Black tort vs Tortoise?

[houston]

Hey all, attempting to do some genetic charting and the pedigree I'm looking at (Holland Lop) lists "Tort - Black" and "Tortoise" as colors. The individuals come from the same breeder, so I don't think its a matter of different recordkeeping styles.

Is a "Tortoise" not a black tort (aaB_C_D_ee)? If not, what's the genetics behind it?

Thanks!

 

[SableSteel]

They're the same color. Could be the breeder changed their record-keeping program between the two, or just wrote something down as short hand. The full correct name for the pattern is Black Tortoise.

 

[hotzcatz]

They probably meant 'tortoiseshell' but many folks shorten it to 'tort'. Generally, unless it's something other than black, it's assumed to be a black based tort.

Required genes for a black based tort are: aa B_ C_ D_ ee. It's the double recessive on the 'e' which makes the tort.

aa B_ C_ D_ ee = 'standard' black based tortoiseshell
aa bb C_ D_ ee = chocolate tortoiseshell
aa bb C_ dd ee = lilac tortoiseshell

Should you breed a tort to a tort but they both carry a recessive 'c', it's possible to get a white tort. That would be: aa __ cc __ ee. For a more rare color, a lilac tort carrying a recessive 'c' bred to another lilac tort carrying a recessive 'c', if you got a REW from that pair, then it would be all recessives: aa bb cc dd ee.