EYEBALLING THE FRESH-WATER AND TIDE-WATER FISHES IN OUR AREA:

A TYRO'S GUIDE TO LOOKING IN-SEINE

Developed by Joseph Travis for ZOO 4343C, Florida State University

    This is a crude guide to the more common types of fishes encountered in the local streams, ponds, and springs. This is not a key, but a list arranged by family and common genera. It is not organized in strict phylogenetic arrangements, either, nor is it a complete list of either genera or species. You should use it as a guide to help you review the most commonly encountered fish in our area, recognize those fish, or at least narrow your choices for fish you can't identify completely. It may also help you learn the most readily observable characteristics of the major families of fish in our areas. I've covered families and genera commonly found in fresh-water or brackish-water seine hauls, or, if not common, remarkable when caught.

1.  Lepisosteidae: Gars.

    Long, cylindrical bodies, almost as if armored; long jaws with sharp teeth.

    Lepisosteus osseus, longnose gar (long, slender snout).

    Lepisosteus platyrhincus, Florida gar (short, broad snout).

2.  Amiidae: Amia calva, bowfin.

    Long dorsal fin, nearly to caudal fin.

3.  Anguillidae: Anguilla rostrata, American eel.

    One and only eel in fresh water.

4.  Esocidae: Pikes and pickerels.

    Long, cylindrical bodies; soft dorsal fin quite posterior; duck-billed with sharp teeth.

    Esox americanus, redfin pickerel (vertical streaks or wavy bars; young striped with brown and gold).

    Esox niger, chain pickerel (network of dark lines).

    These species are distinct in the number of lateral-line scales.

5.  Cyprinidae: Minnows, carp, stonerollers, shiners, dace, chub.

Small, "joe fish" types with forked tails; no teeth in the mouth, no spines on species in this region, only 8-10 dorsal fin rays. Definite diagnosis often requires examination of the pharyngeal teeth. Our area is depauperate in these fish relative to the rest of North America.

Notropis spp. There are at least 12 other species in this genus in north Florida, but most of them occur in the Apalachicola drainage or westward of that drainage. They are often partial to a particular drainage, habitat, and microhabitat. They are fun to key out.

Notemigonus crysoleucas, golden shiner. Found in many types of habitats. Body is deep for its length and colored metallic silver or gold. Lateral line deeply decurved.

Other genera. There are four other genera of cyprinid fishes in north Florida (Ericymba, Hybognathus, Hybopsis, and Semotilus), but most of them really occur much to the west of here.

6.  Catostomidae: Suckers.

    Erimyzon succetta, lake chubsucker. Lakes, still water, no lateral line.

Moxostoma, redhorses. Various reports of redhorses exist, known from western part of panhandle and  probably elsehwere.

7.  Ictaluridae: Catfish.

Scaleless bodies, heavy pectoral and dorsal spines, long barbels (4 under jaw, 2 above, 1 at each side of maxillary).

    Ameiurus, bullheads: adipose fin free of caudal fin

    Noturus, madtoms: adipose fin united to caudal fin or separated only by a small notch

8.  Aphredoderidae: Aphredoderus sayanus, pirate perch.

Olive-green; dark, unforked tail; "joe fish" type; small spine on the operculum. Adults have the anus just under the throat--I'm not kidding. Young individuals could be harder to recognize because the anus starts out in a respectable position in young fish. Slow-moving water, but also found in protected areas of rivers with lots of vegetation. Tend to be more abundant in limestone-base waters. Tail squarish, body never banded. The young pirate perch could be confused with Elassoma, I guess--although once you seen enough pirate perch, you come to recognize them, and Elassoma does not have the opercular spine.

9.  Cyprinodontidae: Killifish.

Small, "joe-fish" types with squarish or rounded caudal fins, incomplete lateral lines, often with a "snub-nosed" appearance.  Dimorphism is common, with males generally brighter, more colorful, and more speckled or flecked with color. The third anal ray is always branched (Poeciliidae are always  unbranched). This family is very useful for diagnosing the location and habitat type of a collection  in our area, so I'll go into some detail.

    Relatively deep-bodied killifish (largely in brackish water and exclusively along the coast):

Jordanella floridae, flagfish. First ray of dorsal fin is a grooved spine. For a deep-bodied killifish, the spine is a giveaway. Diffuse bars on body, a spot just above midline, above pelvic fins, and often a spot at posterior edge of dorsal fin. Found in low-salinity pools in our area.

Cyprinodon variegatus, sheepshead minnow. Greenish color with triangular bars extending around dorsum down sides of body. Hump-backed appearance. Can be found in coastal pools and streams from 0o/oo to full seawater.

Adinia xenica, diamond killifish. Greenish, like the preceding species, but with many fine bars (dark green and white in adults, darker and lighter green in young) in caudal region.  Widespread.

Long, narrow, easy-to-identify killifish (found anywhere):

Lucania parva, rainwater killifish. This Gambusia look-alike is found along the coast, in fresh, brackish, or saline water, but most likely in brackish water. It looks a lot like Gambusia, but its mouth is clearly at the front of its head, whereas Gambusia's mouth appears at the top of its head.  Lucania has "visible lips"; Gambusia doesn't appear to have any "lips."

Lucania goodei, bluefin killifish. Olive-colored but with a black stripe from snout to caudal fin and a second black stripe from vent area to base of caudal fin. Could be confused at first glance on early field trips with the cyprinid Notropis harperi, but look for the squarish tail as the "sign of the killifish." Males have basal areas of dorsal and anal fins black also, but this feature may disappear outside of breeding season. Fresh-water, from streams to swatched by any local Fundulus (see p. 140 of Eddy and Underhill), which makes sense when you realize it's largely found in swamps and slow-moving backwaters; (2) it has a spot at the base of the rounded caudal fin (females have a spot just above the anal fin); and (c) it has only one row of teeth Fundulus have two rows). Males have 5-6 bars that make them resemble a Fundulus. This species is most common on south side of the Cody scarp.

Fundulus. This genus can seem nightmarish. Obviously you can't go wrong if you use the key, but you  can do pretty well by learning a few simple eyeball dichotomies. There are three estuarine species  (grandis, similis, confluentus) and five fresh-water species of note in the area(chrysotus,       cingulatus, escambiae, lineolatus, seminolis).

    The estuarine species confluentus has a dorsal fin that begins behind or at the same point as the anal fin (the pattern in all of the fresh-water species); grandis and similis have dorsal fins distinctly ahead of the anal fin. Similis is the pale olive fish with 10-15 crossbars and long snout; grandis is the bright green fish with flecks of yellow (males have bright yellow fins).

    The five fresh-water species are all olive-colored, with orange or yellow fins on males. You'd best use the key. The least common in our area is seminolis, which is more common to the east and in peninsular Florida. The remaining species can be a great guide to where a collection was made and in what habitat, though they are all found in slow-moving water. You should not use habitat association patterns as a strict guide to identification, of course.

    escambiae and lineolatus: In both species males are supposed to have a dark, teardrop-shaped bar below the eye. In escambiae, the bar is solid, whereas it is diffuse in lineolatus and appears wholly absent in some populations. This mark is no help if you have a female in hand. The lines in lineolatus always appear more solid, whereas those in escambiae are often more "dashed." The head shapes are different, with escambiae's head appearing smaller and shorter - this isn't helpful until you’ve seen each one.   The species lineolatus is more common north of U.S. 20, above the Cody scarp, and east of the Ochlockonee river. The species escambiae is more common below the scarp, south of U.S. 20. Both species are in the Ochlockonee drainage, and lineolatus is well-established in some of the National Forest lakes and ponds just below the scarp.

    chrysotus and cingulatus: Cingulatus has a narrow, middorsal gold line anterior to the dorsal fin and no goldspot above and behind the eye; chrysotus does not have the line but does have the spot. The species  chrysotus tends to occur in stained waters atop an organic, mucky bottom and is found throughout our area. Cingulatus is more characteristic of sandy bottoms, often lakes and creeks in the shallow, slow-moving areas; it is generally found below the Cody Scarp. The number of crossbars is supposed to be less than 12 for chrysotus and more than 12 for cingulatus.

    Many of the key characters are in the form of "usually" or "generally," so it helps to collect a series of fish to examine if you're going to use the keys. 

10. Poeciliidae: Topminnows.

Killifish-looking "joe-fish" types, but with mouths that appear to point up. Generally flat headed in appearance; mature males possess the unique gonopodium.

Poecilia latipinna, sailfin molly. Greenish fish with rows of dashes or dots along the body; males may have bright orange, yellow, and blue spots on dorsal and caudal fins. In our area found along coast in every tidal habitat (mucky bottom marsh). Only found in fresh water in spring-fed rivers (Wacissa, St. Marks, Wakulla).

Gambusia holbrooki, mosquitofish. Ubiquitous fish of shallow, vegetated areas in almost any freshwater or brackish habitat.

Heterandria formosa, least killifish. Reddish-brown to dark olive, distinct stripe along midbody and dark bars; belly golden. Females have a conspicuous spot on the anal fin and the dorsal fin. Ubiquitous in heavy vegetation in shallow water.

11. Atherinidae: Silversides.

Long, narrow fish that are fragile in seineing; a silver stripe along the side and a prominently forked tail.

    Menidia beryllina, tidewater silverside. Found along coast in brackish and saline areas, tidal streams.

    Labidesthes sicculus, brook silverside. Fresh water.

12. Centrarchidae: Sunfishes.

Spinous and soft portions of the dorsal fin united (as opposed to Percidae, Serranidae, and Percichthyidae); pelvic fins right under pectoral fins. We tend to catch small species and immature stages of larger species and distinguishing among some species can be difficult.

Long sunfish:

Micropterus, bass. The largemouths, salmoides, have the prominent maxilla but also an elongated dark caudal spot. The others (punctulatus and notius) have the shorter maxilla and if they have a caudal spot, it is about as long as it is wide. The shape of the spot is rarely a helpful character on small ones but what the heck.

Oblong sunfish:

Acantharchus pomotis, mud sunfish. Rounded caudal fin and large mouth (large means the maxillary extends to or beyond the middle of the eye). Dorsal fin much longer than anal fin Anal spines 5, 11-13 dorsal spines. Found in muddy, weedy areas from St. Marks to east.

Short, squat sunfish.

    Anal spines 3

Enneacanthus, sunfish. Swampy, slow current areas. This genus has a rounded caudal fin but a small mouth. We have two species in our area:

obesus: curved, vertical bars, often faint;

gloriosus: no bars at all, irregular rows of blue spots

Lepomis, sunfishes. Forked caudal fins and small mouths; these fish are widespread. The species you might encounter appear to have distinct habitat preferences, some in flowing water and some in still water. You'll largely encounter small immatures, so the habitat types may not be useful.

Use the key; the native taxa include auritus, gulosus, macrochirus, marginatus, megalotis, microlophus, and punctatus.

    Anal spines 5-8; dorsal fin much longer than anal fin

Ambloplites rupestris, rockbass. Green to brassy with rows of dots like Centrarchus but even more prominent; the dorsal fin is longer than the anal fin. Dorsal spines 11-13. Forked caudal fin.

    Anal spines 5-8; dorsal fin only slightly longer than anal fin

Pomoxis nigromaculatus, black crappy. Forked caudal fin, large mouth, silver with black or dark green mottling. Dorsal spines 7-8.

Centrarchus macropterus, flier. Green body with rows of dots much like mollies. Easy one: the base of the dorsal fin is as long or only slightly longer than the base of the anal fin; only the crappy has a comparable dorsal/anal fin profile and it has only 7-8 spines (vs. the 11-13 on the flier) and in fact crappies look very different than fliers so you won't confuse them. Found in vegetated areas of swamps, stained water, areas of little or no current. Fins generally luxurient-looking. Forked caudal fin.

13. Elassomatidae: Pygmy sunfishes, genus Elassoma.

    These are small, olive to brownish fish with variable markings. They are found in older keys and books within the sunfish family. Some students have confused them at first with small Enneacanthus; however, those true sunfishes have a shorter, squatter shape (vs. the longer, slender pygmy sunfishes) and Enneacanthus species have 8-10 dorsal spines, whereas the Elassoma species have only 3-6 dorsal spines (both groups have ~3 anal spines). We have three species in our area:

zonatum: 8 or more dark, evenly spaced bars on body; pre-ocular and postocular lines dark and clear; top of head between the eyes has no scales; 8-9 soft dorsal rays and 4-5 soft anal rays.

    The other two species have highly variable coloration but do not have the evenly spaced bars or the pre- and postocular lines of zonatum evergladei: the only species with scales on top of the head; has 8-10 soft dorsal rays and 4-5 soft anal rays.

okefenokee: no scales atop the head between the eyes; has 10-13 soft dorsal rays and 6-8 soft anal rays.

So if you know you're holding a pygmy sunfish but the coloration is not helping you, look first for the zonatum-like bars as small "hash marks" on the dorsum (which is how they sometimes appear). If you can, look for scales atop the head (the presence of which would signify evergladei). If there are no scales, remember that okefenokee has 10-13 soft dorsal rays/6-8 soft anal rays and that zonatum has only 8-9 soft dorsals and 4-5 soft anals.

14. Percidae: Perches and darters.

    Separate dorsal fins and, in our area, long, delicate-looking bodies.  Our area is depauperate in these       fish.

    Percina nigrofasciata, black-banded darter. Found in moving water.

Etheostoma, "swamp" darters. Found in slow water.

E. swaini, Gulf darter. Dots on scales form irregular longitudinal lines.

E. fusiforme, swamp darter. Slender, "fragile-looking fish" with regular blotches on the side and 3-4 small but distinct spots across the caudal peduncle at the fin base.

E. edwini, brown darter. More robust-looking than fusiforme, with 8-9 distinct spots along the lateral line.

These fish are more common, and the "darter" fauna is more diverse in the Piedmont and mountain areas. As you go west, you encounter E. parvipinne when you hit the Apalachicola (this species is also found in the Altamaha drainage in Georgia--ask me about this) and E. okaloosae when you hit some streams in the Choctawhatchee drainage (can be distinguished from E. edwini, which it resembles closely, by the number of scales along the lateral line - 35 or fewer in this case, as opposed to edwini, which has 36 or more - and by the fact that okaloosae has the first anal spine longer than the second, whereas in edwini the first anal spine is as long as or shorter than the second).