PLATE VII. FIG. 2. Twice nat. size.
Fig. 2 _a_. Nat. size.
Fig. 2 _b_. Portion of the hispid cuticle magnified.[17]
_A. pallidè rubro-aurantius, dorso nigricante, pinnis nigro-maculatis:
corpore hispido, altitudine tertiam partem longitudinis æquante;
spirits nasalibus duâbus parvis recurvis; vomere dentibus velutinis
minutissimis instructo: pinnâ dorsali inæquali, anticè allevatâ,
spinis quartâ et quintâ paulo longissimis, succedentibus gradatim
diminutis, ultimâ radiis articulatis multò breviori._
D. 17/13; A. 1/8; C. 13, &c.; P. 9; V. 1/5.
LONG. unc. 1. lin. 9.
FORM.—General form resembling that of the _A. torvus_, but the depth
much greater, equalling one-third of the entire length, or very
nearly. Length of the head somewhat less than the depth of the body.
The line of greatest depth passes through the insertion of the
pectorals. The profile viewed apart from the superciliary ridges,
which are sharp and prominent, falls in a straight but very oblique
line from the commencement of the dorsal to the mouth. On each side
of the median line of the snout, in advance of the eyes, is a small
but sharp spine, directed upwards and backwards. There are also two
minute spines on the first suborbital immediately above and behind
the end of the maxillary; these are placed one over the other, the
uppermost, which is the sharpest and most conspicuous, taking an
upward direction like the nasal spines, the lowermost, which is
blunt and not so obvious, a downward one. Mouth small, without any
teeth that can be discerned even with a lens; but a decided
roughness can be felt on the vomer, seeming to indicate the presence
of minute teeth on that part. The superciliary ridges, already
alluded to, are slightly granulated, and terminate behind in two
sharp triangular points. The occipital ridges, a ridge on the
posterior suborbital immediately beneath the eye, and an interrupted
ridge on the temples and suprascapulars, are in like manner
granulated, or rather obscurely crenated. The opercle and preopercle
are marked with a few striæ, but show neither granulations nor
spines. Gill-opening very small. No scales on any part of the head
and body; but the whole surface of the latter is hispid with minute
bristly appendages to the cuticle, each springing from a minute
papilla. There are also a number of fine lines traversing the
cuticle in two directions, and forming a kind of network. The
lateral line commences at the suprascapular, and terminates a little
beyond the end of the dorsal, not reaching quite to the caudal; its
course is nearly, but not exactly, parallel to the dorsal line, the
distance between them being at first one-third, but towards the
caudal between one-third and one-fourth of the depth.
Dorsal very much elevated anteriorly, but its height by no means
uniform throughout; the first spine one-fourth shorter than the
second; this again a little shorter than the third; and this last a
very little shorter than the fourth and fifth, which are longest,
and which equal three-fourths of the depth of the body; sixth and
succeeding ones gradually decreasing, the ninth being about equal to
the first, the twelfth about one-third shorter; the next four are
scarcely shorter than the twelfth, and the seventeenth or last is a
little higher than the sixteenth; then follows the soft portion of
the fin, which is here again elevated, the soft rays being nearly
double the length of the last spinous.[18] The anal answers in
position to the first two-thirds of the soft dorsal, terminating
before that fin, as in _A. torvus_: the fourth, fifth, and sixth
soft rays are longest, and much longer than the soft rays of the
dorsal; the spine is short and slender, and not much more than half
the length of the first soft ray. The last ray of both dorsal and
anal is divided quite to the root so as to appear as two. The caudal
appears to have been rounded, but the ends of the rays are worn and
broken. Pectorals long, equalling one-third of the entire length:
they consist of nine rays, the three middle ones of which are
longest; the three upper and the three lower ones are respectively
equal; all the rays simple. Ventrals much shorter than the
pectorals, and, though attached rather more behind, not reaching so
far; their spine is rather stout, much more so than that of the
anal, and about three-fourths the length of the first two soft rays,
which are the longest in the fin.
COLOUR.—“Pale reddish orange, with black spots on the fins, and a
dusky shade on the back.”—D.
_A second specimen_ only differs from the above in having the teeth in
the jaws more sensible to the touch, though still scarcely to be
seen; and in the superciliary and occipital ridges being less
granulated or crenated at the edges. The colours also are a little
darker. The fin-ray formula is exactly the same in both specimens.
Habitat, Peninsula of Tres Montes, Archipelago of Chiloe.
This species approaches most nearly the _A. Peruvianus_ of Cuvier and
Valenciennes, with which it agrees in the great depth of the body, and
in the presence of two nasal spines; but it differs in the roughness of
the skin (that species being described as smooth), and in the greater
inequality of the dorsal fin. Perhaps it may be the same as the species
brought from the coast of Chili by Mr. Cuming, and briefly noticed by
Mr. Bennett in the “Proceedings of the Zoological Society” (1832, p.
5.), but which this last gentleman did not venture to describe as new,
from the circumstance of its general agreement with the _A. Peruvianus_.
The principal deviation in Mr. Cuming’s fish from the species just
mentioned is stated to have occurred in the number of the fin-rays;
those of the spinous portion of the dorsal fin being seventeen (one less
than in the _A. Peruvianus_), while of the soft rays of the anal there
were ten (three more than in the species referred to). Mr. Darwin’s fish
agrees with Mr. Cuming’s in the number of the dorsal spines, but not in
that of the soft rays of the anal, which is eight, being one more than
in the _A. Peruvianus_ and two less than in Mr. Cuming’s; and it is
observable that both the specimens obtained by Mr. Darwin agree in this
particular. Mr. Bennett has not noticed any of the other characters of
Mr. Cuming’s fish.[19]
One of the most distinguishing peculiarities in the species here
described is the existence of vomerine teeth, which though extremely
minute are quite sensible to the touch. As these teeth are denied by
Cuvier to the whole genus, we have here another instance, similar to
that of the _Aspidophorus Chiloensis_ already mentioned, of the slight
value of the character which their presence or absence affords.
Possibly, however, they may disappear in the adult state. Both Mr.
Darwin’s specimens are small, neither equalling two inches; and if they
are immature, which is probably the case, some of the other characters
mentioned in the description, perhaps even the hispidity of the skin,
may result from this circumstance. They must therefore be received with
caution until larger specimens shall have been obtained.