Pterophyllum scalare

I am currently observing a pair that have usually spawned well and taken good care of their brood. this spawn (hatched about 50h ago) is huge, I estimate around 800-1000, the biggest I've had so far.

Momma is gathering and re-sticking against the rear wall (futile since the fry is starting to become free-swimming), but to be fair, dad is cruising the tank collecting all the early developers and depositing back into the corner nearest mom. this he does whenever she prods him gently in the side. the rest of the time he's on guard duty.

He has three guard stations;

1. Keeping a tiny (> 1" (2.5 cm)) pleco at bay - the pleco is allowed to do his thing in the right half of the tank.
2. Displaying his total side view to the neighboring tank with another spawning pair of angels.
3. Watching me!, every time I come to have a look he abandons all else and looks me straight in the eye with the typical, aggressive jerking head movement. he also almost jumps out of the tank when I reach above (got food etc. stored there) the tank.

Just to backtrack to the beginning, the pair were moved to their current tank last week when it became clear that they wanted to spawn. they defended a corner in the main tank and started cleaning the glass etc. (there was also a change in barometric pressure + a full moon coming up).

The tank was cleaned a few days earlier but was starting to develop some algae, which is why the pleco was in there. since this pleco was so small I decided to take a chance and leave him. two days later they spawned and I thought, wow, this is a lot. 48h later the first wrigglers appeared.

The next morning, shock, they were all gone from the piece of tile they had been on. suspect: pleco. but the parents were hovering in the farthest corner and the pleco in the opposite one so after careful examination I saw that the wrigglers were bunched up tight in that corner.

The next step was that daddy was dispatched to do some cleaning in another part of the tank and a few hours later their brood was moved to this patch. both of them being involved in this in perfect synch; the new batch was being watched over by one parent while the other gathered a new mouthful. the moment the "mover" left the old bunch, the "watcher" would move as well and the positions became reversed, both batches being unattended for less than 2 seconds. This whole process was and is repeated every few hours and will be for quite some time. even when the fry are free-swimming, they will be kept in a closely guarded swarm. ok, enough of the story, some basic facts on fish and tank;

Fish: a mated pair with 5 previous spawns, about 1 year old. she's 6cm body size, he a goo 8cm. both have well developed fins, but are not veiltails. also both have two broad black stripes on their bodies, one across the eye and one on the base of the tail. their dorsal fins are long and look thin but can be widened effortlessly when displaying. all in all on of my nicest pairs.

Tank: 35 x 38 x 78cm = 100odd liters. bare bottom, open top. a few small plants in pots, two pieces of wood, the "spawning" tile, heater and a air powered sponge filter. this is turned down to minimum at the moment and i gradually increase the power as the fry become stronger and larger. one 60W incandescent bulb 10cm above the water.

Temperature: 24deg. celsius (i know its a bit low but its one of those ancient heaters that have to be dismantled to change).

Chemical parameters: pH : 6.8, ammonia, nitrates were at 0 at spawning and I do daily water changes once the fry are free swimming to keep them there.

Food: the parents were fed on tetra bits and wholesale flakes, the fry will get newly hatched brine shrimp, which will be augmented with finely ground flakes in stages until flake only can be fed, at which stage i usually sell them.

One last thing that might be of interest; I splited the larger fry on a regular basis until the largest end up in the bathtub and ultimately the fish store.