cuttlefish
魷 centers on a specific sea creature: the cuttlefish. The meaning is narrow and concrete, with no clear abstract extensions.
魷 combines the fish radical 魚 with 尤, which likely contributes the sound. The exact historical development is uncertain, but the structure is a typical phono-semantic compound for a sea creature name.
The fish radical 魚 on the left tells you it's a sea creature. The right side 尤 looks a bit like a cuttlefish with its tentacles and body shape, making 魷 the cuttlefish kanji.
For ユウ, imagine a cuttlefish saying 'you' as it points a tentacle at you: you -> ユウ, and the cuttlefish is addressing you directly.