BERYCOIDEI
=THE Berycoid Fishes.=—We may place in a separate order a group of
fishes, mostly spiny-rayed, which appeared earlier in geological time
than any other of the spinous forms, and which in several ways represent
the transition from the isospondylous fishes to those of the type of the
mackerel and perch. In the berycoid fishes the ventral fins are always
thoracic, the number of rays almost always greater than I, 5, and in all
cases an orbitosphenoid bone is developed in connection with the septum
between the orbits above. This bone is found in the _Isospondyli_ and
other primitive fishes, but according to the investigations of Mr. E. C.
Starks it is wanting in all percoid and scombroid forms, as well as in
the _Haplomi_ and in all the higher fishes. This trait may therefore,
among thoracic fishes, be held to define the section or suborder of
_Berycoidei_.
[Illustration:
FIG. 198.—Skull of a Berycoid fish, _Beryx splendens_ Cuv. & Val.,
showing the orbitosphenoid (OS), characteristic of all Berycoid
fishes.
]
These fishes, most primitive of the thoracic types, were more abundant
in Cretaceous and Eocene times than now. The possession of an increased
number of soft rays in the ventral fins is archaic, although in one
family, the _Monocentridæ_, the number is reduced to three. Most of the
living _Berycoidei_ retain through life the archaic duct to the
air-bladder characteristic of most abdominal or soft-rayed fishes. In
some however, the duct is lost. For the first time in the fish series
the number of twenty-four vertebræ appears. In most spiny-rayed fishes
of the tropics, of whatever family, this number is retained.
In every case spines are present in the dorsal fin, and in certain cases
the development of the spinous dorsal surpasses that of the most extreme
perch-like forms. In geological times the Berycoids preceded all other
perch-like fishes. They are probably ancestral to all the latter. All
the recent species, in spite of high specialization, retain some archaic
characters.
=The Alfonsinos: Berycidæ.=—The typical family, _Berycidæ_, is composed
of fishes of rather deep water, bright scarlet or black in color, with
the body short and compressed, the scales varying in the different
genera. The single dorsal fin has a few spines in front, and there are
no barbels. The suborbitals are not greatly developed.
[Illustration:
FIG. 199.—_Beryx splendens_ Lowe. Gulf Stream.
]
The species of _Beryx_, called in Spanish _Alfonsino_, _Beryx elegans_
and _Beryx decadactylus_, are widely distributed at moderate depths, the
same species being recorded from Portugal, Madeira, Cuba, the Gulf
Stream, and Japan. The colors are very handsome, being scarlet with
streaks of white or golden. These fishes reach the length of a foot or
more and are valued as food where sufficiently common.
Numerous species of _Beryx_ and closely allied genera are found in all
rocks since Cretaceous times; _Beryx dalmaticus_, from the Cretaceous of
Dalmatia, is perhaps the earliest. _Beryx insculptus_ is found in New
Jersey, but no other Berycoids are yet known as fossils from North
America. _Sphenocephalus_, with four anal spines, is found in the chalk,
as are also species of _Acrogaster_ and _Pycnosterinx_, these being the
earliest of fishes with distinctly spiny fins.
[Illustration:
FIG. 200.—_Hoplopteryx lewesiensis_ (Mantell), restored. English
Cretaceous Family _Berycidæ_. (After Woodward.)
]
The _Trachichthyidæ_ are deep-sea fishes with short bodies, cavernous
skulls, and rough scales. The dorsal is short, with a few spines in
front. The suborbitals are very broad, often covering the cheeks, and
the anal fin is shorter than the dorsal, a character which separates
these fishes from the _Berycidæ_, in which group the anal fin is very
long. The belly has often a serrated edge, and the coloration is red or
black, the black species being softer in body and living in deeper
water. Species of _Hoplostethus_, notably _Hoplostethus mediterraneus_,
are found in most seas at a considerable depth. _Trachichthys_, a genus
scarcely distinguishable from _Hoplostethus_, is found in various seas.
The genus _Paratrachichthys_ is remarkable for the anterior position of
the vent, much as in _Aphredoderus_. Species occur in Japan and
Australia. _Gephyroberyx_, with the dorsal fin notched, is known from
Japan (_G. japonicus_) and Madeira (_G. darwini_).
We may also refer to the _Trachichthyidæ_ certain species of still
deeper waters, black in color and still softer in texture, with smaller
scales which are often peculiar in form. These constitute the genera
_Caulolepis_, _Anoplogaster_, _Melamphaës_, and _Plectromus_. In
_Caulolepis_ the jaws are armed with very strong canines.
Allied to the _Trachichthyidæ_ are also the fossil genera _Hoplopteryx_
and _Homonotus_. _Hoplopteryx lewesiensis_, from the English chalk, is
one of the earliest of the spiny-rayed fishes.
[Illustration:
FIG. 201.—_Paratrachichthys prosthemius_ Jordan & Fowler, Misaki,
Japan. Family _Trachichthyidæ_.
]
=The Soldier-fishes: Holocentridæ.=—The soldier-fishes (_Holocentridæ_),
also known as squirrel-fishes, Welshmen, soldados, matajuelos, malau,
alehi, etc., are shore fishes very characteristic of rocky banks in the
tropical seas. In this family the flesh is firm and the large scales
very hard and with very rough edges. There are eleven spines in the
dorsal and four in the anal, the third being usually very long. The
ventral fins have one spine and seven soft rays. The whole head and body
are rough with prickles. The coloration is always brilliant, the ground
hue being scarlet or crimson, often with lines or stripes of white,
black, or golden. The fishes are valued as food, and they furnish a
large part of the beauty of coloration so characteristic of the fishes
of the coral reefs. The species are active, pugnacious, carnivorous, but
not especially voracious, the mouth being usually small.
[Illustration:
FIG. 202.—Soldier-fish, _Holocentrus ascenscionis_ (Osbeck).
]
[Illustration:
FIG. 203.—Soldier-fish, _Holocentrus ittodai_ Jordan & Fowler. Riu Kiu
Islands, Japan.
]
The genus _Holocentrus_ is characterized by the presence of a large
spine on the angle of the preopercle. Its species are especially
numerous, _Holocentrus ascenscionis_, abundant in Cuba, ranges northward
in the Gulf Stream. _Holocentrus suborbitalis_, the mojarra cardenal, is
a small, relatively dull species swarming about the rocks of western
Mexico. _Holocentrus spinosissimus_ is a characteristic fish of Japan.
Many other species abound throughout Polynesia and the East Indies, as
well as in tropical America. _Holocentrus ruber_ and _Holocentrus
diadema_ are common species of Polynesia and the East Indies. Other
abundant species are _H. spinifer_, _H. microstomus_, and _H.
violascens_.
_Holocentrus marianus_ is the marian of the French West Indies.
_Holocentrus sammara_, and related large-mouthed species occur in
Polynesia.
[Illustration:
FIG. 204.—_Ostichthys japonicus_ (Cuv. & Val.). Giran, Formosa.
]
In _Myripristis_ the preopercular spine is wanting and the air-bladder
is divided into two parts, the anterior extending to the ear.
_Myripristis jacobus_ is the brilliantly colored candil, or "Frère
Jacques," of the West Indies. Species of _Myripristis_ are known in
Hawaii as _u-u_. A curious method of catching _Myripristis murdjan_ is
pursued on the Island of Hawaii. A living fish is suspended by a cord in
front of a reef inhabited by this species. It remains with scarlet fins
spread and glistening red scales. Its presence is a challenge to other
individuals, who rush out to attack it. These are then drawn out by a
concealed scoop-net, and a fresh specimen is taken as a decoy.
_Myripristis pralinius_, _M. multiradiatus_, and other species occur in
Polynesia. _Ostichthys_ is allied to _Myripristis_ but with very large
rough scales. _Ostichthys japonicus_ is a large and showy fish of the
waters of Japan. _Ostichthys pillwaxi_ occurs at Honolulu. _Holotrachys
lima_ is a small, brick-red fish with small very rough scales found
throughout Polynesia.
Fossil species of _Holocentrus_, _Myripristis_, and related extinct
genera occur in the Eocene and Miocene. _Holocentrus macrocephalus_,
from Monte Bolca Eocene, is one of the best known. _Myricanthus
leptacanthus_ from the same region, has very slender spines in the fins.
[Illustration:
FIG. 205.—Pine-cone Fish, _Monocentris japonicus_ (Houttuyn). Waka,
Japan.
]
=The Polymixiidæ.=—The family of _Polymixiidæ_, or barbudos, is one of
the most interesting in Ichthyology from its bewildering combination of
characters belonging to different groups. With the general aspect of a
Berycoid, the ventral rays I, 7, and the single dorsal fin with a few
spines, _Polymixia_ has the scales rather smooth and at the chin are two
long barbels which look remarkably like those of the family of _Mullidæ_
or _Surmullets_. As in the _Mullidæ_, there are but four
branchiostegals. In other regards the two groups seem to have little in
common. According to Starks, the specialized feelers at the chin are
different in structure and must have been independently developed in the
two groups. In _Polymixia_, each barbel is suspended from the hypohyal;
three rudimentary branchiostegals forming its thickened base. In
_Mullus_, each barbel is suspended from the trip of a slender projection
of the ceratohyal, having no connection with the branchiostegals.
_Polymixia_ possesses the orbitosphenoid bone and is a true berycoid,
while the _Mullidæ_ are genuine percoid fishes.
Four species of _Polymixia_ are recorded from rather deep water:
_Polymixia nobilis_ from Madeira, _Polymixia lowei_ from the West
Indies, _Polymixia berndti_ from Hawaii, and _Polymixia japonica_ from
Japan. All are plainly colored, without red.
=The Pine-cone Fishes: Monocentridæ.=—Among the most extraordinary of
all fishes is the little family of _Monocentridæ_, or pine-cone fishes.
_Monocentris japonicus_, the best-known species, is common on the coasts
of Japan. It reaches the length of five inches. The body is covered with
a coat of mail, made of rough plates which look as though carelessly put
together. The dorsal spines are very strong, and each ventral fin is
replaced by a very strong rough spine. The animal fully justifies the
remark of its discoverer, Houttuyn (1782), that it is "the most
remarkable fish which exists." It is dull golden brown in color, and in
movement as sluggish as a trunkfish. A similar species, called
knightfish, _Monocentris gloriæ-maris_, is found in Australia. No
fossils allied to _Monocentris_ are known.