#Pyth, 64 48 50 bytes
#jdhfqzsTsm^+msXtjCk2U2"<>""
\r.1"",<..>,"dlzB
Version that doesn't take forever ($O(9^{n/3}$) here, in 52 bytes.
This is the brute force approach, generate all sequences and check whether any sum to the input. Fish diagrams compressed as characters, whose binary representations are the >
and <
. The whole thing is wrapped in a try-catch block so that no output occurs when no results are found.
This is an $O(9^n)$ solution.
Some characters are stripped above, because control characters are used. They are reproduced faithfully at the link above.
xxd output:
0000000: 236a 6468 6671 7a73 5473 6d5e 2b6d 7358 #jdhfqzsTsm^+msX
0000010: 746a 436b 3255 3222 3c3e 2222 0a5c 7212 tjCk2U2"<>"".\r.
0000020: 141b 1d2e 3122 222c 3c2e 2e3e 2c22 646c ....1"",<..>,"dl
0000030: 7a42 zB