堅魚[katsuo] skipjack tuna
堅い[katai] hard
堅果[kenka] nut
堅苦しい[katakurushii] formal
堅固[kengo] solid

堅持[kenji] holding on to
堅城[kenjou] strong fortress
堅陣[kenjin] stronghold
堅調[kenchou] bullish
堅忍[kennin] perseverance

馬酔木[asebi] Japanese andromeda (Pieris japonica)
梶木[kajiki] marlin
ゴムの木[gomunoki] rubber tree
トロイの木馬[toroinomokuba] Trojan horse
木乃伊[miira] mummy

伊佐木[isaki] chicken grunt (species of fish, Parapristipoma trilineatum)
一木[ichiboku] one tree
稲木[inagi] rice-drying rack
猿も木から落ちる[sarumokikaraochiru] even monkeys fall from trees
横木[yokoki] crosspiece

天魚[amago] land-locked variety of red-spotted masu trout (Oncorhynchus masou ishikawae)
海鷂魚[ei] ray (fish)
斉魚[etsu] Japanese grenadier anchovy (Coilia nasus)
旗魚[kajiki] marlin
鶏魚[isagi] chicken grunt (species of fish, Parapristipoma trilineatum)

杜父魚[tofugyo] sculpin (any fish of family Cottidae, inc. the bullheads and the miller's-thumb)
堅魚[katsuo] skipjack tuna
魚網[gyomou] fishing net
魚屋[sakanaya] fish market
魚貝[gyokai] marine products

鰹節[katsubushi] katsuobushi
真魚鰹[managatsuo] butterfish (any fish of family Stromateidae, esp. species Pampus punctatissimus)
鰹木[katsuogi] log on the roof of a shrine set perpendicular to the ridgepole
花鰹[hanagatsuo] dried bonito shavings
鰹の烏帽子[katsuonoeboshi] Portuguese man-of-war (Physalia physalis)

鰹節虫[katsuobushimushi] dermestid beetle
猫に鰹節[nekonikatsuobushi] temptation one can't resist
初鰹[hatsugatsuo] the first bonito of the season
歯鰹[hagatsuo] striped bonito (Sarda orientalis)