cockroach
Referring to two similar species of freshwater fish; both of which originate from the common roach variety. Each breed can be identified as follows:

Long Wang :- A roach which has genitals similar in size and shape to a fully grown human male.
Cockbody :- A roach whose body itself looks similar to a human penis.
Lad 1: Hey, there's a vibrating dildo in your fishing basket.
Lad 2: Nah, that's just the cockroach I caught earlier.