shrimp, prawn, lobster
蝦 centers on crustaceans with a hard shell and segmented body, especially shrimp, prawns, and lobsters.
蝦 combines 虫 (insect/creature) with 叚, which likely contributes the sound. The character originally referred to a type of shrimp or prawn, and the 虫 radical groups it with small animals.
The left side 虫 is a bug-like creature, and the right side 叚 looks like a shell with legs. Picture a shrimp with its curved body and tiny legs: 蝦 is a shrimp.
For カ, imagine a shrimp driving a tiny car: car -> カ, and the shrimp is behind the wheel.
Emishi; Ezo; non-Yamato peoples in northern Japan
Hokkaido sika (Cervus nippon yesoensis); Yezo sika
mantis shrimp (any marine crustacean of order Stomatopoda, esp. the species Oratosquilla oratoria); mantis crab; squilla
tadpole shrimp (Triopsidae spp.); shield shrimp
Yamato shrimp (Caridina multidentata); Amano shrimp
arthritic neptune (species of whelk, Neptunea arthritica)
double-sculptured neptune (species of whelk, Neptunea intersculpta)
lake prawn (Palaemon paucidens)
kangaroo shrimp (Glyphus marsupialis)
broad velvet shrimp (Metapenaeopsis lata)
Japanese glass shrimp (Pasiphaea japonica)
Indian bait prawn (Palaemon pacificus)
Japanese mud shrimp (Upogebia major)
Angelica ursina (species of perennial herb)
chives (Allium schoenoprasum var. schoenoprasum)
bird cherry (Prunus padus)
Siberian ginseng (Eleutherococcus senticosus); eleuthero; ciwujia
Yezo (northern part of Meiji-era Japan, esp. Hokkaido, but also Sakhalin and the Kuril Islands)
wedgeleaf primrose (Primula cuneifolia); pixie-eye primrose
sargent cherry (Prunus sargentii)