times interorbital width (Fig. 2); 2-3 median abdominal scutes at anterior of abdomen (Fig. 6b) ......
  Farlowella platorynchus
  
  
  • 22b. In adult, snout-mouth length > 3.3 times interorbital width; usually 1 median abdominal scute at anterior of the abdomen .........
    Farlowella amazona
• 23a. Snout-mouth length/interorbital width (Fig. 2) <= 1.8 in adult male; outer rays (except outermost ray) of lower caudal fin lobe usually not entirely darkly pigmented from fin base to tip .......24
  • 23b. Snout-mouth length/interorbital width (Fig. 2) > 1.9 in adult male; outer rays (except outermost ray) of lower caudal fin lobe darkly pigmented from fin base to tip but may be interrupted by clear ocellus bar ...
    Farlowella vittata
• 24a. Pectoral fin does not reach pelvic fin origin; mid-dorsal ridge of head absent in adults ......
  Farlowella acus
  • 24b. Pectoral fin almost reaches or extends past pelvic fin origin; mid-dorsal ridge present in adults ...............25
• 25a. Head covered by medium-sized breeding odontodes ....
  Farlowella venezuelensis
  • 25b. Head not covered by medium-sized breeding odontodes. Small breeding odontodes on preorbital ridge (Fig. 3) only or absent ...26
• 26a. Interradial membranes of caudal fin clear; many small breeding odontodes on preorbital ridge (Fig. 3) .....
  Farlowella martini
  • 26b. Interradial membranes of caudal fin darkly pigmented, few, if any, very small breeding odontodes on preorbital ridge (Fig. 3) .......
    Farlowella colombiensis

MODERATOR NOTE: The following key was originally created in May 2020. It was subsequently updated in April 2023 to include the new species, Farlowella wuyjugu. Rather than disturb the entire key with all it's steps, I simply added a step "0" (which is not a normal thing to do) in order to keep as much of the old key as possible.



Okay I tried a thing... This is Obsessive-Compulsive Disorder having its way with me and my time. I read through the articles on the five Farlowella species described since Retzer & Page (1997), and I've integrated them into the Retzer and Page (1997) key. I believe it works. The portions I've added or modified are shaded a reddish-orange color and the new species are highlighted in the table below.
Retzer & Page (1997) KEY TO THE SPECIES OF FARLOWELLA, revised to accommodate the Farlowella species described between 1998 and 2019: (For a summary on the newer species, see the post linked here: https://www.planetcatfish.com/forum/vie ... 90#p322690)

• 0a. Gular plates absent (Dopazo et al., Fig 3); five rows of anterior lateral scutes (Fig. 6f) .....
  Farlowella wuyjugu
  • 0b. Gular plates present; four or five rows of anterior lateral scutes (Fig. 6d-f) .........1
• 1a. Median row of abdominal scutes incomplete; 2-5 anterior scutes present (Fig. 6b) .......2
  • 1b. Median row of abdominal scutes absent (Fig. 6a) or complete (Fig. 6c); 0 – 1 anterior median scutes present .........5
• 2a. Breeding odontodes on side of head short, second row (Fig. 6d) of anterior lateral scutes flat and smoothly keeled ridge absent ......3
  • 2b. Breeding odontodes on side of head long, second row (Fig. 6d) of anterior lateral scutes thickened and forming a smoothly keeled ridge .....10
• 3a. Snout-mouth length/pectoral fin length <0.6 (Fig. 2) ....
  Farlowella colombiensis
  • 3b. Snout-mouth length/pectoral fin length > 1.0 (Fig. 2) .....4
• 4a. Snout-mouth length/head length <=0.5, snout narrow, eyes not elevated on head (Fig. 2) .....
  Farlowella mitoupibo
  • 4b. Snout-mouth length/head length >0.5, snout wide, eyes elevated on head (Fig. 2) .....
    Farlowella platorynchus
• 5a. Three rows of abdominal scutes (Fig. 6c) .....6
  • 5b. Two rows of abdominal scutes (Fig. 6a) ....23
• 6a. Four rows of anterior lateral scutes (Fig. 2c), all rows complete (Fig. 6d) ............ 7
  • 6b. Five rows of anterior lateral scutes, middle row may be complete or incomplete (Fig. 6e, f) ....15
• 7a. Snout-mouth length/head length < 0.5 (Fig. 2) .........8
  • 7b. Snout-mouth length/head length >= 0.5 (Fig. 2) .....13
• 8a. Outer rays (except outermost ray) of lower caudal fin lobe darkly pigmented to base (Fig. 4, character state 1); breeding male with head and snout almost totally covered with breeding odontodes ......9
  • 8b. Outer rays (except outermost ray) of lower caudal fin lobe pigmented only at distal end (Fig. 4, character state 2); breeding male with head and snout not almost totally covered with breeding odontodes ......11
• 9a. Male with small breeding odontodes on head and snout; snout fairly long and narrow .....
  Farlowella mariaelenae
  • 9b. Male with long breeding odontodes on side of head; snout short and broad .......10
• 10a. In adult male, with body depth less than snout-mouth length (Fig. 2) .......
  Farlowella taphorni
  • 10b. In adult male, body depth greater than snout-mouth length (Fig. 2) .......
    Farlowella curtirostra
• 11a. Scutes of head and snout lack very dark reticulations ........
  Farlowella paraguayensis
  • 11b. Scutes of head and snout with very dark reticulations .....12
• 12a. Caudal fin with distinct clear ocellus bar in dark stripes ......
  Farlowella knerii
  • 12b. Caudal fin lacks distinct clear ocellus bar in dark stripes ......
    Farlowella schreitmuelleri
• 13a. Head and snout of breeding male densely covered with breeding odontodes; males mature at small size (<100 mm); lower body of cleithrum narrow (Fig. 5, character state 0); snout narrow ......
  Farlowella smithi
  • 13b. Head and snout of breeding male sparsely covered with breeding odontodes; males mature at large size (>125 mm); lower body of cleithrum broad (Fig. 5, character state 2); snout broad .........14
• 14a. Anterior body scutes diamond in shape (Fig. 7, character state 0); caudal peduncle narrow, last few dorsal scutes longer than wide; no breeding odontodes on preorbital ridge (Fig. 3b) ......
  Farlowella reticulata
  • 14b. Anterior body scutes hexagonal in shape (Fig. 7, character state 1); caudal peduncle broad, last few dorsal scutes wider than long; breeding odontodes on preorbital ridge (Fig. 3b)......
    Farlowella oxyrryncha
    or
    Farlowella hahni
    (see description of H. hani for more information)
• 15a. Snout-mouth length/head length <0.5 (Fig. 2)......16
  • 15b. Snout-mouth length/head length >= 0.5 (Fig. 2) ......19
• 16.a Snout darkly pigmented dorsally .........17
  • 16.b Snout with dark pigment only laterally (Ballen et al., Fig. 2/Fig. 3) .........18
• 17.a Snout fully pigmented dorsally (Ballen et al., Fig. 2/Fig. 3) .........
  Farlowella jauruensis
  • 17.a Snout pigmentation dorsally appears marbled (Terán et al., Fig. 2) .........
    Farlowella azpelicuetae
• 18.a Body width at dorsal origin to SL 4.4-5.8%, body depth. to SL 4.5-5.4% .........
  Farlowella gianetii
  • 18.b Body width at dorsal origin to SL 6.4-8.1%, body depth. to SL 5.4-6.5% .........
    Farlowella altocorpus
• 19a. Body depth/pelvic fin length >= 0.86 (Fig. 2) .........
  Farlowella hasemani
  • 19b. Body depth/pelvic fin length <0.86 (Fig. 2) .............20
• 20a. Pectoral fin length/snout-mouth length <0.62 (Fig. 2) ......
  Farlowella gracilis
  • 20b. Pectoral fin length/snout-mouth length >0.65 (Fig. 2) ...........21
• 21a. Breeding odontodes not greatly enlarged on lateral scutes; on some individuals first anal and dorsal rays entirely darkly pigmented, other dorsal and anal rays not entirely pigmented ......
  Farlowella nattereri
  • 21b. Large breeding odontodes on lateral scutes; first anal and dorsal rays never more darkly pigmented than other dorsal and anal rays ......22
• 22a. Snout-mouth length/pectoral fin length <= 1.0 (Fig. 2); pectoral and pelvic fin rays and spines with distinct spots .......
  Farlowella isbruckeri
  • 22b. Snout-mouth length/pectoral fin length > 1.25 (Fig. 2); pectoral and pelvic fin rays and spines uniformly pigmented, without distinct dark spots ...........
    Farlowella odontotumulus
• 23a. Median abdominal scute at base of pelvic fins (Fig. 6b) ......24
  • 23b. No median abdominal scute at base of pelvic fins (Fig. 6a) ......27
• 24a. In adult, lower body of cleithrum narrow, may be in two parts (Fig. 5, character state 1); preorbital ridge and eye elevated over head ......
  Farlowella rugosa
  • 24b. In adult, lower body of cleithrum broad or very broad (Fig. 5, character states 2, 3); only eye elevated over head (Fig. 3) .......25
• 25a. Body of cleithrum very broad (Fig. 5. character state 3) ......
  Farlowella henriquei
  • 25b. Body of cleithrum broad (Fig. 5, character state 2) .....26
• 26a. In adult, snout-mouth length < 3.0 times interorbital width (Fig. 2); 2-3 median abdominal scutes at anterior of abdomen (Fig. 6b) ......
  Farlowella platorynchus
  • 26b. In adult, snout-mouth length > 3.3 times interorbital width; usually 1 median abdominal scute at anterior of the abdomen .........
    Farlowella amazona
• 27a. Median anterior lateral row of plates diamond-shaped (Fig. 7, character state 0) ......
  Farlowella yarigui
  • 27b. Median anterior lateral row of plates hexagonal in shape (Fig. 7, character state 1) ......28
• 28a. Snout-mouth length/interorbital width (Fig. 2) > 1.9 in adult male; outer rays (except outermost ray) of lower caudal fin lobe darkly pigmented from fin base to tip but may be interrupted by clear ocellus bar ...
  Farlowella vittata
  • 28b. Snout-mouth length/interorbital width (Fig. 2) <= 1.8 in adult male; outer rays (except outermost ray) of lower caudal fin lobe usually not entirely darkly pigmented from fin base to tip .......29
• 29a. Pectoral fin does not reach pelvic fin origin; mid-dorsal ridge of head absent in adults ......
  Farlowella acus
  • 29b. Pectoral fin almost reaches or extends past pelvic fin origin; mid-dorsal ridge present in adults ...............30
• 30a. Head covered by medium-sized breeding odontodes ....
  Farlowella venezuelensis
  • 30b. Head not covered by medium-sized breeding odontodes. Small breeding odontodes on preorbital ridge (Fig. 3) only or absent ...31
• 31a. Interradial membranes of caudal fin clear; many small breeding odontodes on preorbital ridge (Fig. 3) .....
  Farlowella martini
  • 31b. Interradial membranes of caudal fin darkly pigmented, few, if any, very small breeding odontodes on preorbital ridge (Fig. 3) .......
    Farlowella colombiensis