G. Brown (George Brown) Goode.

The fisheries and fishery industries of the United States (Volume 1:1) online

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they are very unlike the parent, having a very much simpler structure and often resembling one
of the lower groups of crustaceans. The larva of the Lobster, for instance, is somewhat similar
in structure and appearance to one of the simplest groups of Shrimps, the so-called SchizojKMls.

The free-swimming habits of the young furnish some of the most serious obstacles to the
breeding of Lobsters. The embryos, after hatching, rise to the surface of the water, where they
spend much of their time, and are borne hither and thither at the mercy of the currents, being
often carried beyond the favorable influences necessary to their development. In many Lobster
regions along our coast, in calm and clear weather, large quantities of the young may be dipped
from the surface of the water, in the eddies and smooth streaks formed by the meeting of tidal
currents. In these quiet spots the varied minute animal life characterizing the upper strata of
the sea are collected together in the same manner as bits of wood and clusters of seaweed, which.
from their larger size, are more familiar to the dwellers upon our coast. In stormy weather this
surface life descends, in greater part, to lower levels. This vagrant life of the young Lobsters
exposes them to the attacks of all kinds of predaceous surface-feeding animals, which consume
them iu immense numbers. In this manner a great mortality occurs a much greater one,
undoubtedly, than would arise did the young remain upon the bottom, where they could find some
shelter and protection from their enemies. The means of caring for and protecting these waj \vaid
young should be the first consideration of the would-be Lobster-breeder, and iu this matter he will
probably encounter his greatest difficulties. The length of time required for the yoong to attain



796 NATURAL HISTOEY OF AQUATIC ANIMALS.

the adult size is another matter of prime importance, as the breeder's success must also depend on
his producing an early harvest. The age of what may be considered adult Lobsters (ten to
eleven inches) is not known, estimates by different observers placing it all the way from three
to a dozen years. If the latter estimate be correct, we would be almost forced to consider lobster-
breeding as an industry impracticable from the start, as the care, during ten or twelve years, of
the number of young necessary to produce salable Lobsters in marketable quantities would involve
an expense quite out of proportion to the prices which could be obtained for them. We very
much doubt, however, this prolonged extension of the immature stage of the Lobster, although
we have no direct proof to the contrary. Lobstermen, as a rule, consider that Lobsters grow to
be ten inches long in the course of three to five years, and they base their conclusions mainly
on the fact that the increase in size at each molt is considerable; but this question is discussed
elsewhere in this report. We do not pretend to say that, in case the slow growth of Lobsters
is proved, breeding would be without many good results; for, if the growth and habits of Lobsters
could be well understood, much care and protection might be accorded them, which would
materially increase their numbers. Any new and carefully made observations on the spawning
habits and growth of Lobsters would be gladly welcomed by all who are interested in the lobster
question, whether from a scientific or a practical standpoint.

SPAWNING SEASON. Lobsters appear to have no definite spawning season, as they are
found with eggs, in different stages of development, during the entire year. According to the
statements of lobster fishermen and others who have had abundant means of observation in this
line, spawning takes place mainly from March until September. It should be remembered,
however, that the winter lobster fishery is of very much less importance than the summer, and
that during the farmer season the number of Lobsters handled does not in any way compare with
the number taken in the latter, so that the proportion of spawning Lobsters to non-spawning
ones, in the two seasons, may not be as great as would seem to appear. Winter observations on
the nat iirnl history of the Lobster, as well as of many other of our marine food invertebrates, are
very much desired. It is said that on the northern New England coast, from Capo Cod eastward,
Lobsters with spawn about ready for extrusion from the body begin to appear abundantly in
March, and with the spawn or eggs on the outside, as well as hatching, are most abundant from
June to September. In the Bay of Fundy, Lobsters spawn principally from the last of June to
the last of August. Southward of these limits the spawning season begins earlier.

Considering, now, the fact that spawning Lobsters occur throughout the entire year, we are
left without data as to the frequency of spawning in each individual Lobster. Did a short,
definite spawning period exist for each year, we might assume that Lobsters spawned only once
a year, or at least we could assert that they spawned no oftener than once a year. The ouly way
of determining the fact positively would be to study individual Lobsters for a certain period of
time, in their natural haunts and under natural conditions, and every one knows how difficult
such an undertaking would be with most marine animals. As it is, the possibility exists of
Lobsters spawning more than once a year, and there is no evidence to prove that they spawn
with any exact regularity as to time. We have the .jtatements of several individuals, some
published and others not, to the effect that quite fully developed eggs are sometimes apparent
in the ovaries when the Lobster is carrying spawn on the outside of the body. But there is no
way of determining how long a time must elapse before the second lot of spawn might be
fertilized and made ready for extrusion. We are justified in believing, however, that, as a rule,
Lobsters spawn but once a year. In the Lobster, as in many other marine animals, only a portion
of the ova is fertilized and developed at each spawning time, often leaving the ovaries still quite



SPAWNING HABITS. 797

expanded with their contents, and therefore we must always expect to find spawn in some stage
of development within the adult female, whether she is carrying external spawn or not. This
statement will serve to explain to lobstertnen the fact, which they often regard with some
surprise, of females carrying both internal and external spawn at the same time, the former, of
course, tar less developed than the latter.

The mature ovaries form two elongate lobes of considerable size, on the upper side of the
body, just within the shell, and immediately before spawning Lobsters arc considered to be in
very good, if not the best, condition for eating; it is probable also that at about this stage the
spawn first attracts the attention of most fishermen.

HABITATS WHILE SPAWNING. Nothing definite seems to be known regarding the haunts
of spawning Lobsters, or as to whether they change their ground at such times. It is probable
that, to some extent, they do prefer certain localities for this purpose; but as Lobsters with
spawn are taken by the fishermen in their traps at all seasons of the year, and in all depths, this
rule cannot, by any means, be regarded as universal. By assuming that certain regions are more
favorable for the development and hatching of the eggs, we can readily explain the great prepon-
derance of female Lobsters with spawn on the sandy shores about Provincetown, Cape Cod,
during the summer months. Yet, in direct contrast with this region stands nearly the entire
coast of Maine, rocky in the extreme, where Lobsters are even more abundant, and where they
probably reproduce in equal proportions.

SIZE OF SPAWNING LOBSTERS. Lobsters do not generally begin to spawn until they have
attained a length of about ten and a half to eleven inches (exclusive of the claws), which is about
the legal size of marketable Lobsters. We are informed by several correspondents, however,
i hat spawning Lobsters have been taken as small as eight, nine, and ten inches; -but such as these
are very rare. It is probable that they become mature at a smaller size at the South than at
the North, as Lobsters average smaller in Southern New England than in Northern New
England, and yet the age may average the same in both cases. Mr. S. M. Johnson, of Boston,
who has handled many thousands of Lobsters, states that he has never seen from east of
Cape Cod more than two or three specimens bearing spawn under ten and a half inches. He
thinks that but few begin to spawn much under eleven inches in length, and this size, in his
opinion, would be the proper limit below which none should be sold in order to fully protect the
species.

PAIRING. So far as we are aware, no one has ever witnessed the operation of pairing in
Lobsters, and all that we know concerning it is mere conjecture. Many of the female Lobsters
obtained from sandy bottoms, as at Provincetown, Cape Cod, are said, by observers, to have the
carapax more or less abraded along the top, and also somewhat worn over a limited area upon
the sides. This has led the fishermen to believe that, in pairing, the female Lobster lies upon her
back with the male on top, clasping her about the carapax with his claws. While in this
position any strong agitation of the water by the waves in slight depths would probably cause
I lie pairs to oscillate backward and forward, and might account for the abraded carapaces of
the female, which are said to be of common occurrence. This story has beeu told us by several
reliable parties, entirely independent of one another; but we cannot say how much reliance
should be placed upon it, and the evidence is certainly very slight

A large New York dealer in Cray-fishes, who keeps large quantities of these lobster-like
crustaceans on hand during their season, says that he has frequently witnessed them pairing, and
that the males and females come together belly to belly, with the claws of one tightly claspiug
those of the other, and spread out so as to form with the bodies a rude Y-shaped figure.



798 NATURAL HISTOKY OF AQUATIC ANIMALS.

NUMBER OP EGGS. The Lobster, like many other crustaceans, carries a very large amount
of spawn on the exterior of the body at each spawning time. The number varies with the age
and size of the Lobster, but to what extent is not known. Mr. S. M. Johnson, of Boston, states
that two and a half pound Lobsters bear externally, on an average, about twenty thousand eggs
at a time, according to several careful computations, made by comparing the weight of a certain
number of eggs with the weight of the entire mass of spawn attached to the swimmerets.

Two females which I examined at Eastport, Maine, in the summer of 1882, gave the following
results as regards the number of eggs carried on the swimmerets. The first specimen, measuring
13jj inches in length, had 875 grains of eggs, there being 20 eggs to a grain, making a total of
17,500 eggs. The second specimen measured 13 inches long and carried 480 grains of eggs, with
25 eggs to a grain, making a sum total of about 12,000 eggs. Neither of the above specimens,
however, appeared to have their full quota of eggs, as many of the bunches seemed to have been
more or less brushed away, probably by rough handling. In the last specimen, especially, had all
the bunches been of equal and full size, the number would have been increased fully one-half.

According to Mr. Frank Bucklaud, "the [English] Berried Lobster carries five bunches of
eggs on each side underneath the tail, making ten bunches in all. I have counted the eggs in
one bunch and find that there are 2,496, making the number of eggs in this one lobster 24,960.
Lobsters are found with berries all the year round; March, April, May are the mouths wheu they
are fullest"

DESIGNATIONS OF SPAWN. Lobster spawn is variously designated, on different parts of the
coast, as "spawn," "roe," "eggs," "berry," "seed," "pea," "sweetbread," "coral," etc.; but in most
places it is known simply as "spawn," "eggs," or "berry." On the Nova Scotia coast the term
"coral " is sometimes used to designate the nearly mature spawn while still within the body of the
Lobster, and after it has passed to the outside it is called " eggs.'' In the Bay of Fundy the terms
" coral, " roe," and " sweetbread " refer to the spawn before extrusion from the body, and they
may also be used in a similar way on other parts of the coast. In some portions of Long Island
Sound, Lobsters with external spawn are called " Black-egg Lobsters."

THE SPAWN AS FOOD. Before the spawn has passed from the body to the external appendages
it is very much esteemed as food, and is generally eaten whenever it can be obtained; it is also
canned. The external spawn, however, although sometimes used to garnish fish dishes and
salads, is not usually regarded as edible.

EXTRUSION OF THE EGGS, ETC. The spawning of the Lobster is accomplished in about the
same manner as with the Cray fish, regarding which many more carefully recorded observations
are extant According to Huxley, the fecundating material of the Cray-fish, which is extruded
from a small aperture on the basal joint of the hindermost pair of legs, is a "thickish fluid,
which sets into a white solid after extrusion." This substance is deposited by the male on the
thorax of the female, between the bases of the hindermost pair of thoracic limbs. The apertures
for the outward passage of the eggs are situated on the bases of the second pair of legs, back of
the large claws. The eggs, " as they leave the apertures of the oviducts, are coated with a viscid
matter, which is readily drawn out into a short thread. The end of the thread attaches itself to
one of the long hairs with which the swimmerets are fringed, and as the viscid matter rapidly
hardens, the egg thus becomes attached to the limb by a stalk. The operation is repeated until
sometimes a couple of hundred eggs are thus glued on to the swimmerets. Partaking in the move-
ments of the swimmerets, they are washed backward and forward in the water, and thus aerated
and kept free of impurities."

The process of development is slow, and the young, when first hatched, bear a general



DEVELOPMENT OF THE YOUNG. 799

resemblance to tin- pan-til. Kor sonic time at'ti-r they arc hatched they In. 1,1 on to the swimmerets
of the mother, ami are carried aliout protected by her abdomen. AH they become more active

the\ s limes leave ilie mother when she is resting quietly ami creep about a short distance off,

but quickly return to her on the first semblance of danger. A few days later they gradually
forsake her for good. The, earlier stages of tbe embryo Lobster differ considerably from those
of the Cray-fish, as described further ou. The eggs of the Lobster lire probably extruded in
a similar manner, and are attached to tbe swimmerets by the same viscid substance. Accord-
ing to s e American observers, however, the viscid substance is first extruded from the openings

of the, oviducts and appears as a thick, globular muss, which is brushed back over the swim-
merets by the movements of the posterior pair of thoracic legs. The eggs are said to follow
immediately afterwards and to be spread about in the same manner. Becoming thus securely
attached to the swimmerets, they remain well protected and are kept constantly aerated by the
movements of these posterior flaps until the young are batched. Without further observations
we cannot strongly indorse the idea of the viscid material being first excreted; but if such
occurs in the beginning, there is still no reason why the eggs may not be also covered with the
same substance as they are laid. The eggs are not attached to the smooth surface of the
s\\immerets of the Lobster, but to the long, slender hairs which project from along their sides.
In that way they hang more loosely and can be given freer motion.

SHEDDING AFTER SPAWNING. As explained under "shedding," it is probable that, as a
rule, the females shed their shells soon after their eggs are hatched, as there is no other way of
ridding themselves of the broken egg-shells adhering so firmly to the swimmerets by means of
the tough little threads. Lobsters with very ripe spawn have frequently been seen in a condition
preparatory to shedding, thus, in a measure, corroborating the above conjecture. According to
Prof. S. I. Smith this shedding after spawning is known to occur in some of the Grabs. This
peculiarity is also affirmed with regard to the European female Lobster, as described elsewhere.

DEVELOPMENT OF THE YOUNG. The earlier embryonic stages of the Lobster have been
studied by Prof. S. I. Smith, of Yale College, whose observations, however, extended over onlj- a
limited period. They were made at Wood's Holl, Massachusetts, and New Haven, Connecticut.
K-'g.i with the embryos well advanced, taken from the females May 2, had the shape of slightly
elongate spheroids, about 2.l mm long and 1.9 mni across. " One side is rendered very opaque dark
green by the unabsorbed yolk mass, while the other shows the eyes as two large black spots,
and the red pigment spots on the edge of the carapax, bases of the legs, etc., as irregular lines
of pink markings. . . . Fully one-half the embryo is still occupied by the unabsorbed port ion
of the yolk. . . . The eyes are large, nearly round, and with a central portion of black
pigment. . . . The five pairs of cephalo-thoracic legs are all similar and of about the same
si/.e, except the main branch of the first pair, which is much larger than that of the others. . . .
The subsequent development of the embryo within the egg was not observed."

In the account of his observations, Professor Smith goes on to describe such of the embryonic
stages following hatching as he was able to obtain. From his long and technical descriptions we
extract only those portions which can be best understood by the general reader, and which it will
be well for the breeder to become acquainted with to aid him in his practical labors. We would
suggest here that the breeder himself, or some intelligent man in his employ, should t'amiliari/i-
himself with the workings of an ordinary low-power microscope, in order that he may follow the
development of the young Lobsters under his care, and observe whether they are doing well or
die off soon after hatching. Unless such precautions as these are taken, he might continue to
work for a long time completely in the dork, and without knowing whether he was making



800 NATURAL HISTORY OF AQUATIC ANIMALS.

progress or not A continuous series of observations would enable him, at all times, to follow
the success of his experiments, or determine, perhaps, the causes of his failures.

The exact number of changes or moltings which take place between the last egg stage and
the first stage having the general shape and characters of the adult, is not known. Professor
Smith observed three such stages, but supposes others to be wanting. His account of these
stages is as follows :

"The following observations on the young lame, after they have left the eggs, have all been
made upon specimens obtained in Vineyard Sound, or the adjacent waters, during July. These
specimens were mostly taken at the surface in the daytime, either with the towing or hand net.
They represent three quite different stages in the true larval condition, besides a later stage
approaching closely the adult. The exact age of the larvae of the first stage was not ascertained,
but was probably only a few days, and they had, most likely, molted not more than once.
Between the third stage, here described, and the last there is probably an intermediate form
wanting.

" First stage. In this stage the young are free-swimming Schizopods ' about a third of an
inch (7.8 mm to S.O"" 11 ) in length, without abdominal appendages, and with six pairs of pediform
cephalo-thoracic appendages, each with the exopodus developed into a powerful swimming organ.
The eyes are bright blue; the anterior portion and the lower margin of the carapax and the
bases of the legs are speckled with orange; the lower margin, the whole of the penultimate, and
the basal portion of the ultimate segment of the abdomen are brilliant reddish-orange. The
antenna? have large, well-developed scales, furnished along the inner margin with long, plumose
hairs. . . . The anterior cephalo-thoracic legs, which in the adult develop into the big claws,
are exactly alike and no longer than the exterior maxillipeds. The pediform (outer) branch
is, however, somewhat stouter than in the other legs, and subcheliform (bearing an imperfect
claw); the legs of the second and third pairs are similar to the first, but not as stout. The legs of
the fourth and fifth pairs are still more slender, and styliform at the extremity, as in the adult."
Very rudimentary branchiae or gills are observed on all of the legs and the external maxillipeds.
"The abdomen is slender, the second to the fifth segments each armed with a large dorsal spine,
curved backward, and with the lateral angles produced into long spines, and the sixth segment
with two dorsal spines. The posterior margin of the last segment is armed with a long and stout
central spine, and each side with fourteen or fifteen plumose spines or setae, which are articulated
to the margin.

"In this stage the young were first taken July 1, when they were seen swimming rapidly
about at the surface of the water among great numbers of Zoeae, Megalops, and Copepods. Their
motions and habits recall at once the species of Mysis and Thysanopoda, but their motions are not
quite as rapid, and are more irregular. Their bright colors render them conspicuous objects, and
they must be readily seen and captured by fishes. They were frequently taken at the surface in
different parts of Vineyard Sound from July 1 to 7, and several were taken off Newport, Rhode
Island, as late as July 15, and they would very likely be found also in June, judging from the
stage of development to which the embryos had advanced early in May in Long Island Sound.
Besides the specimens taken in the open water of the Sound, a great number were obtained July
from the well of a lobster-smack, where they were swimming in great abundance near the
surface of the water, having undoubtedly been recently hatched from the eggs carried by the



1 The Schizopods are a gronp of Shrimps, lower in organization than our common Shrimp (Orangon vulgaris), and very
abundant along the New England coast. They generally swim in large schools, either at the surface or at intermediate
depths between the surface and the bottom, oltcn at some distance from land.



DEVELOPMENT OF Till: YOUNG. 801

female Lobsters coiiflncd iu the well. Some of these specimens lived in vessels of fresh sea-water
for two days, but all efforts to keep them alive long enough to observe their molting failed. They
appeared, while thus in confinement, to feed principally upon very minute animals of different
kinds, but were .several times seen to devour small Zoeae, and occasionally when much crowded, so
that some of them became exhausted, they fed upon each other, the stronger ones eating the
weaker.

"Second stage. In the next stage the young Lobsters have increased somewhat in size, and
the abdominal legs of the second to the fifth segments have appeared. The rostrum is much
broader and there are several teeth along the edges. The basal segments of the antenuulae have
become defined, and the secondary flagellum has appeared, but is not subdivided into segments.
The autcnuiB and mouth organs have undergone but slight changes. The first cepbalo-thoracio
legs are proportionally larger and stouter than in the first stage, and have become truly cheli-
forrn. The succeeding legs have changed little. The epipodi of all the legs and of the external
maxilhpeds have increased in size, and the branchial processes are distinctly lobed along the
edges, and have begun to assume the form of true branchiae. The segments of the abdomen have
the same number of spines, but they are relatively somewhat smaller, and the last segment is
relatively -smaller and broader at base. The appendages of the second to the fifth segments differ
considerably in size indifferent specimens, but are nearly as long as the segments themselves;
their terminal lamella?, however, are represented only by simple, sack-like appendages, without
sign of segmentation, or clothing of hairs or set. The penultimate segment is still without
appendages. Specimens in this stage were taken only twice, July 1 and 15. They have the same
habits and general appearance as in the first stage, but are readily distinguished by the posses-



Online LibraryG. Brown (George Brown) GoodeThe fisheries and fishery industries of the United States (Volume 1:1) → online text (page 132 of 146)