You don't need Lu Shang's for these... Even though they cap at 46, at 30 Fishing you can easily catch these in East Sarutabaruta (sometimes for skillups) using a Halcyon Rod and Sinking Minnow. They will be the hardest of the non-"you have a bad feeling"/non-!!! catches. Ogre Eels will be the middle (these are sometimes Novice guild point items), and Pamtam Kelp and Rusty Buckets will be the easiest.
Also, they are an ingredient for a 68 Cooking synth "Shrimp Cracker", which as of the date of this comment, isn't currently listed on FFXIAH for Gold Lobster.
You can catch these guys with Lu Shang's rod of the coast of Sarubaruta, along with some Bastore Breams to boot. For those hardcore fishing types like me, this is an excellent, yet seemingly lesser known opportunity.
