Pterois volitans (Lionfish)
The marine aquarium hobby
and service business would definitely be poorer were it not
for the lionfishes. They are the archetypal 'stock' captive
fishes. Hardy, readily available, second only to damsels in
accepting disastrous water conditions. Able to be trained to
accept almost all types of foods and amongst the most disease
resistant of specimens, lions are, would seem to be the best
of captive aquatic life; and they are.
Except for the very real
probability of getting stung by their venom bearing fins by
being careless, the only downside of lionfish keeping lies in
picking out healthy individuals and not overfeeding them.
The Various Lionfish and
Lionfishes are members of
the scorpion- or rockfish family Scorpaenidae
("Score-pea-nah-dee") a group of fishes important to
humans as food fishes and sources of envenomation (the
subfamilies Synanceinae, the stonefishes, and Pteroinae, the
lionfishes, among others). The non-toxic, but still very spiny
rockfishes, in the genera Sebastes, and Sebastolobus
are prominent table fare, sold as 'Pacific Snapper' in the
U.S. though they are not in the snapper family, Lutjanidae. As
Billy Shakespeare might say (or write) what's in a name;
For those few of us into
higher taxonomy, you're referred to Nelson's latest edition of
Fishes of the World, 1994. Scorpaenids are part of the
Order Scorpaeniformes, the 'Mail-Cheeked Fishes', referring to
the numerous processes on these fishes gill covers. A brief
synopsis here for sake of granting you insights into the
breadth of this group, and logical links to pages on the WWM
Order Scorpaeniformes, the
"Mail-Cheeked Fishes", 25 families, about 166
genera, 1,271 species.
Family Dactylopteridae, the Flying Gurnards. Two genera, about
Contains world's most venomous fishes. Seven families, about
96 genera, 544 species.
Family Scorpaenidae, the
Scorpionfishes and Rockfishes. 56 plus genera and 388 species.
Subfamily Sebastinae, the
Rockfishes. Important foodfishes. Four genera, about 128
various Scorpionfishes. 15 plus genera with more than 150
Three genera of five species.
One genus, two species.
Subfamily Pteroinae. The
Lionfishes and Turkeyfishes discussed here
Three genera, five species.
Two genera, twelve species.
Subfamily Apistinae. Three
Tetraroginae, Sailback Scorpionfishes or Wasp Fishes. 11
plus genera and 35 species.
Subfamily Minoinae. One
genus, 11 species.
Choridactylinae (Inimicinae). Two genera, ten species.
Synanceinae, the Stonefishes proper. Six genera, ten
Orbicular Velvetfishes. One genus, four species.
Family Aploactinidae, the
Velvetfishes. Approximately 17 genera and 37 species.
Australian Prowfishes. Three genera and nine species.
Family Gnathacanthidae, the
Red Velvetfish. One species.
Family Congiopodidae, the
(bizarre) Racehorses, aka Pigfishes, Horsefishes. Four genera,
Triglidae, the Searobins or Gurnards. Divided into two
subfamilies and three Tribes.
Crocodilefishes, Flatheads. Three families, 23 genera, about
Family Bembridae, the
Deepwater Flatheads. Four genera, five species.
Platycephalidae, Crocodilefishes or Flatheads. 18 genera
of about 60 species.
Family Hoplichthyidae, the
Ghost Flatheads. One genus, ten species
And more I/we'll eventually
list and go over like the sculpins/cottids, agonids/poachers,
hexagrammids/greenlings... but not today.
Back to the Family At
The family Scorpaenidae's
widespread importance is reflected in it's many colorful
common names: Upside-Down Flying Cod, Butterfly Cod,
Turkeyfish, Firefish, Scorpionfish, Zebrafish, Stonefish,
Rockfish, among many others.
And The subfamily
Pteroinae, Aquarium Lionfishes: 5 Genera, 17 Species
For our purposes here let's
limit the discussion to the Lionfish species important to the
pet fish hobby and industry; those of the genera Pterois,
Dendrochirus, and Brachypterois. The first genus
Pterois (Tare-oh-ease) are considered the
"true" full-size lions, with huge pectoral fins,
featuring unbranched rays with degrees of connecting membranes
extending beyond the body at their insertion.
The other two genera are
more often sold as 'dwarf' lions. They display smaller,
branched-ray pectoral fins with the rays sporting almost
A brief mention here
regarding 'other Lion' species. There are several other genera
in the scorpaenid family offered from time to time as
Lionfishes. For the most part these miscellaneous fishes are
not as desirable as the species we will go over here. They are
more secretive and far less appealing physically and color and
pattern-wise. But, they probably are all venomous. Much
more about this later, but it bears re, re, repeating: all
Lionfishes are venomous and amazingly easy to get
'stuck' by. Yes, it's painful and may be very dangerous,
especially is you have allergic reactions to proteinaceous
stings (Stung, interested? See Wound
Management for Aquarists).
as regards the 'Freshwater Lionfish' sold in the trade; these
are actually Sculpins, family Cottidae, related not too
distantly to scorpaenids (in the same Order). For the record,
besides not being Lionfishes, they are not venomous, or
freshwater. There are some sort-of brackish water
Scorpaeniform fishes, like the Bullroats, that do make forays
into freshwater, but they are not permanent residents.
The Lionfishes You'll
Likely Encounter Include:
(Bloch 1787), the Antennata Lion or Broad-Banded
Firefish to science. This is the third lion confused
with the volitans and luna species. You won't make this
mistake. Antennata lions have strikingly different
pectoral fin rays. These are long, the thickness of
pencil lead and bright white. Also, remember the
connection, between the name Antennata for it's
relation to the black and white antennae (supraorbital
flaps) and the six prominent spots on their face. To
eight inches long.
Temminck & Schlegel 1843 , the Luna Lion, is too
often mis-offered in stores as 'red volitans'. Luna
lions lack the beautiful head flaps on the supraorbital
bones, and have more rounded, less angular heads than
volitans lions. Look closely at the two; most luna
pectoral rays are connected by a web of tissue about
two-thirds of their length; volitans almost totally lack
this webbing. P. lunulata are typically rusty red-brown
against a creamy background; occasionally specimens are
offered that bear gorgeous bluish-green color at the
tips of their unpaired fins. Indo-Pacific
miles (Bennett 1828), the Devil Firefish. Indian Ocean
and Red Sea. To fourteen inches in length. An occasional
import from the Red Sea, though so similar to the
Volitans and more expensive to transport to the west
that is rarely seen in the U.S. Red Sea images.
Pterois radiata Cuvier
1829, the Two-Bar Lion is the Radial Firefish.
The most chameleonic of lions showing overtones of
green, black and various shades of red over shocking
white. The salient identifying characteristic of this
species is the two while horizontal bars on the caudal
peduncle, the part of the body right before the tail.
Aquarium and Red Sea specimens. To nine inches.
Jordan & Evermann 1903, the endemic Hawaiian
("Dwarf") Lion; often mistakenly sold as
Antennata lions which they closely resemble in terms of
pectoral finnage. Sphex lion fins are shorter, less
colorful and more clubbed in appearance. Though more
costly than the majority of lions which are imported
from the Philippines and Indonesia, Hawaiian lions are
my favorite for hardiness. To eight inches.
("Tare-oh-ease vawl-it-tanz) (Linnaeus 1758),
is the Lionfish to most folks. It is the most
commonly displayed and sold member of the family; the
quintessential marine aquarium specimen, with it's long
flowing pectoral and dorsal fin rays. Volitans lions
span the color range of banded red to black against
alternating creamy white. Yes, black and red volitans
lions are the same species. These images from the Red
'Dwarf' Lionfishes in the
genera Dendrochirus ("Den-droh-kear-us) and Brachypterois
("Brack-ee-tear-oys") are labeled as such for their
smaller size and more sedentary, bottom-dwelling habits.
1928), the Twin-Spot, Roo or Fu Man Chu Lion is
unmistakable with it's two eye spots on the rear dorsal
fin area, and two whisker-like appendages extending from
the lower jaw. To almost five inches in length. Aquarium
("Brack-hip-tur-us") (Cuvier 1829), The
Shortfin Dwarf Lion is a rarer, more heavy bodied dwarf,
often showing up with a good deal of yellow, brown and
green mixed with red markings. Brach dwarfs are aptly
named in reference to their very large pectoral fins
with almost no emerging ray tips. This is one of the
most personable marine species, quickly getting to
recognize and respond to it's owners presence.
1829), the Zebra Turkeyfish, is the most common dwarf
lion is similar in many ways and degrees to P.
antennata and P. sphex. The one sure
distinguishing mark of D. zebra is the presence
of two white spheres on it's caudal peduncle. To ten
inches in length. Shown: an individual and
"tree" of individuals in captivity.
the permission of Robert (Bob) Fenner webmaster
Photos of Pterois Volitans by George J. Reclos - MCH