Commentary below video links
Regular version:
High Definition version:
YouTube make it impossible to link to HD version, but it is worth the effort, go to
ie.youtube.com/user/DaraghOwens
don't click the large video on the top but select "Corydoras Schultzei Spawning" for the list of all video and then click
Watch in HD
(If anyone knows how to embed the HD version, please let me know)
C. schultzei or Gold Shoulder Cory are closely related to the Bronze Cory, C Aeneus. They are very prolific and lay hundreds of small eggs. The video was cut from 18 minutes of filming last night, the whole spawning process went on for over 8 hours. I estimated the number of eggs today at 350 from a single female, however at least 40% or more were infertile.
After a slow start things get a bit more interesting, just so you know what is going on here are some key points:
0:46 female lays a batch of eggs she has been carrying around since the start of the clip. There were 24 in that batch!! Most corys lay 1, 2, 3 eggs at a time, but C aeneus types lay more, but I never realised it was that many.
1:00 Female takes a rest, then the males (3) chase her each trying to be the one that fertilises the next batch of eggs. The eggs are fertilised by the female clamping onto the males ventral fins, whether fertilisation is internal or external is open for debate, personally I think external. Anyway this position is know as the “T” position and you can see it at 1:35 & 1:45.
2:00 Female attaches another batch of eggs to the glass. More frantic chasing ensues to see who will be daddy next time, someone was successful behind the plants and the female takes a rest at 3:15 before going off to place them on the glass. Meanwhile the other tank occupants a group of C trilineatus are unexcited by the activity and don’t unfortunately follow the lead and spawn themselves.
3:32 more eggs placed on glass, 3:42 female picks up a white handbag which is actually a piece of white gravel that is stuck to her pelvic fin by a single egg. The eggs are extremely soft and sticky when freshly laid, within a couple of hours they become hard enough to roll off the glass with your fingers. 3:55 “T” position again then the female rests while a C trilineatus goes about the important business of looking for food, totally unphased by all this activity. 4:18 you can see the eggs clamped in the females ventral fins and she rest on a pectoral fin to keep her body off the bottom.
5:00 Here are some I prepared earlier. A few days ago another pair of C schultzei spawned and I put the eggs which were mainly attach to the anubias plant in a small lshow tank with a small sponge filter. 5:20 the small brown thing in the centre at the bottom of the tank is an alder cone which produces tannin and helps prevent the spread of fungus from unfertilised eggs, the tannins turn the water tea coloured. 5:33 the white and brown lump to the right is a batch of eggs, unusually for this type of cory they laid a lot of eggs in one spot like a bunch of grapes (S Barbatus do this naturally, but most Corys spread their eggs out one deep again the glass of plant) because they were so tightly packed fungus has spread to the good eggs too and most of them will not hatch. These fry are newly hatched a maximum of 12 hours old, the spinners are fry trying to escape the egg casing.
The music is Leonard Coen, The Future, an appropriate title.
Daragh
