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LONGFIN BATFISH
(Longfin Spadefish)
Platax teira (Forsskal, 1775)
Family Ephippidae
Now here's a find! On 15 Dec. 2003 Bo Lusher and Andy Schwanke at Mike
Severns Diving, operating out of Kihei, Maui, saw this batfish at a rarely-dived
site near Pu'u Ola'i at a depth of 85 ft. Since everyone knows that batfish
do not occur in Hawai`i, the sighting was unusual, to say the least. The
following day they went back to locate it again, but it wasn't there.
The day after that, however, they saw it at the wreck of the St. Anthony
about 3 miles away, where Pauline Fiene snapped this shot. Since Andy
had photographed it the first day, it was easily identified as the same
individual fish by the identical markings and tears in the fins.
My theory is that it's an aquarium release. (People buy them when they're
small, and release them when they outgrow the tank. Of course no one should
EVER release an alien species into our waters--but it does happen.) Longfin
Batfish are schooling fish and this one was probably roving far and wide
in search of others of its kind. Maui has a long coastline and the odds
of the same dive boat finding the same wandering fish again must be almost
as bad as the odds of the batfish finding a mate in Hawaii.
I said earlier that batfish do not occur
in Hawaii. Strictly speaking, that's not true. In April 1980 several Golden
Batfish (Platax boersii) were seen under the cargo pier at Midway
Atoll over 1000 miles northwest of the main Hawaiian Islands. One was
speared and its identity confirmed. As far as I know, the species has
not been reported again in the Hawaiian chain. It would be almost impossible
for the Midway specimens to have been aquarium releases. What probably
happened was that some Golden Batfish larvae drifted into Hawaiian waters
via the Kuroshio Current from Japan. A few grew to maturity, but did not
succeed in reproducing here. Of course, drifting larvae could be the origin
of this Longfin Batfish as well--evidently, this is not the first time
the species has been seen in Hawaii. We'll probably never know unless
more of them turn up.
If you see a batfish, how do you know if it's
a Golden Batfish or a Longfin Batfish? The two are similar, but the Golden
Batfish, as it's name implies, has a yellowish tinge overall. The best
way to identify the Longfin is by the dark spot low on the body above
the ventral fins. There is often a narrow vertical dark mark just behind
it. Both are clearly visible in this photo.
By the way, many ichthyologists seem to prefer
calling fishes of this genus "spadefishes" on the grounds that
fishes of the somewhat obscure family Ogcocephalidae are also called "batfishes."
However, the term "batfish" in reference to the large, common,
and showy fishes of the genus Platax (family Ephippidae) is firmly
entrenched among divers and aquarists. The problem is easily solved by
calling the Ogcocephalid fishes "walking batfishes," as suggested
by Scott Michael; this name is actually quite descriptive of these crawling
bottom-dwellers.
Update April 2005:
Longfin Batfish have recently been seen off O`ahu. One appeared at the
wreck of the Sea Tiger, off Waikiki, and Brian Zgliczynski reports seeing
several, possibly three, at the offshore moi cages (where moi, or threadfins,
are raised commercially). The species may be here to stay. Bill Keen of
Bill's Dive Locker took the photo
below of the Sea Tiger batfish. The photo was taken in February 2005 and
kindly sent to me by Rill Partlow of See
in Sea Scuba.

Longfin Batfish and
Hawaiian Cleaner Wrasse - Bill Keen - Sea Tiger wreck
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