
The Lyre Goby, Evorthodus lyricus
By Robert J. Goldstein
reprinted from American Currents, July-Aug. 1982
On a recent summer trip to Carolina and Kure Beaches, NC, I collected in a brackish
pond several specimens of Gambusia affinis, including two melanistic males for
purposes of selective breeding. During the collecting, two specimens of a then
unidentified species of goby were taken and placed in the same aquarium with the
mosquitofish.
The gobies at that time were mottled, blunt-headed, and with a dark spot in the spiny
dorsal fin. Since that time, one of the specimens has changed shape, finnage, and markings
in the course of maturation. The fish can now be identified as lyre gobies (Evorthodus
lyricus).
Information on the lyre goby can be found in Jerry Walls' Fishes of the Northern Gulf
of Mexico, Hoese and Moore' Fishes of the Gulf of Mexico, Hildebrand and Schroeder's
Fishes of Chesapeake Bay, and a few other sources of lesser import. In the aquarium
literature, it is covered briefly (and inaccurately) in Sterba's Freshwater Fishes of the
World under the names Evorthodus breviceps and Gobius lyricus. These are
just two of the names used in the past for this very variable fish. In Hildebrand and
Schroeder it is listed as Mugilostoma gobio. It has also been called, at various
times and in various publications, Gobius wurdemanni, Smaragdus costalesi, Gobionellus
costalesi, Euctenogobius lyricus, and all sorts of combinations of the above.
There are several reasons for the confusion. The fish is wide-ranging, occurring from
Chesapeake Bay south along the Atlantic Coast to the Gulf Coast, and into the Caribbean
region and Central America. It alters external shape markedly during development. Its
colors appear to have been described differently, possibly a reflection of natural
variation among individuals, possibly reflecting diet, possibly something else. Its
markings develop in stages, and each stage has been described separately. Internally,
there are also differences in that very important character, dentition. Males, females,
and juveniles all have apparently differing dentition, with this phenomenon compounded by
the presence of a papillary skin ridge alongside the teeth, the papules having been
confused in the past with an additional row of teeth.
Let us also look at some of the illustrations of this fish. Compare these sources of
pictures:
--Sterba, figs. 1141 (P. 766 my edition), and 1050 (p. 676) ;
--Walls, P. 324 (drawing); and
--Hoese & Moore, fig. 387 (p, 83).
In the drawings, there is a strong tendency to put ocelli on the upper part of the
caudal fin, and sometimes streaks in their place. There is also a strong tendency to show
bold lines radiating from the eye on the male, and to show the forward rays connected by a
membrane (in the dorsal fin) and sweeping back like a tapered rag. The photo in Sterba
tends to reinforce this illusion.
My male, in fact, has no black smudges, ocelli, lines, or anything else in his tail fin
other than two submarginal bands of orange-yellow. The rest of the fin is clear. There are
no bold marks radiating from the eye , The dorsal fin rays are elongated filaments but not
connected by any membrane above their normal level, so that the rays alone may be erected
or flow backward, but not the fin proper.
Characteristic of the fish is a very blunt head, with the mouth subterminal. The female
has a black mark in her spiny dorsal fin which is quite bold, but not sharply defined. In
both sexes there are two black marks on the caudal peduncle just before the fin, one above
the other.
But the real giveaway on this fish is its habit of feeding upon detritus. That may have
something to do with its mullet-like mouth arrangement, for mullet are also
detritus-feeders, and few fishes are. While many killies will feed on detritus, they will
quickly attack other foods as preferable.
Not so with the lyre goby. When frozen adult brine shrimp or flake food or freeze-dried
ocean plankton or even live baby brine shrimp are placed in their aquarium, they make no
alterations in their feeding patterns, but continue to lope along the bottom, dipping
their heads and picking up detritus, which they chew and partly spit out. As their bellies
are always well rounded, it seems clear they are eating much of the detritus, and not
merely selecting portions of its contents for swallowing.
The tank is set up with mud from my garden overlaying an undergravel bed and filter,
with planted Sagittaria and floating watersprite and duckweed. The water has been hardened
with plaster of paris, and only recently (after maturation) did I add a slight amount of
sea water (one cup to ten gallons of freshwater) in an attempt to stimulate the gobies
into more attentive (to one another) behavior. It made no differences; the fish may still
be a bit young for hanky-panky.
I collected these fish in a pond which was of extremely low salinity, on the coast
behind the dunes. The bottom was muddy, and there were few emergent plants, though the
gobies were collected among those plants. I suspected at the time that they were
associated with the stems of the plants but not the roots, since they were not taken along
portions of the shoreline rich in entwined submerged vegetation.
There is one scientific report on this fish that is at once thorough, comprehensive,
restricted to this one subject, and clearly written. That is a paper by Isaac Ginsburg:
Juvenile and sex characters of Evorthodus lyricus (Fam. Gobiidae), Bulletin of the
(U.S.) Bureau of Fisheries, 1931, pp. 117-123. I suggest you get it from a university
library. If they don't have it there, you can order a xerox copy through Interlibrary Loan
Service. Just ask the librarian for this service. It is free, but for the cost of
duplicating the paper and mailing it.
Of special interest is the distribution of the fish. While it is probably quite
uncommon along the Atlantic Coast, it has been reported as common along the Gulf Coast,
particularly in the vicinity of Louisiana. I suspect it may be found just about anywhere
along our seaboard, if one merely takes the trouble to collect in obnoxious habitats. As
indicated, it occurs in very low salinity regions, generally ponds connected at high tide
with some tidal sea source. If there is muck and Gambusia, then it might be there. It
tends to congregate in areas that have been stirred up-or perhaps the stirring is getting
them out of the muck. In any case, one should seine the same spot over and over, and the
gobies should start appearing in the later drags.
I hope aquarists living along seaboards will search for this fish. Look for any small
goby with dark smudges on its flanks and a blunt nose. Place what you collect in a
mud-bottom or silt-bottom tank and look for detritus-feeding behavior. That should clinch
the identification, since it is such a rare occurrence--especially among gobies, which
tend to be predaceous.
I have offered my fish PVC pipes for possible breeding, plus a variety of rock caves,
and one PVC pipe standing upward in case these fish are plant-stem spawners.
I have described where I caught mine. Now let me quote to you from Ginsburg (1931):
"It was not obtained in seining open beaches. It was found chiefly in two marshy
lagoons connected with
Bay, at the east end of Grand Isle.... These lagoons, at low
tide, are reduced to mere ponds disconnected from the main body of water. The bottom is
muddy...by dragging the seine back and forth, they would be taken in considerable
numbers," 'Nough said?
I also suggest that local members of NANFA, or clubs located near such habitats, make
efforts to bring more of these fishes into the hobby and attempt to spawn them. The
feeding habits of the fish, combined with its beauty, finnage, and tendency to occur in
practically fresh water, all indicate that there is a good chance for breeding success
with the fish. The fry may adapt very well to the infusoria in detritus, as well as baby
brine shrimp at some stage of early development. The fish has great promise, and the first
aquarist to breed it deserves a pat on the back from the rest of us.
Used with permission. Article copyright retained by author.
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