I have 2 Wegner jrs. I never heard about fish sign. However, for people who might wonder why fish symbol is used as a Christan sign - here is an explanation
ΙΧΘΥΣ (Ichthys) is an acronym for "Ίησοῦς Χριστός, Θεοῦ Υἱός, Σωτήρ", (Iēsous Christos, Theou Yios, Sōtēr), which translates into English as "Jesus Christ, God's Son, Savior".
Iota (i) is the first letter of Iēsous (Ἰησοῦς , Greek for "Jesus".
Chi (ch) is the first letter of Christos (Χριστός , Greek for "anointed".
Theta (th) is the first letter of Theou (Θεου , Greek for "God's", the genitive case of Θεóς, Theos, Greek for "God".
Ypsilon (y) is the first letter of (h)yios (Υἱός , Greek for "Son".
Sigma (s) is the first letter of sōtēr (Σωτήρ , Greek for "Savior".
Well, the 'fish' in Greek is written ΙΧΘΥΣ, and for Christians, the letters have the meaning as above explained. During the terror, torture, killings of Christians the drawing of fish - ΙΧΘΥΣ - was a secret Christian code to recognize each other in a clandestine way.
Wegner jr. is, IMO, the best Spyderco ever, among 2-3 in the the same category.