a) Temperature range: 78F
b) pH: 7 - 7.5
c) GH: 30 - 60ppm
d) KH: 40 - 80ppm
e)Ammonia: 0
Nitrate: 20ppm
Nitrite: 0
f) Water change frequency: 30% every 7-10 days
2. Tank set up
a) Size: 40 Breeder
b) Substrate: Fluval Stratum capped with river rocks
c) Filtration: Eheim2215 cannister, Eheim Skim350
d) Furnishings: Dragon stone, driftwood, heavily planted, 2 circulation pumps, low tech (no CO2 system)
e) tank mates:
1x L471 Dwarf Hypancistrus ~2inches "Spot" (injured)
1x L107 "super red" Ancistrus sp. ~5+inches (aggressor)
7x yoyo loaches 4-6inches (not involved in pleco drama)
f) How long has it been set-up?: 2 years
g) When was the last new fish added?: 21 months ago
h) Foods used and frequency?:
2x daily: (rotate) fluval bug bites bottom feeder granules, fluval bug bites algae crisps, Hikari bottom feeder wafers, Omega One shrimp pellets
1x weekly: frozen bloodworms or frozen brine shrimp
1x weekly fast day
Occasionally raw or blanched veggies.
3. Symptoms / Problem description
I noticed a grey circlular patch where scales appear to be missing around dorsal fin of L471 (Spot) following apparent bristlenose attack.
Spot tends to be more strictly nocturnal/reclusive in general, and is the smallest fish (~2in) in my heavily planted tank. It's pretty common to go a few weeks at a time without seeing him, but the past two weeks I've caught him hanging out early almost every night (and get excited every time!
). I've never seen the other fish in the tank bother him, but they are pretty rambunctious at feeding time so when Spot is out, I drop food on the opposite sides of the tank as a decoy and then drop (the same type of) food near Spot so that he's not caught in a swarm of yoyos.I did this last night and while Spot was eating I observed my Bristlenose leap onto him and then both darted out of sight. It looked like an ambush, but I've never seen my bn do anything like this before and have always understood them to be peaceful with other fish. About an hour later, Spot was out again and I noticed a grey circle around his dorsal fin where his scales seem to be missing. Since he's been so visible recently, I've gotten a good look at him several times this week and am fairly confident there were no signs of the grey patch prior to the altercation. I've had Spot and 3 of the yoyos for over 2 years and added the bn and 4 yoyos almost 2 years ago - there are no previous instances of illness/injury/disease for any of the fish. My questions:
Does the "ambush" behavior I observed from my bn seem like aggression?
Does the grey patch look like it was caused by my bn? If not, what else could cause it?
If bn is the likely culprit, how should I proceed? Observe? Feed more/differently? Remove bn or Spot from the tank immediately?
Also curious if anyone can help determine sex of both plecos based on the pictures. I suspect they're both male. My bn does have bristles on mouth and head, but they're not very prominent. If it is male, will the bristles get bigger? Idk what characteristics are used to sex L471, but I've observed Spot "fanning" outside his cave and found some evidence that's male behavior.
