THE BLENNIES: BLENNIIDÆ
[Illustration:
FIG. 447.—Sarcastic Blenny, _Neoclinus satiricus_ Girard. Monterey.
]
THE great family of blennies, _Blenniidæ_, contains a vast number of
species with elongate body, numerous dorsal spines, without suborbital
stay or sucking-disk, and the ventrals jugular, where present, and of
one spine and less than five soft rays. Most of them are of small size,
living about rocks on the sea-shores of all regions. In general they are
active fishes, of handsome but dark coloration, and in the different
parts of the group is found great variety of structure. The tropical
forms differ from those of arctic regions in the much shorter bodies and
fewer vertebræ. These forms are most like ordinary fishes in appearance
and structure and are doubtless the most primitive. Of the five hundred
known species of blennies, we can note only a few of the most prominent.
To _Clinus_ and related genera belong many species of the warm seas,
scaly and ovoviviparous, at least for the most part. The largest of
these is the great kelpfish of the coast of California, _Heterostichus
rostratus_, a food-fish of importance, reaching the length of two feet.
Others of this type scarcely exceed two inches. _Neoclinus satiricus_,
also of California, is remarkable for the great length of the upper jaw,
which is formed as in _Opisthognathus_. Its membranes are brightly
colored, being edged with bright yellow. _Gibbonsia elegans_ is the
pretty "señorita" of the coralline-lined rock-pools of California.
_Lepisoma nuchipinne_, with a fringe of filaments at the nape, is very
abundant in rock-pools of the West Indies. The species of
_Auchenopterus_ abound in the rock-pools of tropical America. These are
very small neatly colored fishes with but one soft ray in the long
dorsal fin. Species of _Tripterygion_, _Myxodes_, _Cristiceps_, and
other genera abound in the South Pacific.
[Illustration:
FIG. 448.—Kelp Blenny, _Gibbonsia evides_ Jordan & Gilbert. San Diego.
]
[Illustration:
FIG. 449.—_Blennius cristatus_ L. Florida.
]
In _Blennius_ and its relatives the body is scaleless and the slender
teeth are arranged like the teeth of a comb. In most species long,
fang-like posterior canines are developed in the jaws. _Blennius_ is
represented in Europe by many species, _Blennius galerita_, _ocellaris_,
and _basiliscus_ being among the most common. Certain species inhabit
Italian lakes, having assumed a fresh-water habit. The numerous American
species mostly belong to other related genera, _Chasmodes bosquianus_
being most common. _Blennius yatabei_ abounds in Japan. In
_Petroscirtes_ and its allies the gill-openings are much restricted. The
species are mainly Asiatic and Polynesian and are very prettily colored.
_Petroscirtes elegans_ and _P. trossulus_ adorn the Japanese rock-pools
and others, often deep blue in color, abound in the coral reefs of
Polynesia.
[Illustration:
FIG. 450.—Rock-skipper, _Alticus atlanticus_. San Cristobal, Lower
Cal.
]
[Illustration:
FIG. 451.—Lizard-skipper, _Alticus saliens_ (Forster). A blenny which
lies out of water on lava rocks, leaping from one to another with
great agility. From nature; specimen from Point Distress, Tutuila
Island, Samoa. (About one-half size.)
]
[Illustration:
FIG. 452.—_Emblemaria atlantica_ Jordan. Pensacola, Fla.
]
The rock-skippers (Salarias, Alticus, etc.) are herbivorous, with
serrated teeth set loosely in the jaws. These live in the rock-pools of
the tropics and leap from rock to rock when disturbed with the agility
of lizards. They are dusky or gray in color with handsome markings. One
of them, _Erpichthys_ or _Alticus saliens_ in Samoa, lives about lava
rocks between tide-marks, and at low tide remains on the rocks, over
which it runs with the greatest ease and with much speed, its movements
being precisely like those of _Periophthalmus_. As in the species of the
latter genus, otherwise wholly different, this _Alticus_ has short
ventral fins padded with muscle.
[Illustration:
FIG. 453.—_Scartichthys enosimæ_ Jordan & Snyder, a fish of the
rock-pools of the sacred island of Enoshima, Japan. Family
_Blenniidæ_.
]
_Erpichthys atlanticus_ is found in abundance on both coasts of tropical
America. Many species abound in Polynesia and in both Indies. _Salarias
enosimæ_ lives in the clefts of lava rocks on the shores of Japan.
_Ophioblennius_ (_webbi_) is remarkable for its strong teeth,
_Emblemaria_ (_nivipes_, _Atlantica_) for its very high dorsal. Many
other genera allied to _Blennius_, _Clinus_, and _Salarias_ abound in
the warm seas.
[Illustration:
FIG. 454.—_Zacalles bryope_ Jordan & Snyder. Misaki, Japan.
]
[Illustration:
FIG. 455.—_Bryostemma tarsodes_ Jordan & Snyder. Unalaska.
]
[Illustration:
FIG. 456.—_Exerpes asper_ Jenkins & Evermann. Guaymas, Mexico. Family
_Blenniidæ_.
]
=The Northern Blennies: Xiphidiinæ, Stichæiniæ, etc.=—The blennies of
the north temperate and arctic zones have the dorsal fin more elongate,
the dorsal fin usually but not always composed entirely of spines. The
scales are small and the ventral fins generally reduced in size. These
are divided by Dr. Gill into several distinct families, but the groups
recognized by him are subject to intergradations.
[Illustration:
FIG. 457.—Gunnel, _Pholis gunnellus_ (L.). Gloucester, Mass.
]
[Illustration:
FIG. 458.—_Xiphistes chirus_ Jordan & Gilbert. Amchitka I., Alaska.
]
_Chirolophis_ (_ascanii_) of north Europe is remarkable for the tufted
filaments on the head. These are still more developed in _Bryostemma_ of
the North Pacific, _Bryostemma polyactocephalum_ and several other
species being common from Puget Sound to Japan. _Apodichthys_
(_flavidus_) of California is remarkable for a large quill-shaped anal
spine and for the great variation in color, the hue being yellow,
grass-green, or crimson, according to the color of the algæ about it.
There is no evidence, however, that the individual fish can change its
color, and these color forms seem to be distinct races within the
species. _Xererpes fucorum_ of California lies quiescent in the seaweed
(_Fucus_) after the tide recedes, its form, color, and substance seeming
to correspond exactly with those of the stems of algæ. _Pholis
gunnellus_ is the common gunnel (gunwale), or butter-fish, of both
shores of the North Atlantic, with numerous allies in the North Pacific.
Of these, _Enedrias nebulosus_, the ginpo, or silver-tail, is especially
common in Japan. _Xiphidion_ and _Xiphistes_ of the California coast,
and _Dictyosoma_ of Japan, among others, are remarkable for the great
number of lateral lines, these extending crosswise as well as
lengthwise. _Cebedichthys violaceus_, a large blenny of California, has
the posterior half of the dorsal made of soft rays. _Opisthocentrus_ of
Siberia and north Japan has the dorsal spines flexible, only the
posterior ones being short and stiff. The snake-blennies (_Lumpenus_),
numerous in the far North, are extremely slender, with well-developed
pectorals and ventrals. _Lumpenus lampetræformis_ is found on both
shores of the Atlantic. In _Stichæus_ a lateral line is present. There
is none in _Lumpenus_, and in _Ernogrammus_ and _Ozorthe_ there are
three. All these are elongate fishes, of some value as food and
especially characteristic of the Northern seas. Fossil blennies are
almost unknown. _Pterygocephalus paradoxus_ of the Eocene resembles the
living _Cristiceps_, a genus which differs from _Clinus_ in having the
first few dorsal spines detached, inserted on the head. The first spine
alone in _Pterygocephalus_ is detached and is very strong. A species
called _Clinus gracilis_ is described from the Miocene near Vienna,
_Blennius fossilis_ from the Miocene of Croatia, and an uncertain
_Oncolepis isseli_ from Monte Bolca. The family is certainly one of the
most recent in geologic times. The family of _Blenniidæ_, as here
recognized, includes a very great variety of forms and should perhaps be
subdivided into several families, as Dr. Gill has suggested. At present
there is, however, no satisfactory basis of division known.
[Illustration:
FIG. 459.—_Ozorthe dictyogramma_ (Hertzenstein), a Japanese blenny
from Hakodate: showing increased number of lateral lines, a trait
characteristic of many fishes of the north Pacific.
]
[Illustration:
FIG. 460.—_Stichæus punctatus_ Fabricius. St. Michael, Alaska.
]
=The Quillfishes: Ptilichthyidæ.=—The _Ptilichthyidæ_, or quillfishes,
are small and slender blennies of the North Pacific, with very numerous
fin-rays. _Ptilichthys goodei_ has 90 dorsal spines and 145 soft rays.
Another group of very slender naked blennies is the small family of
_Xiphasiidæ_ from the South Pacific. The jaws have excessively long
canines; there are no ventral fins. The dorsal fin is very high and the
caudal ends in a long thread.
[Illustration:
FIG. 461.—_Bryostemma otohime_ Jordan & Snyder. Hakodate, Japan.
Family _Blenniidæ_.
]
[Illustration:
FIG. 462.—Quillfish, _Ptilichthys goodei_ Bean. Unalaska.
]
[Illustration:
FIG. 463.—_Blochius longirostris_ Volta, restored. Upper Eocene of
Monte Bolca. (After Woodward.)
]
=The Blochiidæ.=—Of doubtful relationship is the extinct family of
_Blochiidæ_. In this group the body is elongate, covered with keeled
plates imbricated like shingles. The dorsal is composed of many slender
spines, and the vertebræ much elongate. In _Blochius longirostris_
(Monte Bolca Eocene) has very long jaws, lined with small teeth. Zittel
regards the family as allied to the _Belonorhynchidæ_, but the
prolongation of the jaws may be a character of analogy merely. Woodward
places it next to the _Blenniidæ_, supposing it to have small and
jugular ventral fins. But as the presence of ventral fins is uncertain,
the position of the family cannot be ascertained and it may really
belong in the neighborhood of _Ammodytes_. The dorsal rays are figured
by Woodward as simple.
[Illustration:
FIG. 464.—_Xiphasia setifera_ Swainson. India. (After Day.)
]
=The Patæcidæ etc.=—The _Patæcidæ_ are blenny-like fishes of Australia,
having the form of _Congriopus_, the spinous dorsal being very high and
inserted before the eyes, forming a crest. _Patæcus fronto_ is not rare
in South Australia. The _Gnathanacanthidæ_ is another small group of
peculiar blennies from the Pacific. The _Acanthoclinidæ_ are small
blennies of New Zealand with numerous spines in the anal fin.
_Acanthoclinus littoreus_ is the only known species.
=The Gadopsidæ, etc.=—The family of _Gadopsidæ_ of the rivers of New
Zealand and southern Australia consists of a single species, _Gadopsis
marmoratus_, resembling the scaly blennies called _Clinus_, but with
long ventrals of a single ray, and three spines in the anal fin besides
other peculiarities. The species is locally very common and with various
other fishes in regions where true trout are unknown, it is called
"trout."
The _Cerdalidæ_ are small band-shaped blennies of the Pacific coast of
Panama. The slender dorsal spines pass gradually into soft rays. Three
species are known.
[Illustration:
FIG. 465.—Wrymouth, _Cryptacanthodes maculatus_. New York.
]
The wrymouths, or _Cryptacanthodidæ_, are large blennies of the northern
seas, with the mouth almost vertical and the head cuboid. The wrymouth
or ghostfish, _Cryptacanthodes maculatus_, is frequently taken from Long
Island northward. It is usually dusky in color, but sometimes pure
white. Other genera are found in the north Pacific.
=The Wolf-fishes: Anarhichadidæ.=—The wolf-fishes (_Anarhichadidæ_) are
large blennies of the northern seas, remarkable for their strong teeth.
Those in front are conical canines. Those behind are coarse molars. The
dorsal is high, of flexible spines. The species are large, powerful,
voracious fishes, known as wolf-fishes. _Anarhichas lupus_ is the common
wolf-fish of the north Atlantic, reaching a length of four to six feet,
the body marked by dark cross-bands. Other similar species are found
both in the north Pacific and north Atlantic. _Anarhichas lepturus_,
plain brown in color, is common about the Aleutian Islands.
[Illustration:
FIG. 466.—Wolf-fish, _Anarhichas lupus_ (L.). Georges Bank.
]
[Illustration:
FIG. 467.—Skull of _Anarrhichthys ocellatus_ Ayres.
]
In the wolf-eel (_Anarrhichthys ocellatus_) of the coast of California,
the head is formed as in _Anarhichas_ but the body is band-shaped, being
drawn out into a very long and tapering tail. This species, which is
often supposed to be a "sea-serpent," sometimes reaches a length of
eight feet. It is used for food. It feeds on sea-urchins and
sand-dollars (_Echinarachinius_) which it readily crushes with its
tremendous teeth.
The skull of a fossil genus, _Laparus_ (_alticeps_), with a resemblance
to _Anarhichas_, is recorded from the Eocene of England.
=The Eel-pouts: Zoarcidæ.=—The remaining blenny-like forms lack fin
spines, agreeing in this respect with the codfishes and their allies. In
all of the latter, however, the hypercoracoid is imperforate, the
pseudobranchiæ are obsolete, and the tail isocercal. The forms allied to
_Zoarces_ and _Ophidion_, and which we may regard as degraded blennies,
have homocercal (rarely leptocercal) tails, generally but not always
well-developed pseudobranchiæ and the usual foramen in the
hypercoracoid.
[Illustration:
_Fig. 463._—Eel-pout, _Zoarces anguillaris_ Peck. Eastport, Me.
]
The _Zoarcidæ_, or eel-pouts, have the body elongate, naked, or covered
with small scales, the dorsal and anal of many soft rays and the
gill-openings confined to the side. Most of the species live in rather
deep water in the Arctic and Antarctic regions. _Zoarces viviparus_, the
"mother of eels," is a common fish of the coasts of northern Europe. In
the genus _Zoarces_, the last rays of the dorsal are short and stiff,
like spines. The species are viviparous; the young being eel-like in
form, the name "mother of eels" has naturally arisen in popular
language. The American eel-pout, sometimes called mutton-fish, _Zoarces
anguillaris_, is rather common north of Cape Cod, and a similar species,
_Zoarces elongatus_, is found in northern Japan. _Lycodopsis pacifica_,
without spines in the dorsal, replaces _Zoarces_ in California. The
species of _Lycodes_, without spines in the dorsal, and with teeth on
the vomer and palatines, are very abundant in the northern seas,
extending into deep waters farther south. _Lycodes reticulatus_ is the
most abundant of these fishes, which are valued chiefly by the Esquimaux
and other Arctic races of people. Numerous related genera are recorded
from deep-sea explorations, and several others occur about Tierra del
Fuego. _Gymnelis_, small, naked species brightly colored, is represented
by _Gymnelis viridis_ in the Arctic and by _Gymnelis pictus_ about Cape
Horn.
[Illustration:
FIG. 469.—Eel-pout, _Lycodes reticulatus_ Reinhardt. Banquereau.
]
[Illustration:
FIG. 470.—_Lycenchelys verrilli_ (Goode & Bean). Chebucto, Nova
Scotia.
]
[Illustration:
FIG. 471.—_Scytalina cerdale_ Jordan & Gilbert. Straits of Fuca.
]
The family of _Scytalinidæ_ contains a single species, _Scytalina
cerdale_, a small snake-shaped fish which lives in wet gravel between
tide-marks, on Waada Island near Cape Flattery in Washington, not having
yet been found elsewhere. It dives among the wet stones with great
celerity, and can only be taken by active digging.
To the family of _Congrogadidæ_ belong several species of eel-shaped
blennies with soft rays only, found on the coasts of Asia. Another small
family, _Derepodichthyidæ_, is represented by one species, a scaleless
little fish from the shores of British Columbia.
The _Xenocephalidæ_ consist of a single peculiar species, _Xenocephalus
armatus_, from the island of New Ireland. The head is very large,
helmeted with bony plates and armed with spines. The body is short and
slender, the ventrals with five rays, the dorsal and anal short.
=The Cusk-eels: Ophidiidæ.=—The more important family of _Ophidiidæ_, or
cusk-eels, is characterized by the extremely anterior position of the
ventral fins, which are inserted at the throat, each one appearing as a
long forked barbel. The tail is leptocercal, attenuate, the dorsal and
anal confluent around it. _Ophidion barbatum_ and _Rissola rochei_ are
common in southern Europe. _Rissola marginata_ is the commonest species
on our Atlantic coast, and _Chilara taylori_ in California. Other
species are found farther south, and still others in deep water.
_Genypterus_ contains numerous species of the south Pacific, some of
which reach the length of five feet, forming a commercial substitute for
cod. _Genypterus capensis_ is the klipvisch of the Cape of Good Hope,
and _Genypterus australis_ the "Cloudy Bay cod" or "rock ling" of New
England. Another large species, _Genypterus maculatus_, occurs in Chile.
A few fragments doubtfully referred to _Ophidion_ and _Fierasfer_ occur
in the Eocene and later rocks. The _Lycodapodidæ_ contain a few small,
scaleless fishes (_Lycodapus_) dredged in the north Pacific.
[Illustration:
FIG. 472.—Cusk-eel, _Rissola marginata_ (De Kay). Virginia.
]
[Illustration:
FIG. 473.—_Lycodapus dermatinus_ Gilbert. Lower California.
]
=Sand-lances: Ammodytidæ.=—Near the _Ophidiidæ_ are placed the small
family of sand-lances (_Ammodytidæ_). This family comprises small,
slender, silvery fishes, of both Arctic and tropical seas, living along
shore and having the habit of burying themselves in the sand under the
surf in shallow water. The jaws are toothless, the body scarcely scaly
and crossed by many cross-folds of skin, the many-rayed dorsal fin is
without spines, and the ventral fins when present are jugular. The
species of the family are very much alike. From their great abundance
they have sometimes much value as food, more perhaps as bait, still more
as food for salmon and other fishes, from which they escape by plunging
into the sand. Sometimes a falling tide leaves a sandy beach fairly
covered with living "lants" looking like a moving foam of silver.
_Ammodytes tobianus_ is the sand-lance or lant of northern Europe.
_Ammodytes americanus_, scarcely distinguishable, replaces it in
America; and _Ammodytes personatus_ in California, Alaska, and Japan.
This is a most excellent pan fish, and the Japanese, who regard little
things, value it highly.
[Illustration:
FIG. 474.—Sand-lance, _Ammodytes americanus_ De Kay. Nantucket.
]
[Illustration:
FIG. 475.—_Embolichthys mitsukurii_ (Jordan & Evermann). Formosa.
]
In the genus _Hyperoplus_ there is a large tooth on the vomer. In the
tropical genera there is a much smaller number of vertebræ and the body
is covered with ordinary scales instead of delicate, oblique cross-folds
of skin. These tropical species must probably be detached from the
_Ammodytidæ_ to form a distinct family, _Bleekeriidæ_. _Bleekeria
kallolepis_ is found in India, _Bleekeria gilli_ is from an unknown
locality, and the most primitive species of sand-lance, _Embolichthys
mitsukurii_, occurs in Formosa. In this species, alone of the
sand-lances, the ventral fins are retained. These are jugular in
position, as in the _Zoarcidæ_, and the rays are I, 3. The discovery of
this species makes it necessary to separate the _Ammodytidæ_ and
_Bleekeriidæ_ widely from the _Percesoces_, and especially from the
extinct families of _Crossognathidæ_ and _Cobitopsidæ_ with which its
structure in other regards has led Woodward, Boulenger, and the present
writer to associate it.
Although an alleged sand-lance, _Rhynchias septipinnis_, with ventral
fins abdominal, was described a century ago by Pallas, no one has since
seen it, and it may not exist, or, if it exists, it may belong among the
_Percesoces_. The relation of _Ammodytes_ to _Embolichthys_ is too close
to doubt their close relationship. According to Dr. Gill the
_Ammodytidæ_ belong near the _Hemerocœtidæ_.
[Illustration:
FIG. 476.—Pearlfish, _Fierasfer dubius_ Putnam, embedded in a layer of
mother-of-pearl. La Paz, Lower California. (Photograph by Capt. M.
Castro.)
]
=The Pearlfishes: Fierasferidæ.=—In the little group of pearlfishes,
called _Fierasferidæ_ or _Carapidæ_, the body is eel-shaped with a
rather large head, and the vent is at the throat. Numerous species of
_Fierasfer_ (_Carapus_) are found in the warm seas. These little fishes
enter the cavities of sea-cucumbers (Holothurians) and other animals
which offer shelter, being frequently taken from the pearl-oyster. In
the Museum of Comparative Zoology, according to Professor Putnam, is
"one valve of a pearl-oyster in which a specimen of _Fierasfer dubius_
is beautifully inclosed in a pearly covering deposited on it by the
oyster." A photograph of a similar specimen is given above. The species
found in Holothurians are transparent in texture, with a bright pearly
luster. Species living among lava rocks, as _Jordanicus umbratilis_ of
the south seas, are mottled black. Since this was written a specimen of
this black species has been obtained from a Holothurian in Hilo, Hawaii,
by Mr. H. W. Henshaw.
[Illustration:
FIG. 477.—Pearlfish, _Fierasfer acus_ (Linnæus), issuing from a
Holothurian. Coast of Italy. (After Emery.)
]
=The Brotulidæ.=—The _Brotulidæ_ constitute a large family of fishes,
resembling codfishes, but differing in the character of the
hypercoracoid, as well as in the form of the tail. The resemblance
between the two groups is largely superficial. We may look upon the
_Brotulidæ_ as degraded blennies, but the _Gadidæ_ have an earlier and
different origin which has not yet been clearly made out. Most of the
_Brotulidæ_ live in deep water and are without common name or economic
relations. Two species have been landlocked in cave streams in Cuba,
where they have, like other cavefishes, lost their sight, a phenomenon
which richly deserves careful study, and which has been recently
investigated by Dr. C. H. Eigenmann. These blind Brotulids, called Pez
Ciego in Cuba, are found in different caves in the county of San
Antonio, where they reach a length of about five inches. As in other
blindfishes, the body is translucent and colorless. These species are
known as _Lucifuga subterranea_ and _Stygicola dentata_. They are
descended from allies of the genera called _Brotula_ and
_Dinematichthys_. _Brotula barbata_ is a cusk-like fish, occasionally
found in the markets of Havana. Similar species, _Brotula multibarbata_
and _Sirembo inermis_, are common in Japan, and _Brosmophycis
marginatus_, beautifully red in color, is occasionally seen on the coast
of California. Many other genera and species abound in the depths of the
sea and in crevices of coral reefs, showing much variety in form and
structure.
[Illustration:
FIG. 478.—_Brotula barbata_ Schneider. Cuba.
]
[Illustration:
FIG. 479.—Blind Brotula. _Lucifuga subterranea_ (Poey), showing
viviparous habit. Joignan Cave, Pinar del Rio, Cuba. (Photograph by
Dr. Eigenmann.)
]
The _Bregmacerotidæ_ are small fishes, closely related to the Brotulids,
having the hypercoracoid perforate, but with several minor
peculiarities, the first ray of the dorsal being free and much elongate.
They live near the surface in the open sea. _Bregmaceros macclellandi_
is widely diffused in the Pacific.
=Ateleopodidæ.=—The small family of _Ateleopodidæ_ includes long-bodied,
deep-water fishes of the Pacific, resembling _Macrourus_, but with
smooth scales. The group has the coracoids as in _Brotulidæ_, and the
actinosts are united in an undivided plate. _Ateleopus japonicus_ is the
species taken in Japan.
=Suborder Haplodoci.=—We may here place the peculiar family of
_Batrachoididæ_, or toadfishes. It constitutes the suborder of
_Haplodoci_ (ἁπλόος, simple; δόκος, shaft) from the simple form of the
post-temporal. This order is characterized by the undivided
post-temporal bone and by the reduction of the gill-arches to three. A
second bone behind the post-temporal connects the shoulder-girdle above
to the vertebral column. The coracoid bones are more or less elongate,
suggesting the arm seen in pediculate fishes.
The single family has the general form of the _Cottidæ_, the body
robust, with large head, large mouth, strong teeth, and short spinous
dorsal fin. The shoulder-girdle and its structures differ little from
the blennioid type. There are no pseudobranchiæ and the tail is
homocercal. The species are relatively few, chiefly confined to the warm
seas and mostly American, none being found in Europe or Asia. Some of
them ascend rivers, and all are carnivorous and voracious. None are
valued as food, being coarse-grained in flesh. The group is probably
nearest allied to the _Trachinidæ_ or _Uranoscopidæ_.
[Illustration:
FIG. 480.—Leopard Toadfish, _Opsanus pardus_ (Goode & Bean).
Pensacola.
]
_Opsanus tau_, the common toadfish, or oyster-fish, of our Atlantic
coast, is very common in rocky places, the young clinging to stones by a
sucking-disk on the belly, a structure which is early lost. It reaches a
length of about fifteen inches. _Opsanus pardus_, the leopard toadfish,
or sapo, of the Gulf coast, lives in deeper water and is prettily marked
with dark-brown spots on a light yellowish ground.
In _Opsanus_ the body is naked and there is a large foramen, or mucous
pore, in the axil of the pectoral. In the _Marcgravia cryptocentra_, a
large Brazilian toadfish, this foramen is absent. In _Batrachoides_, a
South American genus, the body is covered with cycloid scales.
_Batrachoides surinamensis_ is a common species of the West Indies.
_Batrachoides pacifici_ occurs at Panama. The genus _Porichthys_ is
remarkable for the development of series of mucous pores and luminous
spots in several different lateral lines which cover the body. These
luminous spots are quite unlike those found in the lantern-fishes
(_Myctophidæ_) and other _Iniomi_. Their structure has been worked out
in detail by Dr. Charles Wilson Greene, a summary of whose conclusions
are given on page 191, Vol. I.
The common midshipman, or singing fish, of the coast of California is
_Porichthys notatus_. This species, named midshipman from its rows of
shining spots like brass buttons, is found among rocks and kelp and
makes a peculiar quivering or humming noise with its large air-bladder.
_Porichthys porosissimus_, the bagre sapo, is common on all coasts of
the Gulf of Mexico and the Caribbean Sea. _Porichthys margaritatus_ is
found about Panama and _Porichthys porosus_ in Chile.
[Illustration:
FIG. 481.—Singing Fish or Bagre Sapo, _Porichthys porosissimus_ (Cuv.
& Val.). Galveston.
]
The species of _Thalassophryne_ and _Thalassothia_, the poison
toadfishes, are found along the coasts of South America, where they
sometimes ascend the rivers. In these species there is an elaborate
series of venom glands connected with the hollow spines of the opercle
and the dorsal spines. Dr. Günther gives the following account of this
structure as shown in _Thalassophryne reticulata_, a species from
Panama:
"In this species I first observed and closely examined the poison organ
with which the fishes of this genus are provided. Its structure is as
follows: (1) The opercular part: The operculum is very narrow,
vertically styliform and very mobile; it is armed behind with a spine,
eight lines long in a specimen of 10½ inches, and of the same form as
the venom fang of a snake; it is, however, somewhat less curved, being
only slightly bent upward. It has a longish slit at the outer side of
its extremity which leads into a canal perfectly closed and running
along the whole length of its interior; a bristle introduced into the
canal reappears through another opening at the base of the spine,
entering into a sac situated on the opercle and along the basal half of
the spine; the sac is of an oblong-ovate shape and about double the size
of an oat grain. Though the specimen had been preserved in spirits for
about nine months it still contained a whitish substance of the
consistency of thick cream, which on the slightest pressure freely
flowed from the opening in the extremity of the spine. On the other
hand, the sac could be easily filled with air or fluid from the foramen
of the spine. No gland could be discovered in the immediate neighborhood
of the sac; but on a more careful inspection I found a minute tube
floating free in the sac, whilst on the left-hand side there is only a
small opening instead of the tube. The attempts to introduce a bristle
into this opening for any distance failed, as it appears to lead into
the interior of the basal portion of the operculum, to which the sac
firmly adheres at this spot. (2) The dorsal part is composed of the two
dorsal spines, each of which is ten lines long. The whole arrangement is
the same as in the opercular spines; their slit is at the front side of
the point; each has a separate sac, which occupies the front of the
basal portion; the contents were the same as in the opercular sacs, but
in somewhat greater quantity. A strong branch of the lateral line
ascends to the immediate neighborhood of their base. Thus we have four
poison spines, each with a sac at its base; the walls of the sacs are
thin, composed of a fibrous membrane, the interior of which is coated
over with mucus. There are no secretory glands embedded between these
membranes, and these sacs are probably merely the reservoirs in which
the fluid secreted accumulates. The absence of a secretory organ in the
immediate neighborhood of the reservoirs (an organ the size of which
would be in accordance with the quantity of fluid secreted), the
diversity of the osseous spines which have been modified into poison
organs, and the actual communication indicated by the foramen in the sac
lead me to the opinion that the organ of secretion is either that system
of muciferous channels which is found in nearly the whole class of
fishes, and the secretion of which has poisonous qualities in a few of
them, or at least an independent portion of it. This description was
made from the first example; through the kindness of Captain Dow I
received two other specimens, and in the hope of proving the connection
of the poison bags with the lateral-line system, I asked Dr. Pettigrew,
of the Royal College of Surgeons, a gentleman whose great skill has
enriched that collection with a series of the most admirable anatomical
preparations, to lend me his assistance in injecting the canals. The
injection of the bags through the opening of the spine was easily
accomplished; but we failed to drive the fluid beyond the bag or to fill
with it any other part of the system of muciferous channels. This,
however, does not disprove the connection of the poison bags with that
system, inasmuch as it became apparent that if there be minute openings
they are so contracted by the action of the spirit in which the
specimens were preserved as to be impassable to the fluid of injection.
A great part of the lateral-line system consists of open canals;
however, on some parts of the body, these canals are entirely covered by
the skin; thus, for instance, the open lateral line ceases apparently in
the suprascapular region, being continued in the parietal region. We
could not discover any trace of an opening by which the open canal leads
to below the skin; yet we could distinctly trace the existence of the
continuation of the canal by a depressed line, so that it is quite
evident that such openings do exist, although they may be passable only
in fresh specimens. Thus likewise the existence of openings in the bags,
as I believed to have found in the first specimen dissected, may be
proved by examination of fresh examples. The sacs are without an
external muscular layer and situated immediately below the loose thick
skin which envelops their spines to their extremity. The injection of
the poison into a living animal, therefore, can only be effected by the
pressure to which the sac is subjected the moment the spine enters
another body. Nobody will suppose that a complicated apparatus like the
one described can be intended for conveying an innocuous substance, and
therefore I have not hesitated to designate it as poisonous; and,
Captain Dow informs me in a letter lately received, 'the natives of
Panama seemed quite familiar with the existence of the spines and of the
emission from them of a poison which, when introduced into a wound,
caused fever, an effect somewhat similar to that produced by the sting
of a scorpion; but in no case was a wound caused by one of them known to
result seriously. The slightest pressure of the finger at the base of
the spine caused the poison to jet a foot or more from the opening of
the spine.' The greatest importance must be attached to this fact,
inasmuch as it assists us in our inquiries into the nature of the
functions of the muciferous system, the idea of its being a secretory
organ having lately been superseded by the notion that it serves merely
as a stratum for the distribution of peripheric nerves. Also the
objection that the sting-rays and many Siluroid fishes are not poisonous
because they have no poison organ cannot be maintained, although the
organs conveying their poison are neither so well adapted for this
purpose nor in such a perfect connection with the secretory mucous
system as in _Thalassophryne_. The poison organ serves merely as a
weapon of defense. All the Batrachoids with obtuse teeth on the palate
and in the lower jaw feed on Mollusca and Crustaceans."
No fossil _Batrachoididæ_ are known.
=Suborder Xenopterygii.=—The clingfishes, forming the suborder
_Xenopterygii_ (ξενός, strange; πτερύξ, fin), are, perhaps, allied to
the toadfishes. The ventral fins are jugular, the rays I, 4 or I, 5, and
between them is developed an elaborate sucking-disk, not derived from
modified fins, but from folds of the skin and underlying muscles.
The structure of this disk in _Gobiesox sanguineus_ is thus described by
Dr. Günther:
"The whole disk is exceedingly large, subcircular, longer than broad,
its length being (often) one-third of the whole length of the fish. The
central portion is formed merely by skin, which is separated from the
pelvic or pubic bones by several layers of muscles. The peripheric
portion is divided into an anterior and posterior part by a deep notch
behind the ventrals. The anterior peripheric portion is formed by the
ventral rays, the membrane between them and a broad fringe which extends
anteriorly from one ventral to the other. This fringe is a fold of the
skin, containing on one side the rudimentary ventral spine, but no
cartilage. The posterior peripheric portion is suspended on each side on
the coracoid, the upper bone of which is exceedingly broad, becoming a
free, movable plate behind the pectoral. The lower bone of the coracoid
is of a triangular form, and supports a very broad fold of the skin,
extending from one side to the other, and containing a cartilage which
runs through the whole of that fold. Fine processes of the cartilage are
continued into the soft striated margin, in which the disk terminates
posteriorly. The face of the disk is coated with a thick epidermis, like
the sole of the foot in higher animals. The epidermis is divided into
many polygonal plates. There are no such plates between the roots of the
ventral fins."
[Illustration:
FIG. 482.—_Aspasma ciconiæ_ Jordan & Snyder. Wakanoura, Japan.
]
The body is formed much as in the toadfishes. The skin is naked and
there is no spinous dorsal fin. The skeleton shows several
peculiarities; there is no suborbital ring, the palatine arcade is
reduced, as are the gill-arches, the opercle is reduced to a spine-like
projection, and the vertebræ are numerous. The species are found in
tide-pools in the warm seas, where they cling tightly to the rocks with
their large ventral disks.
Several species of _Lepadogaster_ and _Mirbelia_ are found in the
Mediterranean. _Lepadogaster gouani_ is the best-known European species.
_Aspasma ciconiæ_ and _minima_ occur about the rocks in the bays of
Japan.
[Illustration:
FIG. 483.—Clingfish, _Caularchus mæandricus_ (Girard). Monterey, Cal.
]
Most of the West Indian species belong to _Gobiesox_, with entire teeth,
and to _Arbaciosa_, with serrated teeth. Some of these species are deep
crimson in color, but most of them are dull olive. _Gobiesox virgatulus_
is common on the Gulf Coast. _Caularchus mæandricus_, a very large
species, reaching a length of six inches, abounds along the coast of
California. Other genera are found at the Cape of Good Hope, especially
about New Zealand. _Chorisochismus dentex_, from the Cape of Good Hope,
reaches the length of a foot.