In our field trips we saw local members of about 20 of the 600+ families of fishes. Here is an artificial key to highlight the salient characters of a selection of 39 important families. 1a) no jaws . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1b) jaws present . . . . . . . . . . . . . . . . . . . . . . . . 3 2a) mouth with tentacles, eyes reduced . . . . . hagfish, MYXINIDAE 2b) mouth a toothed funnel-shaped disc .. lampreys, PETROMYZONTIDAE 3a) cartilaginous jaws with series of slicing or crushing teeth; small placoid scales; males with paired pelvic claspers . . . . 4 3b) bony skeleton or bony scales or plates; jaw teeth usually conical or absent; no paired pelvic claspers . . . . . . . . . . 6 4a) 5-7 pairs of gill openings . . . . . . . . . . . . . . . . . 5 4b) single pair of gill openings, clasper on forehead...CHIMAERIDAE 5a) eyes and nostrils on extensions .. hammerhead shark, SPHYRNIDAE 5b) pectoral fins form a large rounded disk . . . . . ray, RAJIDAE 6a) paired fins filamentous . . . . . . lungfish, LEPIDOSIRENIDAE 6b) paired fins not filamentous, but a fan of fin rays . . . . . 7 7a) large, extremely heterocercal caudal fin . . . . . . . . . . 8 7b) slightly heterocercal or homocercal or reduced caudal . . . 9 8a) upper jaw extended to a long paddle . . . . . . . POLYODONTIDAE 8b) upper jaw a flat triangle with barbels . . . . . ACIPENSERIDAE 9a) thick, rhombic scales . . . . . . . . . . . . . . . . . . . 10 9b) scales thin, bony, cycloid, ctenoid, or absent . . . . . . . 11 10a) ca. 10 widely separated dorsal finlets...bichirs, POLYPTERIDAE 10b) One, posterior, dorsal fin . . . . . . . gars, LEPISOSTEIDAE 11a) large gular plate between lower jaw bones . . . . . . AMIIDAE 11b) no large bony plate between lower jaw bones . . . . . . . . 12 12a) long anal fin to caudal; small dorsal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . knife fish, NOTOPTERIDAE 12b) anal fin separated at caudal or no caudal fin . . . . . . . 13 13a) main teeth are on tongue . . . . . bonytongue, OSTEOGLOSSIDAE 13b) main teeth on jaws or pharyngeals . . . . . . . . . . . . . 14 14a) long, straight caudal peduncle, electric . . . . . MORMYRIDAE 14b) caudal peduncle not long, slightly tapered . . . . . . . . 15 15a) pectoral fins absent . . . . . . . . . moray eel, MURAENIDAE 15b) pectoral fins present . . . . . . . . . . . . . . . . . . . 16 16a) maxilla elongated well beyond eye . . . anchovies, ENGRAULIDAE 16b) maxilla short or extends little beyond eye . . . . . . . . 17 17a) saw-tooth ridge on abdomen . . . . . . . herrings, CLUPEIDAE 17b) abdomen rounded without a toothed ridge . . . . . . . . . . 18 18a) adipose fin present . . . . . . . . . . . . . . . . . . . . 19 18b) adipose fin absent . . . . . . . . . . . . . . . . . . . . 20 19a) maxillary teeth prominent, no spines . . characins, CHARACIDAE 19b) fin spines and bony plates . . . armored catfish LORICARIIDAE 20a) anal fin of males a slender gonopodium . . . . . . POECILIIDAE 20b) anal fin of males with normal rays and membranes . . . . . 21 21a) pelvic fins abdominal, not under pectoral fins . . . . . . 22 21b) pelvic fins thoracic, mostly under pectorals, or absent . . 25 22a) vent on throat, eyes reduced . . . . cave fish, AMBLYOPSIDAE 22b) vent and eyes normal . . . . . . . . . . . . . . . . . . . 23 23a) small gill openings over frog-like P1 fins . . OGCOCEPHALIDAE 23b) large gill openings anterior to pectoral (P1) fins . . . . 24 24a) tubular mouth, tail slender . . . . . sea horse, SYNGNATHIDAE 24b) pectoral fins large & inserted high...flying fish, EXOCOETIDAE 25a) pelvic fins with 1 spine and 5 well develped rays . . . . . 26 25b) pelvic fins absent, reduced or not as above . . . . . . . . 36 26a) long jaws & large blade-like teeth . . barracuda, SPHYRAENIDAE 26b) jaws rounded (except bill fish), teeth conical . . . . . . 27 27a) a sucking disk on top of head . . . . . . remoras, ECHINEIDAE 27b) dorsal fin normal, no sucking disc on head . . . . . . . . 28 28a) bony brace from suborbital to preopercle . . . . . . . . . 29 28b) no bony brace connecting suborbital and preopercle . . . . 30 29a) lower pectoral rays separated as feelers..searobins, TRIGLIDAE 29b) lower pectoral rays not separated . . . . . . . SCORPAENIDAE 30a) 1 pair of nostrils . . . . . . . . . . . . . . . . . . . . 31 30b) 2 pair of nostrils . . . . . . . . . . . . . . . . . . . . 32 31a) no subocular shelf; lower pharyngeals fused . . . . CICHLIDAE 31b) subocular shelf present . . . . . . damselfish, POMACENTRIDAE 32a) dorsal #1 short, #2 long, peduncle...slender jacks, CARANGIDAE 32b) dorsal fins subequal, peduncle deep . . . . . . . . . . . 33 33a) 4 complete gill arches . . . . . . . . . . . . . . . . . . 34 33b) 3 1/2 gill arches (one row of filaments on 4th) . . . . . 35 34a) mouth large, pharyngeals not fused . . . snappers, LUTJANIDAE 34b) mouth small, lower pharyngeals fused . . . . . . EMBIOTOCIDAE 35a) large, separate jaw teeth . . . . . . . . . wrasses, LABRIDAE 35b) jaw teeth fused into a beak . . . . . parrotfishes, SCARIDAE 36a) dorsal and anal fins long . . . . . . . . . . . . . . . . 37 36b) dorsal fin short . . . . . . . . . . . . . . . . . . . . . 38 37a) left and right eyes . . . . . . . . . . . blennies, CLINIDAE 37b) eyes on left side in adults . . . . . . . . . soles, SOLEIDAE 38a) 1st dorsal fin with 3 spines . . . . . triggerfish, BALISTIDAE 38b) jaw teeth fused into beak . . . . . . puffers, TETRAODONTIDAE