| wadi |
| waif |
| Wallace's line |
| warm monomictic |
| warm spring |
| warm water |
| Warmgerookte gezouten haring |
| warmwater fishes |
| warp |
| Warty anglers (handfishes) |
| Waryfishes |
| wash zone |
| washing |
| waste |
| wastewater |
| water column |
| water content |
| water hardness |
| water haul |
| water mass |
| water parting |
| water table |
| water-hardening |
| watercourse |
| waterfall |
| watershed |
| weak |
| weaning |
| Weasel sharks |
| Weber's line |
| Weberian apparatus |
| Weberian ossicles |
| Weberian vertebrae |
| weed fish |
| Weeverfishes |
| weir |
| West india |
| West indian |
| West Pacific |
| Westark Community College, Arkansas |
| Westerlies |
| Western Australian Museum |
| Westoll lines |
| wet cured |
| wet deposition |
| wet fish |
| wet reduction |
| wet salted |
| Wet salted fish |
| wet stack |
| wet weight |
| wetlands |
| Whale shark |
| Whalelike catfishes |
| Whiptail breams |
| White fish |
| White Sea |
| White sharks |
| white wings |
| whitebait |
| whitebait stage |
| whole fish |
| Wichita State University, Kansas |
| wicker trap |
| Wide Area Information Server |
| Wide Area Network |
| width |
| width of perivitelline space |
| Wiener Linie |
| Wiener Zoll |
| wild |
| wild spawning |
| wild species |
| wild stock |
| Wilfrid Laurier University Zoological Museum Ichthyological Collection, Ontario |
| wind dried fish |
| windward |
| Winf |
| wing |
| winter pond |
| wintering |
| winterkill |
| withdrawal period |
| within family selection |
| Wolf herrings |
| Wolffian duct |
| Wolffishes |
| work |
| work of an animal |
| Workstation |
| World Wide Web |
| Worm or spaghetti eels |
| Wormfishes |
| wounding gear |
| wrap |
| wrapping |
| Wrasses |
| Wreckfishes |
| Wrymouths |
