G. Brown (George Brown) Goode.

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fall being "blackened by millions of little Eels about as long as a finger, which were constantly
urging their way up the moist rock beside the fall." "Thousands," he adds, "died; but their
bodies, remaining, served as a ladder by which the rest could make their way; and I saw some
ascending even perpendicular stones, making their way through wet moss or adhering to some
Eels that had died iu the attempt." 2

Such is the energy of these little animals that they continued to find their way in immense
numbers to Loch Erne.

In the little Eels which ascend the rivers there are no traces of sexual organs, but in the fresh
water they develop only into females. One of the most recent observations made by Dr. Pauly,
in Munich, would appear to contradict this idea, since he discovered male Eels among the fish
which were brought with a lot of young Eels to Hiiningen, were kept there for two years in ponds,
and were finally released in the fish pond of Court-fisherman Kufler. We should bear in mindj
however, that these young Eels were captured at the mouths of fresh rivers in brackish water ;
and that among the numerous small Eels which swim in the brackish water there must be many
larger specimens, in which the male organs have already begun to develop. Such are doubtless
those which were sent in the male condition to Hiiningen and Munich, and were there recognized
as males. This presumption can be set aside only if male Eels shall hereafter be found among the
fish which are caught in the upper part of rivers in the condition of young fry.

Concerning another important fact which is connected with the movements of the young fry of
the Eel, I became acquainted last year (in the course of an exploration of the waters of the district of

1 Professor Benecke had in his possession some of the young Eels, which escaped from all the vessels in which
they were confined, and even climbed to the ceiling of his room.

- l.i i i ML- IN CONNECTICUT. Fresh-water Eels may be caught in large numbers, in weirs along the lake
streams, when descending at the fall equinox to deposit their spawn in some lower region, and in the following
August their offspring, from three to six inches long, return in immense numbers. The basin of the Still River
Falls, near Colebrook line, is for several days alive with them. They may be seen laboriously crawling up every
rock which is moistened by the spray of the fall, and endeavoring to reach their ancestral lake or dam. At the foot
of the Niagara Falls this phenomenon may be witnessed on a largo scale at the same season of the year or later, and
probably in other places where the fall is too high and the current too swift for the young Eels to stem it without
contact with the rocks. BOYD : Annals of Winchester, Connecticut, p. 26.



JACOBY'S JOUENEY TO COMACCHIO.

Konitzkunde) with the river Brahe, at Miihlhof, above Rittol, where a high dam was built in 1840
and 1847 for the puq>ose of watering a large system of meadows by the overflowing of the stream.
Below the daui is an inclined plane (constructed of boards), about three hundred feet long, built
for the purpose of preventing the water, which rushes out when the sluice-gate is opened, from
washing away the bottom of the stream and its banks. This plank floor consists of two layers, the
lower one of two-inch, the upper one of three-inch boards. The grade of the dam at Miihlhof
(thirty three feet three inches) has entirely cut off the ascent of the fry of the Eel into the ii|>i -r
pan of the Brahe and the lakes tributary to it, and the number of Eels caught above the dam
which was formerly very considerable has become reduced almost to nothing. In the year 1847
the construction of the dam and the inclined plane was completed. In 1852 the upper layer of the
planks on the plane had warped aud sprung up in many places, so that it had to be torn up for
repairs. The cause of the warping was immediately discovered ; thousands of Eels, as thick as a
man's finger, somewhat flattened in shape, and, on account of the absence of light, of a pure
white color, filled the space between the two layers of planks, and their united pressure from
beneath had caused the upper layer to yield ; these Eels had found their way between the boards
as fry, where they had found sufficient food and had grown to such a size that the pressure of their
united strength had pushed up the roof of their prison. These facts, observed by an old mill-
wright, were communicated to me by Privy Councillor Schmid, of Marienwerder, who supervised
the construction of the Miihlhof dam, and ho fully confirmed them.

Eels of four inches in length, which in May are plenty in fish ponds, by the end of October
reach a length of ten inches and the thickness of a man's little finger; in the following fall they
measure from twenty to twenty-four inches, and in the third year are ready to be eaten. On
account of their rapid growth and hardy nature, in consequence of which latter they live in mud-
holes and unprofitable waters of all kinds, the breeding of Eels is a very remunerative business.
The young fish (of which, at the time of their first appearance at the mouths of rivers, it lakes
1,500 to 1,700 to make a pound, while, when taken later and a little farther from the sea, it takes
only 350 to 400 for the same weight) may be obtained at low prices from France through Hiiuingen,
or in Germany from Randesberg, and, through the Berlin Aquarium, from Wittenberge, and, when
the temperature of the air is not too high, may be carried in soft moss throughout all Germany.

According to the statement of the well-known Paris fish-merchant, Millet, two pounds of
Eels, planted in a muddy pond in 1840, in five years yielded 5,000 pounds of fine Eels.

JACOBY'S TOUR TO COMACCHIO IN 1877, AND HIS CONCLUSIONS. " In the fall of 1877," writes
Jacoby, "I undertook a journey from Trieste, by way of Ravenna, to Comacchio. Convinced of
the difficulty of the questions to be solved by my own previous labors, I had not great hopes of
finding sexually mature Eels, either gravid females or mature males. My highest aim was at
the beginning to determine the following points: (1) Whether evidences of preparation for breed-
ing might not be found in the Eels which were wandering in the fall toward the sea; (2) to what
extent Eels with the organ of Syrski could be found participating in this migration; (3) as far as
possible to obtain Eels from the sea at a distance from the coast in order to compare their organs
of reproduction with those of the Eels in the lagoons.

"In determining the answers to the first two questions I was able to make some new and inter-
esting discoveries, but with regard to the latter, my most diligent efforts were absolutely fruitless.

"I found that the Eels when migrating to the sea in the fall took no food. In many hundreds
examined by me, caught during their movement, I found stomach and intestines entirely empty;
that the Eels during their migrations eat nothing is also known to all fishermen and watermen of
Comacchio. At the same time, the Eels which remained in the lagoons were more or less filled



654



NATURAL HISTORY OF AQUATIC ANIMALS.



with food, not only those which were not sufficiently mature to migrate, but also a breed of Eels
which never goes to the sea, but remains throughout its entire life in the lagoons.

"There may be found in Comacchio, and doubtless everywhere where Eels live in great num-
bers in brackish water along the coast, a peculiar group of Eels which, as far as I could deter-
mine, consists entirely of sterile females. These female Eels with ovaries present a very peculiar
phenomenon; when they are opened one finds, instead of the well-known yellowish-white, very
fatty, cufl'-shaped organ, a thin, scummy, slightly folded membrane, not at all fatty, often as trans-
parent as glass, and of about the same proportional size as the so-called cuff-shaped organ. When
this membrane is examined under the microscope there may be seen in it eggs very transparent in
appearance, with yolk-dots absent or with yolk-dots very small and lew. This organ appears to be
an abnormally developed ovary incapable of fertilization. These sterile females, which I found
of all sizes, even up to the length of twenty-seven inches, present all of the acknowledged female
characters in great prominence and in an exaggerated degree: the snout is broader, and often,
especially at the tip of the under jaw, extraordinarily broad ; the dorsal fins are, on the average,
higher; the eyes are much smaller, especially in large specimens, and the coloring is clearer; the
back of a clearer green and the belly yellower than in the normal female. The flesh of these
sterile females lias a very delicate flavor, and quite different from that of other Eels. I was quite
astonished at the fine flavor when I tasted them for the first time in Comacchio. The flesh, as the
expression goes, melts upon the tongue. It is even possible to distinguish them while living, by
feeling them with the hand, their soft bodies being very different from the hard, solid, muscular
flesh of the others.

"In Comacchio these Eels are called 'Pasciuti.' Coste called them 'Priscetti,' and defined
them to be those Eels which had not become ripe, but which were at least a pound in weight. The
name 'Priscetti' is, however, very incorrect, as I have become convinced by questiouing the fish
inspectors and by hearing the conversations of the fishermen. 'Pasciuto' means 'pastured,' and
the fishermen understand by this, those Eels which do not migrate, but which remain through the
whole year feeding in the lagoons. They include, however, under this name, Eels of two kinds
the sterile females already described, and the Eels which are not yet ripe, as well as the normal
females and supposed males whose period of migration is somewhat remote. This circumstance
is a cause of much difficulty to the investigator. 1

"The studies on the second point to be solved were of special interest, viz, the determina-

"It has been noticed by many early writers that there are certain Eels which never come to the sea Risso, in his
"Histoire Naturelle," tome 3, p. 108, ami S. Nilsson, in his "Scandinavisk Fauna," tomo 4, p. 663. The latter called
this variety "Grasaal," or Grass-Eel, and spoke of its yellowish-green coloration and the soft, delicious flesh. Strange
enough, both these writers spoke of the sharper snout of this Eel, and Risso, who founded upon it another species,
Angiiilla arntirostrix, described it as blackish above and silvery below. These descriptions apply in every particular
to thi) non-migratory Kel of Comaccliio. Jacoby remarks that all the sterile females brought to him under the name
"Pascinti" were distinguished by their broad snouts. The following tables were prepared at Comacchio. a gives
the total length of the body of the Eel ; 6, tho breadth of the snout between the nasal tubes, in millimeters.



ASterile femileo or 1'Mcinti.


B. Normal female*.


C. Eela with supposed male organs.




a.


b.




a.


6.




a.


6.




















I


506


10


i


511


8


I






II


480


as


it


497


7


11


480


6


m


458 11


m


46S


9


III


470


6


IV 443


9


IV


447


7 IV


445


5


V 426 8. 5


y


425





V


428


5


VT 408 8 VI


407


6


VT


403


5


VII SOJ 11


VII


M


7


VII


39!


5.5



OI:SI.I;VATIONS or .i.\coi;v.






856



lion of llit- presence at ( 'omacchio. and the behavior of Eels with organs of Syrski. I can answer
this question \er\ lirieily, sinew among twelve hundred siMH-imens examined by mo at the
fishing stations ami at tin- so called eel factories (with the exception of the largest specimens,
which arc always females) I found an average of five per cent, with the organ of Syrski; of
the Kels under liftccii inches in length (forty-five centimeters) on an average there were twenty
per cent., so that the conclusions as to their abundance were very similar to those at Trieste, where
the fish market is supplied, for the greater part, with Eels from Chioggia, and to a less extent with
those from Coniacchio.

"In Coniacchio the largest Eels with the organ of Syrski, which I have observed, were about
seventeen inches (forty-eight centimeters) in length, the smallest about nine inches (twenty-four
centimeters). All of these were found among the Eels taken during their migration to the sea,
and, like the females, were found with stomachs completely empty or slightly tilled with a slimy
substance. It was impossible to find in any specimen a more advanced development of the Syr-
skian organ than in those examined in summer at Trieste.

"With reference to the third question undertaken by me, which relates to the actual kernel of
the eel question, that is, the possibility of obtaining the Eels which have migrated out to sea, in
order to obtain in this manner the sexually mature milters and spawners, I have been unable to
obtain any results. I have, so far as my opportunities permitted, left no stone unturned to gain
its solution. I went out to sea from Magnavacca and from Codigoro, on Chioggian vessels, and
many times have fished myself, and have stimulated the fishermen by offers of reward to endeavor
to obtain Eels at sea, but I am forced to the conclusion that with the ordinary means this cannot
be done.

"Intelligent, gray-headed fishermen of Chioggia, who by means of their fishing apparatus
know this part of the Adriatic as well as they know their own pockets, have assured me that
throughout their entire lives they have never caught a grown-up river Eel in the sea at any dis-
tance from the coast. The Eels which were brought to me at Mannbach as having been caught
in the sea, and which I found to be the ordinary females, or Eels with the Syrskian organ, were
either from localities close to the shore where they are not rare, or were taken in the Palotta
Canal. There was no lack of attempts at deception. Fishermen took Eels from the shore with
them in order to be able, on their return, to claim that they had been caught at sea. In the imme-
diate neighborhood of the coast they are, as it has been stated, in the spring-time not rare, and
there are not the slightest differences between these and the Eels of the lagoons. I fonnd l>oth
females and Eels with the organ of Syrski with thoir reproductive organs in the same immature
condition as inComacchio; evidently they had just come through the Palotta Canal from the
lagoon into the sea. A certain distance, perhaps one or two marine miles from the coast, every
trace is lost of the adult Eels which wander by the many thousand into the sea. Strange as this
problem appears at hist sight, it is easily understood when the character of the fishing apparatus
is considered: the nets are those used in the capture of lobsters, and are thrown over the bottom;
they have meshes much too large to hold the Eels, or, when they are small-meshed, they do not
touch the bottom. The problem can only be solved by using apparatus constructed especially for
the purpose." 1

Jacoby proposes the following questions, which, in his opinion, cover the still unanswered
points concerning the natural history of the Eel, and answers them in accordance with the results
of his own observations:




1 JACOBY: Der Fischfang in der Lagune von Comacchio, pp. 45-63.



656 NATUKAL HISTOHY OF AQUATIC ANIMALS.

Question 1. How can the fact be accounted for that no one has ever found mature females and
males, spawners and milters, among the Eels t

Answer. The Eels require the influence of sea-water for the development of their reproductive
organs. As is now definitely understood, they leave the rivers and the brackish lakes on account
of the undeveloped condition of their reproductive organs, for the purpose of becoming sexually
mature at sea. That these migrations to the sea take place for the purpose of reproduction appears
to be certainly proved by the fact that the young Eels leave the sea in the spring, and that the
migrating Eels, like other fishes at the spawning season, abstain from eating.

Q. 2. When and where occurs the necessary development of the reproductive organs of the
Eel to a condition in which they are capable of fertilization ?

A. Development of the reproductive organs takes place in the sea, not close to the shore,
but at a distance and in deep waters. This development is extraordinarily rapid, when the
immature state in which the migrating Eels are found is taken into consideration; they must
become sexually mature within a few, probably five or six, weeks of the time that they enter the
sea. At Comacchio the emigration takes place between the beginning of October and the end of
December.

Q. 3. Where does the act of spawning take place, the fertilization, and the deposition of
the eggs t

A. There are probably certain definite spawning places in the sea, off the mouths of the
rivers. These are the mud-banks to which the Eels go, for the purpose of spawning, in great
numbers. The young fish are developed upon these mud- banks, and from eight to ten weeks
after their birth, at the beginning of spring, find their way to the mouths of rivers, which they
ascend.

Q. 4. What becomes of the grown-up Eels after spawning time, and why do they remain
lost to sight and never again come back into the rivers t

A. The old Eels, male and female, without doubt, die soon after the spawning season.
The very unusual rapid development of their reproductive organs has such an effect upon the
systems of the adult Eels that they die soon after the act of reproduction. That is the reason
why they are never seen to wander back again. 1

An intelligent Chioggian, the owner of a fishing vessel, in answer to my question as to where
the old Eels staid, answered, " They die on the mud-banks after they have propagated their
young."

This hypothesis may be confirmed in a scientific manner by the analogous circumstances in
the history of the Lamprey. Panizza, in his description of the sea Lamprey, Petromyzon marina,
remarks that both the males and females of this species after the spawning period are brought,
up dead. Concerning the river Lamprey, P. fluviatilis, Statius Miiller remarks that when they
spawn they slowly fall away and die. Concerning the little Lamprey, P. planeri, August Miiller,
the discoverer of its larval form, has recorded the same opinion. 8

192. THE CONGEE EEL CONGER, OE LEPTOCEPHALUS CONGEE.

The Conger Eel is occasionally seen in the summer on the coast of the New England and
middle States, and is known to our fishermen as the " Sea Eel." No observations ha,ve been
made of its habits by American zoologists.

>! confirmation of this view, von Siebold was the first to make tins hypothesis.
Op. cit., pp. 53-56.



IIKK.MKS >l;>i:i;\ ATIONS.



667



The observations of Dr. Otto Hermes, director of the Berlin Aquarium, who has recently dis.
covered the true nature of the organ of Syrski in the Conger, are extremely interesting:

"Since S.vrski, in 1874, found the organs in Anguilla vulyariit which are called by his name
and which, by him and most zoologists, were taken for the male reproductive organs it is only



JTJ.




FIG. 9. A. Jiip male rtproductire organ* of

t'liagrr Eel thirty inches in length,

I natural lite,
a. Inlentinnl raual.
d', upper, d". middle, d'", lower portion

of the liver, which baa been thrown

to one Hide.
/. Air-bladder.
ff. G^ll-l.l...l.l,i.
h. Anal aperture.

i,, i' t . u. " Fold* of the left nuermary.
ti, In, h. tt, fa. Folds of the right sper-

inary.

I. Seminal pf.ncb.
m. Urinary bladder.
p. Skinny covering of the upennary.
H. Spermatozoa.




Flo. 10. C Undtreloptd rfproductirt organ of a/tmaU
Conatr Ktl thirty-four \nclut long, | nat-
ural tixe.
a. Stomnch.
6. Circal appendage.
e. Spleen.

d. Liver.

e. Right ovary.
if. Left ovary.
/. A ! l.l.i.l.l. r.
a. (inll M.idili-r.
\. Anal aperture,
m- U inary bladder.
p. End vf left ovary.



necessary that a ripe male Eel should be found in order to settle forever the question of the sexes
of the Eel. Up to this time all efforts have failed to reach the desired result. The histiological
investigations of the Syrskian organs pursued by S. Freud render it more probable that these were
young roes; yet there remained all the time a doubt, since the spermatozoa had not been actually
42 p



658 NATURAL HISTOKY OF AQUATIC ANIMALS.

observed, aiid this uncertainty is aii insuperable obstacle to tbe acceptance of the Syrskian dis
covery. The supposed discovery of spermatozoa by A. S. Packard in the male Eel proved to be
another delusion. The contradiction of this imaginary discovery appeared in No. 26 of the second
volume of the Zoologischer Auzeiger, p. 193, in which it was stated that the motile bodies were not
spermatozoa, but yolk particles. This correction was also made by von Siebold's assistant, Dr.
Pauly, 1 and by S. Th. Cattie.

"The reproductive organs of Conger vulgar is are very similar to those of A ngml la vulgaris; in
the undeveloped condition they show the ovaries lying in the same position in a cuff-shaped band
of a proportionally large size. Since C. vulgaris reaches nearly twice the size of A. vulgaris, indi-
viduals of six feet in length are not rare. The ovary is developed in captivity, and this, I am
convinced, is often the cause of the death of the Eel. In a Conger which died in the Berlin Aqua-
rium, and was cut open, the ovaries protruded very extensively, and a specimen which lies in the
Frankfort Aquarium burst on account of the extraordinary development of the ovaries. The ova-
ries of this Eel, which weighed twenty-two and one-half pounds, themselves weighed eight pounds,
and the number of eggs was about 3,300,000. The want of a natural opening for tbe escape of the
eggs was evidently in this case the cause of death. Male specimens of the Conger in an undeveloped
condition I have hitherto never had the opportunity to investigate. I received, however, in the
fall of 1879 a number of sea Eels, taken in the vicinity of Havre, whose average length was from
twenty-four to twenty-seven inches. These Eels ate greedily and grew rapidly. Only one was
tardy in its development, so that it could be easily distinguished from the rest. This, which was
the smallest of the Congers in the aquarium, died on the 20th of June, 1880, and was examined by
me on the same day. I was very much delighted when I found the sexual organs very different
from those which I had ever noticed before. After a single cut into them, there flowed out a milky
fluid, which, under the microscope, with a power of 450 diameters, showed a great number of sper-
matozoa, in the liveliest motion, and in which head and tail were evidently visible. There could
be no doubt that I had found a sexually mature male of Conger vulgaris. Two fragments of the
roc were laid aside for further investigation, and the Eel, which was twenty-eight inches long, was
prepared first in alcohol and then in Wickersheimer fluid."

In the paper before us Dr. Jacoby presents a full anatomical description of the generative
organs of the Conger as demonstrated by himself and Dr. Rabl-Ruckhard. It seems unnecessary
to repeat this description, since the organs are very similar to those in the common Eel. By the
kindness of Dr. Hermes we are permitted to reproduce the drawings which accompany this
description.

Compared with the description of the roe, and the figure of the organ found by Syrski and by
Hermes, called " Lappenorgan," a great similarity is noticed between them. It must be borne in
mind that in this case we were comparing the entirely undeveloped organs of the Eel with the
fully ripe reproductive organs of the Conger, so every doubt as to the male nature of the Syrskian
organs ought to be thrown aside. Also in the comparison of the size of the male with that of the
female the Conger shows the same relations as the Eel investigated by Syrski, to wit, that the
males are smaller than the females.



'Austrian Fishery Gazette, 1880, No. 12, p. 90.



V. STURGEONS, SKATES, SHARKS, AND LAMPREYS.

193. THE BOWFINS AMIIDJE.
THE BOWFIN oil JOHNNY GRINDLE AMIA CALVA.

The one species belonging to the single genus in this family is peculiar to the fresh water*
of the United States. It occurs in the Great Lakes, where it is called "Dogfish" and "Sawyer";
in the streams of Western Vermont, where it is the "Mud-flsh"(!), as also in the streams
of the Southern Atlantic coast from the Neuse southward. It is also abundant in the smaller
rivers flowing into the Gulf of Mexico and in all parts of the Mississippi Valley, where it



Online LibraryG. Brown (George Brown) GoodeThe fisheries and fishery industries of the United States (Volume 1:1) → online text (page 110 of 146)